[off camera] Well if you looked at the night's sky through a soda straw what would you
see. Turns out quite a lot using the Hubble Space Telescope.
Hubble's newest and final frontier field image shows us how
vast and crowded our universe is when it looked at just a tiny
portion of the sky. So what exactly is a galaxy
and what superpower did Hubble use to capture this new image. We're joined
by Dr. Padi Boyd at NASA's Goddard Space Flight Center. Thanks for joining us.
[Boyd] My pleasure thanks for having me. [off camera] So start by telling us what is a galaxy
and can you show us what Hubble has seen?
[Boyd] Well a galaxy is a collection of many stars. The Milky Way galaxy, our galaxy
has about a hundred billion or more stars in it. The star is just one of
a hundred billion or million. We live in a beautiful spiral galaxy
That's about a disk shape that has gas and stars
orbiting around the center. And this is a beautiful Hubble image of
two spiral galaxies. One is seen edge on, where we see that dust
and ther one one is seen more face on where we can start to see the structure of the spirals.
Galaxies near us look like that, but when we look at something a very small
region of the sky and we stare at it for hours and hours up to a
100 hours. We start to see galaxies coming out from
very far distances from us. And we're looking at the evolution
of galaxies as a function of time in these frontier fields.
[off camera] Talk about what superpower did Hubble use to see the faint and distant galaxies
in this new image. [Boyd] Well it's nothing more than the superpower
of gravity. We know that mass influences space
time and Einstein's theory of relativity predicted that
mass bends space time and that even light would bend around it. What that
means is that very massive structures can bend
the light from behind it like a funhouse mirror. And in images like
frontier fields, the mass of the foreground galaxy cluster
magnifies the galaxies behind it so that we can start to put
a picture together of those most distant galaxies. We can even use the
mass to magnify galaxies that started, that were forming
in the first 100 million years of the history of the universe
and those little red specks there are what we think are some of the first galaxies
to form. [off camera] Now I understand there's something
called dark matter. That sounds like something a villain would use. How do
missions like Hubble help us learn more about one of nature's biggest secrets?
[Boyd] It is one of nature's biggest secrets because we can't study it by
using traditional methods like looking at the light that it gives off. That's
exactly why we call it dark matter. But even though it's dark to our eyes
it does have mass and you can't get away from the fact that mass does have mass
that impacts it surroundings. It impacts space time. So using an image like
the frontier fields here and how it's distorting the galaxies behind us
behind it, actually allows us to map out the dark
matter. And that dark matter then we can use it as a lens
to look further behind in the universe. We now know that dark matter makes up
80 percent or more of the mass of the universe.
And that's just an amazing fact. Dark matter is in individual galaxies
and impacts the way that the stars move in those galaxies. So we can study
the motions of stars in individual spiral galaxies and get another handle
and a hint about where dark matter is and how it's distributed.
[off camera] Now Hubble just celebrated it's 27th birthday. What
is next for the famous space telescope? [Boyd] So 27 years on
orbit and Hubble is still going strong. And that's because
during it's lifetime astronauts visited the telescope and they outfit it with
new components and new instruments. And the last time astronauts visited
the telescope they really tuned it up. So it's still at the peak of it's scientific capabilities.
And we expect that to continue for years, working very closely
really hard to make sure that Hubble is still operational when we launch the next
big thing. The Webb Space Telescope which will launch in 2018.
Together these two very powerful space telescopes will be able to
look at the universe in slightly different types of light and give us
a broad picture of what's happening in galaxies nearby and even in the distant universe.
[off camera] Where can we learn more and see some
more of Hubble's images? [Boyd] If you go to nasa.gov/hubble or you follow us on
Twitter @NASAHubble you can find all kinds of information
and images we discussed today and many of the other programs that the Hubble Space Telescope
has done from galaxies to objects in our solar system
to stars, star forming nebulas. Check it out and learn more.
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