If you have never given much thought to the wonders of the universe – from the largest star to the most distant galaxies – you might be forgiven for thinking space is rather boring. For perhaps thinking that it was little more than a vast empty expanse that goes on forever. And that planets are lifeless rocks and the stars nothing more than bright dots with little more purpose than making clear nights look prettier.
But you’d be wrong, as the universe is brimming with incredible goings on! Here we look at some of the most mind-boggling things to be found beyond the borders of our little blue marble of a planet. They’re literally out of this world…
NOTE: Most astronomical distances are provided in light years. This is the amount of time it takes for light to travel in one year. Light is the fastest thing in existence, with a speed of 186,282 miles per second. Therefore, one light year is equal to approximately 5.8 trillion miles.
1. The Largest Star
The Sun is what’s known as a main sequence star, not unlike millions of other stars in our galaxy. It has a diameter of around 865,000 miles, making it about 109 times wider than the Earth. That’s pretty enormous.
However, one star currently believed to be the largest in the universe is VY Canis Majoris — which is 1,420 TIMES bigger than the Sun in terms of diameter. It lies approximately 3,900 light years from our own solar system, about 23,000,000,000,000,000 miles away (that’s 23 thousand trillion miles).
It is classed as a red hypergiant, and is drawing to the end of its lifetime. If it were to be placed in our own solar system, it would extend from where the sun sits beyond the orbit of Jupiter. Our own star will eventually reach the red giant stage of its life in a few billion years’ time, and while it will swallow Mercury, and probably Venus as well, it will never grow anything near as large as VY Canis Majoris.
The truth is humanity doesn’t actually know what the largest star in the universe is, as there may well be much larger stars than VY Canis Majoris out there hidden from our sight by other galaxies and space debris.
2. The Most Distant Galaxies
Galaxies are enormously large gravitationally-bound celestial clusters composed of many millions of stars and planets as well as nebulae of dust and gas. Our own star, the Sun, is one of at least a hundred-million in the Milky Way Galaxy.
The nearest large galaxy to ours is Andromeda, about 2.5 million light years away. However, the most distant galaxy observed so far by human kind is a staggering 13.37 billion light years away. Since it has taken the light so long to reach us from this distant point in space we are actually seeing how this galaxy looked and where it was not long after the Big Bang, the birth of the Universe and everything which we know exists.
We are seeing it when it was a protogalaxy, rather like our own Milky Way in the earliest stages of its formation. Where this galaxy is now is completely unknown because we are now 13.37 billion years ahead of what we’re seeing. Though due to the fact that the Universe is expanding, it is likely around three times further away today. On the other hand, it might not even exist anymore.
You can view some great galaxy images in our pic archive.
3. The Furthest Man-Made Objects from Earth
On September 5, 1977, the Voyager 1 space probe was launched from Cape Canaveral on a mission to explore the outer planets of our Solar System. It took the first close-up images of Jupiter and Saturn and their extensive systems of moons. Ever since then, Voyager 1 has been continuing on its voyage into the unending depths of space. Almost 40 years after launch, its plutonium-powered instruments are still sending data back to Earth, and should continue to do so until its last instruments shut down sometime around 2025.
Currently, it takes a staggering 17 hours for its broadcasts to reach Earth. Not only is Voyager 1 the furthest man-made object from Earth; it has broken the astounding record of becoming the first man-made object to leave our solar system and head out into interstellar space. It continues its remarkable journey travelling at a speed of eleven miles PER SECOND relative to the Sun, but even at these speeds, it would still take 72,000 years to reach the next nearest star to our own, if it were headed in that direction.
4. The Fastest Man-Made Object
If you think eleven miles per second seems speedy, consider the Helios 1 and Helios 2 space probes. Launched in 1974 and 1976 respectively, these probes were sent in orbit of the Sun to study solar processes. They are both travelling at around 43 MILES per second on their joyrides through the Solar System. That is around 157,000 miles per hour. Although launch speeds were far lower than this, the probes accelerated enormously due to gravitational assists from the Sun.
The fastest launch speed ever achieved was that of the New Horizons space probe, sent in 2006 to study Pluto and its moons. By the time the last engine of its launcher had been shut down, it achieved a speed of ten miles per second. Keep in mind that a minimum speed of around seven miles per second is required to escape Earth’s gravitational forces and reach orbit.
5. Fastest Hypervelocity Star
The Sun potters around the centre of the Milky Way galaxy at 136 miles per second. Even at these speeds however, our solar system completes one galactic year — the time it takes to completely orbit the center of the Milky Way — every 225-250 million Earth years. Hypervelocity stars are a completely different matter, however. These stars are moving so quickly that they are even able to escape the gravitational forces of their own galaxies and end up in the vast intergalactic medium. Obliterating anything unfortunate enough to stand in their way, hypervelocity stars can move at speeds of up to two-million miles per hour. One of the fastest hypervelocity stars is located in the constellation of Hydra, currently breaking away from the galaxy at 1.5 million miles per hour.
From the size of the largest star to trying to comprehend the size of the universe, this is truly mind-boggling stuff. If you have any incredible space facts to share with the world — and the rest of the universe — make sure to add them in the comments section below!