[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 up to 35 miles an hour.
Before Phoenix shut down, it also discovered snow falling from the clouds. So conditions were setting up for a cold, blustery winter in the northern plains of Mars. [more wind]
If it's not too blustery here on Earth, look for bright orange Mars trailing the Moon across the sky late tonight. They rise in late evening, with Mars to the lower left of the Moon.
More about Mars and the Moon tomorrow.
Script by Damond Benningfield, Copyright 2009
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