Moon and Mars [audio: cold, dry wind; add echo(?) and fade out]
December brings cold winds across much of the United States --
like icy needles pricking your skin. Another place with cold
winds is the planet Mars. A recent Martian lander measured wind
speeds of up to 35 miles an hour. Combined with temperatures as
low as a hundred below, that's quite a windchill. Phoenix landed
in the high northern plains, not far below the polar ice cap. It
operated for about five months -- until the Sun dropped too low
in the sky to power its solar batteries. It discovered frozen
water just inches below the surface, and measured the
composition of the soil. Phoenix also operated a weather
station. It measured temperature and wind speed, and took
pictures of the clouds streaking above it. The craft landed
during the Martian summer, and recorded fairly steady winds from
the east. As autumn approached, though, the wind got stronger,
and began blowing from the west. As cold fronts passed by, the
wind got stronger, with gusts of