You might have heard that this week, for the first time ever, mankind landed a probe on a comet. But long before that happened, the spacecraft that took the Philae probe to Comet 67P/C-G, Rosetta, was in orbit around the comet's nucleus—and Matt Wang made this incredible graphic that compares the size of the comet to downtown Los Angeles. Wang created the image in 2011 by combining a photo of LA with a photo of the comet snapped by Rosetta before the rendezvous.
If you're still having trouble visualizing what the comet looks like, check out this graphic from the New York Times, which shows 67P/C-G compared to 2.5 mile-long Central Park. You can find precise measurements of the comet here.
The mission ran into an unexpected snafu when the robotic Philae probe touched down not once but three times before coming to rest in a shadow, where it's receiving just 1 to 2 hours of sunlight a day instead of the expected 6 to 7. The paltry amount of sunlight isn't enough sunlight to charge its secondary batteries, which could jeopardize the mission.