SPACE.com -- Amazing Live Images: Sungrazing Comet Possibly Hit by Solar Eruption

Comet NEAT near the Sun on Feb. 18 as a coronal mass ejection billows out. The horizontal line running through the comet's head is an artifact caused by saturation of the imager. The circle in the middle is created by a device that blocks out the main disk of the Sun.

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	Amazing Live Images: Sungrazing Comet Possibly Hit by Solar Eruption By Robert Roy Britt Senior Science Writer posted: 09:40 am ET 18 February 2003

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The SOHO spacecraft is currently generating spectacular images of a recently found comet called NEAT as the icy body circles the Sun and appears to have been struck by a massive solar eruption. The chance encounter could lead to new discoveries about the interactions of comets with hot, charged particles billowing from the Sun.

NEAT is putting on what may turn out to be the most remarkable comet show ever witnessed by SOHO, which has photographed more than 500 comets rounding the Sun.

"It is far the brightest and largest comet seen," Paal Brekke, SOHO deputy project scientist, told SPACE.com.

SOHO stands for Solar and Heliospheric Observatory. The satellite sits partway between Earth and the Sun and is designed primarily to monitor space weather like the eruption currently witnessed. Live images of the comet and the eruptive event are available at the SOHO website to anyone with an Internet connection.

The comet, officially C/2002 V1, should be visible in SOHO's LASCO-3 camera through the pre-dawn hours Thursday.

A solar eruption, called a coronal mass ejection (CME), appears to have hit the comet Monday, Brekke said. Scientists think they observed a kink propagating down the comet's ion tail.

"Certainly such effects from a CME could give us new information about comets, their tails and how they interact with the solar wind," said Brekke, who works for the European Space Agency out of an office at NASA's Goddard Space Flight Center. SOHO is a joint project between the two agencies.

Another eruption lifted off the Sun early Tuesday [as seen in the picture near the top-right of this page] but it's not clear yet which direction it is aimed.

NEAT was just one-tenth of Earth's distance from the Sun when it made its closest approach to the Sun this week. Solar energy boils gas and dust from the comet's nucleus. Sunlight then reflects off this fresh material, creating the glowing head and tail of the comet. The tail always points away from the Sun, driven by solar radiation.

The comet was faintly visible in the evening sky last week for viewers with dark sky conditions. It has been in LASCO's field of view since Sunday. It will begin to drop out of the picture, in the lower right, at about 4 or 5 a.m. EST on Thursday, Feb. 20.

NEAT will then begin a long journey back out into the fringes of the solar system. While Earth orbits the Sun every year, comet NEAT requires about 37,000 years to make a single, elongated loop.

Live and archived pictures and animations of NEAT, taken by the LASCO-3 imager, are available on the SOHO website.