Hang the Transit of Venus on your wall! Hubble-quality images from NASA's Solar Dynamics Observatory are now available as metallic posters in the Space Weather Store.
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SIGNIFICANT SOLAR FLARE, NOT EARTH-DIRECTED: A magnetic filament snaking over the sun's northeastern limb erupted on August 18th (01:02 UT), producing a significant M5.5-class solar flare. Click to view a movie of the eruption recorded by NASA's Solar Dynamics Observatory:
A coronal mass ejection (CME) flew away from the blast site, but the cloud is not heading for Earth. This eruption was not geoeffective.
The magnetic filament reformed, post-eruption, and appears to be connected to an active sunspot group on the farside of the sun. Although the sunspot is hidden behind the limb, the Solar Dynamics Observatory can see the sunspot's towering magnetic canopy flashing and hurling plasma over the edge of the sun. Click on the image to set the scene in motion:
A great way to see the hidden sunspot is using NASA's 3D Sun app, which shows our star as a 3-dimensional globe that you can spin and inspect from any angle. Data for the app come from a fleet of three spacecraft (SDO + STEREO) that surround the sun. Download the app and look around the globe for a hot spot labeled 'farside AR.' (AR="active region")
Soon, the sun's rotation will turn the sunspot from the farside to the Earthside of the sun. A significant uptick in geoeffective solar activity is possible in the days ahead. Solar flare alerts: text, phone.
Realtime Space Weather Photo Gallery
RETURN OF THE ARCTIC AURORAS: It has been a while since sky watchers around the Arctic Circle have enjoyed the Northern Lights. Auroras are hard to see through the glare of the midnight sun. As summer comes to an end, however, aurora season is beginning again. On August 16th, B.Art Braafhart spotted a splash of green over Salla in the Finnish Lapland:
"Finally, after three nights hunting for 'the green lights,' I made the first catch of the new season," says Braafhart. "The nice temperature (+12C) was accompanied by zooming mosquitos around midnight. The apparition was brief, the colors thin and light, but after an absence of 4 months exciting again!" Aurora alerts: text, phone.
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 August 19, 2012 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 |