Astronomy Picture of the Day - The ISS Transits the Moon

Explanation: Nope, that is not an alien spaceship landing on the Moon! This is an image of the International Space Station (ISS) as it begins to transit in front of the Moon. The ISS is in low-Earth orbit (LEO) where it wizzes around the Earth every 90 minutes. Orbiting the Earth 16 times per day for 25 years, the ISS has photobombed many familiar celestial objects including Venus, Mars, Saturn, and the Sun. Thousands of experiments led by researchers from over one hundred countries have been conducted on the ISS. Growing protein crystals in low gravity was one of the...