This week's programme is all about meteorites and asteroids. Not too far from
the Rough Science base on the edge of Death Valley is
Meteor Crater. Iain, Kathy
and Mike have to work out how
big the meteor that caused this huge crater must have
been.
But it's not just the Earth that gets hit by objects
from outer space - the moon is also a target, as evidenced
by its heavily cratered surface. So Jonathan
and Ellen have to pick a crater
on the moon - any crater will do and measure how big
it is. And because they'll be doing their measurements
at night, Ellen has to come up with some lights.
The Meteor Crater team decide they have to split their
work. Kathy and Iain head off to the crater itself to
try and measure its diameter. This is the first essential
step if they are to work out how big the meteor was
that caused the crater. At the same time, they are hoping
to find out more about the meteor in the hope this will
give them clues about its size. Meanwhile Mike stays
behind to try and make his own crater. He performs a
series of impact experiments, dropping heavy objects
into sand in an effort to work out the relationship
between the size of an object and the size of crater
it forms.
Jonathan and Ellen have been given a high quality optical
mirror, and so to find and measure a crater on the moon,
they build a reflecting telescope. Their plan is to
time how long it takes the whole moon to travel across
a fixed point in their eyepiece, and then time how long
it takes their chosen crater to travel across that same
fixed point. Because they know that the moon is 3500
kilometres across, they can use this as a starting point
to calculate the diameter of the crater.
For her lights Ellen heads to the hills and collects
pine sap. She melts it to remove some of the most volatile
compounds, and then uses bark fibres as wicks, to make
highly effective Rough Science candles.
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