Pi is this incredibly important number
in mathematics and science.
It's just the ratio of the circumference
of a circle to its diameter.
It just so happens
that the first three digits of pi
or 3.14.
The third month
and the 14th day
becomes Pi Day.
And this lunar eclipse
is going to happen
on Pi Day.
That happens once every
350 years or so.
So it's quite unusual.
When I do eclipse calculations
to figure out where the shadow
is going to fall,
that involves trigonometry.
And all of trigonometry
is built on pi.
It's a fun way to celebrate
not just the Moon, but
math and pi--
of both kinds.
So think of fruit pies
and pizza pies and
all kinds of things
that you can add to your
observation of the Moon
and your celebration of science.
I'm old enough to
remember the Apollo era.
We're now going back with,
not only NASA itself,
but its commercial partners
to sample the surface
and explore.
And the Moon is a great
destination for this
because it remembers
everything that has happened
over the 4.6 billion years
the solar system has been in existence.
This is how we can find out
where we came from,
where the Earth came from,
where the Moon came from,
how the solar system formed.