00:00Well, any astronomer was very interested in this object, including me,
00:05because this was the first time we had confirmed that an object
00:09was coming in from outside of our own solar system.
00:12This was the first thing we ever saw that was not part of our solar system.
00:16There were a few things about Oumuamua that were, you know,
00:19the specific object that were unexpected and unusual.
00:23So initially people thought that it was this very long, like, cigar-shaped object.
00:27So when we saw it, people initially thought that it was an asteroid
00:31because it didn't have a tail, it was just a point of light.
00:36You know, comets have these big, beautiful tails
00:39because they are evaporating lots of gases like water and carbon dioxide.
00:45If we could figure out what unusual circumstances
00:47or what circumstances at the beginning of our solar system
00:50might have created an object just like Oumuamua and give it a natural explanation.
00:55When we had more observations, we found that there was this small rocket effect
01:01like you get for a comet, which was then, okay, how do you match the fact
01:07that it has this comet-like rocket effect but you didn't see the comet tail?
01:12And we settled on the composition of nitrogen ice, frozen ice.
01:16And this was very attractive from the very beginning because this is an ice
01:20that we do see in our own solar system on the surface of Pluto.
01:23So it was, we reasoned it was possible that there could have been Plutos
01:28in other solar systems with nitrogen ice on their surfaces
01:32and a piece of it knocked off could have entered our solar system
01:35and explained everything we saw.
01:36And so then we went through the calculations and the reflectiveness that you need
01:40to exactly reproduce the rocket effect that we observed
01:44is the reflectiveness of the surface of Pluto,
01:47which has a lot of nitrogen ice on the surface.
01:50So that was like, we hadn't necessarily been expecting that
01:53and it just fell out and I was like, okay, that's amazing. That's great.
01:58Since this fits everything we know about it, it seems reasonable to conclude
02:02it is a piece of another planet and it's a planet like Pluto.
02:06That's exciting to have a piece like that in our own backyard.
02:10And more than that, it tells us that the things that happened
02:13in our own solar system where you had Pluto's forming
02:16and banging into other icy objects and fragments flying off,
02:21all of these things, we learned that that probably did happen
02:24in our solar system as a result of this research.
02:27And it tells us this is probably a near universal process
02:30and that other solar systems are doing the same thing that our solar system did.
02:34In the process of doing that, just like if you have a bar of soap
02:37and you're using it in the shower, once you've been using it for a long time,
02:42you might start off with a fairly chunky bar,
02:44but you end up with this annoying little sliver.
02:47And exactly the same kind of thing happens,
02:49that if you're just removing layers of material off the surface,
02:53then it slowly makes that flattening more extreme.
02:59And so that very naturally also explains why it was so flat when we observed it.
03:07It wasn't that flat when it came into the solar system.
03:10It's just that during the course of going through the solar system,
03:14it lost something like 95% of its mass because it went closer to the sun than Mercury.
03:20And that evaporated so much material that we were just left with the little soap sliver
03:26by the time we actually saw it.
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