Article Posted on : - Jun 10, 2010

The comet, with a green atmosphere, will be closer to Earth on June 15-16. A NASA photo

MUMBAI (PTI): A comet is swinging through the inner solar system and is brightening rapidly even as it approaches the Sun, according to US space agency NASA.

Comet McNaught (C/2009 R1), which has a vivid green head and a long wispy tail, can be found low in the northeastern sky before dawn gliding through the constellation Perseus. It is brightening as it approaches Earth for a 1.13 AU close encounter on June 15th and 16th, NASA said.

“By the end of the month it could be visible to the naked eye perhaps as bright as the stars of the Big Dipper...Because this is the comet's first visit to the inner solar system, predictions of future brightness are necessarily uncertain; amateur astronomers should be alert for the unexpected,” NASA said in its website www.spaceweather.com.

The comet’s green atmosphere is larger than the planet Jupiter, while the long willowy ion tail stretches more than a million kilometres through space. These dimensions make the comet a fine target for backyard telescopes.

Mid-June is when McNaught should be most interesting, offering the best compromise between its increasing brightness and its decreasing altitude at the start of dawn. Moreover, the sky will be free of moonlight, according to astronomy journal 'Sky and Telescope'.