Introduction and Monthly Reminders
The cooler temperatures are definitely settling in over Utah. We experienced a couple of stormy days with the mountains receiving snow. Even with the cooler weather and stormy days, I could view Jupiter as it reached opposition on the 3rd. I could also view Venus and Jupiter in the early morning sky and Orion the Hunter with his two hunting dogs, Canis Major and Canis Minor. Uranus also reached opposition during the first half of the month and a close encounter between the Moon and Antares on the 14th. I wanted to travel down to Richfield, Utah, again during the first half of November to attempt an astrophotography timelapse, but unfortunately, the weather intervened.
Observers can still view the Leonid Meteor Shower on the evening of the 17th and early morning hours of the 18th. There will also be many close approaches between the Moon and the outer planets of the solar system. Mercury will pass close to Antares on the 16th, while Venus will pass close to Spica on the 28th.
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| Venus |
Last month, I discussed Mercury's formation, traits, and missions. This month, the solar system tour will continue with the second closest planet to the Sun, Venus. The second planet out from the Sun formed at the same time as the rest of the solar system, approximately 4.6 billion years ago. It can be found about 0.72 AU (67 million miles), on average, from the Sun, where the Earth is 1 AU (93 million miles). Venus is the third brightest object in the sky, trailing only behind the Sun and the Moon. Venus is so bright that it can even be seen during the day if the air is free of pollution. Venus is named after the Roman goddess of love and beauty and is the only planet named after a female god.
The interior of Venus closely resembles that of the Earth. It is theorized that if the Earth and Venus were cut in half and placed next to each other, an observer could not tell the two apart. Venus is also similar in size to Earth, being only 405 miles smaller across than the Earth. These similarities have earned Venus the nickname "Sister Planet" to the Earth. Unfortunately, this is where the similarities end.
Venus is a planet of extremes. If Earth and Venus were twins, the Earth would be the even-tempered twin while Venus would be the extraordinarily aggressive and hot-tempered sibling. The surface of Venus is estimated to have over 1600 major volcanoes and thousands more smaller ones, a majority of which are active. These active volcanoes aid in constantly resurfacing the planet, allowing very few impact craters to be seen, similar to Earth. The surface of Venus can reach lead-melting temperatures of 870° Fahrenheit, the hottest surface temperature of any other planet in the solar system. These extreme temperatures are caused by Venus' closeness to the Sun and its thick carbon dioxide atmosphere that traps heat. Venus also has mountains and valleys like the Earth, but of course, it does not have any liquid water since water turns to steam at temperatures above 212 degrees Fahrenheit.
While the Earth and Venus both have an iron core encased by a mantle and a thin rocky exterior, our Sister Planet does not have a magnetosphere of its own. Venus instead gets its weak magnetic field from the Sun's magnetic field interacting with the planet's atmosphere. As mentioned, the atmosphere of Venus is mostly made up of carbon dioxide, the same gas that is behind the greenhouse effect on Earth. Instead of having clouds made up of water vapor like the Earth, Venus has clouds composed of sulfuric acid. Higher in the planet's atmosphere, the temperatures ease a bit with a range of 86 degrees to 158 degrees Fahrenheit. In this region of the atmosphere, Venus experiences wind speeds up to 224 miles per hour, about the same speed as hurricane-force winds on Earth. The thick atmosphere of Venus also contributes to its high albedo, or reflective properties, causing the planet to appear bright in our sky. Venus has an albedo of approximately 0.7 which means nearly 70% of the Sun's light is reflected. Recall that the albedo of Mercury was only 0.14, and the Moon has an albedo of 0.1.
Since Venus is on the inside track around the Sun, compared to the Earth, observers can view the planet go through phases, like the Moon. A pair of binoculars can reveal these phases, although personally, I have had better luck with a telescope. Unlike the Moon and other planets in the solar system, Venus (and Mercury) can never have a "full" phase since when they are opposite of the Sun from our Earthly perspective, they will be behind our star. However, the inner planets can pass between the Sun and the Earth, creating a planetary transit. The last transit of Venus occurred in 2012 and won't happen again until 2117. I was able to capture a few blurry images during the 2012 transit. The best of which is included below.
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| Transit of Venus in 2012. Some sunspots were also visible. |
The Earth's evil sister planet also has a much different spin than what humans are used to. Venus rotates about its axis in the opposite direction as the Earth, meaning the Sun rises in the west and sets in the east. Venus also spins extremely slow, with a day on the planet being longer than a year. Venus does not experience seasons like the Earth either, due to it only having a 3 degree tilt while our planet has about a 23 degree tilt.
There have been many missions to Venus, most of which have been Russian missions. There are currently three known missions in the works to return to Venus.`
Spin
Day vs year length
missions
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| Now get outside and look up! |
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