Saturday, October 9, 2010

Comet 103P/Hartley

Comet 103P/Hartley is promising to be the brightest comet of 2010. It won't be a fill-the-sky-feast-for-the-eyes comet, though. Not every comet can be a Hale-Bopp or a McNaught. In fact, it will be barely visible to the naked eye under dark skies. Right now, it can best be viewed in telescopes, and even so it is just a fuzzy green dot. But when it comes to comets, we take what we can get!

Comet 103P/Hartley is a periodic comet that orbits the Sun once about every 6.5 years. It was discovered in 1986 by astronomer Malcolm Hartley. Its closest approach to Earth, at about 11 million miles, will occur on October 20, 2010. It should reach magnitude 5, which is pretty dim, but not impossible to see in dark skies.

On October 8 and 9, 103P/Hartley passed near the Double Cluster in the constellation Perseus. I compiled this image from several individual images taken on October 8. The comet is the green patch in the upper-right. The nucleus of the comet is the bright green streak. The streak indicates how far the comet traveled during a 24-minute period.

Comet 103P/Hartley passing in front of the Double Cluster in Perseus.


  1. Brilliant! Well done - looks excellent. I am really miffed that I missed this opportunity. You captured it very well.

  2. Lovely shot, Rory! You've caught not just the comet on the run but some of the depth of the star field there! Congrats.