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I’ve lost count of how many times I’ve had to say this, but, spoiler alert:
we did not find aliens.
Ever get a missed call from a blocked number?
It’s the most frustrating thing.
Maybe it was just a scammer, but it could also have been someone
you actually wanted to talk to.
And you might never find out who it was.
Now imagine if that missed call came from an alien star system.
That’s what happened to a group of researchers from the University of Puerto Rico, and when
they announced it a couple weeks ago, it started a furious hunt for the source.
The team was using the Arecibo Observatory in Puerto Rico to study some nearby stars
when they picked up a really weird signal... which they called the “Weird!
Signal”, because astronomers are creative that way.
For radio telescopes like Arecibo, strange signals aren’t all that rare.
Lots of things emit radio waves that can interfere with measurements,
from microwave ovens to air traffic control radar.
That’s why we tend to build big radio telescopes out in the middle of nowhere.
But this signal was especially unusual.
For one thing, it seemed to come from a single spot in the sky,
in the same direction as a red dwarf star called Ross 128.
The signal also showed what’s known as dispersion,
meaning that the frequency of the signal changed over time.
There were a few possible explanations
for the Weird! Signal:
One was that the signal was coming from the star itself.
Red dwarfs are some of the most dynamic stars in the galaxy, so maybe this was just a way
they emit radio waves that we’ve never seen before.
It could have also been some strange activity from something else along the telescope’s
line of sight, either in front of or behind the star, that we couldn’t see.
The third main possibility was that the signal didn’t come from deep space at all, and
we were just seeing some interference from a satellite.
Problem is, none of those explanations fit perfectly.
Which is why a lot of people latched onto the other option, the one that astronomers
don’t like to bring up too much because people tend to get carried away:
It could be aliens.
For the research team, that was always at the bottom of the list, probability-wise.
In theory, anything we see in space that we can’t explain could be caused by aliens.
But astronomers have discovered a lot of unexpected things over the years,
and so far aliens have never been the answer.
But you know the internet.
An astronomer says the words “extraterrestrial life” and suddenly there are headlines about
how we’ve discovered little green people.
So, while social media and the more tabloid-y side of the internet was collectively freaking
out, astronomers around the world started using other telescopes to look at Ross 128.
The first results are in, and surprise: it’s not aliens.
The signal’s probably coming from geostationary satellites: satellites that orbit with the
Earth’s rotation so they stay at the same point in the sky all the time.
These satellites tend to hang out at the Earth’s equator, which is exactly where the astronomers
pointed their telescope to observe Ross 128.
That explains why astronomers only saw the signal
while they were looking at that one star.
Geostationary satellites also use similar frequencies to the ones detected,
so it all makes sense.
But there’s still one thing researchers aren’t totally sure how to explain:
that weird dispersion effect.
Normally, signals from satellites don’t change frequencies in that kind of pattern.
The original Puerto Rican team thinks the dispersion might come from
the radio waves reflecting somehow, but they’ll need more time
to figure out exactly what’s going on.
Meanwhile, we’ll have to hunt for E.T. somewhere else.
But the Weird! Signal isn’t the only weird thing that happened recently.
Last week, Elon Musk said that he’s pretty sure SpaceX’s new Falcon Heavy rocket will
explode during its first test launch, which is supposed to happen later this year.
Once it’s up and running, the Falcon Heavy will be the company’s first
heavy-duty launcher and the most powerful rocket in the world.
And they fully expect this giant rocket to explode
the first time they try launching it.
No big.
But it does kind of make sense.
Creating the Falcon Heavy has been a long road.
SpaceX originally wanted it to be ready by 2013,
but four years later it hasn’t even been test-launched yet.
Part of the problem is that the rocket’s design is tricky: it’s basically three of
the company’s smaller Falcon 9 rockets duct-taped together.
Since SpaceX has been flying the Falcon 9 for years, you might think it would be an
easy transition; Musk himself admitted as much.
But it turns out that a rocket with 27 engines is a lot different than one with nine.
For the Falcon Heavy to fly straight, all 27 need to be operating in perfect unison,
but that’s not the only challenge.
All those extra engines also mean a ton of extra vibration and a lot more physical stress,
so SpaceX engineers have had to totally redesign the main body of the rocket
to keep it from ripping apart.
They’re also planning to start pairs of engines a few milliseconds after each other,
because the force from all those engines starting up at once could warp the rocket’s structure.
So there are a lot of complicated challenges and new designs with this rocket,
and the only way to find out if it actually works is to fly it.
And odds are at least one of the things they’re trying isn’t going to work.
Which means the rocket will blow up.
Musk says he just hopes the explosion happens long enough after liftoff
to keep it from damaging the launchpad, too.
But even if the rocket explodes, the data from the test will help engineers
figure out what they need to fix.
Plus, if a rocket’s going to explode, you definitely want it to happen during the testing
phase, and not afterward when it’s flying actual missions.
And it’s worth the effort: once the kinks are worked out, the Falcon Heavy will be able
to launch more than four times as much as the Falcon 9.
That’s a big deal for companies looking to fly bigger satellites, and it might be
an even bigger deal for exploring the solar system.
A more powerful rocket can go farther and faster, and it can also carry more,
which would allow scientists to include more instruments on future missions.
But first, there might be a few explosions.
Thanks for watching this episode of SciShow Space News!
The Great American Solar Eclipse is just three weeks away, and if you’re looking for a
safe way to see it, you can check out our SciShow pinhole projector card at dftba.com/scishow!
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