[slate] Well this is a really exciting
event for us because the transit of Mercury only happens rarely once every
the last one was 10 years ago. And it happens when Mercury passes
between us and the sun. It blocks out part of the light from the sun
Now today this transit is starting at 7:12 a.m.
East coast time and will end at 2:30 p.m. Again East coast time.
And you can observe it from the ground if you have the right equipment particularly
safety equipment. But really the best place to observe it by going to
the NASA website and watching the live stream data coming from the Solar Dynamics Observatory
[slate]
Well astronomers have been using transit data to understand our solar system
and beyond for literally hundreds of years.
Originally those transits were used to establish a yard stick
to measure the sizes of things in our own solar system. But since then
we've also used transits to understand the atmospheres of the planets in our solar system.
We've used the transit of Mercury in fact as the first
test of general relativity. And now we're using transits
to learn for planets around distant stars. To look for exoplanets.
[slate]
Well the sun is fascinating. It's obviously very important to us. And one of the things
we've discovered over years and years of study is that every time you look at the sun
in more detail, you find more structure. And in fact
now the Solar Dynamics Observatory is looking at the sun with
the best resolution ever. And we're learning more than ever before about
the magnetic fields of the sun. About flares, about spots
about the activity that's going on in our own sun. And
by understanding that we start to understand how the sun can actually
have an effect on us here on Earth. [slate]
Well astronomers have been using the transit method
to find exoplanets for a number of years now. And in fact we've found literally thousands
of exoplanets so far. But the upcoming TESS mission -the
Transiting Exoplanet Survey Satellite - is going to survey the entire sky looking for
transiting planets around bright, nearby stars
Now these exoplanets, this list of targets
is going to be the perfect list of targets for follow up observations
using telescopes such as the James Webb Space Telescope or other facilities
to try to get the follow up data to help us understand these planets.
And that means understanding what they're made out of. Understanding
what they're atmospheres are like and maybe even finding signs of habitability.
[slate]
Well go to www.nasa.gov/transit
And if you go to that website you will find an array of
stunning images of the sun and of the transit. And importantly you'll find a link
to the live stream data coming from the Solar Dynamics Observatory
as it happens.