Earth’s Twisted Sister
As the suns sets and the sky darkens, Venus beckons in the west at the feet of Leo and less than 10 degrees from the lion’s heart, Regulus.
Venus is called our sister planet, but that puts a hellish twist on familial relationships. Yes, Venus and Earth are similar in size. And Venus has a gravitational field similar to that of Earth. Like Earth, Venus has a cloud-based atmosphere. But there the similarities end.
Long ago the planet began heating up, its water evaporating, leaving an atmosphere made up almost entirely of carbon dioxide. This in turn trapped more and more heat, causing an irreversible greenhouse effect with temperatures that near 1,000 degrees. Additionally, the planet is covered with thousands of volcanoes that have spewed toxic chemicals into the air over countless millennia, adding to the miles-deep cloud cover of mercury,
ferric chloride and sulphuric acid.
Venus spins on its axis very slowly, taking 243 earth days from one sunrise to another. On the other hand, Venus orbits the sun in a period of roughly 225 earth days, meaning the planet’s day is longer than its year. Despite its slow rotation, Venus is buffeted with winds reaching 500 miles an hour, some of the fastest in the solar system.
But from here on Earth, Venus is a beauty to behold, the brightest object in the heavens other than the sun and moon. When our sister planet hovers over the horizon, its light can appear to pulse and shake, leading to some of the most common purported UFO sightings.
At the other edge of darkness this week, Mercury, Mars and Jupiter hover above the east horizon an hour before sunrise, joined by the thin waning crescent moon August 3 and 4. Jupiter is the highest and brightest, with
Mars a little lower than Jupiter and Mercury closest to the horizon but surprisingly bright.