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What If You Traveled Through The Oort Cloud? | Unveiled

VOICE OVER: Noah Baum WRITTEN BY: Dylan Musselman
Humanity dreams of one day visiting distant star systems and alien planets. But to do so, we'll have to break through the mysterious Oort cloud. So, what awaits us in the darkest confines of our solar system? In this video, Unveiled takes a tour across space to explore the final divide between our star system and the interstellar medium... Hundreds of thousands of astronomical units away from the sun, here's where space starts to get really weird!
Transcript

What If You Traveled Through the Oort Cloud?


Humanity dreams of one day visiting distant star systems and potentially habitable planets. But to do so, not only will we need to devise a way to travel much faster than we’re currently able to, we’ll also have to navigate through the mysterious Oort cloud. So, what awaits us in the darkest confines of our solar system?

This is Unveiled and today we’re answering the extraordinary question; What if you traveled through the Oort Cloud?

NASA defines the Oort cloud as “the most distant region of our solar system”. A theorised structure, it consists of the last objects to be caught in the sun’s gravitational pull and it marks the final divide between us and interstellar space. It’s thought to be a massive sphere or shell encompassing all sides of the solar system and is mostly made of icy chunks of space debris. The exact size and mass of the Oort Cloud has never actually been verified, but it’s believed to contain trillions of icy rocks… the sizes of which vary wildly, with some just meters across and others the size of mountains! This “outer shell” is also where some comets come from, as certain bits of the debris soar inwards, pulled by the sun to mostly just flash across the sky… but occasionally smash into a planet.

The reason the Oort Cloud has never been verified or observed is because it’s just too far away! Our telescopes aren’t capable of catching all “non-luminous” objects that are that far from us. We can see distant stars much further afield than the Oort Cloud because they release light and radiation; and we can detect planets around those stars by - among other methods - noticing a dimming effect as they pass in front of their star from our perspective, called Transit. The Oort cloud has nothing like this, however, so it can’t be seen unless we send a probe there. And that’s a tall order in itself! The Cloud is thought to start at around 2,000 to 5,000 astronomical units away from us… and to end somewhere between 10,000 to 100,000 AU. With one astronomical unit being the average distance between the sun and Earth, it’s a gigantic distance between us and it. We have some spacecraft which are en-route to reach the Cloud eventually, though. Voyager 1, for example, should breach the Oort Cloud in about 300 years’ time. Unfortunately, it’s also expected to have run out of power long before then!

On a prospective, but totally hypothetical, manned mission to the Oort Cloud, then, the journey there would be eventful in itself! Depending on the time and direction you’d set off in, your spaceship could pass by most of the planets in the solar system and through the Kuiper Belt and Scattered Disc.

A number of dwarf planets are also thought to exist between the Kuiper Belt and the Oort Cloud. One of the largest is Sedna, which is about three-quarters the size of Pluto and currently around 86 AU away. Another is “2015 RG387” - more catchily known as “the Goblin”, and around 80 AU away. Neither has ever been seen up close by even our furthest flung machines, but they could cross our path on our mission out of the solar system. Both may also spend part of their millennia-long orbits inside the Oort Cloud, as well - though their paths are an ongoing debate for astronomers.

The prospect of landing on such a distant world might feel unlikely, but we have managed something at least a little similar before - by remotely piloting the Philae module from the spacecraft Rosetta onto the surface of a comet, in 2014. True, the distances we were dealing with then were much smaller in comparison… but if we had the tech to even travel as far as the likes of Sedna, perhaps we’d also have the know-how to land on it!

Once inside the Oort Cloud itself, we’d have those totally unknown and unpredictable icy masses to contend with - potentially in their trillions. And, given that they’d all be travelling extremely quickly, striving to complete their widest of solar orbits, manoeuvring through them could present a challenge… Except, it probably wouldn’t. Similar to how the inner Asteroid Belt is often misrepresented in sci-fi movies as an unthinkably dense and dangerous minefield (when in real life, you could likely pass through quite easily), the Oort Cloud (despite all its icy rocks) would also offer vast expanses of, well, nothingness… The Cloud covers such a massive area, that even with everything that we think is inside it, it would still feel very empty if you were actually there! In the event that your ship did collide with anything, you’d be cast out into the vacuum of space; in the event that you simply ran out of fuel, your ship could eventually be pulled back into the solar system, covered in ice; if anything goes wrong this far from home, the situation could very quickly turn critical!

The trade off? An unprecedented research opportunity! The chances of finding life in the Oort Cloud are thought to be low, but scientists are very interested in the basic molecules that exist on some of the comets. Molecules obtained from comet samples are sometimes older than the sun, giving us access to some of the earliest building blocks of the universe. But studying them on Earth is difficult because they’re not suited to our environment. Take samples from the source, then, from out in the Oort Cloud, and we could achieve a better-than-ever understanding of the formation and evolution of the solar system, and beyond.

And that “beyond” would be our last great hurdle. Because, in the event that we not only reached the Oort Cloud but also reached the other side of it - a feat which, if we were traveling at the same speed as Voyager 1 is now, would take around 30,000 years to complete - we’d be greeted with, well, nothingness. A far-far-reaching blanket of emptiness known as interstellar space between us and the next-nearest star system, Alpha Centauri, which is more than four lightyears away!

Clearly, this is one journey that we’re still very far away from actually making. For human eyes to ever see the Oort Cloud we’d need a ship traveling much faster than anything we’ve built so far… and we’d need it to be big enough to carry people… and we’d need it to preserve its astronauts’ safety in all the usual ways - by protecting against radiation, storing enough food and water, withstanding freezing temperatures and providing reliable communications as well as enough space to live. It would also need to run off of an endless, renewable fuel source, or at least off of a fuel that can be mined and stored - even across the vast and lonely plains of space.

And yet, if humanity ever wants to visit other star systems, then crossing this most mysterious of cosmic borders is something that we’ll one day have to do. But, whether it’s via a far-future means of prolonged, close to lightspeed travel… or its as one of countless generations on board a generation ship… that’s what would happen if you travelled through the Oort Cloud.
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