Even less feasible than permanently changing Earth’s climate with tiny amounts of trace gases, but theorists have ideas to test.
– – –
We have exactly one world, in all the Universe, that we know for a fact to be hospitable to life: ours, says Science Alert.
So when we’re looking for habitable planets in other planetary systems, beyond our own corner of the galaxy, we often use Earth as the perfect template.
But a new study has revealed Earth isn’t as habitable as it could be. In fact, it could be even more livable, if Jupiter’s orbit shifted slightly.
It’s an important study because there are many moving parts and ingredients in the Solar System, and figuring out which ones contribute to Earth’s habitability is extremely tricky.
It could also help us better understand what makes a habitable world habitable.
“If Jupiter’s position remained the same, but the shape of its orbit changed, it could actually increase this planet’s habitability,” says planetary scientist Pam Vervoort of the University of California, Riverside.
“Many are convinced that Earth is the epitome of a habitable planet and that any change in Jupiter’s orbit, being the massive planet it is, could only be bad for Earth. We show that both assumptions are wrong.”
The results also have implications for the search for habitable worlds outside the Solar System, by providing a new set of parameters by which potential habitability can be assessed.
Although we don’t currently have any tools that can conclusively gauge the habitability of an exoplanet – planets that orbit stars outside our Solar System – scientists have been collecting a population of worlds at which we ought to take a closer look, based on several characteristics.
The first is where the exoplanet is in relation to its host star – it needs to be at a distance not so close that any surface liquid water would evaporate, nor so distant that the water would freeze.
The second is the size and mass of the exoplanet – is it likely to be rocky, like Earth, Venus, or Mars? Or gassy, like Jupiter, Saturn, or Uranus?
Increasingly, it has seemed that a Jupiter-like gas giant in the same system might be a good indicator for habitability. But there seem to be some caveats.
In 2019, the international team of researchers published a study in which they showed, based on simulations, that altering the orbit of Jupiter could very quickly make the entire Solar System unstable.
Now more simulations have shown that the opposite can be true, which will help narrow down the range of gas giant orbits that help or hinder habitability.
The study was based on the eccentricity of Jupiter’s orbit – the degree to which that orbit is elongated and elliptical.
Currently, Jupiter has only a very slightly elliptical orbit; it’s almost circular.
Full article here.
via Tallbloke’s Talkshop
September 12, 2022 at 05:46AM