It’s Venus

Couldn’t figure out what we were seeing tonight…the answer is Venus. Amazing all month. Venus as a crescent, seen from the Hubble Space Telescope in orbit above the Earth. NASA/JPL [larger image]

Venus is often considered the Evening Star or the Morning Star, depending on which time of day it is up and dominating the twilight. For example, until late September 2010, Venus will appear as a brilliant yellow star in the evening sky, right after sunset. Located 20° above the western horizon one hour after sundown, it remains on view until after 10 P.M. local daylight time. At the beginning of May, Venus spans 11″ across and shows a gibbous disk 88-percent lit. By late in the month, the disk has grown to 13″ and the phase has shrunk to 81-percent illumination. The planet shines at a stunning -4 magnitude, about ten times brighter than the brightest star Sirius, and by far the brightest celestial object after the Sun and Moon. Venus is so bright due to a combination of factors. Venus is covered with an opaque layer of highly reflective clouds of sulfuric acid. These clouds reflect 70-percent of the sunlight that hits them.

For comparison, the Earth reflects 36-percent and Mars and the Moon around 15- percent of the sunlight striking them. Venus is also rather large, being only a bit smaller than the Earth – its radius is 95-percent as large as Earth’s. The final piece of Venus’ brightness puzzle is its close distance to Earth. Right now, the planet is 1.4 astronomical units (130 million miles) from Earth.

This information came from www.nightskyinfo.com.

Tags: evening star, morning star, night sky link, Venus