NASA is celebrating a big anniversary, it's the 10th
anniversary of the STEREO satellites that are orbiting
the Sun and returning some interesting data and here to tell us about what NASA
is learning about the Sun is Dr. Eric Christian at NASA's Goddard Space Flight Center
thanks for joining us. [Eric] Thank you. [Voice off Screen] Now, start by telling us
What is space weather and why does it matter to us on earth?
So the Sun actually has storms, so
the storms from the Sun can affect us here on Earth.
Luckily we're mostly protected by the Earth's magnetic field and the
Earth's atmosphere, but even so, se can see
the wonderful aurora that's caused by space weather but it can also
cause problems with the power grid. Power outages actually have been caused by solar storm
it can affect communications, and as we get more technology and as we
explore the solar system, it can affect satellites
it can certainly affect astronauts especially as they get further away from the Earth, let's say on their way to Mars
[Voice off Screen] Now how has STEREO changed our understanding
of the Sun? [Eric] So STEREO has done two things for the first time
One is, that the two STEREO spacecraft had identical cameras
and just as you need two eyes to see three dimensions
STEREO gave us 3d images of these solar storms, there coronal mass
ejections, these solar flares, these prominences so that we could really understand
the structure of them in three dimensions. The other thing is that
these two STEREO spacecraft drifted away from the Earth and right now they are on the backside
of the Sun, and so with STEREO.. Before STEREO we were only able to see the side
of the Sun that was facing the Earth, now for the first time we can see
the entire Sun 360 degrees at one time.
And really understand how the entire Sun is changing.
[Voice off Screen] Now we're gearing up for the solar event of the century in the US, the August
2017 solar eclipse, how does and eclipse like this help us understand
the Sun? [Eric] So one, an eclipse is an amazing
to see, I've seen two in my life, they are absolutely awe inspiring, but
we can actually do science from the eclipse and there's two
useful things we can do. One is, that even though we have fake
solar eclipses, we have telescopes that are called coronagraphs that block the light
behind the sun and look the much dimmer solar atmosphere, the solar corona.
They can't get all the way to the surface of the Sun where all
action is happening. The Moon happens to be almost a perfect fit in size
for the Sun, so we can see the solar corona all the way down to the
surface of the Sun. The other thing is that
solar eclipses, we can test instruments that are looking at the solar corona
here on the ground, which is a lot cheaper than flying them into space.
[Voice off Screen] NASA has an upcoming mission that will for the first time
actually touch the Sun which sounds pretty amazing, tell us about
this mission. [Eric] So in two years we're going to launch Solar Probe Plus,
and Solar Pro Plus is going to travel 25 times closer to the Sun
than the Earth is, within four million miles of the surface of the Sun
and we can learn a lot of the Sun from looking at it from Earth
but, getting right in to where the
solar corona is heating up and where the solar wind is accelerated, we're going to learn so much
more, it's going to be a fantastic mission. [Voice off Screen] Now we heard that
STEREO-B was giving NASA the silent treatment for a while, tell us
what happened. So after eight years of working great
as we were getting ready for the two STEREO spacecraft to cross behind the Sun
during which we knew we were going to lose communications with them because you can't send a radio
signal right through the Sun, during the testing for that period
STEREO-B had an anomaly and it started to drift so that
the solar arrays were no longer pointed at the Sun and the antenna was no longer pointed at the
Earth, and we lost contact with it. A couple months ago
we actually heard from it again, and were able to get some data and some commands back in
forth, and then lost it once more but we've got real hope
that as it gets closer to the Earth, we'll be able to pick it up again and completely recover
STEREO-B, STEREO-A is working great.
[Voice off Screen] Where can we learn more and see some of these images?
So NASA has a really wide presence on the internet in social media
and you can go to the nasa.gov website and theres
a backslash stereo part of that, that gives you the images that
directly come from the STEREO mission, and we've got a Twitter feed
@NASASunEarth where you can find out a lot of what's happening with space weather.
[Voice off Screen] Great, thanks so much for joining us. [Eric] Thank you.