59. The Oort cloud

The Oort cloud is a hypothetical region in our solar system, far beyond what the world's best telescopes could see. Estimated to be around 2050 astronomical units (Distance from the Earth to the sun) from the middle of our solar system, it is believed to be a thick shell of rocks around our solar system. It is theorised that the Oort Cloud contains hundreds of billions of small icy chunks of rocks in a huge 80,000 astronomical unit area.

The Oort cloud is the most common theory used by scientists to explain where most long distance comets originate from. Examples are Hale-Bopp and Halley's comet (Halley's comet has become a Kuiper Belt object). This theory has been around for a while, first proposed in 1950 with a Dutch astronomer Jan Oort theorising its presence, Thus getting the name. Over the years there has been lots of evidence to show that it is real, not a theory, but not enough to confirm its existence.

100,000 AU is the distance between the sun and the edge of the Oort cloud, one and a half light years. This is the boundaries of the solar system, which means its going to take Voyager 1 30,000 years to even make it out of our solar system! Many speculate that the Oort cloud is twice as big, which I don't think is the case. The nearest star is 4 light years away and if it was twice as big it would reach three quarters of the way there. Also, the sun is just has too small of a gravitational pull to grab in the rocks from 3 light years.

Rough estimates suggest there is approximately two trillion objects floating in the Oort cloud. Most of them are small, maybe 10 meters or so, but the size varies greatly. Some people have suggested that there is even a small planetoid in the Oort cloud somewhere, and it was a actually discovered in 2003. It was named 'Sedna' and is a member of the chaotic inner Oort cloud.

The Oort Cloud is different in many ways to the rest of the solar system, just because of how chaotic it is. The rest of the solar system moves in a smooth, nearly circular orbit around the sun going anticlockwise. The Oort Cloud moves in random directions around the sun, up, over and around going in any direction. This means that every millisecond there is probably a collision between two rocks in this massive area. This is why we call it a cloud and not a belt.

I hope you have enjoyed reading about the Oort Cloud. This blog post is barely scratching the surface of this idea so I would recommend going to the official NASA website page on Oort clouds if you want to learn more. Make sure to subscribe to my Youtube Channel and like the blog if you want to see more posts like this.

Until next time, Give Me Space!

Henry