We just had our first interstellar visitor...and it's weird.

[Music] good morning John a little over a year ago we observed the first ever object that wasn't from here a hunk of something that had traveled from another star system maybe thrown out as the system formed maybe flung out much later but now we know officially while we cannot visit other star systems pieces of them can visit us and Omo MOA is not what we expected let's start with what we know an object came into our solar system going around 25 kilometers per second which is pretty fast it was varying in brightness so we'd look at it one day and it would be 10 times brighter than on another day a huge surprise which is where we got the cigar hypothesis it was they supposed long and skinny so when it was like this had reflected more light than when it was like this it was tumbling end over end changing and brightness there are no objects in our solar system shaped like this Omaha has a length to width ratio of 10 to 1 there are barely any objects in our solar system with a ratio of 5 to 1 how would an object like this form we don't know what would it be made of probably something very sturdy or else it couldn't maintain this strange shape it brushed surprisingly close to Earth right into the habitable zone of our Sun and then maybe the weirdest bit of all its velocity changed in ways that could not be explained by gravitation alone there are as far as we can tell only two ways this could have happened one Omaha is a comet and it off gassed 10% of its mass as the Sun heated it up and this is what comments do it's what gives them their big beautiful tails or - instead of being a big rock it's a 50 meter square of shiny foil less than a millimeter thick which fans of space travel and or science fiction will recognize as the description of a solar sail see weirdly enough photons and do not have mass but they do have momentum and when they hit something they give it a tiny push a big sheet of something very reflective but very lightweight can take advantage of that fact and you for propulsion something we humans have actually experimented with but look that can't be right right obviously a comet is a much more likely thing to have floating through interstellar space but until we notice the velocity change we were pretty sure that ol moolah wasn't a comet for one thing it was long and skinny and that is a shape that is very difficult to have occur naturally at all but even more difficult if it's not something that's rigid and comets generally are fairly loosely held together balls of ice and dust the idea is that would definitely break apart especially as it approached a gravitational well like our Sun now it's certainly possible that the change in brightness isn't caused by its unique shape it could be that it's just much darker on one side than the other like Saturn's moon a pitous so maybe we've just learned that it isn't such a weird shape also we didn't think it was a comet because there was no tail as it off gassed that theoretical 10% of its mass we probably would have seen some of that mass but maybe there are comet like things from other solar systems that out gas differently from our comets different compounds different size dust particles that would make it more difficult for us to detect and finally scientists think the off gassing would have changed the rotation of the object which it appears to not have now adding to the solar sail hypothesis the spitzer space telescope pointed at the place where obama was and it did not receive any thermal readings back no infrared radiation meaning that it was very dim in the infrared so probably it had reflected away most of the heat received from the Sun this is maybe the weirdest thing it means that the object has an upper limit on how dark it can be and that limit is shinier than either asteroids or comets from our solar system which like thank you Spitzer Space Telescope this was not what you were designed for but that is very helpful and weird piece of data and then there's this this shouldn't have happened the telescope that spotted Oh Mulla Mulla does a whole Sky Survey and is not designed to catch things like this in fact it didn't spot the object until it was well past its peak brightness the fact that the pan-starrs telescope caught an object like this in the first 10 years of operation means statistically that these events are probably very common but according to our computer models of how solar systems form and how much stuff they throw out it should not be common and this discovery if it's natural and common that we were off by like orders of magnitude and it's actually wonderful news that it did occur because if it means it's more likely then we will have more chances to study objects like this in the future because we definitely do not understand what this thing was I don't know maybe there's a natural way for a solar sail like object to form in the galaxy who knows in general jumping from this is confusing and weird and I don't understand it too it's aliens has tended to be a bad way to answer questions in the past and as Carl Sagan said extraordinary claims require extraordinary evidence which we as Omaha speeds off away from us do not have and will never have now of course arguing against the extraterrestrials created a light sail hypothesis are two main things one why would it be tumbling end over end if you wanted to create a space probe to study a planet you probably would want to keep everything relatively stable so that you could point stuff at the planet to study it - why is it going so slow 25 kilometers per second is very fast to us but very slow in terms of interstellar travel it would take about twelve thousand years if you were going straight at Alpha Centauri to get there from here at that speed this leads to alternate hypotheses like hey there are more shipwrecks under the ocean than ships currently floating on the sea so maybe this is the piece of something that broke down or ripped apart through age or accident or attack its artificially created but it's a hundred percent dead just floating through space because if we're gonna start hypothesizing we might as well start hypothesizing about interstellar war but unless this is an extremely uncommon occurrence debris from an event like that would have to be way too common like I was just be very sad if there was that much detritus floating around in the galaxy theory I haven't heard from anyone except my own brain is that maybe this thing is tumbling end over end and not going very fast because whoever sent it wanted us to see it maybe they thought if there was some group of intelligences significantly advanced they could chase such an object down maybe it's nothing more than an interstellar greeting card blinking off into the distance unruhe sieved this time at least I shouldn't have said that that was pure conjecture and I probably shouldn't even be making this video at all as a person who hosts a science show has a master's degree and looks like this I am credible and I want to hold on to that credibility and also use it wisely observing an interstellar object on its own is huge news it means that these objects are more common and more weird than we thought but the story that would truly captivate all humanity is if we found out for sure that this thing came from somewhere else someone else how captivating an idea is for our minds should not have an effect on how scientists consider that hypothesis but it does have an effect on how it is perceived by us it has an effect on how we're gonna write that headline make that video and whether we're gonna click that link as a science communicator I'm aware that people are gonna see the sentence this is probably not a spaceship and see more of the probably part of the sentence than the is not part so I'm aware that bringing up the possibility that there is explanatory power behind the hypothesis that Omo amou was constructed by an intelligence outside of our solar system is going to inevitably lead people to looking much more at that part of the story than the parts where there might also be lots of other explanations this is for example true of me because I want it to be a spaceship I want to know a new story I want to have an event like that where we all remember where we were when we heard the news not the bad news just the big news so ultimately I know that I'm not gonna be able to trust myself with this one you know I'm trying to look at more things that way knowing that there are certain things that can't really trust myself with because I want things to be a certain way and it's especially easy to see in this case where the event was ephemeral the data have been collected and analyzed and now all that we have left to do is speculate or maybe that isn't true right now we have only one telescope that could have spotted Amla Lua another is going online in just a few years and it will be orders of magnitude better if when we get that telescope online we see objects like this flitting through the solar system all the time we may be able to determine that they are a new class of object to understand them study them even visit them or we could find that blue a mullah like objects are rare and well then we'll know that we saw something special and that will be a big deal but maybe the best argument against the alien hypothesis is simply that the universe is weird many times we've seen things in the night sky and have no way to explain it and thought oh this is it now we find the others and then science caught up to observation this is an object unlike any we have ever encountered before so maybe the fact that it's weird isn't actually that weird John I'll see you on Tuesday I read a lot of good articles listened to a lot of good podcasts watched a lot of good videos prepping for this this one so I've linked to some of those in the description thanks to all of the scientists who worked on this project got together very fast to make this happen to start observing once we realize that we have something weird on the radar educational videos are exempt from the four-minute rule obviously just saying and the project for awesome next week next week next weekend you guys if you're thinking about making a video promoting your charity of choice please do that get it ready because we will as a community next weekend be voting on which of the charities promoted in those videos will be getting grants from the foundation to decrease worldsuck so action do it boom excited we're product for awesomes comic thanks to the educational video exemption for allowing me to just ramble on for a while John I already did that

Channel: vlogbrothers

Views: 1,446,614

Rating: 4.8774724 out of 5

Keywords: oumuamua, astreoid, comet, space ship, nasa, space, stars, interstellar, astronomy, cosmology, astrophysics, telescopes

Id: bManqDAYG1g

Length: 10min 17sec (617 seconds)

Published: Fri Nov 30 2018

Reddit Comments

[u/Eabryt]

I think this is the first of their "premiers" that I've seen, and boy was it a good one.

I saw something about Oumuamua awhile ago (and I think Hank mentioned it on Dear Hank & John) but I hadn't looked too much in to it. Very cool to learn more.

[u/tanhan27]

I want that thing to be aliens so hard!

[u/benjaminikuta]

I really like far out space news.