The two largest planets, Jupiter and Saturn, have nearly the same chemical makeup as the Sun; they are composed primarily of the two elements hydrogen and helium, with 75% of their mass being hydrogen and 25% helium. On Earth, both hydrogen and helium are gases, so Jupiter and Saturn are sometimes called gas planets.

Halley’s Comet is arguably the most famous comet. It is a “periodic” comet and returns to Earth’s vicinity about every 75 years, making it possible for a human to see it twice in his or her lifetime. The last time it was here was in 1986, and it is projected to return in 2061.

We live in one of the arms of a large spiral galaxy called the Milky Way. The Sun and its planets (including Earth) lie in this quiet part of the galaxy, about half way out from the centre

About 4.6 billion years ago, this gigantic cloud was transformed into our Sun. The processes that followed gave rise to the solar system, complete with eight planets, 181 moons, and countless asteroids.

The Andromeda Galaxy, also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy approximately 2.5 million light-years from Earth and the nearest large galaxy to the Milky Way

Venus shines so brightly that it is the first “star” to appear in the sky after the Sun sets, or the last to disappear before the Sun rises. Its orbital position changes, thus causing it to appear at different times of the night throughout the year.

Olympus Mons is an enormous shield volcano on the planet Mars. The volcano has a height of over 21.9 km as measured by the Mars Orbiter Laser Altimeter. Olympus Mons is about two and a half times Mount Everest’s height above sea level.

It is believed that Uranus exhibits an orbit with a tilt like no other planet. The tilt makes the planet spill out a lot of heat into the space thus retaining very little. Consequently it becomes colder than the other planets

Earth is located in one of the spiral arms of the Milky Way (called the Orion Arm) which lies about two-thirds of the way out from the center of the Galaxy. Here we are part of the Solar System – a group of eight planets, as well as numerous comets and asteroids and dwarf planets which orbit the Sun.

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger than only Mercury. This planet is much closer than the ones listed above.