Discuss as:

Past and future Christmas comets

Dan Burbank / NASA file

Comet Lovejoy's tail rises up from near Earth's horizon in an image captured by NASA astronaut Dan Burbank on Dec. 21, 2011.



It was just a year ago that NASA Astronaut Dan Burbank caught sight of what he called "the most amazing thing I have ever seen in space": Comet Lovejoy and its long streams of shining gas and dust, seen from a vantage point 240 miles above Earth.

The spectacle that Burbank saw from the International Space Station, and that other observers watched from the world below, was quickly nicknamed the "Great Christmas Comet of 2011" and the "Star of Wonder." Lovejoy lit up the skies of the Southern Hemisphere — but most northern observers could experience it only vicariously.

Next Christmas, there's a chance that the Northern Hemisphere will get in on a star of wonder: Comet ISON, which is due to make its circuit through the inner solar system next November and December. It's still too early to say whether ISON will be the "Great Christmas Comet of 2013" or a great disappointment. But astronomers are keeping a close eye on the comet, and some are wondering whether they're already seeing the start of a cometary tail.

This Christmas, the rest of us will have to content ourselves with visions of future sugarplum comets — and tales of the original Star of Wonder, more than two millennia ago.

This look back at Comet Lovejoy serves as the penultimate picture from the Cosmic Log Space Advent Calendar, which has been offering up daily images of Earth from space through the month of December. Check back on Christmas for the final picture of this year's series — and check out the links below for the rest of the Advent calendar images:


Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other science and space news coverage, sign up for the Tech & Science newsletter, delivered via email. You can also check out "The Case for Pluto," my book about dwarf planets and the search for new worlds.