Destiny 2’s massive new expansion – Forsaken – appears to largely take place in a part of the Solar System known as The Reef. It’s a rather chaotic, lawless, grit-in-your-teeth locale, which makes it an ideal setting for a tale of sci-fi flavored Western-tinged revenge.
It’s not merely a spaceborne civilization that exists in the spaces between the Asteroid Belt between Mars and Jupiter; rather, it’s a large family of building-covered rocks, tightly packed together, as they orbit around the Sun. The gamer in me is excited to jump in get exploring. The geoscientist in me is wondering how the heck anywhere like The Reef, even with the best space magic available, could ever exist.
The Reef seems to have taken shape after the aforementioned Golden Age of the Solar System. This was a period of time in which a mysterious, huge, sentient sphere known as the Traveler made its appearance, and granted humanity extraordinary technological abilities.
Then, after engaging in battle with a primeval, amorphous foe named the Darkness, much of humanity scattered throughout the cosmic neighborhood was wiped out, with the remnants pushed back to Earth into what became known as the Last City. The Traveler made its last stand, pushed back the Darkness, and went silent – at least, until the end of Destiny 2.
During the largely one-sided conflict, a time known as The Collapse, plenty of human-filled ships tried to make it out of the Solar System. Some tried to evade the Darkness through the Asteroid Belt, but were unfortunately destroyed. Sometime after that, their remnants, along with the asteroids, were brought together and took the form of The Reef.
In this fictional universe, set around seven centuries into the future, there is not only advanced technology, albeit scraps from the Golden Age. It also features what is essentially witchcraft, often fueled by “Light” from the Traveler. The Reef probably has plenty of magic threaded through it, but even so, the asteroids appear to be literally tethered together.
It isn’t clear how vast The Reef is, but the fact that it can contain multiple groups of aliens – from the blue-tinged Awoken to the insectoid, scavenger-like Fallen, for example – living not exactly in peaceful harmony suggests that it’s pretty sizeable. From the wasteland-esque Tangled Shore to the corrupted acropolis of the Dreaming City, there’s plenty going on here.
Movies and videogames always get asteroid fields wrong. I don’t actually mind, because they are almost always thrilling places to film chases and hunts: perfectly alien and, thanks to the close proximity of all the asteroids, an extraplanetary pandemonium. The Reef isn’t just any asteroid field though – it’s exists within the Solar System. This means we can take a look at what we know of it already to see just how anyone could get something like The Reef to stick together in the first place.
The Asteroid Field (or any asteroid collective for that matter) isn’t what you think it is. Although it is indeed a diverse, populous range of generally quite rocky material – the leftovers of the violent birth of the Solar System – they are individually, on average, several million of kilometers apart. They are also, for the most part, rather small; only 100,000 of them are larger than one kilometer (0.62 miles) across, and they would only collide once ever few billion years.
For the most part, it’s empty space. The most interesting parts of it are the somewhat more colossal monsters, like Ceres, which isn’t even an asteroid. Like Pluto, it’s a dwarf planet, one that has a planetary mass, orbits the Sun but hasn’t managed to get an orbit clear of any other pesky objects. It makes up around a quarter of the mass of the entire Asteroid Belt.
So in order to get something like The Reef, you’d need a way to not only draw these incredibly isolated asteroids together, but do so in a way that doesn’t place a massive dwarf planet in the middle of it all, which would eventually lead to a cataclysmic collision. This is certainly easier said than done. In fact, it’s so difficult it makes you wonder why advanced terraforming, spacefaring groups, from humanity to the Awoken, would even bother.
If you lassoed an asteroid, and brought it slowly towards you, it would keep moving until you stopped it with an opposing force. Such force would have to be so precisely tweaked that any overestimate, even the slightest miscalculation, would propel it back away from you again. To do this with hundreds or thousands of fairly big asteroids, then, would be nigh on impossible.
They’d also be spinning in a plethora of ways, which means you’d also have to carefully adjust them all using tiny nudges in order to stop their rotation so that the tethers wouldn’t pull at each other and cause a spectacular shower of destruction. Again, this doesn’t seem possible nor worth it.
Sure, you could decide that the sometimes nauseatingly rapid spins are fine. Ceres, for example, has a 9-hour-long day, with sunrises and sunsets that take just 45 minutes from start to end to occur. The key problem here is that this means you’d be subjected to extreme and rapid temperature changes, even at a distance of three times the Earth-Sun distance.
Per Space.com, in the light, the surface temperature would be a frigid -73°C (-100°F); at night, this drops to -143°C (-225°F). Good luck finding a material for construction that can withstand such extraordinary temperature fluctuations, let alone aliens that can survive them.
There’s more: Jupiter – by far the most massive object in the Solar System with the exception of the Sun – regularly perturbs asteroids in the Belt. This means that you will never have long-term stability here; things will always move somewhat erratically if you give them enough time.
The gravitational fields of most of these asteroids would also be incredibly low. Remember how the Philae lander, launched from Rosetta, almost didn’t land on the distant Comet 67/P after it initially bounced off its surface? Much of that is due to the fact that it’s low mass gave it a pathetic gravity value – and that comet is far more massive than most of the asteroids within the Belt.
In fact, the estimated total mass of all the asteroids in the Belt is equivalent to that of 4 percent of the mass of the Moon. The acceleration due to gravity on the lunar surface, by the way, is 1.63 m/s2. Ceres’ – which, just as a reminder, makes up around 25 percent of the Belt’s total combined mass – is 0.28 m/s2. This is about 17 percent of that of the Moon’s, and 2.8 percent of Earth’s.
So you could walk around on it, but only just. It certainly isn’t anywhere near enough to have an atmosphere, which means that any terraforming wunderkinds approaching it would certainly need to use some of that Light-based space magic to keep those vital life-sustaining gases close to the surface.
Even you crushed every single last scrap of material in the Asteroid Belt together, threw in a few spaceships for good measure, and made sure it was packed together with the density of a fairly decent rocky world, you’d still have an incredibly weak gravitational field strength that’s not conducive to civilization creating.
The gamer in me knows that The Reef is indubitably a brilliant and inspired setting for a dramatic game of cat-and-mouse. The omnipresent scientific side of me, however, is nevertheless failing to shake the fact that the Asteroid Belt is a ludicrously daft place to build anything at all – let alone a ramshackle cobweb of prisons and palaces.