Mercury is the smallest planet in our solar system, and the one that’s closest to the Sun. The planet was named for the Roman messenger god Mercury. The planet is only slightly larger than our own Moon.
Mercury is a rocky planet with an iron-rich core, and almost no atmosphere. The surface of the planet is rich in silicon and carbon in the form of graphite, the form of carbon commonly found in pencil lead.
The planet is covered with impact craters caused by millions of years of comets and asteroids impacting the surface. Temperatures on Mercury span from -270 degrees Fahrenheit on the dark side to 790 degrees Fahrenheit on the side facing the Sun.
The orbit of Mercury around the Sun is more oval, or elliptical than any other planet in the solar system, and the planet takes only 88 Earth days to make one orbit completely around the Sun.
For more information, visit:
Named for the Roman goddess of love, Venus is the second planet from the Sun and is by far the hottest planet in the solar system. Venus is another of the rocky inner planets in the solar system. The planet is covered with geologically active volcanoes that spew carbon dioxide and sulfuric acid gasses into the atmosphere. These are powerful greenhouse gasses, trapping the Sun’s energy in the atmosphere and causing the planet’s temperature to soar. The temperature on the surface of Venus is an average of 867 degrees Fahrenheit, plenty hot enough to melt lead. The thick atmosphere surrounding Venus is 92 times more dense than the air on Earth. Fresh lava flows constantly resurface the planet, and therefore there are few impact craters on the surface of Venus. It’s a hellish planet that could never support life.
The Russians have been exploring Venus for decades, and succeeded in sending back the first images of the planet’s surface. Many planetary probes have been sent to Venus, and some have successfully landed on the surface, but due to crushing pressures and high temperatures none of them survive for more than a few minutes. The current record for survival of a space probe on the surface of Venus was the Russian probe Venera 13, which lasted a little more than two hours.
For more information, visit: