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KIDS: Our World!
EVAN: Today on Our World we’re going to learn about...
Globey, what are you wearing?
X-ray glasses? You know those things don’t actually work, right?
I know, I know, I’d like to have X-ray vision, too.
But there is a space telescope that actually DOES
have X-ray vision...the Chandra X-Ray Observatory.
This state-of-the-art space telescope observes X-rays to
help us learn new things about our universe.
So what is an X-ray? It’s a type of light that has a really short wavelength.
Visible light, or the light we can see, has a wavelength that looks like this.
X-ray wavelengths are much shorter.
This short wave length allows the x-ray to pass through many objects.
That’s why doctors use X-rays to look at broken bones.
X-rays pass through our skin.
The x-rays, however, are stopped by the bone.
X-ray film can be used to detect the x-rays and the
shadow of the things the x-rays cannot pass through.
When you go to the dentist, X-ray pictures are taken so
the dentist can see what’s happening INSIDE your teeth.
X-ray telescopes can be used in a similar way to look at
shadows caused by clouds of dust and gas in space,
but usually they are used to look at "x-ray machines"
in the universe such as hot gas produced by the explosion of a star,
to see a kind of light that isn’t visible with a regular camera.
The Chandra X-ray Observatory is named after a astrophysicist,
Subrahmanyan Chandrasekhar, or Chandra for short.
Chandra made new discoveries on how and why stars change.
He was one of the first scientists to combine physics
(the study of matter and how it moves) with astronomy
(the study of objects in the universe). He was awarded the
Nobel prize for his study of stars.
The Chandra X-ray Observatory was launched in 1999.
It allows NASA scientists to get a whole new view of the universe,
kind of like looking out into space with a pair of "X-ray glasses".
Stars and other matter in space give off X-rays under
certain violent conditions. Scientists can now observe
what it looks like when galaxies collide or supernovas explode.
Seeing these hot spots in the universe gives scientists
information they could never get from taking regular pictures.
So why can the Chandra X-ray telescope capture such brilliant images?
Chandra is the best X-ray imaging telescope ever built.
Its power is like being able to read a stop sign at a distance of 19 kilometers.
But this special telescope wouldn’t work here on Earth.
It had to be placed high in outer space. You see,
Earth’s atmosphere is thick enough that X-rays are not
able to reach Earth’s surface. Chandra’s orbit
around Earth is so big that the farthest points of the
oval shaped orbit are about one third the way to the moon.
Even at is closest approach to Earth, Chandra’s orbit is more than
200 times higher than the circular orbit of Hubble.
This gives the Chandra telescope an ability to look
for X-rays that are being produced by faraway objects in space
in a large region of the sky without the Earth blocking its view.
With the help of special mirrors and a high-resolution camera,
Chandra is able to "see" x-rays in action!
Whoa! That’s some incredible X-ray vision, huh Globey?
Chandra’s observations have led to important discoveries
that are accumulating at a rapid rate as Chandra
observes hundreds of objects each year.
Observations of the collision of two huge clusters of
galaxies has helped to provide the best evidence yet
for the existence of dark matter, a mysterious form of
matter that gives off no detectable light, but is
apparently the dominant form of matter in the universe.
Chandra has also been used to probe the geometry of space around black holes,
and revealed that supermassive black holes can affect an entire galaxy.
If Chandra was still alive today, I’m sure he’d be
thrilled to see all the amazing information the X-ray telescope is providing us.
So the next time you’re at the dentist getting teeth X-rays,
think about the Chandra X-ray Observatory...giving us an
inside look at the “X-ray machines” of the universe!
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KIDS: Our World!