Venus
Days on Venus seem endless. Venus is
the second planet from the Sun. One day on Venus is as long as 243 days on
Earth. A year on Venus is only 225 Earth days long. So a day on Venus is longer
than a year!
WHY DOES VENUS HAVE LONG DAYS?
Venus orbits, or goes around, the
Sun just as all the planets do. It takes Venus 225 days to go around the Sun.
Earth goes around the Sun in 365 days. We call the time it takes Earth to go
around the Sun a year.
Venus also spins around on its
axis. An axis is an imaginary line going through a planet from top to bottom.
Every planet spins on its axis. One day on Earth is the time it takes for Earth
to turn completely around on its axis. Earth turns once every 24 hours. Venus
turns much more slowly. It takes Venus 243 Earth days just to turn once.
Venus also spins backwards around
its axis. It spins in the opposite direction that Earth spins. On Venus, the Sun
rises in the west and sets in the east.
WHAT IS VENUS LIKE?
Venus is more like Earth in some
ways than any other planet. It is almost the same size as Earth. It is a similar
distance from the Sun compared to the other planets. It is made mostly of rock
and has an atmosphere (gases that surround a planet).
Venus has flat plains and high
places, just like Earth. It has huge extinct (dead) volcanoes and big
craters. Meteorites crashing into the planet made the big craters. But Venus has
no moon.
In other ways, Venus is not at
all like Earth. It is not a place you would like to visit. The atmosphere is
poisonous. It is made up mainly of a gas called carbon dioxide. The clouds are
filled with drops of powerful acid “rain” that would eat through your
clothes—and through you. The atmosphere is so thick that its weight would crush
you. There is no water on Venus.
It is very hot on Venus. The
temperature on the surface is about 864° Fahrenheit (462° Celsius). That’s more
than four times as hot as boiling water. No plants or animals could live in a
place that hot.
WHY IS VENUS SO HOT?
The thick atmosphere of Venus
keeps the planet hot. The carbon dioxide in the atmosphere of Venus is called a
greenhouse gas. It acts like the glass in a greenhouse. Greenhouse glass traps
heat from the Sun. The heat keeps a greenhouse warm all year long.
Earth has just enough carbon
dioxide in its atmosphere to keep our planet warm enough for life. Venus has too
much carbon dioxide. Venus traps too much heat from the Sun. This makes Venus
too hot for anything to live there.
HOW DO WE LEARN ABOUT VENUS?
People in ancient times knew about
Venus. They could see Venus when they looked up at night. Venus is brighter than
any object in the sky other than the Sun and the Moon. Sometimes Venus is the
first object to appear in the sky as it gets dark. Sometimes Venus is the last
object to fade in the morning light. The ancient Romans called Venus the morning
star or the evening star. They named Venus for the ancient Roman goddess of love
and beauty.
Venus was the first planet to be
visited by spacecraft. A United States spacecraft named Mariner 2 flew by Venus
in 1962. Many spacecraft have visited Venus since then. These spacecraft carried
instruments to take measurements. Some of them carried radar to see through the
thick clouds on Venus. Radar “sees” with radio waves. Some U.S. and Russian
spacecraft landed on Venus.
The spacecraft that landed on Venus
had to plunge through thick clouds filled with sulfuric acid. They had to
survive lightning flashes and powerful winds. The weight of the planet’s
atmosphere crushed the spacecraft, and the heat on Venus baked them. Some
spacecraft sent back pictures and measurements before they stopped working.
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Space
