Hi I'm Hank Green!
Welcome to SciShow Space News.
This week, the lesson seems to be that some things that come down to us from space are
more delightful than others.
First off, back on April 20th, SpaceX launched its third resupply mission to the International
Space Station, delivering coffee, an experimental vegetable garden, and a whole bunch of bacteria.
The bacteria were a gift from Project MERCCURI, a crowdsourced NASA program that enlisted
the help of citizen scientists all over the United States to collect samples of bacteria.
People collected bacteria by swabbing things like a basketball used in an NBA game, the
Liberty Bell, and part of a fossilized T. rex.
A little weird, maybe, but that bacteria might help us answer some basic questions about
the nature of pathogenic microbes.
NASA has been sending Salmonella into space since 2006.
And one of the scarier things that they’ve found is that, compared to samples that stay
on Earth, samples incubated on the ISS come back three to seven times more virulent.
But don’t panic though!
NASA’s on top of it!
Biologists think this space-borne virulence may have to do with the effects of microgravity
on the fluid that surrounds a microbe's outer surface.
Typically, this fluid typically exerts a force, called fluid shear, that tells the microbe
where in the body it's located.
Using computer simulations, researchers have found that the fluid shear in microgravity
is very similar to that of human intestines.
So it seems that space Salmonella thinks it's in someone’s intestines, which activates
genes that put it into overdrive.
Biologists are thinking that messing with the pathogen's ability to detect fluid shear
might be a key to creating antibiotics for it.
Meanwhile, the Project MERCCURI samples have just been sent back to Earth, along with swabs
from around the space station itself.
And now, they'll be compared with samples that remained on the ground to study if, and
how, life in space changed them.
Now here’s something headed our way that may make you less anxious -- the Eta Aquarids
meteor shower, which peaks this Monday and Tuesday.
They've been showering down since April 19th and will continue until May 28th, but on May
5th and 6th they'll appear at a rate of about 30 meteors per hour.
Wherever you are in the world, you'll be able to see them in the early morning between moonset
and sunrise of Tuesday, May 6th in the constellation Aquarius.
And they're going to be awesome.
Traveling at about 66 kilometers per second into Earth's atmosphere, they'll leave glowing
trails of burning debris in their wakes.
That debris actually comes from Halley's comet, a 16-kilometer-long bit of ice and rock in
a 76-year orbit with the sun.
When Halley approaches the sun, as it did in 1986, it heats up and leaves a trail of
debris.
Earth crosses through this trail twice a year, once in May and once in October, giving us
the Eta Aquarids and the Orionids.
These remains of Halley should hold us over until its next appearance in the solar system
in 2061.
Finally, there’s one new celestial discovery that you won't be able to see, unfortunately.
Last week NASA's Wide-field Infrared Survey Explorer, or WISE, discovered a star that's
only 7.2 light-years away, making it the fourth-closest star to our own.
If you can call it a star.
It's a brown dwarf, which is sort of like a failed star that’s never achieved fusion.
Brown dwarfs are bigger than planets, but not as big as other stars, and they only give
off a faint bit of energy.
Because of their size and dimness, they're easy to confuse with gas giants like Jupiter—and
they can be hard to detect.
That's why we've only just noticed the new one - even though it’s so close - using
infrared readings of the sky.
At only a few times larger than Jupiter, it’s the smallest and coldest brown dwarf yet discovered.
But as we get better at finding these smaller, cooler brown dwarves, astronomers think we
might start finding them in all sorts of unexpected places.
And this might be an answer to one of the universe's great mysteries: where is all the
matter that should be out there?
Maybe it's hiding in plain sight, just too cold to see.
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