Our Solar System: Planets is part of an eTwinning project entitled AStronomy for Kids. It has been created by the students of all partner countries, including Romania, Greece and Turkey.

Preview audio:

storyj.mp/acdu9533nu8b

THE SUN

The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma. It is by far the most important source of energy for life on Earth.

The Sun was thought of by some cultures as a deity. The synodic rotation of Earth and its orbit around the Sun are the basis of some solar calendars.

Did you know that....

...you can fit 1.3 million Earths inside the Sun?

...the temperature in the centre of the Earth is as high as the temperature on the surface of the Sun?

Mercury is the smallest planet in the Solar System and closest to the Sun. With an orbit equal to about 88 Earth days, it is faster than any other circle in the Solar System. Viewed from Earth, the system appears to orbit every 116 days. It has no known natural satellites.

Apparent magnitude: −2.48 to +7.25

Confluence period: 115.88 g

Major axis: 0.387098 AU; 57,909,050 km

Volume: : 6,083 × 1010 km3; 0.056 Earth

Did you know that....

...Mercury has the most craters in the Solar System?

...Mercury was named after the Greek god of commerce?

MERCURY

VENUS

It is the twin of our planet. (It's about the same size as Earth.)

Venus is also called the Shepherd's Star. It has no moons and no rings.

It is a very hot planet due to the greenhouse effect, due to the intense carbon dioxide in its atmosphere. (400 °C)

It is an inner and terrestrial planet. Unlike other planets, Venus rotates from east to west.

It is the second closest planet to the sun. It is the sixth largest planet in size.

Did you know that...

...a day on Venus is longer than a year on Earth?

... Venus is the second brightest natural object in the night sky after the Moon?

EARTH

The Earth is the planet we live. It's a green blue planet. It has one Moon.

The Earth orbits the Sun and rotates on its axis every 24 hours, defining day and night for surface citizen.

Earth's interior—which is made mostly of silicate rocks and metals—differentiates into four layers.

Earth's atmosphere nourishes life on Earth, but it also protects it.

Did you know that...

... Earth is not a perfect sphere?

... Earth is struck by lighting 100 times per second?

... Earth is 4.54 billion years old?
... Earth has an uneven gravitational field?

MARS

Mars is the fourth planet from the Sun and the second-smallest planet in the solar system. In English, Mars carries the name of the Roman god of war and, because of its colour, is often called the "Red".

Mars can easily be seen from Earth with the naked eye, as can its striking reddish colour. It is among the brightest objects in Earth's sky.

Mars is a terrestrial planet.

Did you know that...

... Mars the second planet with ice at its poles?

... a year on Mars lasts 687 days, that is 1 year and 9 months on Earth.

... Mars has clouds?

...Mars has two small and irregularly shaped moons, Phobos and Deimos.

....Mars has been explored by several uncrewed spacecraft, beginning with Mariner 4 in 1965!