Syfy Insider Exclusive

Create a free profile to get unlimited access to exclusive videos, sweepstakes, and more!

Sign Up For Free to View
SYFY WIRE Bad Astronomy

The Comet and the Galaxy

By Phil Plait

Never say never, especially when it comes to posting comet pictures.

Here is another shot of the beauty that is comet C/2011 L4 (Pan-STARRS), taken in late March as it passed the iconic Andromeda galaxy:

This stunning picture was taken by Smilyk Pavel, an astrophotographer, about 60 kilometers from Syktyvkar, the capital city of the Komi Republic in Russia. Itâs a stack of 12 separate pictures, each two minutes long.

The comet was about 180 million kilometers (110 million miles) away from Earth when this picture was taken. For comparison, the Andromeda galaxy is roughly 25 million trillion kilometers away. Amazingly, they appear to be the same size in the sky, but thatâs a massive, massive illusion due to perspective. The Andromeda galaxy is, well, a galaxy. Those tend to be big, and far away.

I love the scale of this. Andromeda is far larger than the full Moon on the sky, so what youâre seeing here is a pretty big chunk of sky, roughly the size of your palm held at armâs length. And the comet sure looks different now than in earlier pictures; weâre seeing the tail from a different angle, so it looks more spread out and fan-shaped than earlier (though I'll note that the comet is smeared out a bit due to its motion compared to the background stars).

If you want to see this for yourself, tonightâs not a bad time to try. The comet and galaxy are still relatively close to each other in the sky, but since the cometâs on the move that wonât last long. Sky and Telescope has a how-to on viewing. The farther north you are, the better, and youâll need binoculars no matter what. It may be tough, since the two are low to the northwest after sunset, when the sky is still bright, but itâs definitely worth a shot. Itâs not something you get to see very often!

If you want to see more pictures of this amazing comet, I have posted pictures in previous posts: here, here, here, here, here, and here. My thanks to my friends at APOD for helping me track this down; they posted the image earlier today.

Read more about: