Spectacular comet to be visible tonight


A BRILLIANT new comet should be visible over Ireland if the clear skies forecast by the Met Service continue tonight. Comet Hyakutake has already been seen by millions of enthusiastic observers elsewhere in the northern hemisphere and excited astronomers are describing it as one of the most spectacular this century.

Scientists are predicting a bright future for the comet, which will remain visible in our part of the world until early May, but the real treat for Irish viewers will probably come next week when, weather permitting, the comet will be visible alongside the full lunar eclipse on Wednesday night.

Already Comet Hyakutake (pronounced hyah koo tah kay) is visible to the naked eye, and brighter than even the brightest stars. It is not yet as bright as the planet Venus, currently the "evening star" in the south west, but astronomers predict that by late April the comet will outshine even Venus, hanging as a beautiful tailed object in the western twilight sky just after sunset.

Up to yesterday Dr Ian Elliott of Dunsink Observatory had not seen the comet, "because the skies over Ireland this last week were solid". David Moore of Astronomy Ireland was more fortunate. He managed to see Hyakutake 10 days ago, "a bright comet with a fabulous tail".

The comet was discovered only on January 30th, by an amateur Japanese astronomer and comet hunter, Mr Yuji Hyakutake. Although any number of comets pass the Earth each year, this one is likely to be the closest and brightest seen from Earth for hundreds of years.

Last Monday it came within 9.5 million miles, a near miss in astronomical terms. In late April it will be 36 million miles from the sun, which is closer than the planet Mercury. No other comet has passed so close to us, and then gone so close to the sun.

Comets, often described as dirty snowballs, are icy bodies that orbit the sun. This one has a long orbit and will not return for at least 15,000 years.

When a comet is close to the sun the heat warms the "snowball" melting some of the core. This material streams off the comet forming the characteristic tail, which can stretch for millions of miles.

Anyone wanting to see Hyakutake will need to get away from bright lights, letting their eyes grow accustomed to the dark for at least 10 minutes. Ideally, they should also get away from the milky glow of city lights.

The comet is visible to the naked eye, but binoculars can also be used because the comet is so big, a telescope would actually be too powerful. By tonight, Hyakutake should be at or over the Pole Star (to the north) and over the coming few nights it will be moving towards Perseus (to the bottom left of the Pole Star).

Weather permitting, "a little glowing cloud with a brighter core and a dim tail" will be visible, according to Mr Moore. Although the comet is moving at two million miles a day, it will not streak across the sky like a meteorite, although it will have noticeably altered its position from night to night.

Astronomy Ireland is holding impromptu comet watches to exploit the clear weather (details from 01-459-8883), and a special lunar eclipse watch next Wednesday night from 10 p.m. at the car park near the papal cross in the Phoenix Park, Dublin. The eclipse starts about, 10.30 p.m.

Those with access to the World Wide Web can find out more about the comet at a number of sites, including http://www.jpl.nasa.gov/comet/hyakutake/ a NASA site with plenty of up to the minute pictures and information