It’s a question which has fascinated fans of the Big Bang theory for years, but the answer is a surprisingly simple one: it depends on where you live.
The planets closest to the sun and the ones furthest from it are most likely to be inhabited, while the ones farthest away are more likely to have been destroyed.
This means that if you live in the Canary Islands, for example, you’re more likely than your local resident to live in a planet which is either one of the planets closest or the farthest from the sun.
It also means that the most populated planets are those that have been formed through the rapid fusion of stars and planets.
These planets, known as exoplanets, are the ones that have formed after a huge bombardment of massive objects, including massive planets and supermassive black holes.
“There are some planets that are quite close to the stars, or close to their stars, that have planets which are very rocky,” explained Professor Daniel Fuchs, a planetary scientist at the University of Washington in Seattle, USA.
“But those are probably less common, because we can’t get to them very often.”
What is more, we can only see the atmospheres of planets that have experienced the same amount of radiation as Earths.
That’s because Earths atmosphere is so thin that we can see just a tiny fraction of the wavelengths of light which the planet emits, which is why Earths infrared light is so faint.
Planet hunters have found hundreds of planets around stars in the habitable zone, the region where liquid water can exist on a planet, but there are only a handful of planets in the middle of the habitable zones.
These planets are mostly icy and rocky, which means that their atmospheres are mostly made of hydrogen, helium and methane, all of which are elements heavier than water.
“When you see a planet with water ice, you don’t know if it’s rocky or icy,” said Professor Fuchs.
“You don’t even know if there’s a planet at all.”
But the biggest planet hunters have been searching for are the exoplanet candidates which are the closest to their star.
These are planets which orbit the stars closest to them, which are some of the most massive stars in our Milky Way galaxy.
These worlds are in the range of Earth’s orbit, so their atmospherics are probably much thinner, and they also orbit in the constellation of Aquarius, which stands for the animal-headed constellation.
“They’re the planets that we could possibly find with our current technology, and that’s the biggest surprise,” said Fuchs about the planet hunters’ success in finding the worlds with atmospheres that are so thin.
“I’m very excited by it.”
What do these worlds look like?
The planets are all made up of ice, and the planets are in this order.
The closest is Neptune, and then the next are Jupiter and Saturn, which lie between Earth and Mars.
The furthest are Uranus, Neptune and Pluto.
The planets’ sizes are given in astronomical units, and their rotations are given as degrees.
The easiest way to tell them apart is to look at the stars that they orbit.
They are the stars of the Orion Arm, the constellation that we are familiar with from movies like The Hitchhiker’s Guide to the Galaxy.
These stars are the brightest in the night sky, and we can detect them in the ultraviolet part of the spectrum, when light is emitted by hydrogen and helium atoms and is scattered by the atmosphere.
“It’s actually really easy to see if a planet is rocky, because there’s so little light in the UV spectrum,” said Tom Anderson, a PhD candidate at the Universidad Nacional Autónoma de México, Mexico, and a member of the team of astronomers who studied the planets in their infrared spectrum.
“We know what is the color of the light in our visible spectrum, so we can tell what kind of atmosphere that planet has.
It’s not as simple as we might expect, because the planets can be quite different in that wavelength spectrum.””
You can also tell if there is water in the atmosphere,” said Anderson.
“The atmospheres will be slightly different, but I think it’s reasonable to assume that the atmospheria would be different for the rocky planets.”
What about the atmosphers of the other planets?
As well as the atmosphedra of the stars we see in the sky, the atmospheys of other planets are also different.
“You might see methane, and water, and hydrogen in the same atmosphere,” explained Fuchs of the atmosphest planets, “but what we know about the gas is not very good.
So if you see methane or water in a gas-rich environment, it’s probably a rocky planet.””
It depends on the distance between the stars,” added Anderson.