They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store.
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DECREASING CHANCE OF FLARES: Sunspot AR1667 is decaying, and this has prompted NOAA forecasters to lower the odds of an M-flare today to only 10%. Solar activity should remain low for the next 24 hours. Solar flare alerts: text, voice.
CORONAL HOLE: A vast hole in the sun's atmosphere--a "coronal hole"--has opened up in the sun's northern hemisphere, and it is spewing a stream of solar wind into space. NASA's Solar Dynamics Observatory photographed the UV-dark gap during the early hours of Feb. 5th:
Coronal holes are places where the sun's magnetic field opens up and allows solar wind to escape. Material flowing from this particular coronal hole should reach Earth's orbit on Feb. 7-8. Because of the opening's high northern latitude, the solar wind stream will not hit Earth head on; instead it could be a glancing blow. Even so, the impact could spark polar auroras later this week. Aurora alerts: text, voice.
LOUD SOLAR RADIO BURST: Last Saturday, Feb. 2nd, the solar activity forecast called for "quiet." In fact, says amateur radio astronomer Thomas Ashcraft, "it was really loud. There were several strong solar radio emissions including one super-strong Type III burst at 1954 UT. I captured it at 28 MHz and 21.1 MHz as it totally drowned out a shortwave voice transmission." Click to listen:
Dynamic spectrum credit: Dick Flagg, Windward Community College Radio Observatory, Oahu, Hawaii
The source of the burst was sunspot AR1667, which unleashed a C2.9-class solar flare just before the roar emerged from the loudspeaker of Ashcraft's radio telescope. Type III solar radio bursts are produced by electrons accelerated to high energies (1 to 100 keV) by solar flares. As the electrons stream outward from the sun, they excite plasma oscillations and radio waves in the sun's atmosphere. When these radio waves head in the direction of Earth, they make themselves heard in the loudspeakers of shortwave radios around the dayside of the planet.
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COMET LEMMON UPDATE: Glowing much brighter than expected, Comet Lemmon (C/2012 F6) is gliding through the skies of the southern hemisphere about 92 million miles (0.99 AU) from Earth. Amateur astronomer Rolf Wahl Olsen sends this picture from his backyard in Auckland, New Zealand:
"I took this image of Comet Lemmon on the 28th of January," says Olsen. "It has become quite bright now and has also grown a beautiful tail."
Discovered on March 23rd 2012 by the Mount Lemmon survey in Arizona, Comet Lemmon is on an elliptical orbit with a period of approximately 11,000 years. This is its first visit to the inner solar system in a very long time. The comet is brightening as it approaches the sun; light curves suggest that it will reach 2nd or 3rd magnitude, similar to the stars in the Big Dipper, in late March when it approaches the sun at about the same distance as Venus (0.7 AU).
At the moment, the comet is glowing like a 7th magnitude star, just below the limit of naked-eye visibility. To capture the faint details of the comet's filamentary tail, Olsen used a 10-inch telescope, a sensitive CCD camera, and an exposure time of 1 hour 17 minutes. Complete photo details are given here.
Lemmon's green color comes from the gases that make up its coma. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
Northern hemisphere observers will get their first good look at the comet in early April; until then it is a target exclusively for astronomers in the southern hemisphere.
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