1. Planetary system 

Planetary systems are structures with one or more planets. Apart from planets, such systems may also include dwarf planets, asteroids, natural satellites, meteors, comets, and features such as disks around some planets. The Sun together with its orbiting planets, including Earth, is an example of such a planetary system. Nowadays, scientists know that hundreds of planetary systems exist in space, but they still understand little about how they were created.

2. Star cluster

Star clusters are large groups of stars. They can be tight groups of ten thousand to millions of old stars, or they might be more loosely clustered groups with generally less than a few hundred stars, often in their early stages of development. This means they are often very young. The stars within a cluster all originate from the same source and are connected by gravitational forces.

3. Asteroid

An asteroid is a minor planet of the inner Solar System. Their sizes and shapes are very different. They may be 1‑metre rocks or dwarf planets that are as big as 1,000 km. Asteroids orbit the Sun and are made of metal or rock. Of the roughly one million known asteroids the greatest number of them are located between the orbits of Mars and Jupiter.

4. Moon

Moons are large, round objects that circle around planets other than Earth. Some planets have several moons, while Earth has only one. The Earth’s Moon is about one‑quarter of Earth in size. In the Solar System, it is the fifth largest satellite.

5. Comet

A comet is an icy, small Solar System body. When it passes close to the Sun, it warms and begins to release gases and dust. This is what we commonly call a comet’s tail. Comets also come in different sizes. They range from a few hundred metres to tens of kilometres across and they are composed of ice, dust, and small pieces of rock. If a comet is sufficiently bright, you may see it from Earth without a telescope.

6. Black hole

A black hole is a region of space where gravity is so strong that nothing can escape it– not even electromagnetic radiation such as light. The boundary of no escape is called the event horizon. Black holes have no features that you can detect - they have no shape or colour. But, they definitely have a great effect on an object crossing them. You should know that there is a supermassive black hole at the centre of our galaxy. It’s called Sagittarius A* and it has a mass of 4 Suns. However, it does not pose any threat to Earth.

7. Meteorite

A meteor is colloquially known as a shooting star. It is nothing else but a passage of a small, glowing piece of rock through Earth's atmosphere. Such stranded pieces of rocks in space are called meteorites. How are they formed? They may come into being as a result of asteroids smashing into each other. Millions of meteorites occur in Earth's atmosphere daily. The moment they enter our planet’s atmosphere they vaporize and turn into meteors visible as streaks of light in the sky.

8. Supernova

A supernova is a powerful and luminous explosion of a star. The brightest moments of a supernova can be comparable to that of an entire galaxy. The last supernova to be directly observed in the Milky Way took place in 1604. Observations of supernovae in other galaxies suggest they occur in the Milky Way on average about three times every century.