Remember when grandparents and old people, in general, said that they’d seen a ‘falling star’? While it might sound stupid to you now, after accumulating astronomical information, there is somehow a bit of truth in such an expression. Some astronomers have long suspected that there is a strong correlation between stars and comets, but they weren’t sure until now.
Thus, astronomers have discovered that stars are using their gravitational fields to sling comets at Earth, while they have been studying the movements of more than 600 stars.
The Oort Cloud is one of the culprits
Astronomers now know that the Oort Cloud, which lies at the edges of the solar system, is responsible for most of the comets hitting our planet or going near it. A new study describes how scientists calculated the paths of about 650 stars, and they compared the outcome with the orbits of over 270 long-period comets. Scientists concluded that the collective gravitational force of more distant stars could throw comets into long-period orbits.
The lead author Rita Wysoczańska, who is an astronomer at the Institute Astronomical Observatory at Adam Mickiewicz University in Poland, told Live Science the following:
In our study, we discovered only two cases in which this actually happened, and yet, we observe dozens of comets every year,
At this moment, we can say that the mechanism proposed by Oort is not sufficient enough to generate all comets we observe.
The Oort Cloud was discovered half a century ago by the Dutch astronomer Jan Oort. This cloud of predominantly icy planetesimals is known to surround the Sun at distances ranging from 2,000 to 200,000 au. The Oort Cloud is divided into two parts: the core, which is a disc-shaped structure (or a.k.a. Hills cloud), and a spherical outer Oort cloud. Both parts lie beyond the heliosphere and also in interstellar space.