Saturday 22 February 2014

The Earth's Neighbours Planet

The Earth’s Neighbours Planet

Venus and Mars are the nearest planets to the Earth

Venus is closer to the Sun than the Earth while Mars is farther away. Each takes a different amount of time to circle the Sun and we call this its year. A year on Venus is 225 days, on Earth 365 days and on Mars 687 days.

(All we can see of Venus from space are the tops of its clouds. They take Just four days to race right around the planet.)

Venus has poisonous clouds with drops of acid that would burn your skin.

They are not like clouds on Earth, which are made of droplets of water. These thick clouds do not let much sunshine reach the surface of Venus.

(Under its clouds, Venus has hundreds of volcanoes, large and small, all over its surface. We do not know if any of them are still erupting.)

Venus isthe hottest planet.

It is hotter than Mercury, although Mercury is closer to the Sun and gets more of the Sun’s heat. Heat builds up on Venus because it is completely covered by clouds which trap the heat, like the glass in a greenhouse.

Winds on Mars whip up huge dust storms that can cover the whole planet.

Mars is very dry, like a desert, and covered in red dust. When a space probe called Mariner 9 arrived there in 1971, the whole planet was hidden by dust clouds.

(Mariner 9 was the first space probe to circle another planet. it sent back over 7000 pictures of Mars showing giant volcanoes, valleys, ice caps and dried-”Up river beds.)

Mars has the longest volcano in the Solar System.

It is called Olympus Mons and is three times as high as Mount Everest, the tallest mountain on Earth. Olympus Mons is an old volcano and it has not erupted for millions of years.

There are plans to send I astronauts to Mars but the journey would take six months or more.

The astronauts would have to take with them everything they need for the journey there and back and for their stay on Mars.