As of 8-6-08 - There were 971 tracked asteroids 
See chart on that date
On October 3, 2008 , there were 986 potentially hazardous asteroids.
See chart on that date
On 10-12-08 - there are 990 potentially hazardous asteroids.
See chart on that date
One - the size of a car exploded over the Sudan on 10-07-08
On 10-29-08 -there are 993 potentially hazardous asteroids.
On 11-6-08 - there are 996 potentially hazardous asteroids.
On 11-24-08 -- there are 999 potentially hazardous asteroids.
On 12-2-08 - there are 1002 potentially hazardous asteroids.
On 12-12-08 - there are 1010 potentially hazardous asteroids.

SPACE WEATHER 2009
 

Dan Linek of North Bay Shore, New York, was one of the eye witnesses. Combining his own observations with those of others, he created a hand-drawn map of sightings and the probable location of the fireball when it exploded:

CALIFORNIA FIREBALL: A remarkable fireball blazed across Califonia on Dec. 27th around 1:50 am PST. Its brilliant blue-green light caught the attention of onlookers (some inside their homes) all the way from San Francisco Bay in the north to the Los Angeles metropolitan area in the south--a range of more than 340 miles. According to one account, the object exploded with a thunderous boom, producing a spray of golden-colored fragments

"It was as if someone had set off a rescue flare that instantly bathed the countryside in whitish blue-green light," reports Grant Bentley of Bishop, CA. "At one point, the path of the meteor went behind a cirrus-stratus cloud that it backlit in snowy green light. After a brilliant show of less than three seconds, it was gone without a trace. This was easily the most massive object I have ever seen burning up as it entered the Earth's atmosphere."

A solar wind stream flowing from the indicated coronal hole
should arrive on Dec. 30th or 31st.
Credit: SOHO Extreme UV Telescope
 

LAST AURORAS OF 2008: They're coming, the last auroras of 2008. The source of the display is a coronal hole photographed earlier today by Japan's Hinode spacecraft:

Although 2008 has been a year of remarkably low solar activity, polar sky watchers nevertheless have enjoyed many good geomagnetic storms. Galleries: January, February, March, April, May, June, July, August September, October, November, December.
 

"Everyone should take a look before the rings begin to open up again at the end of the month," says Casquinha. A nice bonus: When the rings are thin, Saturn's moons become easier to see. "Note the small spot above the rings on the right; that's Rhea."

more images: from Masa Nakamura of Otawara, Tochigi, Japan; from Koshu Endo of Tokyo Japan (note: Endo's video shows an Earth-orbiting satellite zipping by Saturn)

CHRISTMAS PROMINENCE: So, you received a solar telescope for Christmas? Perfect timing. A plume of hot gas is spewing over the northeastern limb of the sun, beckoning for attention. Take a look!

photos: from S. Billings et al of South Portland, Maine; from Mike Borman of Evansville, Indiana; from Francisco A. Rodriguez of Gran Canaria, Canary Islands; from James Screech of Bedford, England; from Peter Desypris of Athens, Greece; from Stephen Ames of Hodgenville, Kentucky;

NASA's Stereo-B spacecraft is stationed over the sun's eastern limb, but it was not taking pictures at the probable time of the eruption, so details of the blast are unknown. The CME could herald an active region (e.g., a sunspot or perhaps an unstable magnetic filament) turning to face Earth in the days ahead. Stay tuned for updates.

Dec. 16, 2008: NASA's five THEMIS spacecraft have discovered a breach in Earth's magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms. But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.

"At first I didn't believe it," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."

The magnetosphere is a bubble of magnetism that surrounds Earth and protects us from solar wind. Exploring the bubble is a key goal of the THEMIS mission, launched in February 2007. The big discovery came on June 3, 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance. One of the THEMIS probes exploring the space around Earth, an artist's concept. [more]

"The opening was huge—four times wider than Earth itself," says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data. Li's colleague Jimmy Raeder, also of New Hampshire, says "10²⁷ particles per second were flowing into the magnetosphere—that's a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."

The event began with little warning when a gentle gust of solar wind delivered a bundle of magnetic fields from the Sun to Earth. Like an octopus wrapping its tentacles around a big clam, solar magnetic fields draped themselves around the magnetosphere and cracked it open. The cracking was accomplished by means of a process called "magnetic reconnection." High above Earth's poles, solar and terrestrial magnetic fields linked up (reconnected) to form conduits for solar wind. Conduits over the Arctic and Antarctic quickly expanded; within minutes they overlapped over Earth's equator to create the biggest magnetic breach ever recorded by Earth-orbiting spacecraft.

Above: A computer model of solar wind flowing around Earth's magnetic field on June 3, 2007. Background colors represent solar wind density; red is high density, blue is low. Solid black lines trace the outer boundaries of Earth's magnetic field. Note the layer of relatively dense material beneath the tips of the white arrows; that is solar wind entering Earth's magnetic field through the breach. Credit: Jimmy Raeder/UNH. [larger image]

The size of the breach took researchers by surprise. "We've seen things like this before," says Raeder, "but never on such a large scale. The entire day-side of the magnetosphere was open to the solar wind."

The circumstances were even more surprising. Space physicists have long believed that holes in Earth's magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north.

"To the lay person, this may sound like a quibble, but to a space physicist, it is almost seismic," says Sibeck. "When I tell my colleagues, most react with skepticism, as if I'm trying to convince them that the sun rises in the west."

"So, you can imagine our surprise when a northern IMF came along and shields went down instead," says Sibeck. "This completely overturns our understanding of things."

Northern IMF events don't actually trigger geomagnetic storms, notes Raeder, but they do set the stage for storms by loading the magnetosphere with plasma. A loaded magnetosphere is primed for auroras, power outages, and other disturbances that can result when, say, a CME (coronal mass ejection) hits.

The years ahead could be especially lively. Raeder explains: "We're entering Solar Cycle 24. For reasons not fully understood, CMEs in even-numbered solar cycles (like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME should open a breach and load the magnetosphere with plasma just before the storm gets underway. It's the perfect sequence for a really big event."

Sibeck agrees. "This could result in stronger geomagnetic storms than we have seen in many years."

A video version of this story may be found here. For more information about the THEMIS mission, visit http://nasa.gov/themis

Preliminary counts by the International Meteor Organization indicate that the shower peaked at 160 meteors per hour during the early hours of Dec. 14th. Earth is now exiting the Geminid debris stream and meteor rates are falling--but not yet to zero. Subsiding activity could continue for several nights to come: live updates.

UPDATED: 2008 Geminid Meteor Gallery
[previous years: 2007, 2006, 2004, 2002, 2001]

A's STEREO spacecraft photographed a coronal mass ejection
(CME) billowing over the limb of the sun.

CME MOVIE http://sungrazer.nrl.navy.mil/images/p2003_sm_short.mov

Now play it again. Did you see the comet? It's just a speck among the stars and billowing debris; look for it along this ). It was discovered in May 2003 by astronomer Eric Christensen and then, as sometimes happens to new comets with poorly-known orbits, it was lost again. Comet Christensen went missing for more than five years until STEREO found it again. Spacecraft (especially SOHO) have discovered many comets, but this is the first time a spacecraft has recovered one: full story.

New-cycle sunspot 1009 is rotating over the sun's western limb. The spot is crackling with B-class solar flares; the explosions could hurl material over the limb as the sunspot disappears. Readers, if you have a solar telescope, keep an eye on the western limb. Credit: SOHO/MDI
 

  AURORA WATCH: A solar wind stream is heading for Earth and it could spark geomagnetic storms around the arctic circle when it arrives on Dec. 11th. High-latitude sky watchers should be alert for auroras.

COLOR-CODED SUNSPOTS: According to one leading solar physicist, the sun is turning blue. David Hathaway of the NASA Marshall Space Flight Center is using red and blue to tag sunspots of the old and new solar cycles. When he plots the color-coded sunspot numbers, it's clear a change is taking place.

Feeling blue? Now you know why. Stay tuned for updates

more images: from Hank Bartlett of Newburgh, Ontario, Canada; from Stephen Ames of Hodgenville, Kentucky; from M. Ugro et al. of South Portland, Maine; from Roy Golisano of Milford, New Hampshire

Space Weather News for Dec. 6, 2008
http://spaceweather.com

COLORADO FIREBALL:  Last night, a fireball one hundred times brighter than the full Moon lit up the sky near Colorado Springs, Colorado. Astronomer Chris Peterson photographed the event using an all-sky video camera dedicated to meteor studies. "In seven years of operation, this is the brightest fireball I've ever recorded. I estimate the terminal explosion at magnitude -18."  Meteors this bright are called superbolides; they are caused by small (meter-class) asteroids and are likely to pepper the ground with meteorites when they explode. 

See VIDEO

Fireballs this bright belong to a rare category of meteors called superbolides. They are caused by small asteroids measuring a few to 10 meters in diameter and massing hundreds of metric tons. Superbolides trigger seismic detectors on the ground, produce waves of infrasound that can travel thousands of miles, and they are tracked by military satellites scanning Earth for nuclear explosions. Recent examples include the El Paso fireball of 1997 and the Slovenian Superbolide of 2007.

Last night's fireball is on the low end of the superbolide scale. Nevertheless, it was still a beauty and likely peppered the ground with meteorites when it exploded. Sighting reports are welcomed; they could help guide the tracking and recovery of debris.

LISTEN! 250 miles south of the fireball, radio astronomer Thomas Ashcraft of New Mexico photographed the flash and recorded radio echoes from the superbolide's ion trail. Click here to listen.

GREAT CONJUNCTION: Postulate: One moon + two planets = the sky show of the year. The proof may be found in this photo submitted by Jamie Russell from the United Kingdom's Isle of Wight:

All around the world, sky watchers watched with pleasure as Venus, Jupiter and the Moon gathered in one tiny patch of sky and then dispersed again. But was it really the sky show of the year? Browse the gallery and decide for yourself:

GRAND CONJUNCTION PHOTO GALLERY
 

Earth is entering a solar wind stream flowing from the indicated coronal hole. Credit: SOHO Extreme UV Telescope

A solar wind stream flowing from the indicated coronal hole should reach Earth on Dec. 3rd or 4th. Credit: SOHO Extreme UV

Near Earth Asteroids
Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On December 2, 2008 there were 1002 potentially hazardous asteroids. Dec. 2008 Earth-asteroid encounters: Asteroid Date(UT) Miss Distance Mag. Size 2008 WY94 Dec. 5 3.2 LD 19 35 m 2008 WG14 Dec. 5 4.8 LD 17 49 m 2006 VB14 Dec. 14 36 LD 15 795 m 2008 EV5 Dec. 23 8.4 LD 13 435 m Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

more images: from Stephen O'Meara of Kilauea, Volcano, Hawaii; from Brian Kennedy of Orlando, Florida; from John Gauvreau of Binbrook, Ontario, Canada; from Stephen McCaul on the coast of Scotland overlooking the Isle of Skye; from Claudio Bottari of Locorotondo, Italy; from Bum-Suk Yeom of Daejeon, South Korea; from Mike O'Leary of San Diego, CA; from Bill Smith of Cherry Creek, NY; from Albert Engert of Würzburg, Germany; from Marion Haligowski of Phoenix, Arizona; from Gregg Waldron of Morristown, NJ; from Joe Ricci of Rochester, New York; from Katy and John Stetson of Portland, Maine; from Adrian Guzman of San Jose, California; from Claudio Pincelli of Southampton, Massachusetts; from Thierry Demange of Erstein, Alsace, France; from Martin Mc Kenna of Maghera, Co. Derry, N. Ireland;

THE OTHER CONJUNCTION: While all eyes are on Venus and Jupiter in the evening sky, another conjunction is taking place at high noon. Mars and Mercury are having a close encounter of their own within 3^o of the sun:

NOT-A-SUNSPOT: A large, diffuse magnetic dipole is emerging in the sun's northern hemisphere: map. It's too spread out to form a sunspot, but it may prove interesting nevertheless. In the neutral folds of such regions, dark filaments of plasma are known to form and sometimes erupt.

more images: from Zlatko Pasko of Stara Pazova, Serbia; from Patrick Boomer of Alberta, Canada; from Jens Hackmann of Weikersheim, Germany; from Mahdi Zamani of Kan, Iran; from Cindy Safina of Tsimshatsui, Hong Kong; from Alan Conrad of Liverpool,Nova Scotia; from Jim Werle of Henderson, Nevada; from Martin Mc Kenna of Maghera, Co. Derry, N. Ireland

THANKSGIVING SUN: This morning Greg Piepol of Rockville, Maryland, looked through the eyepiece of his backyard solar telescope and observed a very curious sunspot:

"Happy Thanksgiving!" says Piepol. "I must have been thinking about dinner because when I did a double-take the turkey was gone." The real Thanksgiving sun is pictured here. A new sunspot is forming near the center of the sun's disk but it has not yet formed a dark turkey-core. Stay tuned for updates.

more images: from Andy Yeung of Hong Kong; from Stephen Ames of Hodgenville, Kentucky

Click to view a 1 MB movie

A coronagraph onboard the Solar and Heliospheric Observatory (SOHO) is monitoring the progress of the expanding CME. The cloud is not directed at Earth and should cause no geomagnetic activity on our planet. It is, however, a promising "sign of life" on the sun. Slowly but surely, solar minimum is coming to an end.
 

A solar wind stream flowing from the indicated coronal hole should reach Earth late on Nov. 25th or Nov. 26th. Credit: Hinode X-ray Telescope

Coronal holes are places in the sun's atmosphere where the magnetic field opens up and allows solar wind to escape. In images taken by X-ray telescopes, such as the one Hinode uses, coronal holes appear dark because the hot glowing gas which would otherwise fill them has spilled out in the solar wind. A stream of gas flowing from this particular hole is heading for Earth. High-latitude sky watchers should be alert for auroras when it arrives on Nov. 25th or 26th.
  11-22-08  The sun is blank today

Andy Bartlett video-recorded the event from a 10th-floor apartment in Edmonton, Alberta:

Click to play the video

A screen capture from an amateur video sent to Global Television Edmonton of a meteor streaking across the southeastern sky in Edmonton last Thursday, just after dusk.

"The brilliant fireball appeared to be closer than the airplane in the upper right corner of this video," says Bartlett. "I made the movie using a Canon A510."

The fireball was almost certainly a small asteroid disintegrating in Earth's atmosphere. A space rock measuring a few to ten meters wide moving at typical local-asteroid velocities would account for the fireball's speed and brightness. Reentry of manmade space junk has now been ruled out. Fragments of the impactor may have reached the ground; if so, they remain undiscovered and/or unreported.

VIDEO UPDATE: A spectacular video of the fireball was recorded by the dashboard camera of a police car on patrol in Edmonton, Alberta. Click to play.

11-29-08

Nov. 21, 2008: Researchers have found new evidence that the atmosphere of Mars is being stripped away by solar wind. It's not a gently continuous erosion, but rather a ripping process in which chunks of Martian air detach themselves from the planet and tumble into deep space. This surprising mechanism could help solve a longstanding mystery about the Red Planet.

"It helps explain why Mars has so little air," says David Brain of UC Berkeley, who presented the findings at the 2008 Huntsville Plasma Workshop on October 27th.

Billions of years ago, Mars had a lot more air than it does today. (Note: Martian "air" is primarily carbon dioxide, not the nitrogen-oxygen mix we breathe on Earth.) Ancient martian lake-beds and river channels tell the tale of a planet covered by abundant water and wrapped in an atmosphere thick enough to prevent that water from evaporating into space. Some researchers believe the atmosphere of Mars was once as thick as Earth's. Today, however, all those lakes and rivers are dry and the atmospheric pressure on Mars is only 1% that of Earth at sea-level. A cup of water placed almost anywhere on the Martian surface would quickly and violently boil away—a result of the super-low air pressure.

Above: An artist's concept of ancient Mars with abundant air and water. [Larger image]

NOTE:  The Chinese recorded watching Venus go past Mars and rip it's atmosphere off - so there is a discrepancy between what science is telling us and what the Chinese reported.

Brain has uncovered a new possibility--a daily ripping process intermediate between the great cataclysm and slow erosion models. The evidence comes from NASA's now-retired Mars Global Surveyor (MGS) spacecraft.

In 1998, MGS discovered that Mars has a very strange magnetic field. Instead of a global bubble, like Earth's, the Martian field is in the form of magnetic umbrellas that sprout out of the ground and reach beyond the top of Mars' atmosphere. These umbrellas number in the dozens and they cover about 40% of the planet’s surface, mainly in the southern hemisphere.

For years, researchers thought the umbrellas protected the Martian atmosphere, shielding pockets of air beneath them from erosion by the solar wind. Surprisingly, Brain finds that the opposite can be true as well: "The umbrellas are where coherent chunks of air are torn away."

Above: Solar wind blowing against Mars tears atmosphere-filled plasmoids from the tops of magnetic umbrellas. Credit: Graphic artist Steve Bartlett. [Larger image]

Addressing his colleagues at the Workshop, he described how he made the discovery just a few months ago:

Brain was scrolling through archival data from Global Surveyor's particles and fields sensors. "We have measurements from 25,000 orbits," he says. During one of those orbits, MGS passed through the top of a magnetic umbrella. Brain noticed that the umbrella's magnetic field had linked up with the magnetic field in the solar wind. Physicists call this "magnetic reconnection." What happened next is not 100% certain, but Global Surveyor's readings are consistent with the following scenario: "The joined fields wrapped themselves around a packet of gas at the top of the Martian atmosphere, forming a magnetic capsule a thousand kilometers wide with ionized air trapped inside," says Brain. "Solar wind pressure caused the capsule to 'pinch off' and it blew away, taking its cargo of air with it." Brain has since found a dozen more examples. The magnetic capsules or "plasmoids" tend to blow over the south pole of Mars, mainly because most of the umbrellas are located in Mars' southern hemisphere.

Above: Dave Brain of UC Berkeley presented this slide at the 2008 Huntsville Plasma Workshop to explain in cartoon fashion how plasmoids carry air away from Mars. [Larger image]

Brain isn't ready to declare the mystery solved. "We're still not sure how often the plasmoids form or how much gas each one contains." The problem is, Mars Global Surveyor wasn't designed to study the phenomenon. The spacecraft was only equipped to sense electrons, not the heavier ions which would make up the bulk of any trapped gas. "Ions and electrons don't always behave the same way," he cautions. Also, MGS sampled the umbrellas at fixed altitudes and at the same local time each day. "We need to sample many altitudes and times of day to truly understand these dynamic events."

In short, he told the audience, "we need more data."

Brain is pinning his hopes on a new NASA mission named MAVEN. Short for "Mars Atmosphere and Volatile Evolution," MAVEN is an upper atmosphere orbiter currently approved for launch to Mars in 2013. The probe is specifically designed to study atmospheric erosion. MAVEN will be able to detect electrons, ions and neutral atoms; it will be able to measure both magnetic and electric fields; it will travel around Mars in an elliptical orbit, piercing magnetic umbrellas at different altitudes, angles, and times of day; and it will explore regions both near and far from the umbrellas, giving researchers the complete picture they need.

If magnetized chunks of air are truly being torn free, MAVEN will see it happening and measure the atmospheric loss rate. "Personally, I think this mechanism is important," says Brain, "but MAVEN may yet prove me wrong."

Meanwhile, the Mystery of the Missing Martian Air is shaping up to be a ripping good yarn

From: http://science.nasa.gov/headlines/y2008/21nov_plasmoids.htm

CONVERGING PLANETS: "The anticipation builds as Venus and Jupiter approach each other for their spectacular conjunction with the Moon on December 1st," says astronomy professor Jimmy Westlake of Colorado Mountain College. "In the meantime, the view of the sky's two brightest planets set against the star clouds of the Milky Way isn't half bad, either!"

Not everyone has skies so dark and starry. Fortunately, you don't need dark skies to witness the ongoing convergence of Jupiter and Venus. The two bright planets beam through clouds, twilight and even urban light pollution. Step outside at sunset and take a look.Sky maps: Nov.19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, Dec 1.

more images: from Doug Zubenel at Kill Creek Park near De Soto, Kansas; from Tyler Burg of Omaha, Nebraska; from Bill Davis of Albuquerque, New Mexico; from Katy Giorgio of Boston, Massachusetts; from Val Germann of Columbia, Missouri;

LEONID OUTBURST: Just as predicted, the Leonid meteor shower surged during the early hours of Nov. 17th. "Earth passed through a filament of debris shed by parent comet 55P/Tempel-Tuttle in the year 1466," says forecaster Jérémie Vaubaillon of Caltech. The result was a sharp flurry of meteors numbering almost 90 per hour. "In Slovakia, we saw many bright and quick Leonids during the peak," reports Roman Piffl.
 

The two planets are converging on the Sun and next week, during the days around Thanksgiving in the USA, the trio will gather inside a circle less than three degrees in diameter. Looking up at noon, you'd never

Click here for live images from SOHO.

These images come from P. Edward Murray of Yardley, Pennsylvania: "Last May, I was looking at a National Geographic map of the Moon (left) when suddenly I saw the Basketball Player in the Moon," he says. "Later, I sketched him onto a photo of a full Moon (right) I took using a 4.25-inch Astroscan telescope. My discovery was published in the August 2008 edition of The Lunar Observer, a monthly publication of ALPO. The basketball player can be seen a few days before full Moon and after."

Only one question remains: Which basketball player is it?

LunaBron James, of course.

more images: from Doug Zubenel of De Soto, Kansas; from Becky Ramotowski of Tijeras, New Mexico;

"The sun is waking up and winking at us today," says Wainwright.

The "smile" is a filament of plasma connecting the two magnetic poles of sunspot 1008. Magnetograms of the active region reveal a N-S polarity characteristic of Solar Cycle 24: this is a new-cycle sunspot. The appearance of 1008 continues a recent trend of increasing new-cycle sunspot counts, which began in Oct. 2008. Solar activity is on the rise; if you have a solar telescope, take a look!

more images: from B. Shelzi and J. Stetson of South Portland, Maine; from Paul Haese of Blackwood, South Australia; from Jan Timmermans of Valkenswaard, the Netherlands; from Pete Lawrence of Selsey, West Sussex, UK; from Peter Paice of Belfast, Northern Ireland; from Andy Yeung of Hong Kong;

Using an H-alpha filter tuned to the red glow of solar hydrogen, Pete Lawrence of Selsey UK witnessed "the formation of a lovely magnetic filament" connecting opposite ends of the sunspot group: photo.

Judging from its high latitude, active region 1008 is a member of new Solar Cycle 24. The appearance of 1008 continues a recent trend of increasing new-cycle sunspot counts, which began in Oct. 2008. Solar activity is on the rise; tf you have a solar telescope, take a look!

more images: from Franck Charlier of Marines, Val d'Oise, France; from David Leong of Hong Kong; from Andy Yeung of Hong Kong; from Peter Paice of Belfast, Northern Ireland; from Denis Joye of Boulogne, France; from Catalin M. Timosca of Turda, Romania;

November is picking up where October left off with the formation of yet another new-cycle sunspot, provisionally numbered 1008. It appeared today at the location circled in this SOHO UV image of the sun:

Inside that bright nest of magnetic loops, a dark sunspot is rapidly coelescing. Howard Eskildsen photographed it from his backyard observatory in Ocala, Florida. Readers, if you have a solar telescope, now is your chance to watch sunspot genesis in action.

more images: from Stephen Ames of Hodgenville, Kentucky; from Adrian Guzman of San Jose, California;

"It reminds me of jello," says atmospheric optics expert Les Cowley. "Near the horizon the sun always sports a slender green rim. Our sphere-shaped atmosphere acts as a lens to lift the sun's image. The blue and green 'suns' are lifted more than the red one, but we rarely see the blue rim because blue light is mostly scattered away to form the sky color above us. The mirage conditions here have distorted the sun and vertically magnified the green rim to generate mini green flashes."

"The California Coast with its cold ocean currents overlaid by warm winds from the land is ideal for seeing sights like these." Sunset jello: another reason to go to the beach!
  AURORA WATCH: On Nov. 9th, flying photographer Brian Whittaker was 35,000 feet over the Arctic Circle when he looked out the window of his airplane and saw this:

It's time to book another flight. On Nov. 24th or 25th, a solar wind stream will hit Earth and probably spark a new round of Northern Lights. High-latitude sky watchers should be alert for auroras.

Other observers saw it, too: Stephen Ames of Hodgenville, Kentucky, called it "a real WOWser!" Jan Timmermans of the Netherlands measured the prominence and found it surging "four times higher than Earth itself. It was huge." John Boyd of Santa Barbara, California, said "it was the biggest prominence I've seen in a long time. I'm glad the sun is getting active again."

Indeed it is. The month of October brought four new-cycle sunspots, doubling the total of the previous nine months. For the first time in 2008, new-cycle active regions are outnumbering their old-cycle counterparts. Solar Cycle 24 is definitely picking up steam and this fiery prominence may be a further sign of things to come.

Readers, if you have a solar telescope, take a look at the increasingly active sun.

more images: from David Leong of Hong Kong; from Jan Timmermans of Valkenswaard, the Netherlands; from Steve Irvine of Big Bay, Ontario, Canada; from Adrian Guzman of San Jose, California;

24-hr: A9 1135 UT Nov06
explanation | more data
Updated: Today at: 2355 UT

A solar wind stream flowing from this coronal hole
could reach Earth on Nov. 6th or 7th.
Credit: Hinode X-ray Telescope

Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

more images: from Larry Alvarez of Flower Mound, Texas; from Stephen W. Ramsden of Atlanta, Georgia;

Current conditions

Current conditions

On November 6, 2008 there were 996 potentially hazardous asteroids. Nov. 2008 Earth-asteroid encounters: Asteroid Date(UT) Miss Distance Mag. Size Nov. 1 9 LD 19 45 m 2008 UT95 Nov. 2 1.5 LD 17 15 m 2008 UC7 Nov. 2 4.5 LD 20 17 m 4179 Toutatis Nov. 9 20 LD 14 3.8 km Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

This is the fourth time in October that a new-cycle sunspot has breached the sun's surface. (The previous three occasions were Oct. 4th, 11th and 17th.) In a year of almost no sunspots, four in a single month is a large number, and their association with the new solar cycle is significant. It is a sign that the sun is beginning a slow ascent out of solar minimum to a more active phase in the months and years ahead. Solar minimum is not a permanent condition!

Readers, if you have a solar telescope, train it on sunspot 1007 to witness a sign of things to come.

more images: from J. Fairfull and J. Stetson of South Portland, Maine; from Peter Paice of Belfast, Northern Ireland; from Pavol Rapavy of Rimavska Sobota, Slovakia; from Stephen Ames of Hodgenville, Kentucky;

Earth is inside a solar wind stream flowing from the indicated coronal hole.
Credit: SOHO Extreme UV Telescope

Click to view videos of the fireball

On Oct. 28th at 7:29 pm Mountain Daylight Time, a random meteoroid hit Earth's atmosphere and disintegrated with the luminosity of a full Moon. The impact, which could've happened anywhere, took place directly above an all-sky video camera in Guffey, Colorado.

"I've received more than 100 eyewitness reports," says astronomer Chris Peterson, who operates the camera as part of a nightly fireball monitoring program. Combining the data at hand, he estimates that "the meteor had a ground path about 170 miles long and traveled from east to west at 34 km/s (76,000 mph)."

"I was lucky enough to see it myself from inside my house through a window," adds Thomas Ashcraft. What's amazing about that is he was located 300 miles away in New Mexico. "It was brilliant turquoise and green and lasted more than nine seconds." Ashcraft is an amateur radio astronomer and his receivers picked up echoes of distant TV transmitters bouncing off the fireball's ionized trail: listen.

Using a computer model of Earth's meteoroid environment, Bill qa3n3uvdbktfc4pmr5u0"> that fireballs this bright come along once every five months or so. Rarely, however, are they witnessed. About 70% of all fireballs streak over uninhabited ocean while half appear during the day, invisible in sunny skies. To catch one in the crosshairs of a meteor camera on a dark albeit cloudy night is good luck indeed.

Photo details: Nikon D3, ISO 1600, 3 secs

"The auroras were very fast moving and trimmed with pink edges," he says. "Some of the lights went directly overhead."

Gusts of solar wind continue to buffet Earth's magnetic field and this could spark another round of geomagnetic storms tonight. High latitude sky watchers should remain alert for auroras.

Oct. 2008 Aurora Gallery
[Previous Octobers: 2007, 2006, 2004, 2003, 2002, 2001, 2000]

Asteroids near earth on these dates.
 

2005 VN	Oct. 29	4.1 LD	15	116 m
2008 TX3	Nov. 1	9 LD	19	45 m
4179 Toutatis	Nov. 9	20 LD	14	3.8 km

Click to launch a 0.3 MB movie

The CME was not aimed at Earth (for the record, it is heading in the general direction of Saturn), so there will be no space weather consequences for our planet. What caused the explosion? Possibilities include a farside sunspot or a collapsing magnetic filament. Whatever the source, it was a break from the relentless calm of recent months. The sun is alive, after all.

Hackmann's camera, a Canon 40D, caught a piece of Halley's Comet hitting Earth's atmosphere. Every year around this time, Earth crosses a stream of debris from Halley and the encounter creates a meteor shower called the Orionids. This year's display was not only strong (a maximum of 40 meteors/hr on Oct. 21st) but also persistent: The shower lasted for five days and is only now subsiding. Browse the gallery for more meteors "getting in the way":

2008 Orionid Meteor Gallery
[IMO meteor counts] [2006 Orionids]

A solar wind stream flowing from the indicated coronal hole should reach Earth on or about Oct. 28th. Credit: SOHO Extreme UV Telescope

What happened to Comet Holmes? Just-released observations by NASA's Spitzer Space Telescope define the mass and velocity of the explosion: "The energy of the blast was about 10¹⁴ joules and the total mass was of order 10¹⁰ kg," says Bill Reach of Caltech. In other words, Holmes exploded like 24 kilotons of TNT and ejected 10 million metric tons of dust and gas into space. These numbers fit a model favored by Reach in which a cavern of ice some hundred meters beneath the comet's crust changed phase, from amorphous to crystalline, releasing in transition enough heat to cause Holmes to blow its top.

Holmes has exploded twice in recorded history--in 1892 and 2007. Two caverns down, how many to go? No one knows. Browse the gallery for a preview of what the next blast might look like:

Comet Holmes Photo Gallery
[JPL press release] [Night Sky Cameras]

Also see:  http://www.greatdreams.com/comets/comets-2007.htm

Click to view a larger movie (2 MB gif)

In the movie, the "floodlight" arcing slowly across the sky is the Moon. "Lunar glare should have spoiled the show, but the shower was so bright, we saw it despite the Moon's interference," says Bill Cooke of NASA's Meteoroid Environment Office.

The source of the Orionid meteor shower is Halley's Comet. Every year in October, Earth's crosses a stream of Halley-dust, and meteors fly out of the constellation Orion. The extra Orionids of 2008 probably came from a denser-than-usual filament of dust. This is the third October in a row Orionids have surged, suggesting a trend. Maybe next year's outburst won't be such a surprise!

UPDATED: 2008 Orionid Meteor Gallery
[IMO meteor counts] [2006 Orionids]

"The explosion left a bubble of glowing debris that expanded for at least 15 minutes," says photographer Marsha Adams. She took pictures at one minute intervals and assembled them to show the aftermath of the blast.

Orionid meteors are specks of debris from Halley's Comet. The extra Orionids of 2008 probably came from a denser-than-usual filament of comet dust crossing Earth's orbit. This is the third October in a row this has happened, suggesting a trend. Maybe next year's outburst won't be such a surprise!

In years past, the longest-range forecasts of solar wind streams amounted to six or seven days. Stereo-B has extended the range to eight or nine days. It does this trick by looking over the sun's eastern horizon to find coronal holes before they can be seen from Earth. The orbit of Stereo-B is similar to Earth's, yet it lags 38^o behind our planet, giving it an "around-the-bend" view of the sun.

Arctic sky watchers should be alert for auroras at the end of the month. A Halloween storm could be brewing.

What happened? The interplanetary magnetic field (IMF) near Earth tipped south, opening a crack in our planet's magnetic defenses against the solar wind. Solar wind poured in and fueled the display.

"The clouds cleared just in time for some heavy auroras," says Thomas Hagen of Tromsø, Norway. "[It's] the greatest show on Earth!"

Held aloft by solar magnetism, the cloud of glowing hydrogen stretched more than 20 Earth diameters from end to end. It curled backwards over the sun's horizon and for a while seemed to promise days of unfolding entertainment. Then it collapsed. All that's left today is smooth horizon.

more images: from Pete Lawrence of Selsey, West Sussex, UK; from Thierry Legault of Paris, France; from Kristian Molnar of Senec, Slovakia; from Cai-Uso Wohler of Bispingen, Germany; from Denis Joye of Boulonge, France; from James Screech of Bedford, England; from Stephen Ames of Hodgenville, Kentucky; from Alan C Tough of Elgin, Moray, Scotland

"It's so big that I couldn't fit it all in one frame--a stunning arch of plasma that now appears to be reaching back towards the surface at the other end," he says.

more images: from Emiel Veldhuis of Zwolle, the Netherlands; from Cai-Uso Wohler of Bispingen, Germany; from Denis Joye of Boulonge, France; from James Screech of Bedford, England; from Stephen Ames of Hodgenville, Kentucky;

Tiny fading sunspots 1005 and 1006 are both members of Solar Cycle 24.
Credit: SOHO/MDI

SOLAR HOT SPOTS: NASA's Stereo-B spacecraft is monitoring a string of hot spots where magnetic fields are poking through the solar surface. All four are located at high latitude, a sign that they belong to new Solar Cycle 24:

Does this mean Solar Cycle 24 is picking up steam? Probably, yes, but only a little. Just one of these active regions is a full-fledged sunspot (numbered 1005), while the others are merely "proto-sunspots" without a dark sunspot-core. It beats another blank day on the sun! Stay tuned for developments

For the record, she used a Nikon D40X digital camera, but it wasn't the camera that did the trick. Careful but straightforward processing in Photoshop can turn almost any digital photo of the full Moon into a mineral map. Astronomers working with the Hubble Space Telescope use similar techniques to find valuable ores for future lunar settlements.

Look at the Moon tonight. Does it really seem so gray?

moon photos: from Piotr Majewski of Torun, Poland; from Mohammad Soltanolkottabi of Esfahan, Iran; from Thad V'Soske of Grand Valley, Colorado; from P-M Hedén of Vallentuna, Sweden; from Elias Chasiotis of Markopoulo, Greece; from Martin Mc Kenna of Maghera, Co. Derry, N. Ireland; from Tamas Ladanyi of Veszprem, Hungary; from C.J. Wood of Ridgely, Maryland; from Mila Zinkova of San Francisco, California; from Hunter Outten of Frankford, Delaware; from Edmund E Kasaitis of Manchester, Maryland; from Don Poggensee of Ida Grove, Iowa;

 Current conditions

NEW-CYCLE SUNSPOT: A "new-cycle" sunspot belonging to Solar Cycle 24 has emerged near the sun's northeastern limb. Sunspot 1005 has a two dark cores (one of them busily fragmenting) and a simple bipolar magnetic field that poses no threat for solar flares. "It's a lovely little group of spots," says Pete Lawrence, who sends this picture from his backyard observatory in Selsey, UK:

more images: from Mike Borman of Evansville, Indiana; from Alan Friedman of Buffalo, NY; from Pete Lawrence of Selsey, UK; from Wouter Verhesen of Sittard, The Netherlands; from J. Fairfull and J. Stetson of South Portland, Maine; from Greg Piepol of Rockville, Md; from Tibor Horvath of Hegyhatsal, Hungary;

NEW-CYCLE SUNSPOT: A "new-cycle" sunspot belonging to Solar Cycle 24 has emerged near the sun's northeastern limb. Sunspot 1005 has two fast-growing dark cores wider than Earth and a simple bipolar magnetic field that poses no threat for solar flares. Alan Friedman sends this picture from his backyard observatory in Buffalo, New York:

On October 12, 2008 there were 990 potentially hazardous asteroids. Oct. 2008 Earth-asteroid encounters: Asteroid Date(UT) Miss Distance Mag. Size 2008 QS11 Oct. 2 11 LD 14 470 m 2008 SH148 Oct. 4 5.8 LD 19 26 m 2005 GN59 Oct. 6 20 LD 15 1.4 km 2008 TC3 Oct. 7 IMPACT -13 3 m 2008 TZ Oct. 10 5.3 LD 18 37 m 1999 VP11 Oct. 16 72 LD 17 860 m 2001 UY4 Oct. 18 74 LD 17 1.1 km Comet Barnard-Boattini Oct. 22 75 LD 16 unknown 2008 TT26 Oct. 23 3.6 LD 15 70 m 2000 EX106 Oct. 23 69 LD 18 1.1 km 2005 VN Oct. 29 4.1 LD 15 116 m 4179 Toutatis Nov. 9 20 LD 14 3.8 km Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

Finally some good auroras and no clouds!" he says. Bright moonlight added beauty to the scene by illuminating the landscape. Koski made a series of exposures using a Nikon D3 digital camera, opening the shutter for 6 seconds at 800 ASA.

High-latitude sky watchers should remain alert for auroras as the solar wind continues to blow.

  Current conditions

Click to launch a 1.4 MB movie

NASA's STEREO-A spacecraft recorded this spectacular prominence on Sept. 29th. No sunspot was involved. A magnetic filament snaking around the sun's north pole suddenly became unstable and erupted, disgorging a cloud of hydrogen large enough to swallow a hundred Earths.

How and why prominences erupt is a topic of ongoing research. The blasts are unpredictable, which is why today's sun is so full of promise: image. By the standard of prominences, solar activity is looking up.

(Updated Oct. 15th)  Last week when asteroid 2008 TC3 entered Earth's atmosphere over Sudan, "classified assets" were watching. Without naming names, the US government has released a summary of what they saw: "Sensors aboard US satellites detected the impact of a bolide over Africa on 7 October 2008 at 02:45:40 UT. Initial observations put the object at 65.4 km altitude at 20.9^o N, 31.4^o E. The object detonated at an altitude of approximately 37 km at 20.8 ^o N, 32.2^o E. The total radiated energy was approximately 4.0X10¹¹ joules, equivalent to ~0.1 kilotons of TNT."

(Updated Oct. 8th) On Oct. 7th, asteroid 2008 TC3 hit Earth and exploded in the atmosphere over northern Sudan. An infrasound array in Kenya recorded the impact: map. Dr. Peter Brown of the University of Western Ontario has inspected the data and he estimates that the asteroid hit at 0243 UTC with an energy between 1.1 and 2.1 kilotons of TNT. The explosion was imaged by the weather satellite Meteosat 8:

So far, no ground pictures of the fireball have been submitted; the impact occurred in a remote area with few and possibly no onlookers capable of recording the event. The only report of a visual sighting comes from Jacob Kuiper, General Aviation meteorologist at the National Weather Service in the Netherlands:

"Half an hour before the predicted impact of asteroid 2008 TC3, I informed an official of Air-France-KLM at Amsterdam airport about the possibility that crews of their airliners in the vicinity of impact would have a chance to see a fireball. And it was a success! I have received confirmation that a KLM airliner, roughly 750 nautical miles southwest of the predicted atmospheric impact position, has observed a short flash just before the expected impact time 0246 UTC. Because of the distance it was not a very large phenomenon, but still a confirmation that some bright meteor has been seen in the predicted direction. Projected on an infrared satellite image from Meteosat 7, I have indicated the position of the plane (+) and the predicted impact area in Sudan (0)."

2008 TC3 was discovered on Oct. 6th by astronomers using the Mt. Lemmon telescope in Arizona as part of the NASA-funded Catalina Sky Survey for near-Earth objects. Asteroids the size of 2008 TC3 hit Earth 5 to 10 times a year, but this is the first time one has been discovered before it hit.

BONUS: 2008 TC3 was so close to Earth, different observers around the globe saw the asteroid trace different paths among the stars. This effect, called parallax, is beautifully illustrated in a compilation of 566 published observations prepared by Matthias Busch: image.
 

MOUNTAIN VIEW -- Nasa scientists at Ames Research Center in Mountain View say scientists did something Monday night that they've never been able to do before. They were able to predict where and when an asteroid would enter the earth's atmosphere.

So far there are no reports of damage. It is believed that the space rock burned up before reaching the ground, although small pieces could have made it to the ground.

But this time, they were able to predict the impact 12 hours in advance. David Morrison, of the NASA Lunar Science Institute, said "Our Spaceguard telescopes, the telescopes looking up and doing a catalog of asteroids happened by good luck to see this just one night before it hit."

An asteroid collision with earth has been a subject of science fiction for many years. In reality, it's happened in the past and will likely happen again in the future. "If it's big enough to get through the atmosphere, it hardly slows down. It hits the ground 3 or 4 seconds after it enters the atmosphere, and there's just an explosion. It's like a big bomb going off," said Morrison.

Some people believe the dinosaurs disappeared 65 million years ago because a space rock ten miles across smashed into the earth.

Nasa's David Morrison sees a practical application. "If you predicted the impact with just a few days or weeks warning, you could at least evacuate. If you have decades of warning then we have the space technology to go out with a space craft and actually deflect it, so it misses the Earth a little bit."

ASTEROID 2008 TC3:  A small, newly-discovered asteroid named 2008 TC3 is approaching Earth and chances are good that it will hit. Measuring only a few meters across, the space rock poses no threat to people or structures on the ground, but it should create a spectacular fireball, releasing about a kiloton of energy as it disintegrates and explodes in the high atmosphere.  At least one expert estimates that atmospheric entry will occur on Oct 7th at 0246 UTC over northern Sudan. 
 

HOW ROUND IS THE SUN? Scientists using NASA's RHESSI spacecraft have measured the roundness of the sun with unprecedented precision, and they find that it is not a perfect sphere. During years of high solar activity the sun develops a rough "cantaloupe skin" that increases the sun's oblateness

The crinkles, shown here in a July 2005 photo taken by astrophotographer Gary Palmer, brighten and fatten the "stellar waist," adding more than 10 milli-arcseconds to the sun's equatorial angular diameter. Solar physicists have long known about these crinkles, which are made of magnetism and trace bubbling "supergranules" on the sun's surface, but only now has RHESSI revealed their unexpected effect on the sun's global shape. This research has far ranging implications for solar physics and theories of gravity: full story

Earth is inside a solar wind stream flowing
from the indicated coronal hole.
Credit: Hinode X-ray

Readers, if you have a solar telesscope, monitoring is encouraged.

more images: from Pavol Rapavy of Rimavska Sobota, Slovakia

A solar wind stream flowing from
the indicated coronal hole should
reach Earth on Oct. 1st or 2nd.
Credit: SOHO Extreme UV

GREAT PROMINENCE: A prominence of rare beauty is dancing along the sun's southern rim.

A prominence is a cloud of hot gas held in the grip of solar magnetic fields. With that in mind, watch the movie again. The motions you just witnessed are a major puzzle for solar physicists. No one understands why the top of the prominence cascades down as fast as it does; the "magnetic diffusion coefficient" of the medium shouldn't allow it. At the same time, swirls and vortices indicate an exquisite degree of magnetic control so far impossible to duplicate in Earth laboratories. How does the sun do these things? It's a beautiful mystery. If you have a solar telescope, take a look.

more images: from Jack Newton of Osoyoos, British Columbia; from Wouter Verhesen of Sittard, The Netherlands; from Larry Alvarez of Flower Mound, Texas; from Didier Favre of Brétigny-sur-Orge, France; from Robert Arnold of Isle of Skye, Scotland; from Cai-Uso Wohler of Bispingen, Germany; from P-M Hedén of Vallentuna, Sweden; from Steve Wainwright of Swansea, South Wales; from Les Cowley of the UK; from Emiel Veldhuis of Zwolle, the Netherlands; from Stephen Ames of Hodgenville, Kentucky; from Adrian Guzman of San Jose, California;

A solar wind stream flowing
from the indicated coronal hole
should reach Earth on or about
Oct. 1st. Credit: Hinode X-ray Telescope

more images: from Alan Friedman of Buffalo, New York; from N. Hebert et al. of South Portland, Maine

Current conditions

Current conditions

Solar wind
speed: 290.0 km/sec
density: 3.3 protons/cm³
explanation | more data
Updated: Today at 2247 UT <{> X-ray Solar Flares
6-hr max: A0 2245 UT Sep23
24-hr: A0 0020 UT Sep23
explanation | more data
Updated: Today at: 2245 UT

This is a closeup of sunspot 1002

Solar Wind Loses Power, Hits 50-year Low

Sept. 23, 2008: In a briefing today at NASA headquarters, solar physicists announced that the solar wind is losing power.

"The average pressure of the solar wind has dropped more than 20% since the mid-1990s," says Dave McComas of the Southwest Research Institute in San Antonio, Texas. "This is the weakest it's been since we began monitoring solar wind almost 50 years ago."

McComas is principal investigator for the SWOOPS solar wind sensor onboard the Ulysses spacecraft, which measured the decrease. Ulysses, launched in 1990, circles the sun in a unique orbit that carries it over both the sun's poles and equator, giving Ulysses a global view of solar wind activity:

Above: Global measurements of solar wind pressure by Ulysses. Green curves trace the solar wind in 1992-1998, while blue curves denote lower pressure winds in 2004-2008. [Larger image]

Curiously, the speed of the million mph solar wind hasn't decreased much—only 3%. The change in pressure comes mainly from reductions in temperature and density. The solar wind is 13% cooler and 20% less dense.

"What we're seeing is a long term trend, a steady decrease in pressure that began sometime in the mid-1990s," explains Arik Posner, NASA's Ulysses Program Scientist in Washington DC.

How unusual is this event?

"It's hard to say. We've only been monitoring solar wind since the early years of the Space Age—from the early 60s to the present," says Posner. "Over that period of time, it's unique. How the event stands out over centuries or millennia, however, is anybody's guess. We don't have data going back that far."

Flagging solar wind has repercussions across the entire solar system—beginning with the heliosphere.

The heliosphere is a bubble of magnetism springing from the sun and inflated to colossal proportions by the solar wind. Every planet from Mercury to Pluto and beyond is inside it. The heliosphere is our solar system's first line of defense against galactic cosmic rays. High-energy particles from black holes and supernovas try to enter the solar system, but most are deflected by the heliosphere's magnetic fields.

"The solar wind isn't inflating the heliosphere as much as it used to," says McComas. "That means less shielding against cosmic rays."

In addition to weakened solar wind, "Ulysses also finds that the sun's underlying magnetic field has weakened by more than 30% since the mid-1990s," says Posner. "This reduces natural shielding even more."

Unpublished Ulysses cosmic ray data show that, indeed, high energy (GeV) electrons, a minor but telltale component of cosmic rays around Earth, have jumped in number by about 20%.

These extra particles pose no threat to people on Earth's surface. Our thick atmosphere and planetary magnetic field provide additional layers of protection that keep us safe.

But any extra cosmic rays can have consequences. If the trend continues, astronauts on the Moon or en route to Mars would get a higher dose of space radiation. Robotic space probes and satellites in high Earth orbit face an increased risk of instrument malfunctions and reboots due to cosmic ray strikes. Also, there are controversial studies linking cosmic ray fluxes to cloudiness and climate change on Earth. That link may be tested in the years ahead.

9-22-08

NEW SUNSPOT: For the first time in months, a significant sunspot is emerging on the sun.  It is a fast-growing active region with two dark cores, each larger than Earth.  The magnetic polarity of the sunspot identifies it as a member of new Sunspot Cycle 24.  Because the year 2008 has brought so many blank suns, some observers have wondered if we are ever going to climb out of the ongoing deep solar minimum.  Today's new sunspot is an encouraging sign that the 11-year solar cycle is indeed progressing, albeit slowly.  

Current conditions

 SOLAR ACTIVITY: By the standard of sunspot counts, solar activity is low. Maybe there should be another standard:

"The face of the sun was pretty bare today, but the limb was a different story. There was a really big prominence," says Larry Alvarez of Flower Mound, Texas. "It looked like a raging 'wire of fire.' I took the picture using my Coronado 90mm solar filter and a homemade ccd camera."

FOOTBALL-SHAPED PLANET: The International Astronomical Union (IAU) has just named the solar system's fifth dwarf planet, Haumea, after the Hawaiian goddess of childbirth and fertility. Located just beyond Pluto, Haumea spins so rapidly that it has been elongated like a football approximately 2200 km long. The strange planet has two moons, Hi'iaka and Namaka: IAU press release.

Current conditions

Solar wind
speed: 363.3 km/sec
density: 1.9 protons/cm³
explanation | more data
Updated: Today at 2245 UT

X-ray Solar Flares
6-hr max: A0 2245 UT Sep19
24-hr: A0 0800 UT Sep19
explanation | more data
Updated: Today at: 2245 UT

MICKEY MOUSE EARS: Ultraviolet photos taken by the Solar and Heliospheric Observatory (SOHO) reveal the a strange pair of "Mickey Mouse" ears on the sun. They've been sighted many times in recent weeks and are especially prominent today:

What are they? Coronal cavities--regions of low density, high temperature gas contained by loops of magnetic field. Coronal cavities are where prominences are born. Indeed, there is a prominence inside the righthand cavity; look for it in the red image, above, also from SOHO.

There's more to this story. The two ears appear to be two distinct cavities. In fact, they are one. The actual cavity is a collosal ring encircling the north pole of the sun. Geometrically, it is similar to the auroral ovals of Earth. The two ears are cross-sections of the translucent ring, distinctly visible because they hang out over the edge of the solar disk.

The ring-shaped cavity is also known as the sun's "polar crown" and it spawns some truly beautiful prominences. The polar crown is easiest to see during solar minimum when the sun is not cluttered with spots--so now is the perfect time. Look for the ears in daily images from SOHO.

"It's the International Space Station," says Stetson. "The ISS was 233 miles above Goosefair Bay when it passed directly in front of the 89% illuminated Moon." Because the ISS was in Earth's shadow at the time of the overpass, it made a dark-as-night silhouette against the gray lunar surface.

An even better time to see the ISS is when it is out of Earth's shadow. Sunlight striking the behemoth space station turns it into one of the brightest objects in the night sky, second only to the Moon and sometimes Venus. Its easy to spot if you know when to look.

more images: from Ralf Vandebergh of the Netherlands; from Thomas Dorman of Horizon City, Texas; from Mike Salway of Central Coast, NSW Australia; from John C McConnell of Maghaberry Northern Ireland;

\\

Yesterday, I was testing the focus on my H-alpha scope as the sun was rising,"
says Stephen W. Ramsden of Atlanta, Georgia. "By accident I got this weird
shot of tree limbs in my neighborhood in front of the violent solar disc."

Hundreds of miles away in Flower Mound, Texas, photographer
Larry Alvarez reports that, while "the sun has hit rock bottom,"
 trees are not required for a good shot. "The sun is still pure gold for the solar imager."

more images: from James Kevin Ty of Manila, Philippines;
from Stephen Ames of Hodgenville, Kentucky;
from Alan Friedman of Buffalo, NY;
 from Cai-Uso Wohler of Bispingen, Germany;
 from N. Hebert, J. Fairfull and J. Stetson of South Portland, Maine

Current conditions

9-13-08 - No sunspot today - yesterday's sunspot disappeared again.

Current conditions

EMERGING SUNSPOT: A new sunspot is emerging near the sun's equator. "
Finally!" says Pavol Rapavy who sends this picture from Rimavska Sobota, Slovakia.
Readers with solar telescopes, take a look.

Lesson on sunspot numbers

Current conditions

CORONAL HOLE: Japan's Hinode spacecraft is monitoring a dark hole in the sun's atmosphere--a coronal hole:

FIREBALL OUTBURST: Yesterday, Sept. 9th, with no warning whatsoever, a flurry of bright fireballs lit up the skies of North America. "Our SENTINEL all-sky camera picked up 25 bright meteors in a shower that began at 0620 UT and lasted approximately 4 hours," reports NASA astronomer Bill Cooke of the Marshall Space Flight Center in Huntsville, Alabama. This video "frame-stack" shows the outburst at a glance:

Ongoing analyses of this outburst may reveal the orbit of the meteoroids, the location of the parent comet (if a comet is indeed the parent), and whether more outbursts are in the offing. Stay tuned for updates.

A solar wind stream flowing from the indicated coronal hole
 should reach Earth on or about Sept. 13th.
Credit: Hinode X-ray Telescope
 

Earth is inside a solar wind stream flowing from the indicated coronal hole. Credit: Hinode X-Ray Telescope
 

Photo details: Canon XTI, 300 mm; 1/4000s, f/10, ISO100

"The sun held up by pillars?" asks atmospheric optics expert Les Cowley. "We might say 'Nonsense, it's only a mirage.' But which is the mirage and which is the real sun? Layers of different temperature air have distorted the sun's rays and produced several solar images. All of them are illusions. Even the top bright one is raised up in the sky and flattened."

FIND THE PLEIADES:
When in Iceland, where do you look for the Pleiades? Scan the photo for hints as you scroll down for the answer:

Through a gap in the Northern Lights, of course. Click here.

Sean Scully took the picture on Sept. 6th just outside of Akureyri, Iceland. "The sunsets are now early enough that the sky is dark after 10 p.m. and we can see the auroras again." This display was caused by a solar wind stream buffeting Earth's magnetic field.

Good news: the solar wind is still blowing and more auroras are possible tonight. Sky watchers in Alaska, Canada, Iceland and Scandinavia should be alert for Pleiades peeking through the green.

The source of the display was a solar wind stream, now buffeting Earth's magnetic field for the third day in a row.
NOAA forecasters estimate a 15% chance of continued geomagnetic activity tonight.
Sky watchers in Alaska, Canada and Scandinavia should remain alert for auroras.

A "SECRET LAYER" OF THE SUN: NASA researchers are preparing to launch an experimental telescope that can see a "secret layer" of the sun thought to be the birthplace of space weather.

Sept. 5, 2008: Next April, for a grand total of 8 minutes, NASA astronomers are going to glimpse a secret layer of the sun.

Researchers call it "the transition region." It is a place in the sun's atmosphere, about 5000 km above the stellar surface, where magnetic fields overwhelm the pressure of matter and seize control of the sun's gases. It's where solar flares explode, where coronal mass ejections begin their journey to Earth, where the solar wind is mysteriously accelerated to a million mph.

It is, in short, the birthplace of space weather.

Researchers hope it is about to yield its secrets.

Right: Not far above the surface of the sun lies the "transition region" where magnetic fields seize control of solar gases.

 

Photo credit: NASA/TRACE.

"Early next year, we're going to launch an experimental telescope that can measure vector magnetic fields in the transition region," explains Jonathan Cirtain of the Marshall Space Flight Center (MSFC). Previous studies have measured these fields above and below the transition region—but never inside it. "We hope to be the first."

The name of the telescope is SUMI, short for Solar Ultraviolet Magnetograph Investigation. It was developed by astronomers and engineers at the MSFC and is currently scheduled for launch from White Sands, New Mexico, in April 2009.

SUMI works by means of "Zeeman splitting." Dutch physicist Pieter Zeeman discovered the effect in the 19th century. When a glass tube filled with incandescent gas is dipped into a magnetic field, spectral lines emitted by the gas get split into two slightly different colors—the stronger the field, the bigger the splitting. The same thing happens on the sun. Here, for instance, are some spectral lines from gaseous iron being split by the magnetic field of a sunspot:

Above: Zeeman splitting of spectral lines from a strongly-magnetized sunspot. [more]

By measuring the gap, astronomers estimate the strength of the sunspot's magnetic field. Furthermore, by measuring the polarization of the split line, astronomers can figure out the direction of the magnetic field. Strength + direction = everything you ever wanted to know about a magnetic field!

This trick has been applied to thousands of sunspots on the solar surface, but never to the transition region just a short distance above.

Why not?

"Just bad luck, really," says Cirtain. "Gas in the transition region doesn't produce many strong spectral lines that we can see at visible wavelengths." It does, however, produce lines at UV wavelengths invisible from Earth's surface.

"That's why we have to leave Earth."

SUMI will blast off inside the nose cone of a Black Brant rocket on a sub-orbital flight that takes it to an altitude of 300 km. "We'll be above more than 99.99% of Earth's atmosphere," says Cirtain. About 68 seconds into the flight, payload doors will open, affording SUMI a crystal-clear view of the UV sun. "From that moment, we've only got 8 minutes to work with. We'll target an active region and start taking data."

Right: A Black Brant sounding rocket of the type that will carry SUMI above Earth's atmosphere.

SUMI's "vector magnetograph" is tuned to study a pair of spectral lines: one from triply-ionized carbon (CIV) at 155 nanometers and a second from singly-ionized magnesium (MgII) at 280 nanometers. "There's nothing special about those ions," notes Cirtain. "They just happen to produce the best and brightest lines at temperatures and densities typical of the transition region."

Cirtain anticipates how it will feel to have his precious instrument hurtling 300 km above Earth at 5,000 mph: "Eight minutes of terror." He'll start breathing again when the payload doors close and SUMI begins its descent back to Earth. Cirtain ticks off the stages: "Reentry into the atmosphere. Open parachutes. Landing back at White Sands. Recovery."

The short flight probably won't lead to immediate breakthroughs. "But it will demonstrate the SUMI concept and show us if it's going to work." A successful flight would lead to more flights and eventually to a SUMI-style magnetograph permanently installed on a space telescope.

"That's the dream," he says. Transition region, prepare to yield...

FROM: http://science.nasa.gov/headlines/y2008/05sep_sumi.htm

Earth is inside a solar wind stream flowing from the indicated coronal hole. Credit: SOHO Extreme UV Telescope
 

Similar displays could appear tonight. A solar wind stream is buffeting Earth's magnetic field, causing intermittent geomagnetic storms. Sky watchers in Alaska, Canada and Scandinavia should be alert for auroras.

The coronal hole on the sun responsible for this activity is a broad one, which means the solar wind could blow unabated for days. NOAA forecasters estimate a 10% chance of geomagnetic storms during the next 24 hours; high-latitude sky watchers should remain alert for auroras.

LUNAR PERSEIDS: Amateur astronomers watching last month's Perseid meteor shower saw meteoroids hitting not only Earth but also the Moon. The impacts, which they recorded using backyard telescopes and off-the-shelf video cameras, are featured in today's story from Science@NASA.

No matter where you live, look west at tonight's sunset. The crescent Moon is out again and, if the winds are willing, it might be a Kasatochi Moon.

more images: from Bill Jamison of San Diego, CA; from Kevin Jung of Grand Rapids, Michigan; from Christian Pierson of North Ridgeville, Ohio; from Doug Zubenel near De Soto, Kansas; from Adam Kraft of Jackson, Michigan; from Andrew Catsaitis of Peats Ridge, NSW, Australia; from Rick Gens at Starved Rock State Park in Utica, Illinois; from Jeffrey Berkes at the Assateague Island National Seashore, Maryland; from Tom Soetaert of Lawrence, Kansas; from Karen Webb of Ridgecrest, California; from Scott Sparrow of Pasadena, CA; from David Smoyer of Truckee, CA;

A solar wind stream flowing from the indicated coronal hole
should reach Earth on Sept. 3rd or 4th. Credit: SOHO Extreme UV Telescope

Current conditions

2245 UT Aug30
explanation | more data
Updated: Today at: 2245 UT

EARLY WARNING: NASA's STEREO-B spacecraft follows Earth around the sun, lagging behind our planet by 33^o ("B" stands for "behind"). This allows the spacecraft to see a portion of the sun we on Earth cannot. Here is an example:

There are no coronal black holes either

For the past two days, a colossal prominence has been dancing along the northwestern limb of the sun. "Here's a photo from Aug. 27th," offers Pete Lawrence of Selsey, UK. "The Earth has been added for scale."

Lawrence's photo frames a towering sheet of hydrogen gas stretched 75,000 km high by solar magnetic fields. The foreground is filled by a "shag carpet" of spicules--Texas-sized jets of gas that shoot up from the sun's surface and fall back again on 10 minute time scales. Spicules are the smallest thing in the photo and they're as big as Texas. Have you ever driven across Texas?

The prominence is still active today and makes an easy target for backyard solar telescopes. Take a look, that is, if you can reach the eye piece.

more images: from J. Fairfull and John Stetson of South Portland, Maine; from Stephen Ames of Hodgenville, Kentucky; from James Kevin Ty of Manila, the Philippines; from Roger G. Williams of Kalamazoo, Michigan; from B. Atkins et al of South Portland, Maine; from Pavol Rapavy of Rimavská Sobota, Slovakia

PROMINENCE ALERT: For the second day in a row, astronomers are monitoring a lively prominence
on the sun's northwestern limb. It is at least five times taller than Earth and an easy target for backyard solar telescopes.

Movie formats: 4 MB Quicktime, 7 MB mpg, 31 MB Quicktime

If you counted fewer than four, play it again. In the movie, made by NASA's STEREO-A spacecraft on August 15 and 16, every quadrant of the sun has at least one magnetic prominence surging over the limb. Prominences are clouds of hydrogen held aloft, twisted and sheared, and ultimately hurled into space or pulled back into the inferno by solar magnetic fields. It's a form of solar activity that continues even when sunspots are scarce. The sun: this is as "quiet" as it gets.

 PROTO NEW-CYCLE SUNSPOT: For the second time this month, a new-cycle sunspot is struggling to form. SOHO magnetograms of the sun's surface reveal a planet-sized magnetic dipole with the telltale polarity of Solar Cycle 24:

Last week, these magnetic fields briefly coelesced into a pair of dark cores, then subsided. The apparition was too ephemeral to be included in official daily sunspot counts. For now, put this active region in the category of "struggling proto-sunspot."

Sometimes the ongoing solar minimum seems like it will never end. This proto-sunspot, as well as a similar one in early August, offers hope to observers that the solar cycle is actually moving forward. The calm won't last forever.

more images: from Pete Lawrence of Selsey, West Sussex, UK; from Michael Buxton of Ocean Beach, California

Current conditions