For their Picture of the Week last, uh, week, the Solar Dynamics Observatory crew chose a fantastically cool shot: the Moon cutting across the disk of the Sun!
Wow! This phenomenal shot was taken on October 7, 2010, as the new Moon slipped between the Sun and the observatory. SDO is in Earth orbit, circling our planet 36,000 km (22,000 miles) up (technically, that's the distance from the Earth's center). The orbit is tilted so the Earth itself only rarely gets in the observatory's way as it watches the Sun day in and day out. But every now again, when the celestial objects literally align, the Moon can block the view. From the Earth, the Moon was new, meaning it was near the Sun but not blocking it. But from SDO's point of view the geometry was just right to get this partial eclipse (technically called a transit). I drew ...
