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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SIR PATRICK MOORE, 1923-2012: British astronomer and broadcaster Sir Patrick Moore died on Dec. 9, 2012, at the age of 89. Knighted for his dedication to astronomy outreach, the monocled host of BBC's The Sky at Night inspired millions of lay people to look at the sky and a fair number of children to grow up to be professional scientists. RIP to a great astronomer.
AMAZING STRATOSPHERIC CLOUDS OVER EUROPE: When the sun set over the UK on Dec. 9th, sky watchers were stunned by an unexpected apparition of super-colorful stratospheric clouds. "They were amazing to see and a dream come true to photograph," reports Lesley Jennings of Fraserburgh, Aberdeenshire, Scotland. "There were all sorts of colors. I've never see the like before!" added Rachael Taylor also from Aberdeenshire. Nigel Feilden photographed this specimen from Inverurie, Scotland:
"These are nacreous clouds," explains atmospheric optics expert Les Cowley. "Of all Earth's clouds they are most spectacular, and a very rare treat for skywatchers."
"For up to an hour after sunset or before dawn they glow like eerie electric discharges or gas jets in the darkening sky, their filmy shapes slowly curling and uncurling with intense shifting colors. They are composed of tiny ice crystals more than twice as high as ordinary clouds, 9-16 miles up, in the stratosphere and form at temperatures of minus 85 Celsius and below. The crystals are all of similar size and they diffract the high altitude sunlight to make the colours."
"Search for nacreous clouds at high latitudes (e.g., Scotland, Scandinavia, Iceland, Northern US) in winter and preferably downwind of mountains," Cowley advises. "They like stormy weather that perhaps creates gravity waves to loft the necessary moisture to make them upwards across the tropopause into the stratosphere. Once seen they are never forgotten!"
Realtime Nacreous Cloud Photo Gallery
BIG ASTEROID FLYBY: Large near-Earth asteroid 4179 Toutatis is flying past Earth this week. At closest approach on Dec. 12th, it will be 7 million km away, or 18 times farther than the Moon. Astronomers are taking advantage of the flyby to learn more about the asteroid's orbit, shape, and topography. Here are a few shadowy images of the asteroid illuminated by NASA's Goldstone radar in the Mojave desert:
Measuring 5 km in length, Toutatis is one of the largest known potentially hazardous asteroids (PHAs) and its orbit is inclined less than half-a-degree from Earth's. No other kilometer-sized PHA moves around the Sun in an orbit so nearly coplanar with our own. This makes it an important target for asteroid studies.
Fortunately, there is no danger of a collision with Toutatis for hundreds of years. Radar observations should improve researchers' ability to predict the asteroid's trajectory even farther into the future. Goldstone will pinging Toutatis from now until Dec. 22nd. Stay tuned for daily updates.
Realtime Space Weather Photo Gallery
ANOTHER ERUPTION MISSES EARTH: Magnetic fields around departing sunspot AR1621 became unstable and erupted during the late hours of Dec. 7th, hurling a bulb of plasma off the sun's western limb. NASA's Solar Dynamics Observatory recorded its departure:
Earth was not in the line of fire. No auroras or other space weather effects will be felt as a result of the blast.
Overall, solar activity is very low. The face of the sun is nearly blank (few sunspots) and NOAA forecasters estimate a slight 1% chance of strong flares during the next 24 hours. Solar flare alerts: text, voice.
Realtime Space Weather Photo Gallery
Realtime Aurora Photo Gallery
Realtime Noctilucent Cloud Photo Gallery
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