Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park. | | | THE SUN IS FLATLINING: For the 6th day in a row, solar activity remains very low. No sunspots are flaring, and the sun's X-ray output has flatlined. NOAA forecasters estimate a scant 1% chance of significant solar flares on Feb. 18th. Solar flare alerts: text, voice GEOMAGNETIC STORM: Earth is entering a solar wind stream, and this is sparking G1-class geomagnetic storms around the Arctic Circle. During the late hours of Feb. 17th, an outburst over Björkliden, Sweden, turned the whole landscape green: "I was in Björkliden just coming back down from a mountain hut via snowmobile when I saw that a strong aurora was building," says photographer Oliver Wright. "I jumped off among the snowy trees and took a quick picture. This is only a 1.6 second exposure!" NOAA forecasters estimate a 40% chance of geomagnetic storms on Feb. 18th as the solar wind continues to blow. Aurora alerts: text, voice Realtime Aurora Photo Gallery VENUS AND MARS: When the sun goes down tonight, step outside and face west. Venus is beaming through the twilight, so bright that it is often mistaken for a landing plane. Wait a while as the sky grows darker. Fainter Mars pops out right beside Venus. Didier Van Hellemont photographed the pair at sunset on Feb. 17th over Sint-Laureins, Belgium: In only a few days, the two planets will be dramatically closer together. At closest approach on Feb. 21st, they will be only 0.4o apart, less than the width of a full Moon. The night before closest approach might be best of all: On Feb. 20th, the crescent Moon will pass right by the converging planets. Mark both dates on your calendar, Feb. 20th and 21st, and watch the western sky at sunset. It's a great way to end the day. 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 Feb. 18, 2015, the network reported 25 fireballs. (25 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 February 18, 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 | |