By David Ward
After a long absence from our evening skies, the beautiful, brilliant planet Venus is returning. Permanently shrouded in heavy opaque clouds, Venus has been a mystery to us humans until quite recently. Mysteries tend to enliven the imagination and speculation ran wild about what actually was underneath those clouds. Astronomers 100 years ago imagined they were spotting through their telescopes the tops of Himalayan-sized mountains protruding above the clouds. Science fiction writers wrote fanciful tales of dense exotic jungles populated with primeval people living a charmed life shrouded from view.
Beginning in the 1960s, space probes have been sent to Venus and are showing us a very different world. Having a similar size and composition as Earth and occupying a similar location in space, Venus is often referred to as our “twin sister.” Some astronomers, however, refer to Venus as our “evil twin sister.” Why such a foreboding name for such a beautiful celestial object?
First of all, it is hot. Venus holds the distinction of being the hottest planet in the solar system, hotter even than Mercury, which is closer to the sun. You would not need an oven for cooking there. With the thermostat on Venus set at a constant 870 degrees Fahrenheit, your Thanksgiving turkey would have baked in seconds.
Why is it so hot on Venus? If Earth were moved to the orbit of Venus, it would raise the temperature about 50 degrees, which would obviously be very inconvenient for us earthlings, but nowhere near the extreme heat found on our sister planet. Blame it all on those clouds.
Life on Earth
Here on Earth, we are incredibly fortunate to be enjoying a very mild climate due to an improbable set of biological, geological and astronomical feedback loops. Even though the sun has gotten warmer and warmer over the last few billion years, temperatures on Earth have changed very little for a long, long time, allowing us to live here. If the thermometer here on Earth had risen just one degree every 100 million years since life started evolving on this planet, it would now be far too hot for us to survive. Venus, on the other hand, is experiencing a runaway greenhouse effect from which it will never recover.
Then there are those clouds on Venus, which a century ago were thought to nourish a primitive biosphere of exotic plants and animals. They are composed of mostly carbon dioxide with a healthy dose of concentrated battery acid thrown in for good measure. Also those clouds are heavy. Standing on the surface of Venus would be like standing on the ocean floor under 3,000 feet of water. That is enough weight to flatten a car, not to mention a person!
The surface of Venus is a barren, hostile place with no chance for life to exist. If you had it on your bucket list as a cool place to visit before you die, my advice is to scratch that one off.
To spot Venus, look for her low in the southwest about 30 minutes after sunset, a little above and to the left of where the sun went down. You will need a nearly unobstructed view of the southwest horizon. Venus is the brightest object in the sky other than the sun and moon, outshining all the stars and other planets. It will climb higher in the sky and be easier to spot as winter progresses.
During the second week of January, look for the elusive and rarely seen Mercury just to the right of Venus. The brilliant Venus will outshine Mercury, but the innermost planet should be easy to spot with binoculars.
The planet Mars is above and to the left of Venus, shining with a dimmer reddish glow. It is the only bright object in that area of the sky and can be easily seen with the naked eye when it gets dark. If you have always wanted to see the distant world Neptune, Jan. 19 will be an excellent time to do so. Look for it with a telescope just a hair above Mars, shining like a very dim bluish star.
A little later in the evening the planet Jupiter will make an appearance in the east. It shines with a very bright, steady light and will be visible all night long. Also while you are out there, be sure to take in all the bright stars of winter scattered across that star-filled dome above.
Do things seem to be speeding up in your life lately? There is a reason for that. On Jan. 3, Earth will get to that point in its orbit known as perihelion, our closest approach to the sun for the year. When we are closer to the sun, we also travel faster through space. Right now we are cruising along about 2,000 miles an hour faster than we will be next summer. So hang on tight, it is a crazy ride!