An imposing fireball that originated at the outskirts of our Solar System seems to have captured astronomers’ attention more than ever. It has been proven that the space rock’s composition consists mostly of rock, which is indeed surprising considering that scientists were initially betting on ice as the predominant component. Due to the new discovery, what astronomers know about the birth of our Solar System is now challenged, according to Phys.org.
The Oort Cloud is believed to represent the origin of most comets that appear. The Oort Cloud is located far beyond the orbit of Pluto, which was once considered a planet and the farthest one from the Sun. Meanwhile, Pluto got downgraded to the state of a dwarf planet, although some astronomers disagree even nowadays. The Oort Cloud is also placed way beyond the most distant edges of the Kuiper Belt. Another weird fact about the ‘cloud’ is that it looks like a giant sphere that engulfs the Solar System, which is totally unusual compared to the relatively flat plane that consists of the planets that orbit around the Sun.
Not only icy cosmic objects exist at the edges of the Solar System
The new observations come to contradict the assumption that nothing made of rock could exist at the edges of the Solar System. One basic rule for the understanding of the birth of the Solar System indicates that only icy objects can exist at its outskirts.
Astronomers used state-of-the-art Global Fireball Observatory (GFO) cameras from the University of Alberta. Global Meteor Network tools from the Winchcombe fireball were also used for calculating the orbit of a rocky meteoroid. It has been found that the space object was traveling on an orbit that was usually used only by comets coming from the Oort Cloud that were predominantly made of ice.
Denis Vida, who is a Western meteor physics postdoctoral researcher, explained, as Phys.org quotes:
This discovery supports an entirely different model of the formation of the solar system, one which backs the idea that significant amounts of rocky material co-exist with icy objects within the Oort cloud,
This result is not explained by the currently favored solar system formation models. It’s a complete game changer.
The Oort Cloud is believed to have formed about 4.6 billion years ago, and it formed after the planets took shape from the primordial protoplanetary disc. The ‘cloud’ hasn’t been directly observed yet, but it is believed to stretch incredibly much. It is believed to measure about 100,000 – 200,000 AU from the Sun. One AU (astronomical unit) is the equivalent of the distance that separates our planet from the Sun. That means roughly 150 million kilometers.
There are thought to be 10 to the 12th power icy objects dwelling in the Oort Cloud. Despite these numbers, the cosmic structure is only about five times more massive than our planet.
Hadrien Devillepoix, who is a research associate at Curtin University (Australia), and also the principal investigator of the GFO, explained as the same website mentioned above quotes:
In 70 years of regular fireball observations, this is one of the most peculiar ever recorded. It validates the strategy of the GFO established five years ago, which widened the ‘fishing net’ to 5 million square kilometers of skies, and brought together scientific experts from around the globe,
It not only allows us to find and study precious meteorites, but it is the only way to have a chance of catching these rarer events that are essential to understanding our solar system.
Fireballs are, technically speaking, also meteors, only that they exceed a certain brightness as they hurtle through space.
The new findings were published in Nature Astronomy.
