A comet described as a big green âdirty icebergâ can be seen blazing past earth.
Comet Lovejoy is already visible in the night sky and will be at its brightest on January 7.
But the comet, named after its discoverer and amateur astronomer Terry Lovejoy, wonât return again for 8,000 years.
On January 7 the comet, formally known as C/2014 Q2 (Lovejoy), will make its closest approach to Earth at a distance of 43.6 million miles.
It will then make its closest approach to the sun on January 30 before heading out of the solar system.
The green glow of the comet is caused by chemicals in the cometâs atmosphere surrounding the chunk of ice in the centre. It is thought to have come from the Oort cloud, a cloud of icy objects almost a light year from the sun.
NASA said: "To see the comet, just go outside an hour or so after sunset and look for a fuzzy patch to the right of Orionâs belt. Binoculars and a star chart may help."