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VERY QUIET SUN: Solar activity is very low. Not one of the sunspots on the solar disk is flaring, and as a result the sun's X-ray output has flatlined. NOAA forecasters estimate a scant 5% chance of M-class flares and no more than a 1% chance of X-flares. Solar flare alerts: text, voice
BRIGHT ASTEROID FLYBY: A large asteroid is about to fly past Earth. On the night of Jan. 26-27, mountain-sized space rock 2004 BL86 will be only 3 times farther from us than the Moon. There's no danger of a collision, but the flyby will be easy to observe. Sunlight reflected from the surface of 2004 BL86 will make it glow like a 9th magnitude star. Amateur astronomers with even small backyard telescopes will be able to see it zipping among the stars of the constellation Cancer. Check out this video, prepared by the Sociedad de Astronomia del Caribe, for observing tips:
NASA radars will be observing, too. As the asteroid passes by, astronomers will use the Deep Space Network antenna at Goldstone, California, and the giant Arecibo radar in Puerto Rico to "ping" 2004 BL86, pinpointing the asteroid's location and tracing its shape.
"When we get our radar data back the day after the flyby, we will have the first detailed images," said radar astronomer Lance Benner of JPL, the principal investigator for the Goldstone radar observations of the asteroid. "At present, we know almost nothing about this asteroid, so there are bound to be surprises." Stay tuned!
ICY ARCTIC SUNSET: Yesterday in Rovaniemi, Finland, shortly after local noon, photographer Alexander Kuznetsov stepped outside to watch the sun set. He quickly scrambled back inside to grab his camera. This is why:
"The conditions were freezing, -20°C, but I was rewarded with this extraordinary view: a laser-like sun beam flanked by rainbow-colored sundogs!" says Kuznetsov.
Kuznetsov was standing on a hill looking across an ice-filled valley. Ice crystals floating in the air caught the rays of the setting sun, forming a lower sun pillar, a sub-sun, and two sub-sundogs. Many observers have seen pillars of light and other halo above the sun. These appeared below the sun because that's where the ice crystals were.
The winter months are prime time for Arctic subparhelia. Monitor the photo gallery for more sightings.
Realtime Space Weather Photo Gallery
COSMIC BLUES: This week, bright Comet Lovejoy (C/2014 Q2) is passing by the Pleiades, creating a photogenic conjunction for astrophotographers. The sinuous tail of the comet is on the very doorstep of the Seven Sisters. Alan Dyer, author of "How to Shoot Nightscapes and Timelapses," took this picture on Jan. 18th from a remote corner of New Mexico:
"Lovejoy's long blue ion tail stretched back well past the Pleiades, a distance of at least 12°," says Dyer. "I shot this image from the dark skies of City of Rocks State Park, New Mexico, which has proven to be one of the finest places on the planet for watching the comet!"
Many observers have noted the similar colors of the Pleiades and the comet's tail. Both are a beautiful shade of cosmic blue. Despite their similar appearance, however, the two blues come from different physics. The comet's tail is blue because it contains ionized carbon monoxide (CO+), a gas which fluoresces blue in the near-vacuum of interplanetary space. The nebulosity surrounding the Pleiades is blue because grains of interstellar dust embedded in the gas scatter the blue light of hot young stars at the cluster's core.
Need help finding the comet? Check these finder charts from Sky & Telescope. Also, the Minor Planet Center has published an ephemeris for accurate pointing of telescopes.
Realtime Comet Photo Gallery
Realtime Aurora Photo Gallery
Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com.
On Jan. 20, 2015, the network reported 23 fireballs.
(22 sporadics, 1 xi Coronae Borealid)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]
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 January 20, 2015 there were potentially hazardous asteroids.
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. | The official U.S. government space weather bureau |
| The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| Realtime and archival images of the Sun from SOHO. |
| from the NOAA Space Environment Center |
| the underlying science of space weather |