Modelling has shown that slightly increasing the eccentricity of Jupiter's orbit could improve Earth's climate and make many regions of our planet more habitable.
So far we only know of one habitable planet, our own Earth. Not surprisingly, scientists are focused on it in their search for other worlds suitable for life. While some work shows that Earth may not be ideal, some "super inhabited" planets provide even more comfortable conditions. Earth itself could become more habitable - just change Jupiter's orbit a little.
Astronomers look for potentially habitable worlds based on a number of characteristics of a distant planet. First of all, it is the distance from its parent star: it must be such that the planet is not too hot, but also does not freeze completely, and the surface could be preserved liquid water. The second criterion is the size and mass of the planet, which should not be much larger than on Earth. So far, we cannot imagine that life could appear on a gas giant like Saturn or Jupiter.
Other criteria that are considered important for life on Earth - such as the presence of a large satellite, which stabilises the planet's rotation around its axis and causes the ebb and flow of the tide - may also be involved. Jupiter is sometimes added to this list, weighing many times more than all the other planets in the solar system combined and having a major influence on their orbits. It has been suggested that had Jupiter moved only slightly differently, life on Earth might not have appeared at all.
This influence has been assessed by Pam Vervoort and her colleagues at the University of California, Riverside. By simulating a system of gravitationally bound bodies, astronomers have tracked Earth's movements under conditions if Jupiter's orbit were closer to it - and to the Sun. Calculations showed that such a situation was not very favourable for life, as it increased the tilt of the Earth's axis of rotation. Today it ensures the alternation of the seasons, but a larger tilt may cause excessive temperature variations.
On the other hand, a small change in eccentricity of the orbit of Jupiter itself - without changing its radius - could only benefit. In reality, the orbit of the gas giant is nearly perfectly circular, but if it were slightly extended, so would the orbit of Earth. Modelling by Pam Verwoort and her co-authors has shown that such a change could make the climate of many regions of our planet milder and more suitable for life than it is now.
"Many people are convinced that Earth is the pinnacle of habitable planets, and that any change in the orbit of massive Jupiter would only make it worse," says Pam Verwoort. - "We have shown that both of these assumptions are wrong. Of course, it is unlikely that these findings will ever lead humanity to engage in an orbital 'realignment' of the solar system. But they will allow a more accurate assessment of the potential habitability of planets near other distant stars.