Don’t let the cold weather fool you, as our planet has made its closes approach to the sun on Thursday at 12:19 a.m. Eastern time. This is the point known as perihelion, and it is the time of the year when our planet gets closer to the Sun than ever. Ironically enough, it also reaches its farthest point in July (and that point is known as aphelion).
During the perihelion, Earth gets three million miles closer to our star than during summer. This might seem a lot, but the truth is that this distance is not that vast in the solar system. Our planet has an elliptical orbit, but according to most astronomers, the path can be considered almost circular. While not a perfect circle, it is definitely closer to a circle than an oval.
Is this circular orbit vital for us?
Many astronomers seem to believe that this circular orbit might be in fact the reason why our planet can hold life. An oval orbit could be incredibly devastation for an Earthlike planet. During the point where it approaches the star, that planet will lose its oceans by evaporation, as well as its planet. Major volcanic eruptions will be caused, as well as huge tides. Meanwhile, when reaching its farthest point from the star, the planet would simply freeze.
“This incredible seesaw of extreme conditions would devastate the planet, and I expect that it would not take very long for the planet to become a desiccated, barren rock,” said Stephen Kane, an astronomer at the University of California, Riverside.
Nonetheless, this doesn’t necessarily mean that exoplanets couldn’t hold life. It appears that rocky planets do have in fact circular orbits, so they might have a stable climate and host life after all.