Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift.
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HARVEST MOON: This weekend's full Moon is the Harvest Moon, the full Moon closest to the atumnal equinox. Before electric lights, farmers working after sunset relied on the light of the Harvest Moon to help them gather ripening autumn crops. Now it's just a pretty sight. Look east for the Harvest moonrise on Saturday night.
FARSIDE EXPLOSION: A sunspot on the farside of the sun exploded on Sept. 27th, sparking a bright flare of extreme ultraviolet radiation and hurling a massive CME into space. Although the explosion occurred on the other side of the sun, it was visible on cell phones around Earth. Here is a screenshot from NASA's 3D Sun app:
The 3D Sun is a great way to monitor events on the farside of the sun. It displays a realtime globe, which you can pinch, zoom and spin to examine explosions around the complete circumference of the star. Extreme UV images from NASA's twin STEREO probes and the Solar Dynamics Observatory (SDO) are combined to assemble the 360o view, now available on iPhones, iPads, and Android devices.
The active region could flare again. Download the app to track the blast site as it transits the farside en route to the Earthside late next week. Stay tuned for action. Solar flare alerts: text, voice.
POLAR LIGHTS: A medium-speed (~400 km/s) solar wind stream is brushing against Earth's magnetic field, sparking intermittent auroras around the Arctic Circle. Frank Olsen photographed these colorful streamers over Sortland, Norway, during the early hours of Sept. 27th:
"The auroras shone right through the bright moonlight," says Olsen. "It was a nice [little outburst]."
The display was not caused by a geomagnetic storm, but at this time of year no storm is required. For reasons researchers do not fully understand, equixoxes favor auroras. During the nights of early autumn, even a gentle gust of solar wind can ignite colorful lights at high-latitudes. Browse the gallery for current images:
Realtime Aurora Photo Gallery
Realtime Space Weather 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 September 28, 2012 there were 1332 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 |