When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms. | | | CME IMPACT: A coronal mass ejection (CME) hit Earth's magnetic field on April 13th around 22:45 UT. The impact was not a strong one, but geomagnetic storms could be in the offing as Earth passes through the CME's wake. Stay tuned for updates! Aurora alerts: text, voice. This is the CME, leaving the sun at 600 miles per second on April 11th: The CME was propelled into space by an M6-class eruption in the magnetic canopy of sunspot AR1719. SOHO photographed the expanding cloud using an onboard coronagraph. Speckles near the end of the movie are caused by energetic solar protons hitting the coronagraph's CCD detector. Note that although the CME appears to hit Mars and Venus, there is no actual physical contact. The cloud is merely passing in front of the two planets. Solar Flare alerts: text, voice. Realtime Space Weather Photo Gallery Realtime Comet Photo Gallery Realtime Aurora Photo Gallery Realtime Noctilucent Cloud Photo Gallery [previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011] 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 April 13, 2013 there were 1395 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 | |