Aliens?
Okay, now that I have your attention I can ask the real question…
Aliens?!
If you remember a little over a year ago, we had an interstellar visitor in the form of a long cigar-comet-rock thing. (If you have been living in a box for the past year and haven’t already seen this everywhere, here’s a link to catch you up! https://www.jpl.nasa.gov/news/news.php?feature=7006) The Hawaiian Institute that discovered it named it ‘Oumuamua (oh – MOO uh – MOO uh) and even over a year later they still don’t know exactly what it is. ‘Oumuamua doesn’t fit neatly into any category of space stuff that we’ve already studied, like an asteroid or comet for example, but recently a couple of astronomers from Harvard Smithsonian Center for Astrophysics think that it could be a lightsail from an extraterrestrial civilization.
So. Many. Questions.
Let’s start at the beginning. What is a lightsail?
I’m not going to lie to you here, when I first started seeing the articles I thought it meant the smallest version of a sail like on a sailboat. You know, you use a light sail for easy sailing, a medium sail for a soft breeze, and a heavy sail for a blustery day? Yeah? No, not that kind of “light.” For clarification, a lightsail is also called a solar sail. A “light” sail in that it is propelled by light!
That makes so much more sense, but I am slightly disappointed that Harvard wasn’t imagining a pirate ship style UFO missing a small sail somewhere out in the great wide open.
They did, very specifically, imagine a lightsail though! Which is almost as curious as ET’s pirate ship.
What evidence do they have for this theory?
Well, it’s more about what evidence they have that could disprove their theory. Which is none! But apparently that sort of thinking doesn’t sit well with most of the scientific community. That’s part of the reason I haven’t put this blog up until now, because every space news headline on the planet for the past few weeks has been a form of “Don’t Be Stupid, It Is Not From The Aliens.”
Spoiler Alert: the naysayers are probably right… Regardless, those Harvard astronomers outlined what could suggest ‘Oumuamua is not just your average space rock.
Odd Acceleration
We were all fine and dandy with calling ‘Oumuamua a rock until it headed out of our solar system. According to physics and whatnot, after the slingshot around the Sun and intense amount of gravity exerted on ‘Oumuamua, it should have slowed down, but not only did it not slow down, it sped up!
This would make a little bit of sense if it was releasing gasses but it didn’t do that either! It also would have probably broken apart if it had been a comet (Fun Fact: That’s what gives them big tails!)
So this out of the ordinary acceleration is a big selling point for the lightsail theory, because that is how a lightsail would act in that scenario.
It’s Unlike Anything We’ve Seen Before
Like I said before, it doesn’t fit into the category of an asteroid or a comet, but also it lacks a key similarity of space things: Space dust! Space is made up of space dust so everything in space is usually surrounded by it, but not ‘Oumuamua.
Well, It’s Something Like Things We’ve Seen Before…
… just not in space yet!
Similar things have been built by humans! Japanese-designed IKAROS project and the Starshot Initiative are both ventures to build lightsails to send off to other solar systems to scout for us. (Because obviously our knowledge and inventions are the best and the aliens of course would do things the same way we do, that’s not presumption or pretentious at all. But I digress.) Afterall, ‘Oumuamua in Hawaiian pretty much translates to “Scout”
Annnddddd that’s all they’ve got. Not that all of those things aren’t true, but I see why other science peeps were quick to tell all the commoners like me to sit down. It is true that ‘Oumuamua has some characteristics of a lightsail, but that doesn’t automatically mean that it is a lightsail. Humans have some characteristics of sea sponges, too. Point made.
What other theories could there be?
Could ‘Oumuamua be the flotsam of space?! Could there have been a giant galactic war going on right outside our solar system that we were oblivious to? Or is that why we haven’t seen the aliens? Did they all kill each other in this huge war just before our time? Or even the jetsam!? Could this actually be an object purposely sent off out of distress?
Or perhaps could it instead have been the remnants of a supernova? From a planet exploding into a million fragments because it was too close to the star on D-Day? ‘Oumuamua may be the shrapnel of a distant planetary tragedy.
While we are throwing out alternative theories, then I personally think ‘Oumuamua could be a space amoeba turd. Makes sense to me; long and thin, propelled by gas, came out of seemingly nowhere. If we are going to argue for the aliens, give the space amoebas their limelight, too.
What is it really?
I think it is really neat and very encouraging that so many big names in science are validating the theory of aliens. Even if ‘Oumuamua is not part of an alien recon mission, the fact that the scientific community is willing to argue for the theory tells us that they wholeheartedly believe that the aliens are out there.
In all reality though, it is probably a regular old rock that has an unstudied composition (thus the weird shape and not being able to be categorized as an asteroid or comet) and is experiencing the Yarkovsky effect.
Quick science lesson of the day: The Yarkovsky Effect happens because of solar heated photons cooling off and releasing the radiated pressure to act as thrusters.
It’s difficult to explain, but as far as I can gather, the direction that ‘Oumuamua is rotating plus it’s weird shape causes the sunlight to hit the surface unevenly in favor of the rotation which would push it into a slightly larger orbit. Since it was going too fast to hold in orbit, it just pushed it faster away from the Sun.
Listen y’all, I’m not an astronomer. I’ve got an art degree for God’s sake, so work with me.
The Yarkovsky effect would easily explain the acceleration, and the composition could simply mean that there are other materials out there besides the handful that we know of here on Earth. It was an interesting theory to think about though, Harvard. Thanks for believing.
TL;DR: It’s probably not the aliens. I’m just as disappointed as you are.
Side note, if you don’t quite understand why it is so odd that ‘Oumuamua sped up after its slingshot, go download the app Orbit, it’ll help you understand by example. (Plus it’s a really fun game!)
Also, I know this whole ‘Oumuamua explanation has been told non stop, so my apologizes. My intention wasn’t to be redundant, but to throw out a layman’s version for us non-science people who are still interested in learning about space and keeping up with all the new discoveries and theories. And I wanted to say “space turd” to someone besides my husband.
I think I could have built my own lightsail with all my resources:
What do we know about ‘Oumuamua?
https://www.nasa.gov/feature/jpl/chasing-oumuamua
https://phys.org/news/2018-10-oumuamua-year.html
https://phys.org/news/2018-11-oumuamua-extraterrestrial-solar.html
https://phys.org/news/2018-11-scientists-harvard-alien-spacecraft-theory.html
Dabbling Adult 