WHAT’S UP? Lunar Libration

Does the moon rotate on its axis? Many people would say no, because it  keeps only one face (or hemisphere) pointed at Earth at all times. But, in fact, in order to do this, it must rotate once for every orbit around the Earth it makes. You can demonstrate this with a friend. Try walking around your friend and not changing the direction of your face.

NASA’s SDO Witnesses a Double Eclipse

Early in the morning of Sept. 1, 2016, NASA’s Solar Dynamics Observatory, or SDO, caught both Earth and the moon crossing in front of the sun. SDO keeps a constant eye on the sun, but during SDO’s semiannual eclipse seasons, Earth briefly blocks SDO’s line of sight each day – a consequence of SDO’s geosynchronous orbit. On Sept. 1, Earth completely eclipsed the sun from SDO’s perspective just as the moon began its journey across the face of the sun.

Planning Your Eclipse Party

Many eclipse enthusiasts host parties in local community centers, museums, observatories, parks or open fields. Even your own backyard is a good place to throw a party. It is always a good idea to choose place that has access to shade and facilities. You may also want to check weather-related Web sites for forecasts of your area. If the clouds move in, don’t worry! You can always connect to NASA’s live streaming event.

Enthusiastic for Science Beyond the 2017 Eclipse?

If you’re interested in NASA Eclipse and other Science information, sign up to receive an email newsletter “Weekly on Wednesdays.” Science starts with a question, and so does "Science WOW!" Each week kicks off with a science question with answer link. "Science WOW!" also highlights a NASA science education tool such as NASA apps, interactive games, 3-D printing templates, etc.