Interesting Space Weather/NASA Photos
(Click on thumbnails for larger images.)
GOOD SHOW: Veteran meteor watchers say the Perseids of 2009 were the best in years. One look at this photo shows why. NASA astronomers Danielle Moser and Bill Cooke made the composite of 130+ Perseids that flew over the Marshall Space Flight Center on August 12th. "We recorded a bright meteor or fireball every 3 minutes--a fabulous rate," says Cooke. Their meteor detection system consists of two cameras separated by 100 miles--one in Alabama and one in Georgia. The wide baseline allows Cooke and his team to triangulate the trajectory of meteoroids with some accuracy. Here is a geographic map of the Perseids they saw. "The stars really did fall on Alabama!" he says. Worldwide, observers counted as many as 200 Perseids per hour. Some of the prettiest may be found in the photo gallery.
SWIRLING DEBRIS ON JUPITER: The "Wesley impact cloud" on Jupiter continues to expand and evolve. On August 1st and 2nd, worldwide observers noted that it had transformed from a concentrated, cindery-black spot to an Earth-sized paling swirl. South is up in this just-updated Aug. 3rd image from the cloud's discoverer, Anthony Wesley of Murrumbateman, Australia. "Polar winds seem to be carrying the main body of the cloud westward (to the right in the photo)," says Wesley. "Also, a small stream of dark material is being pulled down and in the opposite direction--perhaps around a cyclone or some other localized weather feature?" Researchers are scrambling to study the cloud before it disperses. Light reflected from the debris may hold clues to the nature of the mystery-impactor. "If the cloud's spectra contain signs of water, that would suggest an icy comet. Otherwise, it's probably a rocky or metallic asteroid," says JPL planetary scientist Glenn Orton. Several teams of professional astronomers are working to obtain the data.Meanwhile, amateur astronomers can monitor the cloud as it shifts and swirls near Jupiter's System II longitude 210°. For the predicted times when it will cross the planet's central meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted transit times for Jupiter's Great Red Spot. [sky map]
JUPITER UPDATE: Something interesting is happening to the dark impact mark on Jupiter. Not only is it growing larger, but also "it seems to be developing two lobes," says amateur astronomer Mike Hood, who sends this picture taken July 28th from his backyard observatory in Kathleen, Georgia. The same result has been obtained by astrophotographer Raffaello Lena of Rome, Italy. "On July 27th, the Jupiter impact site had evolved and now contains two condensed nucleii," he says. These changes are a likely result of dynamics in Jupiter's upper atmosphere. High-resolution images from the Hubble Space Telescope show that the impact cloud is being molded by high-altitude winds and turbulence. On a planet where vortices are ubiquitous, it is no surprise that a cloud would organize itself into two or more swirling spots. Amateur astronomers are encouraged to continue monitoring Jupiter: sky map. The cloud is located near Jupiter's System II longitude 210°. For the predicted times when it will cross the planet's central meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted transit times for Jupiter's Great Red Spot. more images: from Sid Leach of Scottsdale, Arizona; from Tamas Ladanyi of Bakonykoppany, Hungary; from Efrain Morales Rivera of Aguadilla, Puerto Rico
HUBBLE SEES JUPITER IMPACT: The Jupiter impact scar discovered by amateur astronomer Anthony Wesley on July 19th has been photographed by the Hubble Space Telescope. "This July 23rd Hubble photo shows a lumpiness to the debris plume caused by turbulence in Jupiter's atmosphere," says Amy Simon-Miller of NASA's Goddard Space Flight Center. Based on the appearance of the impact zone, she estimates that the diameter of the impacting object was several hundred meters--i.e., several football fields wide. The force of the explosion was likely thousands of times greater than the Tunguska impact of 1908. The impact scar remains an easy target for mid-sized backyard telescopes, and amateur astronomers can contribute to its study by monitoring Jupiter in the nights ahead: sky map. The spot is located near Jupiter's System II longitude 210°. For the predicted times when it will cross the planet's central meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted transit times for Jupiter's Great Red Spot.
RESURGENT SUNSPOT: Yesterday, sunspot 1024 took the day off; the fast-growing active region stopped growing and even decayed a little. Today, the sunspot is growing again. It now measures 125,000 km from end to end, almost as wide as the planet Jupiter. This 3-day movie from the Solar and Heliospheric Observatory (SOHO) shows recent developments (click thumbnail). The size of the spot makes it a fine target for backyard solar telescopes. And it is worth watching. Sunspot 1024 is the first big sunspot of new Solar Cycle 24, and it is crackling with minor but photogenic B-class flares. By itself, this one active region won't bring an end to the deepest solar minimum in a century, but it does show that the sun's magnetic dynamo is still working--a fact some had begun to doubt. More sunspots are coming, so stay tuned.
SUDDEN SUNSPOT: What a difference 48 hours can make. Only two days ago the sun was blank and calm, displaying the sort of unrelenting quiet we've come to expect from the deepest solar minimum in a century. Then, with startling rapidity, sunspot 1024 burst onto the scene: movie. Unlike other recent "sun-specks", this active region is a full-fledged sunspot group with more than a dozen planet-sized dark cores, crackling with B- and C-class solar flares. "Sunspot 1024 is putting on a spectacular show," says amateur astronomer David Tyler of Buckinghamshire UK, who caught it in mid-flare on July 5th. This is the best sunspot I've seen in two years," agrees Michael Buxton of Ocean Beach, California. "Here is a one-hour time lapse movie of activity in the sunspot's core. It is exciting to watch." The magnetic polarity of sunspot 1024 identifies it as a member of new Solar Cycle 24. That makes sense. New research shows that solar jet streams are beginning to stimulate new-cycle sunspot production. Sunspot 1024 appears to be a sign of the process at work, heralding more to come. Monitoring is encouraged.
SUNSPOT ALERT: The most active sunspot of the year so far is emerging in the sun's southern hemisphere: movie. Sunspot 1024 has at least a dozen individual dark cores and it is crackling with B-class solar flares. This morning, amateur astronomer David Tyler caught one of the flares in action from his backyard solar observatory in England; The magnetic polarity of sunspot 1024 identifies it as a member of new Solar Cycle 24. Its rapid emergence on July 3rd and 4th continues the recent (few-month) trend of intensifying new-cycle activity. This sunspot is the best offering yet from the young solar cycle. Monitoring is encouraged.
GREAT RED SPOT RIVAL: Astronomers are monitoring a new red spot forming in Jupiter's northern hemisphere--a brick-red storm nearly as large as the Great Red Spot itself. On June 17th, amateur astronomer Christopher Go of the Philippines photographed it using an 11-inch Celestron telescope. "I have been monitoring the new spot since mid-April," says Go. "At first it was relatively small. In late May it began to grow rapidly, and just last week John Rogers of the British Astronomical Association issued an alert for everyone to observe it." "I hope to get an 890 nanometer 'methane band' image of this object in a few days," adds Go. "A good methane image will prove whether or not the new spot is a genuine anticyclonic storm." Stay tuned! EXTRA: Jupiter's atmosphere is rich in methane (CH4), a molecule which absorbs 890 nm light. Viewed through an 890 nm filter, anticyclonic storms such as the Great Red Spot rise above the absorbing methane layer and appear bright. That is why a methane band image will reveal the nature of the new spot.
TRIANGLE OF FIRE: This weekend, astronomers have been monitoring a colossal "triangle of fire" on the limb of the sun. Click on the image to launch a 1.5 hour movie (DivX required) recorded by Larry Alvarez of Flower Mound, Texas. "The movie shows several blobs of plasma dripping like rain from the arch, while others leap up from the sun's surface to join the action," describes Alvarez. "At the end there is a small explosion off to the left that is extremely quick." Prominences are clouds of hot plasma (ionized gas) held aloft by solar magnetic fields. How "plasma blobs" manage to leap and fall through the magnetic thicket is a matter of keen interest to nuclear engineers. Controlling plasma is key to the development of fusion reactors, and the sun is an excellent laboratory for studying interactions between plasma and magnetic fields. There are many more prominences dancing around the edge of the sun today. Readers, if you have a solar telescope, take a look. more images: from Guenter Kleinschuster of Feldbach, Styria, Austria; from Jacob Bassøe of Copenhagen, Denmark; from Mike Borman of Evansville, Indiana; from P. Fitzpatrick et al of South Portland, Maine; from Didier Favre of Brétigny-sur-Orge, France; from Günther Strauch of Borken, Germany; from Cai-Uso Wohler of Bispingen, Germany; from Matthias Juergens of Gnevsdorf, Germany; from Eric Roel of Valle de Bravo, México;
"We really enjoyed observing and imaging this prominence on the sun's northwestern limb," says Stetson. Although it resembles fire, no combustion is involved. Prominences are glowing clouds of solar plasma held aloft by magnetic fields. The shape of the prominence traces the shape of the underlying magnetic field--in this case a towering triangle. For scale, Earth would fit beneath the arch with room to spare. There are many more prominences dancing around the edge of the sun today. Readers, if you have a solar telescope, take a look. more images: from Matthias Juergens of Gnevsdorf, Germany; from Eric Roel of Valle de Bravo, México; from John Boyd of Santa Barbara, CA; from Patrick Pelletier of Serbannes, France; from Marco Vidovic of Stojnci, Slovenia;
LUNAR IMPACT: Japan's Kaguya spacecraft crashed into the Moon on Wednesday, June 10th, and the impact reportedly produced a flash visible from Earth. This sequence of images comes from the 3.9 meter Anglo-Australian Telescope in New South Wales, Australia. Astronomers Jeremy Bailey and Steve Lee used the observatory's Infrared Imager and Spectrograph (IRIS2) to record the fireball, which appeared at 18:25 UT when the 2,900 kg spacecraft slammed into the lunar surface at 6000 km/hr. The observations were made with a 2.3 micron narrow band filter, and are part of a time series of 1 second exposures with 0.6 seconds dead time between each frame. Information about these observations is still preliminary. Stay tuned for updates.
MAGNETIC MAELSTROM: "Sunspot 1019 continues to put on a show," reports astronomer Pete Lawrence of Selsey UK. "Two distinct main spots are visible with a number of smaller pores scattered around a vast field of magnetic fibrils. The view through an H-alpha 'scope is stunning." Since the sunspot emerged on May 31st, it has rapidly grown and reorganized itself into the double spot visible today: movie. The region is crackling with A- and B-class solar flares, which nicely highlight the sunspot's surroundings for astrophotographers. Readers, if you have a solar telescope, take a look!
How can gas float above the Sun? Twisted magnetic fields arching from the solar surface can trap ionized gas, suspending it in huge looping structures. These majestic plasma arches are seen as prominences above the solar limb. In 1999, September 14 this dramatic and detailed image was recorded by the EIT experiment on board the space-based SOHO observatory in the light emitted by ionized Helium. It shows hot plasma escaping into space as a fiery prominence breaks free from magnetic confinement a hundred thousand kilometers above the Sun. These awesome events bear watching as they can affect communications and power systems over 100 million kilometers away on Planet Earth. Recently, our Sun has been unusually quiet.
EUROPA OCCULTS GANYMEDE: On May 8th, Anthony Wesley of Murrumbateman, Australia, recorded a very rare event--one of Jupiter's moons eclipsing another. "Here," says Wesley, "is an animation of Europa passing directly in front of Ganymede." He made the movie using a 13-inch telescope and a digital video camera. "Seeing was not good, so I was only able to use 250 of the 1200 frames I collected." Nevertheless, it is an extraordinary observation, showing the distant moons as genuine world-like disks as they pass in "mutual occultation." Earth is moving through the orbital plane of Jupiter's satellites, allowing the moons to line up for events such as Wesley recorded on May 8th. This special geometry comes along approximately once every 6 years. The last time was in 2002-2003, and now it is happening again. Between April and December of 2009, observers around the world can see Jupiter's moons passing one in front of another as they circle the giant planet. As part of the International Year of Astronomy, professional astronomers are organizing a worldwide observing campaign to record as many of these events as possible. Click here for details.
SHADOWS IN THE SKY: Friday night when the Moon rose over Key Biscayne, Florida, "a strange phenomenon happened," reports onlooker Emanuele Colognato. "A number of dark beams seemed to be converging on the Moon's location in the east." He quickly photographed the scene through his apartment window. "I call the photo Shadows in the Sky," says Colognato. That's a good name because the dark beams are shadows. As the Moon was rising in the east, the sun was setting in the west. Low-hanging clouds behind Colognato's back blocked the light of the setting sun and cast their shadows all the way across the sky. Perspective effects made the shadows appear to converge on the Moon. Experts call the dark beams anti-crepuscular rays; "Shadows in the Sky" works, too.
THE SUN IS STIRRING: NASA's STEREO-B spacecraft is monitoring an active region hidden behind the sun's eastern limb. On May 5th, it produced an impressive coronal mass ejection (CME, movie) and a burst of Type II radio emissions caused by a shock wave plowing through the sun's outer atmosphere. STEREO-B's extreme UV telescope captured this image during the explosion. At the root of all this activity is probably a sunspot. Its high latitude identifies it as a member of new Solar Cycle 24. The putative sunspot is not yet visible from Earth, but the sun is turning the region toward us for a better view. Readers with solar telescopes should keep an eye on sun's northeastern limb for an emergence on May 7th or 8th.
Lyrid Meteor and Milky Way. On April 22nd, the Lyrid Meteor Shower visited planet Earth's sky, an annual shower produced as the Earth plows through dust from the tail of comet Thatcher. Usually Lyrid meteor watchers see only a drizzle. Just a few meteors per hour stream away from the shower's radiant point near bright star Vega in the constellation Lyra. But photographer Tony Rowell still managed to catch one bright Lyrid meteor. Recorded in early morning hours, his well-composed image looks toward the south from White Mountains of eastern California, USA. During the time exposure, he briefly illuminated an old mining cabin in the region's Ancient Bristlecone Pine Forest in the foreground.
SEVENTEEN MINUTES: With a waistline one hundred times wider than Earth's, the sun is so big and ponderous, you might not think it could move very quickly. But it can.
Click on the image to see how much things can change in just 17 minutes.
"A huge amount of motion is visible over a very short interval of time," says Pete Lawrence who made the movie on April 22nd at his backyard observatory in Selsey, UK. "The prominence underwent many changes of form and at one point I could see real time movement as I watched the action on my computer screen."
Less than 24 hours later, Lawrence's prominence exploded and hurled a billion-ton cloud of gas away from the sun at nearly a million miles per hour: SOHO movie. That's moving. Readers, if you have a solar telescope and 17 minutes of spare time ... you know what to do.
NOT-SO-QUIET SUN: The sun produced an unexpected burst of activity yesterday, April 23rd, when an enormous prominence rose over the northeastern limb and erupted. SOHO recorded the blast from beginning to end with a series of high-cadence UV snapshots. Click on the image to set the scene in motion.
The complex explosion produced not one but two billion-ton coronal mass ejections (CMEs): movie. An impact from such a double-CME would almost surely spark magnetic storms around the poles of Earth, but it is not heading in our direction. The chance of auroras remains low. Click on image to see movement.
VENUS AND THE MOON: On April 22nd, Venus and the Moon converged for close encounter of rare beauty. "What a spectacular view!" says Marc Provencher, who woke up at dawn to take this picture of the pair rising over Mt. Hood near Portland, Oregon.
Minutes later, the Moon passed directly in front of Venus, producing a crescent vs. crescent eclipse. Browse the links below for some of the best shots.
more images: from Adrian New of Fort Davis, Texas; from Greg Stablein of Memphis, Tennessee; from Val Ricks of The Woodlands, Texas; from Paul Kinzer of Galesville, Wisconsin; from Tom Polakis of Tempe, Arizona; from Peggy Collins of Pacoima, California; from Bill Meyers of Omaha, Nebraska; from Bret Dahl of Plano, Texas; from Antonio Estrada of Toluca, México; a movie from John McNair of Monument, Colorado; from Mark Seibold of Portland Oregon;
"Solar minimum? No problem," reports Marco Vidovic of Stojnci, Slovenia. "Lately, every time I point my telescope at the edge of the sun, I see plenty of activity." He took this picture yesterday.
Vidovic uses a telescope equipped with an H-alpha filter tuned to the red glow of solar hydrogen. H-alpha filters are ideal for catching prominences--towering plumes of hydrogen held aloft by the sun's magnetic field. Because prominences are not rooted in sunspots, they do not vanish when the sunspot count plunges to zero.