Look up this week for easy-to-see astronomical events
Posted January 19
There are two astronomical events this week worth braving the cold to see.
Look high in the southwestern sky about 9:15 p.m. Tuesday for the waxing gibbous moon. On the left edge of the moon, you’ll see the bright star Aldebaran, an orange giant star 65 light years away in the constellation Taurus. Over the next 15 minutes, the moon will move in front of the star, also called "occulting." Aldebaran will emerge at 10:27 p.m. on the right side.
Astronomers use occultations to study objects in the outer solar system. The atmosphere of Pluto was studied when they blocked light from a distant star in 2011. The Kepler spacecraft uses occultations to discover planets orbiting distant stars.
While a telescope or binoculars are not required to view tonight’s lunar occultation, bring them out if you have them. The event starts with the unilluminated part of the moon covering the star, revealing craters and other features on the moon normally hidden. Skies should be clear tonight, but bundle up as temperatures in the upper teens to low 20s are expected.
While you are waiting, look to the left of the moon for the constellation Orion. Greek myth tells of Orion the hunter is charging Taurus the bull. Orangey Aldebaran, the 14th brightest star in the sky, forms the bull’s angry, bloodshot eye.
Beginning Wednesday morning for the next four weeks, you’ll have the rare opportunity to see all five naked eye visible planets – Mercury, Venus, Saturn, Mars and Jupiter – in the sky at once. Look to the south before sunrise. Jupiter and Venus will be the brightest, Mars and Mercury the dimmest. Mercury’s orbit so close to the sun places it low on the south-southwestern horizon so try to find somewhere with a low tree line and no buildings.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.