We have exactly one world, in all the universe, that we know for a fact to be hospitable to life: our world.
So when we search for habitable planets in other planetary systems, outside our own corner of the galaxy, we often use Earth as an ideal.
But a new study has revealed that Earth isn’t nearly as habitable as it could be. In fact, it could be more livable, if JupiterIts orbit shifted a little.
It is an important study because tHere are the many moving parts and components of the Solar System, and knowing which ones contribute to Earth’s habitability is very difficult.
It can also help us better understand what makes the world habitable.
“If Jupiter’s position remains the same, but the shape of its orbit changes, it may actually increase the habitability of this planet,” Planetary scientist Pam Vervoort says: from the University of California, Riverside.
“Many are convinced that the Earth is an example of a habitable planet and that any change in the orbit of Jupiter, being the massive planet, can only be harmful to the Earth. We show that both assumptions are wrong.”
The findings also have implications for the search for habitable worlds outside the solar system, by providing a new set of parameters with which to assess potential habitability.
Although we don’t currently have any instruments that can definitively measure the habitability of an exoplanet – planets orbiting stars outside our solar system – scientists have put together a collection of worlds that we should take a closer look at, based on several characteristics.
The first is where the exoplanet is in relation to its host star—it should be not too close for any surface liquid water to evaporate, and not too far away for the water to freeze.
Increasingly, it seemed that a Jupiter-like gas giant in the same system might be a good indicator of habitability. But there seem to be some caveats.
In 2019 the international team of researchers published a study Where they showed, based on simulations, that changing the orbit of Jupiter can make the entire solar system unstable very quickly.
More simulations have now shown that the opposite could be true, which will help narrow the range of gas giant orbits that aid or hinder habitability.
The study was based on the eccentricity of Jupiter’s orbit – the degree to which this orbit is rectangular and elliptical.
Currently, Jupiter has a very little elliptical orbit; It is almost circular.
However, if this orbit were to extend, it would have a very noticeable effect on the rest of the solar system. This is because Jupiter is massive, 2.5 times the mass of the rest of the planets in the solar system combined.
So, adjusting Jupiter’s central eccentricity, and the gravitational effect it will have on other planets is real.
For the Earth, this also means an increase in eccentricity. This means, the researchers found, that some parts of the planet will come close to the sun, heating up in a moderate, habitable range.
But if you move Jupiter closer to the sun, the habitability of the Earth will be affected. This is because it will cause our home planet to tilt more sharply on its rotation axis than it currently does, a feature that gives us seasonal changes.
However, a steep tilt would cause large parts of our planet to freeze, with more extreme seasons. Winter sea ice extends to an area four times larger than it currently is.
These results can be applied to any multi-planetary systems we find, the researchers said, to assess them in relation to their habitability.
But they also highlight the number of factors that may have influenced our presence here on our pale blue dot – how well we may have never existed at all. And what would happen to the solar system if it destabilized.
The presence of water on its surface [is] The first scale is very simple, and does not take into account the shape of the planet’s orbit, or the seasonal changes that the planet may experience,” Astrophysicist Stephen Kane says: from the University of California, Riverside.
“It is important to understand Jupiter’s influence on Earth’s climate through time, how its influence has changed our orbit in the past, and how it may change us again in the future.”
The search was published in Astronomical Journal.