Reporter: Today is an exciting day and that's because Mercury will transit across the face of the sun
and here to tell us about this rare phenomenon is Dr. Alex Young at NASA's Goddard Space Flight Center.
Thanks so much for joining us.
Alex: Thank you
Reporter: So Mercury is trekking across the sun today for the first time in ten years.
How can we see this transit?
Alex: If you're fortunate to have the right kind of solar viewing
equipment, telescope or binoculars with the appropriate filters
you can see it from the ground but the best way to see is from space.
We've got data coming from the Solar Dynamics Observatory
which is going to show this roughly seven hour transit uninterrupted.
Reporter: Why are transits so important to astronomers?
Alex: Well transits have been used for hundreds of years to show
us distances, like a ruler we can figure out how far away
planets and the sun are.
We've also be able to out sizes or even the fact that Venus has
an atmosphere using transits.
But transits are also important because they're how we
figure out if there planets around other stars outside
of our own solar system.
Reporter: Why does NASA watch the sun?
Alex: The sun is constantly putting out huge amounts of energy
and material, it's producing its own space weather
that effects us here on Earth, effects our astronauts in space
and moves through out the entire solar system and
this transit is import because it allows us to fine tune
our observations of the sun to see even better detail
by using the transit itself to fine tune and focus the telescope
to give us the best possible data to show us the sun
in all its glorious detail.
Reporter: So NASA is using the transit method to study planets beyond our
solar system, what do we expect to learn from future missions doing this?
Alex: We've already found thousands of planets around other stars
and we've got future missions like the
Transiting Exoplanet Survey Sattelite or TESS
which is going to look closest, brightest starts
to give us a whole set of potential
candidates that we can then point even more
powerful telescopes like the James Webb space telescope
at to see the atmosphere's of these stars
look for the finger prints of life itself and hopefully get a better
understanding life on other planets and ultimately life on our own planet.
Reporter: Where can we learn more?
Alex: You can go to www.nasa.gov/transit
to see all this amazing imagery, videos,
as well as learn more about transits
or even special kinds of transits called eclipses
and see something about the eclipse in August 21, 2017