Prepare to feel very, very small!
1. Our galaxy, the Milky Way, contains up to 400 billion stars. In the observable universe, there are more than 200 billion galaxies (some estimates put this figure at up to 500 billion) – each with billions or even trillions of stars within it.
This equates to roughly 100,000,000,000,000,000,000,000,000,000 stars in the observable universe.
Of the planets orbiting these stars, astronomers estimate that there are 50,000,000,000,000,000,000,000 (50 sextillion) habitable planets.
And remember – this is in the observable universe, so the real figures may be infinite… Still wondering whether extraterrestrial life is likely to exist?!
2. Many scientists believe in the multiverse – that there are an infinite number of parallel universes that exist alongside our own in other dimensions. This theory would explain some of the peculiarities of quantum mechanics. Detecting a parallel universe is one of the aspirations of the team of scientists working on the CERN Hadron Collider…
3. Planning a trip to outer space? Pack your bikini and your winter coat – solar winds and interstellar gas clouds can reach millions of degrees in temperature (ouch!) but the general background temperature of outer space is around -260C. Brrr!
4. The closest galaxy to our own is Andromeda. Measuring 140,000 light years across and 2.5 million light years away from Earth, if it were bright enough to be seen in the night sky, it would appear six times as large as the Moon.
5. Black holes form when massive stars collapse into themselves and condense their mass into an unbelievably small area. The tiniest are called primordial black holes – these are thought to be the size of an atom, but with the mass of a mountain! The biggest are supermassive black holes – they have masses greater than 1 million suns.
It’s thought that every galaxy has a supermassive black hole at its centre – the Milky Way’s is called Sagittarius A. It has a mass equal to 4 million suns – yet it would fit inside our own sun.
If a human were to become a black hole, that person would have to be compressed to the size of a proton.
6. It’s thought that, over the course of a year, 100 billion stars are born and die throughout the universe.
7. Astronauts returning from space have said that their spacesuits and gear smell like seared steak and hot metal – an odour that’s probably caused by the remnants of dying stars.
8. Back in the days when you’d turn your telly over to a badly tuned channel, the static, or ‘white noise’ you heard was made up of about one per cent radiation left over from the Big Bang. The proper name for this is Cosmic Microwave Background.
9. Space officially begins 62 miles above the earth, at the Karman line.
10. Cast into space on 5 September 1977, space probe Voyager 1 is the furthest man-made object from earth, at 11,136,538,637 miles away. In 1990, it took the first ever image of our solar system from the ‘outside’ – showing the Earth as a teeny-tiny blue pinprick.
The probe carries a gold-plated audio-visual disk that carries scientific information, greetings, photos, sounds, and music from Earth, should the probe ever be discovered by extraterrestrial life.
11. Neutron stars – a crushed core of a massive star with a small radius and extremely high density – can spin at up to 43,000 times a minute, and have a magnetic field one trillion times stronger than Earth.
They are one of the densest objects known – one teaspoon of matter from a neutron star would weigh as much as one billion tons.
12. Space is completely silent. Sound needs an atmosphere to travel through, and since space has no atmosphere, it has no sound. The biggest, most awe-inspiring exploding star wouldn’t even make a peep. Astronauts are able to communicate up there thanks to radio waves, which can travel through space.
13. Talking of atmospheres, the Moon doesn’t have one, either. So, the footprints made by the Apollo astronauts are likely to remain printed on the lunar surface for billions of years.
14. Space is almost a perfect vacuum. As a result, if two lumps of the same metal touch each other, they’ll meld together. This is because the atoms in each piece of material have no air separating them, so the lumps of metal have no way of knowing they’re two different pieces. Imagine the possibilities of construction in space with this handy effect!
Phew, that’s our mind blown then!