In the News: March Skies
March 16, 2017
As spring moves in, Venus moves out of the evening sky, while Jupiter prepares for night-time dominance.
Venus delivered a spectacular show this winter, shining like a diamond high in the southwest. Our closest neighbor currently shines at an incredible apparent magnitude of -4.8 in the west after sunset. Magnitude is a measure of brightness and the lower number, the brighter the object. For comparison, the full moon is magnitude -12 and the sun is -26. Some of the brighter stars are around 1st magnitude. Sixth magnitude stars are just on the edge of naked-eye visibility. Each whole number increase in magnitude means a 100 times increase in brightness.
Venus is so bright because it is currently on the same side of the sun as earth. Because Venus is inside earth’s orbit, a closer look through binoculars or a telescope reveals that Venus is phased like the moon. Right now, Venus looks like a thin crescent close-up. Our current viewing angle only allows us to see a small portion of Venus’ sunlit side, hence the phase.
March is your last chance to see Venus in the evening sky this season. The planet quickly dives toward the setting sun each evening this month. By March 25, Venus is lost from view.
As Venus descends however, Mercury rises into view throughout the month. On March 18 Mercury sits left of Venus at the same altitude. The two worlds reside low in the west around 8 pm, just above the horizon.
Reddish Mars continues to hang stubbornly in the west after sunset. Our red neighbor eventually has a date with the setting sun, but is holding out as long as possible. On March 29, the crescent moon forms a triangle with Mercury below and Mars above at around 8:30 pm.
And lastly, what is that really bright object in the east around 10 pm? That is the planet Jupiter outshining all the stars in the region. Mighty Jupiter is poised to reign over the sky all night next month. The giant planet will be visible throughout spring, summer and even into fall.
Article provided by: Brad Nuest, Space Science Educator
Photo Credit: flickr, hannahisabelnic