What’s Up in the Sky – February, 2020
It’s Venus
If you venture out any time after sunset and look to the southwest, you will be sure to spot a very bright light high over the horizon. Several friends have asked me about it so I thought I would satisfy everyone’s curiosity and confirm your suspicions by telling you that it is indeed the planet Venus. Last week Venus appeared very close to the crescent Moon, a close encounter that will repeat itself this month. On February 27, the two will again form a beautiful, close pair in the western sky for several hours after sunset.
Venus has played quite an important role in human history. In the ancient tradition of attributing that which is unexplained to the “gods”, Venus was named after the goddess of love and beauty. All the planets had special significance to early civilizations because they did not follow the normal behavior of everything else in the sky, Sun and Moon notwithstanding. The visible planets demonstrated god-like behavior, being seen in different locations at different times of year. Being one of the brightest objects in the sky, Venus has been revered by civilizations throughout recorded history.
Mercury and Venus both will be visible this month low in the west after sunset. On Monday, February 10th, look about 40 minutes after sunset. Mercury will be about two fist-widths down and a little to the right of Venus. You will probably need binoculars to see Mercury.
Besides her historical significance, Venus has played an important role in the history of science. It was the first planet to have its positions plotted in the sky, almost four thousand years ago. In the middle ages, Galileo’s observations of the phases of Venus offered evidence of a Sun-centered, not Earth-centered system.
Due to its close approaches to Earth, it was an early target for planetary exploration. When Mariner 2 made its close flyby in 1962, it marked the first time any planet had been visited by a spacecraft. Venus also became the first planet to have a spacecraft from Earth land on its surface when Venera7 did so in 1970.
Venus is the planet with the highest surface temperature (over 850 degrees F) not because of its close proximity to the Sun, but because of global warming. Its atmosphere is about 98% carbon dioxide which traps most the heat from the Sun and creates a runaway warming cycle.
Transits of Venus, when the planet travels directly between the Sun and Earth and appears as a black dot moving across the face of the Sun, are relatively rare events. The last one occurred in 2012 but the next one won’t be until 2117. There is some historical significance to this event. In 1768 Captain Cook sailed to Tahiti to observe a transit of Venus.
Not all the action takes place in the evening this month. I know pre-dawn observing can be a challenge in the workaday world, but on Tuesday, February 18, the crescent Moon will occult (pass in front of and block out) Mars. This will occur at 7:10 am so grab a pair of binocs and start watching around 7. Look every few minutes as their separation until Mars disappears behind the Moon.
I have seen a few occultations and can assure you that you will think it is one of the coolest things you’ve ever witnessed up in the sky.
This month in history:
Feb 01: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb 06: Alan Shepard hits first golf balls on the Moon – 1971
Feb 15: Galileo Galilei born – 1564
Feb 18: Pluto discovered – 1930
Feb 20: John Glenn is first American to orbit Earth – 1962
Feb 24: Detection of first pulsar (by Jocelyn Bell in 1967) is announced – 1968
