Vesta 3-D Movie Plus First Quarter Moon Highlights

Time to dig up a pair of those funky red-blue 3-D glasses and soar with the Dawn space probe as it orbits the asteroid Vesta. This newly-released video takes you on a tour of the asteroid’s Snowman craters, the huge mountain at the south pole and those peculiar parallel troughs that encircle the asteroid’s equator. If you need a pair of colored glasses, there are a variety of websites that sell them – cheap. Check HERE or HERE.

The moon will be just past first quarter this evening. The terminator lies along the left side of the move and advances eastward (to the left) each night until full moon.

Tonight the moon’s a smidge past first quarter phase. That when the line of advancing lunar sunrise changes shape from being concave – curving inward as during the crescent phases – to convex or bulging outward as it will be tonight. Before full moon, the terminator sweeps from right to left (west to east) across the lunar globe. After full, it becomes the encroaching line of sunset, when slice-by-slice the moon is reduced from full to last quarter and finally a slim, morning crescent.

As sunlight advances across the moon’s stark terrain, craters, mountains and seas come into view hour by hour, day by day. The terminator advances at the surprisingly leisurely pace of 9.3 miles per hour at the moon’s equator. That’s the average speed of a person in a moderately-fast run and evokes the interesting scenario of the sun forever stuck on the moon’s horizon from the viewpoint of a runner keeping pace with the terminator’s eastward creep. Should there ever be marathon races on the moon featuring runners with average speeds greater than 9.3 miles per hour, they’d have the pleasure of seeing the sun lower in the sky at race end compared to when they started.

This map shows a wide view of the sky facing south around 7 o’clock local time. The moon is the pivot point for finding the Great Square of the constellation Pegasus and a variety of other objects in the southern half of the sky. Created with Stellarium

While you’re out moongazing, use the moon to help you find some of December’s brighter stars and star-figures in the early evening sky. You can shoot lines from Luna to Jupiter, Deneb Kaitos (brightest star in Cetus the Sea Monster), Fomalhaut (brightest star in Piscis Austrinus the Southern Fish) and Enif, the ‘nose’ of Pegasus the Flying Horse. Directly above the moon, the four stars of the Great Square of Pegasus stand out because they enclose what appears to be a large vacant lot of sky.