Western Slope Skies - Venus In the Evening

Jan 13, 2017

Credit NASA/JPL

What’s that brilliant “evening star,” lingering in the southwest after sunset? It’s often confused with airplane landing lights and has even been reported as a UFO! It’s Venus, Earth’s closest planetary neighbor!

Venus is named for the Roman goddess of love, but the surface of Venus is far from lovely. It’s a baking desert at 860 deg F, bathed in a carbon dioxide-rich atmosphere that presses downward with 90 times the weight of Earth’s air.

Since late summer, Venus has emerged from beyond the Sun as seen from Earth. Venus will be moving progressively nearer to Earth until March 25, when it will be only 26 million miles distant. As seen through a telescope from September through early March, the cloud-shrouded disk of Venus wanes from nearly full to a slender crescent, as the percentage of its sun-illuminated surface diminishes and its angular size increases. Since September, Venus has been getting progressively higher in the evening each week, having reached its largest angular separation from the sun on January 12, when Venus’ disk appeared half-illuminated. Venus will become brightest around mid-February - bright enough to cast shadows after twilight ends!

From mid-January through March 1, Venus will appear to move in tandem with fainter, reddish Mars. This, however, is an illusion created by our Earthly perspective. On January 13, Venus is almost 3 times closer to Earth than Mars, and it will be 6 times closer by March 1. On January 31, Venus will form a tight triangle with a crescent Moon and Mars – that’s going to be a beautiful sight! But enjoy the evening star while you can, because Venus will move rapidly into bright twilight by March 1. After March 15, Venus will become difficult and dangerous to view, due to its proximity to the sun in our skies. By mid-April, however, Venus will re-appear as a “morning star” to dazzle early risers before dawn.

Western Slope Skies is produced by members of the Black Canyon Astronomical Society. This episode was written and recorded by Art Trevena.

Links for more information about Venus:
solarsystem.nasa.gov/planets/venus
www.nasa.gov/venus
www.nakedeyeplanets.com/venus.htm
earthsky.org/astronomy-essentials/venus-july-2016-to-april-2017
en.wikipedia.org/wiki/Phases_of_Venus