Astronomy Facts about the Planet Venus

Venus is the second closest planet to the sun in the solar system. The order of the planets starting from the closest to the farthest is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. The only object in the night sky that is brighter than Venus is the Moon, although the Moon is much brighter. At its brightest, Venus apparent magnitude is -4.6.

Venus was named after the goddess of love and beauty in Roman mythology. Venus is sometimes called the “twin planet” of the Earth because Venus is only a little smaller than the Earth and its inside is similar to that of the Earth’s. Venus is called the Evening Star and Morning Star because it is sometimes seen in the morning and sometimes in the evening.

The rotation of the axis of Venus is in the opposite direction of the other planets. All the planets except Mercury and Venus have a moon. The day is 2802 hours on Venus compared to 24 hours on the Earth. Venus orbits the sun every 224.65 days compared to 365 days for Earth. Venus orbits the Sun at the average distance of 108 million kilometers. This is about 0.7 Astronomical Units (AU), which is the distance from the Earth to the Sun (93 million miles).

Venus comes closer to the Earth than any other planet. It comes within an average distance of about 41 million kilometers from the Earth during inferior conjunction about every 584 days. The planet can come as close to the Earth as 38.2 million kilometers.

There are rings surrounding Jupiter, Saturn, Uranus, and Neptune; but Venus does not have any rings. It is the hottest planet in the solar system with an average surface temperature of 464 degrees Celsius. Its equatorial radius is 6051.8 kilometers compared to Earth’s 6378.1 kilometers. Its mass is 4.868 x 10^24 kilograms, which is 0.815 that of the Earth’s. Its escape velocity is 10.36 kilometers per second compared to Earth’s 11.19 kilometers per second. 

The atmosphere of Venus has thick clouds that make it hard to view its surface. Carbon dioxide composes 96.5 per cent of its atmosphere. The other gases include nitrogen (3.5%), sulphur dioxide (0.015%), argon (.007%), water (.002%), carbon monoxide (0.0017%), helium (0.0012%), and neon 0.0007%). There are traces of carbonyl sulfide, hydrogen chloride, and hydrogen fluoride.  

In 1962 the United States’ Mariner 2 was the first artificial satellite to send data about Venus back to the Earth. The Soviet Union’s Venera 4 made the first examination of the atmosphere of a planet other than the Earth’s in 1967. On December 15, 1970 the Soviet Union’s Venera 7 made the first successful landing on a planet other than the Earth; but it only sent limited data back for 35 minutes. Venera 8 landed on Venus on July 22, 1972 and sent back data including temperaturemand pressure. In 1973 the United States’ Mariner 10 was the first artificial satellite to send data back for two planets (Venus and Mercury). The Russian Venera 9 was the first artificial satellite to orbit Venus. It also sent the first pictures of the planet after landing in 1975.

High quality pictures of Venus were made by Project Magellan 1990 to 1991. It revealed many volcanoes; but lava flow has not been identified to date.