Green Comet Approaching Earth

Feb. 20, 2009 - PRLog -- A green comet! Sounds like something you’d read in a Superman comic, doesn’t it? Well, it isn’t science fiction – but it does have story-like start.

In 1996, a 7-year-old boy in China bent over the eyepiece of a small telescope and saw something that would change his life – a brilliantly lit comet called Hale Bopp, named after the two astronomers who found it. Young Quanzhi Ye vowed to find his own comet one day, and as fate would have it, one day he did.

Fast forward to July 2007. Ye, now a 19 years old University student at China's Sun Yat-sen, bent over his desk to stare at a black and white starfield photo taken a few nights earlier by astronomers at his local observatory. Ye's finger moved from point to point on the photo and stopped. A chill ran down Ye’s back he realised one of the stars was not a star, it was a comet, and this time he saw it first!

Comet Lulin, named after the observatory in Taiwan where the discovery photo was taken, is now approaching Earth. It’s unusual, a green beauty that is just starting to make itself visible to the naked eye from Australia. Our photograph of Comet Lulin was taken by Jack Newton but the tail has been enhanced to presuppose how it may look at closest approach.

“Darker skies will show its greenish colour better so it’s best to get away from the city lights if you can,” said Dave Reneke, news editor of Australia’s Sky and Space magazine. “No one can say for sure how bright it’ll be because this is Lulin's first visit to the inner solar system. Surprises are possible.”

According to Dave comets are ‘dirty snowballs,’ basically, rock covered in thick ice. Lulin's green colour comes from the gases that make up its halo. Is it really made out of kryptonite? Astronomers don’t think so. Jets spewing from the comet's nucleus contain gases that glow green when illuminated by sunlight in the near-vacuum of space.

At closest approach, Comet Lulin will pass by 60 million kilometres from Earth, a long way to most folk but for astronomers used to dealing in larger figures, it’s basically next door. So, set your alarm for 3-4 am, rug up and grab a pair of binoculars and head outside. The comet can be seen now a few hours before sunrise, about 1/3rd of the way up the northern sky in the constellation Virgo.

Closest approach to the earth will be on February 24! On this special morning, Lulin will lie just a few degrees from Saturn in the constellation Leo for southern observers. “It should be a fantastic sight for several days, said Dave. “If this doesn't draw you out of bed, nothing will.”

Somewhere this month, another youngster will bend over an eyepiece, see Comet Lulin, and feel the same thrill Ye did gazing at Comet Hale-Bopp in 1996. And who knows where that might lead...?

Dave Reneke
dave.reneke@skyandspace.com.au