10 Things You Should Know About Venus

Venus is the planet named for the Roman goddess of love and beauty and modeled after the Greek Aphrodite. It probably got its name from being the brightest object in the sky (other than the Sun and the Moon). Venus is often called "Earth's twin", but it's really more like Earth's Evil Twin Skippy. It's rocky, as Earth is, has volcanic activity and an atmosphere as Earth does. But, that blanket of air is incredibly dense, and smothers the planet. The volcanism is constantly changing the surface. As we'll see below, those conditions, and several other characteristics of this planet, have some interesting implications for what it's like on the surface. Let's take a look at Venus!

Edited by Carolyn Collins Petersen.

Where Venus Lies in the Solar System

Digital Illustration of Venus
Photodisc/ Photodisc/ Getty Images

Venus orbits 108,200,000 km (0.72 AU) from the Sun. Its path carries it around the Sun between Mercury and Earth in 225 Earth days. That makes its year shorter than our planet's. 

Venus and Earth Compared

Pictures of Venus - Akna Mountains
Pictures of Venus - Akna Mountains. Copyright 1995-2003, California Institute of Technology

Venus has a diameter of 12,103.6 km and a mass of 4.86924 kg. That makes it almost, but not quite a twin of our home planet in size and mass. It formed about the same time as Earth, and may have begun as a wetter, more temperature planet, possibly even with oceans. Astronomers are still working to understand what happened to turn it into the smothered volcanic desert we see today.

Venus has been called Earth's sister Planet

Pictures of Venus - Arachnoids
Pictures of Venus - Arachnoids. Copyright 1995-2003, California Institute of Technology

Venus has a similar density and chemical composition to Earth. There are few large craters on the planet, mostly because all but the largest impactors vaporize as they travel through the thick Venusian atmosphere.  The largest impactors create craters, which eventually get covered over by volcanic eruptions. Due to its hellish environment (and in particular its thick atmosphere and clouds) there is NO chance of life on Venus.

Venus Is a Hellish Place on the Surface

Pictures of Venus - Coronas in Fortuna
Pictures of Venus - Coronas in Fortuna. Copyright 1995-2003, California Institute of Technology

Venus' atmosphere is composed mostly of carbon dioxide. The surface of the planet is obscured by several layers of clouds many kilometers thick composed largely of sulfuric acid. The clouds help create a greenhouse effect that brings Venus' surface temperature to over 740 K.

Earth and Venus Surfaces are About the Same Age

Pictures of Venus - Bright Plains
Pictures of Venus - Bright Plains. Copyright 1995-2003, California Institute of Technology

Both Earth and Venus have relatively young surfaces, with Venus appearing to have been completely resurfaced some 300 to 500 million years ago. Venus is highly volcanic, which contributed to the resurfacing effort. 

Venus Was Once Thought of as a Star

Pictures of Venus - Corona
Pictures of Venus - Corona. Copyright 1995-2003, California Institute of Technology

Venus has long been known as the morning star (Eosphorus) and the evening star (Hesperus), and not just to the Greeks. Many cultures noted its appearance after sunset and before sunrise. 

Learn More about Venus's Year and Day

Pictures of Venus - Crater Perspective
Pictures of Venus - Crater Perspective. Copyright 1995-2003, California Institute of Technology

Venus takes 243 days to rotate once on on its axis, and 224 days to make one orbit around the Sun. That makes its day longer than its year. Besides that, it rotates retrograde, or "backwards" on its axis, spinning in the opposite direction of its orbit around the Sun. From its surface (if you could see through the clouds), the Sun would seem to rise in the west and set in the east.

Features on Venus are named for Cccomplished Women

Pictures of Venus - Crater with Streak
Pictures of Venus - Crater with Streak. Copyright 1995-2003, California Institute of Technology

Venus' features have received names of women from all of Earth's cultures, including Atalanta Planitia, Guinevere Planitia, Lavinia Planitia, Ishtar Terra, Aphrodite Terra, and Lakshmi Planum, among others.

Venus Has No Moons

Venus Globe - 10 Things You Should Know About Venus
Venus Globe. NASA

Between the 1670s and the 1770s, there were several observations of what appeared to be a satellite approximately a quarter the size of Venus. Many theories exist to explain these sightings, including optical illusions, stars, and even a tenth planet. Recent observations have not revealed any satellite.

Venus Has Been Visited by Many Spacecraft

Pictures of Venus - Twin Summit
Pictures of Venus - Twin Summit. Copyright 1995-2003, California Institute of Technology

Past probes to visit Venus included Mariner 2, Pioneer Venus Orbiter & Pioneer Venus Multiprobe (Pioneer 12 & 13), and Magellan while another mission, called Venus Express, was sent by the European Space Agency. Russian (Soviet) spacecraft landed on the surface and did short-term studies before succumbing to the strong heat and pressure.