Are there other planets like Earth?

 No, we don’t know of any other planets exactly like Earth, with its unique life forms. But Earth has similarities to three other planets orbiting the Sun – Mercury, Venus, and Mars. All four are made of rock and metal, orbit close to the Sun, and have relatively hot surfaces. They are known as the terrestrial or rocky planets.

Mercury

Mercury is named after the Roman messenger to the gods because of its speedy movement. It is the smallest planet – Earth is 2.5 times bigger. It is also the densest planet, with a huge iron core. The temperature of Mercury ranges from 430 degree Celsius in the day to -180 degree Celsius at night. The planet has a dark, dusty, surface, covered with craters and unchanged for a billion years.

Venus

Venus is the easiest planet to see in Earth’s sky. Look out for it in the east just before sunrise and in the west just after sunset. It looks like a brilliant star and is nicknamed the “morning star” and “evening star”.

Venus is named after the Roman goddess of love and beauty. It is surrounded by dense clouds stretching up to 80 km above the surface. The clouds are made of dilute sulphuric acid droplets and reflect 80 per cent of the sunlight, making Venus overcast. Heat is trapped by the clouds in the same way glass traps heat in a greenhouse. Venus has hundreds of volcanoes and about 85 per cent of the planet is covered in volcanic lava. The biggest are shallow shield volcanoes, like those in Hawaii on Earth. 

I don’t believe it!

A Venusian day is longer than a Venusian year. Venus is the slowest spinner of all the planets, taking 243 days to spin once. But as it spins it travels on its orbit around the Sun once every 224.7 days. The time between one sunrise and the next is 117 Earth days.

Martian myths

  Ø  In the 1870s, as Italian astronomer was mistranslated, which led people to believe he had seen             canals on Mars built by Martians.

  Ø  When a radio version of the H G Wells book War of the Worlds was broadcast in 1983, listeners         panicked because they thought they had tuned into a news alert and that Martians had landed on         Earth.

  Ø  Photographs taken by spacecraft in 1976 seemed to show a 3.2 km long human face on Mars’               surface. It later proved to be a huge rock formation.

  Ø  About 50 years ago, astronomers studying Mars’ moon Phobos concluded it was artificial – a metal     hollow sphere made by Martians.

I don’t believe it!

Olympus Mons is the largest volcano on Mars, and in the Solar System. It is 24 km high and 648 km across.

Just over 100 years ago, a large money prize was offered for the first person to communicate with an extra-terrestrial. Mars was excluded from the competition, because it was thought that getting in touch with Martians would be too easy.

Life on Earth

  Ø  Earth is the only place in the Universe where life is known.

  Ø  It is home to 1.5 million distinct forms of life and more are being discovered all the time.

  Ø  Earth is just far enough away from the Sun for liquid water and life to exist. If it were any closer,         Earth would be too hot, any further away, and it would be too cold. 

  Ø  More than 70 per cent of Earth is covered in water. If the planet was perfectly smooth its surface         would be covered with a layer 2.8 km deep.

  Ø  Earth has just the right temperature for its water to be liquid. Mercury and Venus are too hot, and        their water has evaporated. Most of Mars’ water if frozen beneath the surface.

Share on Google Plus

About sammaurya

I am computer and web application programmer. I love working with latest gadgets and tech.