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The Frosted Craters of Northern
Spring and Southern Autumn - Lowell Crater from NASA's
Planetary Photojournal.It is spring in the northern
hemisphere, and frost that accumulated during the most recent
6-month-long winter has been retreating since May. It is
autumn in the southern hemisphere, and frost was seen as early
as August in some craters; later the frost line moved farther
north, and we began to see frost in Lowell Crater in
mid-October.
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People could land on Mars in the next 20 to 30
years provided scientists can find water on the red planet, the head of
NASA's surface exploration mission said on September 16.
Two partially solar-powered "robot geologists" -- Mars Exploration
Rovers, or MERs -- have been trundling across 3 miles of the planet and
into craters since January, beaming back data about the makeup of what
scientists believe is Earth's sister planet.
Asked how long it could be before astronauts land on Mars, Arthur
Thompson, mission manager for MER surface operations said, "My best guess
is 20 to 30 years, if that becomes our primary priority."
The two MER robots, dubbed Spirit and Opportunity, have found ancient
evidence that water was once plentiful -- important for scientists hoping
to know if there was once -- or could still be -- life on Mars.
Without water, the dream of sending astronauts to the often dusty
planet, which has rust-colored rocks and where the sky is red and sunsets
are blue, couldn't unravel.
"If we cannot find water，it really makes it difficult to send humans.
Water is the key," said Thompson, who was attending a mining engineers'
conference.
Such a mission would take 11 to 12 months to get to Mars and it would
be impossible to carry enough water for the astronauts, plus the water
needed to make rocket fuel for the return journey, to cool the spacecraft
and to generate energy.
Thompson said scientists had found a canyon on Mars "that makes the
Grand Canyon look like a small canyon," where water could still be
present.
"There are indications that there is actually water that seeps out the
side of the canyon, and going down the side it evaporates. We believe it's
an ongoing process," he said.
Three satellites now orbiting Mars
are constantly gathering information, and Thompson said, "If there is
water, we believe the chances of finding life are greatly
increased."
(Agencies) |
9月16日，美国国家宇航局地表探测任务小组的负责人表示，如果科学家们能够在火星上找到水源的话，人类就可能在20到30年后登上火星。
两台部分由太阳能驱动的“机器人地质学者”——火星探测漫游者（简称为MERs）自1月份以来已经在火星上移动了3英里，并且进入了火星表面的环形山，同时向地球发回有关火星组成结构的数据。科学家们把火星视为地球的姊妹星。
当问到宇航员还需要多久才能登上火星时，“火星探测漫游者”地表探测任务小组负责人亚瑟·汤普森说：“如果我们把登上火星作为首要目标的话，我预计最快要20到30年。”
这两位火星探测漫游者分别被命名为“勇气号”和“机遇号”，他们发现了可以证明火星上曾经存在大量的水的古老证据，这对想要知道火星上是否曾经存在或仍然存在生命的科学家来说是非常重要的。
火星上尘土飞扬，岩石是铁锈色的，天空是红色的，日落是蓝色的。如果没有水，把宇航员送上火星的梦想就无法实现。
汤普森在参加一个采矿工程师会议时说：“如果我们找不到水的话，把人类送上火星是非常困难的。水是关键因素。”
把宇航员送到火星上的任务需要花11到12个月的时间。宇航员们无法带够所需的水。此外，在返回地球时，需要用水来生成火箭燃料、冷却太空船并产生能量。
汤普森说科学家们在火星上发现了一个峡谷，与这个峡谷相比，“美国大峡谷就显得很渺小了”。这个峡谷现在仍然可能有水。
他说：“有迹象表明确实有水从峡谷的一侧渗出，并沿着这一侧流淌蒸发。我们相信这个过程还在进行中。”
三颗围绕火星运行的卫星正不断地收集信息。汤普森说：“我们相信如果发现水的痕迹，发现生命的可能性就大大增加了。”
（中国日报网站译） |
Updated: 2004-09-17 10:11