Hydrogen-alpha observations of the sun’s edge from the Coronado instrument of the Mauna Loa Solar Observatory showing what the authors believe to be the comet approaching the solar limb. Credit: Claire Raftery, Juan Carlos Martinez-Oliveros,

Samuel Krucker/UC Berkeley

Solar physicists have for the first time captured images of the collision of a comet with the Sun.

This comet apparently survived the heat of the corona and disappeared in the chromosphere, evaporating in the 100,000-degree (Kelvin) heat.

A corona is a type of plasma “atmosphere” of the sun or other celestial body, extending millions of kilometres into space.

The chromosphere is a thin layer of the sun’s atmosphere just above the photosphere — the ball shaped surface that emits light, roughly 2,000 km deep.

Using instruments aboard NASA’s twin STEREO spacecraft, four post-doctoral fellows at University of California, Berkeley’s Space Sciences Lab were able to track the comet as it approached the sun and estimate an approximate time and place of impact.

STEREO (Solar Terrestrial Relations Observatory), launched in 2006, consists of identical spacecraft orbiting the sun, one ahead of earth and one behind earth, providing a stereo view of the Sun.

NASA’s twin STEREO spacecraft caught this image of a comet impacting the sun. The comet apparently survived the intense heat of the sun’s outer atmosphere – called the corona – and disappeared in the chromosphere, which is a thin layer of plasma found between the visible surface of the sun and the corona. Credit: NASA

The researchers then looked at data from the ground-based Mauna Loa Solar Observatory in Hawaii, and found images in the predicted spot of what appears to be a comet approaching the edge of the sun from behind the solar disk.

“We believe this is the first time a comet has been tracked in 3-D space this low down in the solar corona,” said Claire Raftery, post-doctoral fellow newly-arrived at University of California, Berkeley from Dublin’s Trinity College.

The team presented its data and images Monday, at the Miami, Florida meeting of the American Astronomical Society.

Sungrazing comets, comprising dust, rock and ice, are seldom tracked close to the sun because their brightness is overwhelmed by the solar disk.

Based on the comet’s relatively short tail, about three million-km-long, researchers believe that the comet contained heavier elements that do not evaporate readily, a University of California, Berkeley release said.

This would also explain how it penetrated so deeply into the chromosphere, surviving the strong solar wind as well as the extreme temperatures, before evaporating.

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