Venus, What Happened?

Saturday, December 4th is Astronomy Night at Tye Preston Memorial Library, Canyon Lake. If we have a clear enough sky, we’ll start at 6:30 in the library with a brief orientation before going to the observatory. If the sky is not cooperating, we will have a presentation in the library.

Venus is the current dominant, prominent object in our early evening sky. It’s stunning! When I was younger and did not have a telescope I thought wow, Venus must look so cool in a telescope! Then I got a look at Venus in a telescope and…WHAT?!…it’s just a really bright, I mean hard to look at bright blob.  You cannot see the surface, just those super bright clouds. So much for my thinking it would be cool. Not cool, really, really hot! Why?

Well, there is no definitive answer to that question, but planetary astronomers are formulating possible scenarios that would lead to our sister planet being a hellhole instead of a paradise. That’s right, instead of the paradise astronomers once thought Venus to be. Can you believe it, astronomers once portrayed Venus as harboring tropical life, vast oceans, and almost constant rain? Yeah, and astronomers once thought Mars had intelligent life, building canals to deliver water.

OK, the thing about science, and this is central, inherent in science, science does not determine definitive answers or proofs. Leave that to mathematicians. Science is all about the process of learning about stuff, improving understanding of how it works, how it formed. Science is forever correcting itself as new evidence comes to light. Now we see there are no canals on Mars, no indication of intelligent life except for the landers, rovers, and orbiters humans have placed there.

Venus, it’s not paradise. With a surface temperature of nearly 900 degrees F it’s more like your self-cleaning oven. The air pressure (air there is 97% CO2-deadly to humans) is like being 3300 feet underwater. Venus has a layer of sulfuric acid clouds. No place for a VRBO.

One theory says Venus started much like Earth but a warming Sun (its warming increases slowly as it ages) affected Venus strongly (it’s a lot closer to the Sun) and rapid ocean evaporation lead to runaway greenhouse effects. All the water was lost first to the atmosphere, then to space.

Another theory implies extreme and continuous volcanism, and there is evidence of recent eruptions. Volcanos spew sulfur dioxide and CO2 as well as lava. The massive influx of greenhouse gasses might have caused Venus’s current situation.

Some investigators suggest Venus was born this way. That was easy!

We need to go back and examine Venus more closely. We need probes that can stand the heat and pressure!

What’s in the Sky?

December 6; after sunset; south-southwest: A waxing crescent Moon is below Venus

December 10-11; before sunrise; east:  Comet Leonard might be naked eye visible about 25 degrees above the horizon. Use binoculars too.