(NASA Administrator Dan) Golden accepts that the search for life on Mars is not over.
"If we wanna find out what Mars is like, what its weather patterns are like, what its geology is like, where there's potential sources of water and other resources can we generate, the substance of life, breathing gases, water, nutrition on the surface, you must send spacecraft."
In 1996, NASA launched Mars Pathfinder on a seven-month journey to Mars. Twenty years had passed since the first Mars landing. Pathfinder has been designed to test a variety of new technologies for 21st century space exploration. The most challenging aspect of the mission is the landing on the Martian surface. Instead of fuel-guzzling braking engines, Pathfinder uses the planet's own atmosphere to slow it down from 17,000 miles per hour to around 1,000 miles per hour. A parachute slows the vehicle further to about 135 miles per hour. Seconds before impact, computers trigger the firing of small solid rockets and the inflation of a giant collection of airbags to soften the impact which takes place at about 40 miles per hour.
In the light of a Martian day, a solar-powered robot explorer roams an ancient flood plain, collecting samples in the continued search for past or present life.
"When we go to a place like Mars and we ask the question , you know, if we were gonna look for evidence of an ancient biosphere on Mars where would we go to look? Well, it'll be an environment like this. So by studying these places and understanding the processes by which this biological information is captured, we are in a much better position to address those issues on Mars. We know what, first of all, what kind of targets to look for, so that when we send landed missions there, we'll know where to go. Secondly, we know better how to interpret the information contained in those rocks when we bring samples back from Mars. So this is really a good training ground, really, for sample return mission from Mars."
If Mars has ancient salt deposits, scientists might be able to revive some sleeping Martians. Boulby Salt Mine, in the North of England, provides an example of how it might work. Microbiologist, William Grant, is about to tour a saline cemetery for microorganisms.
Boulby Mine is all that remains of an ancient lake. It's one of the deepest mines in the world, also, one of the hottest.
"I'm about a mile below the surface and it's baking hot. I'm standing in part of what, 260 million years ago used to be a vast salt lake, a bit like the Dead Sea or the Great Salt Lake... but much much bigger. And 260 million years ago, this lake teemed with life."
Professor Grant seeks to revive dormant microbial life that might exist in the mine's salt deposits.
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Words in this passage
Pathfinder:探險者, 開創(chuàng)者
guzzle: to eat or drink quickly, eagerly and usually in large amounts:狂飲, 暴食(這里用了擬人化的手法)
roam:to move about or travel, especially without a clear idea of what you are going to do:漫游, 閑逛, 徜徉
salt deposit:鹽層
saline:containing or consisting of salt:鹽的; 與鹽有關(guān)的;含鹽的
teem with sth:o contain large numbers of sth:充滿