The Hubble Space Telescope has captured what space scientists called potentially the "comet of the century", Comet ISON, as it speeds toward Earth at 47,000 mph.
The comet, technically known as C/2012 S1, will pass within 1.1 million miles of Earth seven months from now, and it could be visible with the naked eye if it doesn't break up passing by the sun. It could be so bright, in fact, that it would outshine the full moon, according to Hubble scientists.
In the meantime, the Hubble telescope provides a glimpse.
At the time the image was taken, the comet was nearing halfway between the sun and the Earth, at 4.15 astronomical units (386 million miles) from the sun and 4.24 astronomical units (394 million miles) from Earth.
The image was originally black and white, with its brightness levels translated into bluish hues, according to the scientists. "Such color "maps" can be useful in helping to distinguish subtly varying brightness in an image," they wrote.
The Hubble images show that the comet's nucleus is about 3-4 miles across.
Comets are chunks of ice and dust left over from the formation of stars and planets. As they near the sun or other stars, melting ice forms their signature gaseous tails.