What galaxy are we in?
We’re part of the ‘Milky Way’ galaxy but there are lots of other galaxies (and different types of galaxies) out there in the Universe. The Sun in our solar system is only one of the estimated 100 billion Suns (or stars) that live in the ‘Milky Way’ galaxy.
And what’s a galaxy?
A galaxy is a large group of stars (like our Sun), gas and dust (like the planets in our solar system and in the billions of other solar systems in our galaxy) that are all bound together by the mighty force of gravity.
How many galaxies are there?
We think there are billions of other galaxies in the Universe. From the Earth, we can only see three other galaxies outside the Milky Way without a telescope, which are the Large and Small Magellanic Clouds (about 160,000 light years away) and the Andromeda Galaxy (around 2.5 million light years away). All of the other galaxies are much further away, so they can only be seen through telescopes.
What makes up our solar system?
Our solar system is made up of the Sun, planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) and all other objects like the dwarf planets (Pluto), asteroids, meteorites and comets.
How old is our solar system?
It is thought that our solar system, based on the age of the Sun is estimated to be about 4.5 billion years old – that’s a lot of birthdays.
Have we sent anything outside our solar system?
Yes, we have. In August and September 1977, two spacecraft were launched from Earth named ‘Voyager 1’ and ‘Voyager 2’. Both of these tough little spacecraft are still in operation over 40 years later. They have both travelled further than any other object ever made by humans in history.
In August 2012, Voyager 1 left our solar system, the first human-made object to do so, and is currently travelling through interstellar space. Voyager 2 isn’t that far behind, relatively speaking, and in May 2018 is on the very edge of our solar system and is almost dipping its robotic toe in interstellar space.