[MUSIC]

Student: My question is how fast
is the fastest robot?

Tom McCarthy: Well, it turns out
there is actually some pretty

fast robots out there.
There's actually a running

robot, a cheetah, a robot that's
faster than Usain Bolts.

So, over 28 miles an hour.
Student: My question is why are

moon rovers and mars rovers so
slow?

McCarthy: So the reason why the
Moon and Mars rovers is so slow

is because they have to carry
all of their energy on board

through batteries, or they have
to convert, uh, electrical power

from the sun in some cases and
store it.

And they go slow to conserve
that energy.

They don't, if they go really
fast they'll burn up all their

energy quickly, and then it
takes a long time for them to

charge.
So they meter out their

performance over a long period
of time.

Joan Cartan-Hansen: For more
information about robotics,

check out the science trek
website.

You'll find it at science trek
dot org