Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park. | | | EARLY-MORNING ROCKET LAUNCH--RESCHEDULED: Unexpectedly high wind shears prompted NASA to postpone this morning's launch of the SMAP satellite from Vandenberg AFB. Next try: Friday, Jan. 30th. The three-minute launch window begins at 6:20 am PST. Observers from coastal Los Angeles to the Bay Area may be able to see exhaust from the Delta II rocket criss-crossing the dawn sky in the minutes after launch. Observers closer to Vandenberg could see the rocket itself. Californians, set your alarm for dawn. SOUTHERN CORONAL HOLE: A vast hole has opened in the sun's atmosphere over the sun's south pole. The gap, also known as a 'coronal hole', is colored cobalt blue in this extreme UV image of the sun from NASA's Solar Dynamics Observatory: Coronal holes are places where the sun's magnetic field spreads apart and allows solar wind to escape. Streaming along open lines of magnetic force (see the arrows above), hot gas flows outward at speeds exceeding a million mph. A stream of solar wind from this coronal hole is expected to reach Earth in the days ahead. NOAA forecasters estimate a 55% chance of polar geomagnetic storms when the solar wind arrives. Aurora alerts: text, voice Realtime Aurora Photo Gallery RED AIRGLOW: The OGLE telescope in Las Campanas, Chile, is hunting for signs of Dark Matter in the Milky Way using a technique called "microlensing." This week, to highlight OGLE's mission, astrophotographer Yuri Beletsky lined up his camera behind the observatory dome with the Milky Way in the background. He captured not only the center of the galaxy, but also a fine display of red airglow: "The Milky Way emerged from the top of the dome like a stellar fountain," says Beletsky. "Red airglow is quite prominent in the background." Airglow is aurora-like phenomenon in the upper atmosphere caused by chemical reactions driven mainly by solar ultraviolet radiation. Human eyes seldom notice the faint glow, but It can be photographed on almost any clear dark night, anywhere in the world. The curious thing about Beletsky's photo is not the presence of airglow, but rather its color--red. Airglow is usually green, the color of light from abundant oxygen atoms in a layer 90-100 km high. Red airglow comes from oxygen, too, but in a more rarefied layer of air 150 - 300 km high. Why did red dominate green on the night of Beletsky's photo shoot? The wavy structure of the red glow offers a clue: High-altitude gravity waves might have altered the temperature and density of the upper atmosphere just enough to favor red. Consider it a beautiful mystery. Realtime Space Weather Photo Gallery Realtime Comet 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. 29, 2015, the network reported 7 fireballs. (7 sporadics) 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 29, 2015 there were 1541 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 | |