Your upcoming tour of the Moon just got a
little bit closer.
Because for the first time in history, a private
company just got the go-ahead from the US
government to land on the Moon.
Moon Express, a company based in Florida,
wants to land on the moon by the end of next year.
If they can get their lander to travel 500
meters and send photos and video back to Earth,
they’ll win Google’s Lunar X-Prize, which
comes with a $20 million reward.
But Moon Express’s long-term goal is much
more ambitious: they want to develop the resources
on the Moon.
That means mining for things like water — from
ice — and helium-3, a type of helium that’s
rare on Earth but more common on the Moon.
Water is — well, it’s water.
If we’re going to live on the moon one day,
it’s easier to dig it up there then to take
it with us.
And helium-3 is handy because it could be
used as a source of safe and efficient nuclear power.
So eventually, mining these resources could
help establish a foothold on the moon for
future colonies.
Technically, it is legal for a private company
to go to the moon.
An international treaty that governs outer
space just says that if a private company
wants to go to space, the appropriate government
has to approve and supervise them.
But no private company has ever left Earth’s
orbit before, and the approval process for
it simply didn’t exist.
It took Moon Express 15 months to get permission,
but now that it has, it’ll probably be simpler
for other private space missions to get approval
in the future.
That’s important, because Moon Express isn’t
the only one with their eyes on the Lunar X-Prize.
Some 16 teams want a piece of the action.
Plus, SpaceX has plans to launch its Red Dragon
mission to Mars as early as 2018.
So this first step could lead to a lot more
trips past Earth’s orbit.
380 light years farther from home, in the
constellation Scorpius, astronomers have taken
a second look at a star system called AR Scorpii.
In a paper published this week in the journal
Nature at the end of July, the researchers
announced that this star system is like nothing
they’ve ever seen before.
When observers first discovered Scorpii 40
years ago, they found that it varied in brightness
about every three and a half hours.
They labeled it a standard variable star and
moved on with their lives.
The brightness of ordinary variable stars
can change for all kinds of reasons — like
if they grow or shrink.
Then, last year, a team of both professional
and amateur astronomers went back for a closer
look at Scorpii, and realized it wasn’t
that simple.
Within that 3.56 hour cycle, there was another
level of variability happening on a much shorter
time scale.
The light could change by a factor of 4 within
30 seconds!
This behavior is more consistent with a binary
star system than a single star.
But it gets even weirder.
AR Scorpii is made up of a red dwarf star
and a white dwarf star, and one of them is
sending particles zooming straight at the
other.
That white dwarf is about the same size as
Earth, but 200,000 times more massive.
The red dwarf is much less massive, at only
a third the mass of our Sun.
That white dwarf star is spinning so fast
that it completes a rotation in just under
two minutes.
That’s fast, but it’s slowing down over
time, which leaves a whole lot of energy available
to spew into space, including straight at
its partner star.
How this translates into bursts of light we
can see from Earth isn’t clear yet.
The white dwarf seems to be accelerating electrons
to nearly the speed of light.
It’s not clear whether these electrons come
from the red dwarf or the white dwarf, but
they’re excited by the white dwarf’s magnetic
field.
Those electrons give off wavelengths of light
we can detect, and when electrons bombard
the surface of the red dwarf, they might be
causing a flare of visible and UV light.
As the stars rotate and revolve around each
other, the amount of light we can see from
Earth changes -- rapidly, but predictably.
And this is the first time we’ve seen stars
behave like this.
So it turns out that there’s a lot you can
learn from the way one star system twinkles.
Thank you for watching this episode of SciShow,
brought to you by our President of Space,
Morgan, and The Big Try Hard.
Morgan completed a bicycle trip across the
U.S. raising money for YouTube channels he loves.
Thank you, Morgan!
You can catch up on his journey at thebigtryhard.com.
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