2004-1-19
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VOICE ONE:
This is Science in the News, in VOA Special English. I'm Sarah
Long.
VOICE TWO:
And I'm Bob Doughty. This week -- the news from Mars ... and a
report on President Bush's plan for space exploration.
VOICE ONE:
Plus a warning from scientists who study life, and its future,
here on Earth.
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VOICE TWO:
Scientists are excited about the
progress of Spirit, the American exploration vehicle on Mars. It
landed January third to look for environmental conditions that could
have supported life. Engineers and scientists cheered as the
spacecraft sent its first pictures.
Spirit landed on target in the Gusev Crater, an area fifteen
degrees south of the Martin equator. Scientists chose the Gusev
Crater based on evidence that it may have been an ancient lake.
Hours after landing, the spacecraft began to send detailed
pictures of the surrounding area.
VOICE ONE:
Spirit traveled
four-hundred-eighty-seven-million kilometers to reach Mars. It
stayed in place on its lander for more than a week. NASA officials
wanted to make sure all the equipment worked before they told the
rover to drive onto the surface.
There was a delay. They had to turn the vehicle away from airbags
that softened the landing but then blocked the desired path. Last
Thursday the controllers again cheered as they declared that all six
wheels of the rover were on Martian soil.
Special cameras and devices to identify minerals helped engineers
and scientists decide which direction to send the rover first.
Spirit has a robotic arm to collect rocks and soil to study them for
evidence of water in the past.
VOICE TWO:
Spirit was launched from Florida last June. NASA launched a
second spacecraft in July, called Opportunity. Opportunity will land
on Mars in a few days if all goes as planned,. The landing area
chosen is called the Meridiani Planum. It is on the other side of
the planet from where Spirit landed. NASA officials say the two
areas are very different.
Like Spirit, Opportunity weighs about one-hundred-eighty
kilograms. The two rovers are expected to travel no more than forty
meters each Martian day to search for evidence of water. A Martian
day is about the same length as an Earth day. The exploration is
supposed to continue for at least three months.
VOICE ONE:
On Earth, almost everywhere liquid water exists, so does life.
Today Mars is cold and dry, with huge dust storms. Scientists say
life cannot exist. But evidence from past landings suggest the red
planet was once warmer. Experts say water could have flowed in lakes
or even oceans.
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VOICE TWO:
President Bush has proposed to
send people to Mars. Before that, however, robotic spacecraft would
go to the moon to prepare for the return of humans.
People would return to the moon sometime between
two-thousand-fifteen and two-thousand-twenty. They would go on a new
kind of spaceship to be developed, called the Crew Exploration
Vehicle.
Crews would establish a moon base for scientific research. Later,
that base could be used to launch explorers farther into space.
Mister Bush visited NASA headquarters in Washington last week to
announce the plan to explore what he called "worlds beyond our own."
VOICE ONE:
The first goal is to complete the International Space Station by
two-thousand-ten. Fifteen other nations are also involved in the
program. Mister Bush says the station is needed to study the
long-term effects of radiation and weightlessness on health. He says
there is much to learn before human crews can travel through space
for months at a time.
NASA will need its current space shuttles to complete the
station. But Mister Bush says the three shuttles will be retired
after that. NASA has not launched a shuttle since the Columbia broke
apart on re-entry into the atmosphere last February first. Seven
astronauts were killed.
Mister Bush said the United States will invite other nations to
join his plans in what he called a spirit of cooperation and
friendship. Last October, China sent its first person into orbit
around Earth in a test as the Chinese develop a space program.
VOICE TWO:
Mister Bush says he wants Congress to add one-thousand-million
dollars to the NASA budget over the next five years. In addition,
NASA would move eleven-thousand-million dollars away from existing
programs. The current five-year budget plan for the agency is
eighty-six-thousand-million dollars.
Mister Bush's father, when he was president, also proposed
setting up a moon base and sending people to Mars. The older
President Bush announced his plan in nineteen-eighty-nine. He did so
to mark twenty years since the first moon landing. But that plan
called for a much bigger budget and did not succeed.
Critics call the new plan a political move in an election year.
They say the money would be better spent at home. But President Bush
said in his speech: "We chose to explore space because doing so
improves our lives and lifts our national spirit. So let us continue
the journey."
VOICE ONE:
In the early nineteen-sixties, President John F. Kennedy declared
the goal to put a man on the moon. The space program began as a race
with the Soviet Union. The Soviets were the first to reach space.
But the United States was the first -- and so far only -- country to
land people on the moon. The last of six Apollo landings took place
in December of nineteen-seventy-two.
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VOICE TWO:
International researchers say climate warming caused by human
activity could lead to the destruction of hundreds of kinds of
plants and animals in the next fifty years. Most scientists think
climate change, or global warming, results from the release of
carbon dioxide and other gases. Industrial production and vehicles
release these gases. The gases trap heat in the atmosphere.
The nineteen scientists studied more than
one-thousand-one-hundred species of plants and animals in land areas
around the world. They published their study in the magazine Nature.
VOICE ONE:
The researchers gathered information from earlier studies. These
included examinations of animals that live in deserts, wetlands,
cool climates and other habitats in five areas of the world. The
scientists used several computer models on expected climate change.
The models were divided into levels of possible severity, from
moderate to extreme climate change.
The researchers joined these models with maps of the different
kinds of environments in which the species lived. These maps
provided information about what each species needed from its
environment and how climate change would affect those needs. Then
they studied where those species might have to move in cases where
their needs could no longer be met.
The scientists found that between fifteen and thirty-seven
percent of the species they studied will disappear in fifty years if
climate change continues.
VOICE TWO:There are more than fourteen-million known species of
plants and animals on Earth. Study leader Chris D. Thomas says it
would be helpful to include more in the examination. But, he also
said there is no reason to think the findings would change greatly
if more species were included. Mister Thomas is a scientist at the
University of Leeds in Britain.
Townsend Peterson of the University of Kansas in the United
States was another study team member. He says there are a number of
reasons people should be concerned about the threatened extinction.
He says the information loss from destruction of a species is one
concern.
For example, a threatened plant may contain a substance that
could be used to make an important medicine. But, Mister Peterson
says humans should also care because each species is a part of the
natural history of the planet.
Other scientists criticized with the study. One scientist said it
is too difficult to see into the future and predict results fifty
years from now. Another scientist said the study did not recognize
the ability of species to change or adapt in order to live in higher
temperatures.
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VOICE ONE:
SCIENCE IN THE NEWS was written by Caty Weaver, Avi Arditti and
Cynthia Kirk, who was also our producer. This is Sarah Long.
VOICE TWO:
And this is Bob Doughty. Join us again next week for more news
about science in Special English on the Voice of America.