I can think of no better illustration of a full lunar eclipse than today’s Astronomy Picture of the Day. Several images of the Moon are superimposed at various stages of the eclipse, and you can clearly see the shape and size of Earth’s shadow. In a solar eclipse, the Moon’s shadow isn’t larger than the entire Earth, but Earth’s shadow is much larger than the Moon. (Quick vocabulary lesson: a shadow is called an “umbra”, and the fuzzy region around the shadow is the “penumbra”, meaning “next to the shadow”. Thus, “penultimate” is the next-to-the-last thing and an umbrella is a “little shadow”.)

And more links, albeit less beautiful ones:

• I don’t usually post political matters, but if you live in the United States, it’s essential that you call your Representative and ask him/her to oppose the Stop Piracy Online Act (SOPA). This act is a dangerous piece of censorship that would allow shutting down websites on the suspicion of piracy. Libraries, universities, and even science blogs like mine might be affected. Please act now!
• Does a viral video contain a camera that takes pictures at the speed of light? I was skeptical but didn’t have time to check it out, but Rhett Allain did the work for all of us.
• Tuesday marked the anniversary of the last moonwalk; Amy Shira Teitel takes us back to that sad yet triumphant occasion. As a bonus: here’s a dramatic picture of of astronaut Jack Schmitt, with his home planet in the background.
• Yesterday was the birthday of Tycho Brahe, born December 14, 1546. He was the greatest of the naked-eye astronomers, and despite his rejection of the Copernican model, his observations led Johannes Kepler to the laws of planetary motion and our modern view of the Solar System. Tycho’s astronomy was made possible by his array of fantastic scientific instruments, highlighted in this online exhibit. He was also known as a bit of a hothead, and had to wear a prosthetic nose after getting part of his proboscis trimmed in a swordfight. Mad Art Lab has a template for you to make your own prosthetic nose, though yours won’t be made of copper.

Finally, here’s the latest splash test of the Orion capsule from NASA Langley Research Center (I saw an earlier test last month):