The universe began in a tremendous explosion known as the Big Bang. A period of darkness followed, until about a few hundred million years later - when the first objects flooded the universe with light…

The first stars were much bigger and brighter than any in our nearby universe. These stars first grouped together into mini-galaxies and then merged to form mature galaxies like our own Milky Way.

Then the Sun and the entire Solar System were formed from a collapsing cloud of gas and dust which was twisting through the universe without direction or form.

These whirling solids stuck together to form big clusters of mass. Gradually they got larger and larger, sweeping up all the leftover dust, until they grew into the planets we recognize today.

Mercury is the closest planet to the Sun and has no natural satellites. Mercury's very tenuous atmosphere consists of atoms blasted off its surface by the solar wind.

Venus is close in size to Earth and, like Earth, has an iron core. It’s much drier than Earth, and its atmosphere is ninety times as dense.

Earth is the largest of the inner planets and the only place where life is known to exist. Earth's atmosphere is radically different from those of the other planets, having been altered by the presence of life. It has one natural satellite, the Moon.

Mars, smaller than Earth and Venus has an atmosphere of mostly carbon dioxide. Its surface, peppered with vast volcanoes, is red in colour from rust. Mars has two moons Deimos and Phobos thought to be captured asteroids.

Jupiter is 2.5 times the mass of all the other planets put together. It is composed largely of hydrogen and helium. Jupiter has 79 known moons.

Saturn is distinguished by its extensive ring system. Saturn is the only planet of the Solar System that is less dense than water. Saturn has 82 confirmed satellites composed largely of ice.

Uranus is the lightest of the outer planets. Uniquely among the planets, it orbits the Sun on its side. It has a much colder core than the other giant planets and radiates very little heat into space.

Neptune, though slightly smaller than Uranus, is more more dense. Neptune is accompanied in its orbit by several minor planets, termed Neptune trojans, that are in 1:1 resonance with it.

The dwarf planet Pluto was considered to be the ninth planet. Pluto has a relatively eccentric orbit. Charon, the largest of Pluto's moons, is sometimes described as part of a binary system with Pluto, as the two bodies appear to orbit each other

3.5 billion years ago life evolved on Earth.

All life tends to increase: more organisms are conceived, born, hatched, germinated, sprouted, or produced by cell division (or other means) than can possibly survive.

Today there are 7.5 billion people on earth. And you are one of them.