Venus

Space & astronomy wiki (June 23, 2015)

Venus and Earth are similar in size, composition, and mass. They differ in that Venus does not have oceans or human life, and its temperature during the day reaches 484 degrees Celsius. The daytime temperature is so hot it could melt lead. The dense atmosphere is composed of carbon dioxide and sulfuric acid which acts as a greenhouse and traps the heat. Venus revolves around the Sun in a circular orbit once every 225 Earth days. Venus rotates slowly on its axis in a clockwise direction, which is referred to as a
Venus and Earth are similar in size, composition, and mass. They differ in that Venus does not have oceans or human life, and its temperature during the day reaches 484 degrees Celsius. The daytime temperature is so hot it could melt lead. The dense atmosphere is composed of carbon dioxide and sulfuric acid which acts as a greenhouse and traps the heat. Venus revolves around the Sun in a circular orbit once every 225 Earth days. Venus rotates slowly on its axis in a clockwise direction, which is referred to as a “retrograde” rotation because it is the opposite of the seven other planets. A rotation takes 243 Earth days, so a Venusian day is longer than a Venusian year. As with the other inner planets, the surface of Venus has been shaped by impact craters, tectonic activity, and volcanoes which scientists believe to be ongoing. The volcanic activity is believed to be the source of the sulfur found in the atmosphere. Venus does not have any naturally occurring satellites.

Space & Astronomy Wiki – the planets in the solar system –

At an average distance of 0.72 AU from Sol, Venus is the second planet from the Sun, closest sister planet to Earth in size and mass, and the third densest planet in the solar system at an average density of 5.24 g/cm3.

The second-brightest object in the night sky, with the Moon being the brightest, at between magnitude -3.8 and -4.6, Venus was first recorded by Babylonian astronomers in the 17th century BC and is named after the Roman Goddess of Love and Beauty.  

Called both the Evening Star and Morningstar, Venus is the second largest terrestrial planet in the solar system and the hottest planet with an average surface temperature of 462 degrees Celsius.

Composed of a crust, molten mantle, and core, the surface of Venus is totally obscured by dense clouds of carbon dioxide that trap heat very effectively, producing a runaway greenhouse effect.   

Rotating very slowly on its axis, Venus rotates in the opposite direction to the other planets in the solar system, creating extremely long days and nights, and a west to east movement of the Sun across the sky.

Looking at the surface of Venus you see mountains, valleys, craters, and even evidence of previous volcanic activity. This is deceiving, though, because the geology of the surface of this planet is very different than that of Earth. 

We’ll talk more about the surface geology, atmosphere and life history of Venus in future articles.

You can learn more about Venus here.

 

Learn about the NExSS Coalition’s Search for Habitable Planets and Life Beyond Earth.

Learn how stars seed the cosmos with the elements, the building blocks of the universe.

Learn about the Cassini spacecraft viewing icy geysers on the surface of Saturn’s moon Enceladus.

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Mercury

The innermost planet to the Sun

The innermost planet in our solar system, NASA's MESSENGER and Mariner 10 were the first to get a close up look at Mercury
The innermost planet in our solar system, NASA’s MESSENGER and Mariner 10 were the first to get a close-up look at Mercury

Mercury is the smallest of the first eight planets, with a radius around 2440 km, which is only slightly bigger than the Moon. A desolate, cratered terrestrial world with no Earth-like atmosphere, active volcanoes, moons, or life, Mercury has a rocky surface much like the Moon and is the second densest of the planets at 5.43 g/cm3

Space and Astronomy Wiki – the planets in the solar system –

Mercury is the fastest moving planet, traveling through the solar system almost 50 km (31) miles per seconds faster than any other planet. Every day is 59 Earth days long and a year – the time it takes the planet to orbit the Sun – takes only 88 days, a combination resulting in daylight temperatures reaching 800 degrees Fahrenheit (420 degrees Celsius) and a brisk night at around -290 degrees Fahrenheit (-180 degrees Celsius).

Mercury was visited by Mariner 10 during 1974-1975 and MESSENGER orbited the planet three times between 2008-2009, before going into orbit in March 2011 for an extended analysis. On Thursday, April 30, 2015, MESSENGER ended its mission by creating a new crater on the surface of Mercury.

You can learn more facts & figures about Mercury here.

Learn more about the things MESSENGER taught us about Mercury.

Learn more about the ancient sky watchers of the American Southwest.

Learn about the search for life near Jupiter.