Jimmy Westlake's Celestial News column appears monthly in the Steamboat Today.
Find more columns by Westlake here.
Steamboat Springs After dominating our evening sky for several months, brilliant Jupiter has met its match. The dazzling planet Venus has re-entered our evening sky and has stolen Jupiter's crown as the brightest object visible in the early evening. You might have noticed the solar system's two brightest members while driving home at dusk. They are separated by about two hand spans at arm's length, roughly 30 degrees across the sky, but that gap will rapidly close during the month of November and culminate with a spectacular close conjunction Nov. 30 and Dec. 1.
Venus is nearly the Earth's twin in size, mass and density, but, lying closer to the sun, her surface conditions are far different from Earth's. Enshrouded in sulfuric-acid clouds, Venus' surface is a veritable pressure cooker where the temperature hovers near 900 degrees Fahrenheit, and the weight of the oppressive atmosphere is two-thirds of a ton per square inch. Whereas carbon dioxide gas accounts for only 0.03 percent of Earth's atmospheric composition, it accounts for 96 percent of Venus' air, creating a runaway greenhouse effect that makes for a most inhospitable planet.
Jupiter, on the other hand, is more than five times farther from the sun than Earth, in a very cold environment. Jupiter is an enormous ball of liquid hydrogen surrounding a small, dense core. More than 1,000 Earths would fit inside of Jupiter's colossal globe!
Through a small telescope, one can observe the planet Venus wax and wane through a series of phases reminiscent of the moon's, while Jupiter proudly displays its colorful cloud stripes and four giant moons that dance around the planet from night to night.
The moon, on its monthly sojourn around the sky, will join the sky's two brightest planets for some unforgettable views in early November and then again in early December. Tonight, the crescent moon will appear about midway between Venus, on the right, and Jupiter, on the left. By the next night, Monday, the moon will have moved eastward and will sit just below Jupiter in the colorful twilight. Catch this action between 5:30 and 6:30 p.m.
The real highlight of this planetary conjunction occurs on the evenings of Nov. 30 and Dec. 1. That's when the planets Venus and Jupiter, then only 2 degrees apart, will once again be joined by a thin crescent moon, forming a tight grouping that you can easily hide behind your fist at arm's length.
Celestial gatherings involving the brightest planets and the moon are not common, so if the night is clear, step outside on Nov. 30 and Dec. 1 and face southwest as the sun sinks below the horizon for a gorgeous scene that you won't soon forget. Use binoculars to enhance the view.