For a weather forecaster, there'd probably be no easier gig than the northern plains of Mars. The Phoenix lander touched down there six months ago, at the beginning of summer in Mars's northern hemisphere. For its first few months, the lander found that conditions changed very little from day to day, as mission leader Peter Smith explains:
SMITH: The summer's a very balmy time in the northern Arctic. The temperatures have been very steady day to day, with highs around minus 20 and lows around minus 110. And that's pretty much a repeatable pattern day to day because the Sun's always up, the winds tend to move about the spacecraft throughout the day. We have clouds at about three to five kilometers, and the dust comes in in various patterns throughout the day. [:30]
But the seasons are changing from summer to fall. The Sun is no longer above the horizon around the clock, so the air gets colder. And more dust could fill the skies, robbing Phoenix of power. Mission scientist Peter Taylor describes what the Phoenix team is expecting:
TAYLOR: If you look at the long-term data from Mars, you can see features showing up every few years which indicate intense storms occurring.... And one might expect some effects of that to be observed at the lander site. We'll also start to see much more frost on the ground. When the Sun starts to go below the horizon, the ... range of temperature between night and day could increase, and that in turn could increase the likelihood of dust devils occurring. [:32]
Soon, the Sun will drop from sight completely. And in a few months, Phoenix will be entombed in ice -- throughout the long, predictable winter nights of Mars.
Script by Damond Benningfield, Copyright 2008
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
[1]
