Western Slope Skies - 8/15/14

Aug 15, 2014

Planetary Conjunctions

Late August will be a great time for planet watching, in the morning and the evening. If you are up early on Monday, August 18, you will be rewarded by a spectacular pre-dawn sight. 

Between about 5:15am and 5:40am, Venus and Jupiter will appear very close together above the east-northeastern horizon. Venus (named for the Roman goddess of beauty) is the brightest of planets, mainly due to its closeness to Earth (now about 150 million miles away).  Jupiter (named for the Roman king of the gods) is the largest planet, eleven times the size of Earth or Venus. But Jupiter (now 578 million miles distant) is about four times further than Venus, so it appears one-sixth as bright. They will appear only one-third of a degree apart, less than the apparent diameter of the full moon! 

After August 18, Venus and Jupiter separate rapidly. Venus will appear lower in the sky each morning, while Jupiter will appear higher.  By late September, the Sun’s glare will render Venus nearly invisible. By October, Venus will actually be behind the Sun.  Jupiter, meantime, is emerging now from behind the sun, and drawing a little closer to Earth. By late winter, Jupiter will be high and bright in the evening sky.   

In the evening sky of summer, another conjunction will soon take shape.  If you look to the southwest at about 9:00pm on August 16, you will see two fairly bright “stars” that don’t twinkle. One will be distinctly reddish-orange in color; this will be the planet Mars, named for the Roman god of war.  The other, about as bright but shining yellowish just above and left of Mars, will be slow-moving Saturn (named for the Roman god of time).  From August 16 through August 25, Mars appears to move closer to Saturn.  They draw closest on the evening of August 25, when they will be separated by less than four degrees. That’s only eight times the width of the full moon.

So, take some time during late August to enjoy these planetary happenings!     

Western Slope Skies is produced by members of the Black Canyon Astronomical Society. This episode was written & recorded by Michael Williams.