Learn about supermoons, read the monthly blog from the Dawn mission’s chief engineer and more.
1. This Is the Season for Supermoons
The second of three fall supermoons occurred on November 14 and the final one is December. What are supermoons? Since the moon’s orbit is elliptical, one side (perigee) is about 30,000 miles closer to Earth than the other (apogee). The word syzygy, in addition to being useful in word games, is the scientific name for when the Earth, sun, and moon line up as the moon orbits Earth. When perigee-syzygy of the Earth-moon-sun system occurs and the moon is on the opposite side of the Earth from the sun, we get a perigee moon or more commonly, a supermoon!
On its penultimate close flyby of Saturn’s largest moon Titan, Cassini will use its radio science instrument to scan the great seas of methane near the moon’s North Pole. Titan’s three large northern seas, Punga Mare, Ligeia Mare and Kraken Mare, are each hundreds of miles across, but imaging cameras can’t see them very well because the moon’s surface is veiled by a thick haze. Radio signals, however, can penetrate the moon’s atmosphere, and Cassini has an instrument that uses radio signals to reveal Titan’s dramatic landscapes.
5. The Science of Light, Celebrating Dark Skies in Our National Parks
Learning more about the science of light and human vision will help us understand the value and fragility of natural lightscapes. During the day, the surface of the planet is bathed in light from the sun. The energy in sunlight drives weather, the water cycle, and ecosystems. But at night, in the absence of bright light, our atmosphere turns transparent and allows us to see beyond our planet into the vastness of the cosmos.