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SUBSIDING STORM: A geomagnetic storm that shook Earth's polar magnetic field and sparked bright auroras on March 29th and 30th is subsiding. The cause of the disturbance was a high-speed solar wind stream, which arrived on the 29th. NOAA forecasters estimate a slight 15% chance of continued storming on the 31st as the stream departs. Aurora alerts: text, voice.
BIG, QUIET SUNSPOT: Ten days ago, big sunspot AR1711 was on the farside of the sun hurling CMEs at Venus. Now it is rotating over the sun's southeastern limb where we can see it from Earth. NASA's Solar Dynamics Observatory photographed the spot during the early hours of March 31st:
The sunspot seems to have quieted since it targeted Venus. It is not strongly flaring at this time. NOAA forecasters estimate a slim 10% chance of M-class flares during the next 24 hours. Solar flare alerts: text, voice.
COMET-GALAXY ENCOUNTER: Comet Pan-STARRS is heading for the Andromeda Galaxy (aka M31). On the nights of April 1st through 6th, the bright comet will pass so close to the pinwheel star system that they will be visible as a tight pair in the fields of view of wide-field telescopes and digital cameras. Amateur astronomer Pavel Smilyk of Syktyvkar, Russia, of the comet's approach on March 30th:
"This picture is a guided 2-minute exposure consisting of 12 frames from my Canon 5D Mark2 digital camera," says Smilyk.
At closest approach on April 3-4, the comet's dusty fan-shaped tail should "touch" the galaxy's outermost spiral arms. In fact, no physical contact will occur; the comet is still in the solar system while Andromeda is 2.5 million light years away. Deep-exposure astrophotography will, however, reveal an apparent overlap.
Both the comet and the galaxy are visible to the unaided eye as faint fuzzy patches in the western sky after sunset. To find them, scan the sky with binoculars or set your GOTO telescope to "Andromeda."
More about Pan-STARRS: NASA video, 3D orbit, ephemeris, light curves.
Realtime Comet Photo Gallery
Realtime Space Weather 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 March 31, 2013 there were 1389 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 |