The Hubble Space Telescope is turning 25 this year, and we here at SciShow Space cannot
thank it enough for its outstanding service.
There aren’t many other telescopes that can claim to have revealed distant planets,
and photographed the earliest known galaxies.
But … Hubble is starting to show its age.
Astronomers say it may have just five years of service left, so it’s time to start thinking
about what’s next.
Now we’ve already talked about NASA’s amazing infrared-sensing James Webb Space
Telescope, which is scheduled to launch in October 2018.
And we are very excited about that, and it’s going to be amazing, but when it comes to
space tech, new ideas are always welcome, no matter how crazy they sound.
And I betcha can’t guess what sort of ideas astronomers and engineers have come up with
lately.
So… did you guess umbrellas or glitter?
Because, yeah.
Two of the ideas in planning stages right now involve the space-age versions of those
things.
First, there’s the Aragoscope.
Developed by scientists at the University of Colorado in Boulder, it’s a high-resolution
space telescope concept that might be able to capture images 1,000 times sharper than
Hubble’s.
And that extra resolution will mostly come from the telescope’s most unique feature:
a giant sunshade.
The design concept is named after François Arago, a French scientist who proved that
light waves can actually bend around the edges of an opaque, circular disc and refocus at
a distant point.
That point is called the Arago spot.
The aragoscope’s disc would be pointed at an object we want to look at, like a distant
star.
That star’s light would then bend around the edges of the disc and create an Arago
spot.
And the telescope -- which would be tethered to the giant shade -- would then use that
spot to bring the target into focus.
The larger the disc, the more light it can capture, and the more detail the telescope
can get.
So ideally, we’d want the biggest possible disc for our future Aragoscope.
A disc 100 meters across would potentially reveal details like plasma exchanges between
stars in the Alpha Centauri system, our closest neighbors.
But super larger versions of this disc -- we’re talking up to 10 kilometers in diameter -- might
manage to find things like the event horizon of a black hole.
The problem is, every kilogram of equipment that we send into space costs thousands of
dollars to launch.
So, getting a hundred-meter disc into space could cost a lotta coin, let alone one that’s
10 kilometers wide.
But, that’s the potential genius of the aragoscope.
Its disc would be more like a light-weight parachute, so it could be tucked away during
launch.
Once it reached its destination, around 40,000 kilometers from Earth, the parachute would
unfurl to form the disc.
How exactly that would work has yet to be figured out, ‘cause, remember, it’s only
a concept, just like our next telescope idea … glitter!
Actually, it’s called smart dust, thank you very much, and it’s made out of millions
of tiny photo-polymers, which are light-sensitive plastic particles coated in reflective metal.
Basically: tiny floating mirrors.
This smart dust would be sprayed out from an aerosol container in space and then controlled
by lasers using what’s known as radiation pressure.
Radiation pressure is the faint force that electromagnetic radiation exerts on objects,
and when directed at very, very, small particles, it can be enough to push them around.
So by aiming lasers at particles of smart dust, astronomers could use radiation pressure
to nudge them into position and -- with enough bits of glitter -- they could build huge mirrors
in space.
Larger mirrors mean more light captured mean more detail.
Because smart dust is so light, we could send lots of it into space, allowing us to build
telescope-mirrors that are potentially thousands of kilometers in diameter.
Pretty cool.
But, like I said, it’s still just a concept.
Researchers say we’re still 20 or 30 years away from seeing these ideas take shape in
space.
So there you have it, glitter and space umbrellas… not just for David Bowie concerts anymore!
Also useful for astronomy!
Thanks for joining me for SciShow Space.
If you want to keep exploring the universe with us, just go to youtube.com/scishowspace
and subscribe!