Venus, Mercury and Mars

Pic: Wikipedia

The Venus

Along with Earth and Mars, Venus and Mercury make up the inner planets. These planets all have an atmosphere, but each is very different. Mercury orbits the Sun at a distance of 46-70 million kilometres, while Venus has an average distance from the Sun of 108 million kilometres.

Why is Venus called the evening star?

Venus reflects sunlight so well that it shines like a star. Because it is quite close to the Sun, we can see it in the evening, just after the Sun sets. We can also see it just before sunrise.

'Venus is the second

brightest object in the

night sky,

after the Moon.'

What are the inner planets made of?

Each of the inner planets is formed a little bit like an egg with a hard 'shell' or crust of rock, a white or mantle of soft, semi-molten rock, and a yolk or core of hot, often molten, iron and nickel.

What is the atmosphere like on Venus?

Venus' atmosphere would be deadly for humans. It is very deep, so the pressure on the ground is huge. It is made mainly of poisonous carbon dioxide and is also filled with clouds of sulphuric acid.

The Mercury

Could you breath on Mercury?

Not without your own oxygen supply. Mercury has almost no atmosphere - just a few wisps of sodium because gases are burned off by the nearby Sun.

Mercury's surface is pitted

with craters like the Moon.

It also has mountains and

valleys.

How hot is Mercury?

Temperatures on Mercury veer from one extreme to the other because it has too thin an atmosphere to insulate it. In the day, temperatures soar to 430°C and at night they plunge to -175°C.

Have any spacecraft visited Mercury?

Only two unmanned spacecraft have been close to Mercury. Approaching the planet is difficult because it lies so close to the Sun.

The Mars

The fourth of the inner planets is Mars, which orbits the Sun every 687 days. It is often called the 'Red Planet' because of its reddish appearance. Martian temperatures range from -140°C during winter at its poles to up to 20°C during its summers.

Why is Mars red?

Mars is red because it is rusty. The surface contains a high proportion of iron dust, and this has been oxidized by small amounts of oxygen in the atmosphere.

'Martian Soil - The soil on Mars

is similar to Earth's.

But

the dust is often whipped up

into huge dust storms

that can cover

the whole planet.'

Is there life on Mars?

In the 1970s, unmanned landers of the Viking missions found no trace of life. Then, in 1996, microscopic fossils of what might be mini-viruses were found in a rock from Mars. But these turned out not to be signs of life after all.

Who discovered Mars's Moons?

In 1877, American astronomer Asaph Hall decided to have an early night. But his wife encouraged him to stay up and work - and that night he discovered Mars' two moons. He named them Phobos and Deimos after the attendants of the Roman war god, Mars.

Will humans ever land on Mars?

Both the United States and the European Space Agency have announced that they plan to send manned missions to Mars within the next 30 years.

Which canyon is bigger than the Grand Canyon?

A canyon on Mars! The planet has a great chasm, discovered by the Mariner 9 space probe and called the Valles Marineris. It is more than 3000 kilometres long and four times as deep as the USA's Grand Canyon. It is the largest known chasm in the Solar System.

'Valles Marineris - As Mars cooled

after its formation,

this giant canyon

opened up.'

Where is the biggest volcano?

Mars has a volcano called Olympus Mons which is 25 kilometres high - three times higher than Mount Everest. It was created by lava welling up beneath Mars' surface.

'Olympus Mons - This volcano is

the highest mountain

in the solar system

and is just one of

many volcanoes

on the planet.' 

✒️. collected by: Uttar Tamang