In 1999, the population of the earth
reached six billion (6,000,000). It will probably reach eight billion in
another fifty years. In the future, we may have to find new places for people
to live because there might not be enough room on Earth. People may go to live
in space colonies or they might go to live on the other planets. Scientists
think that Mars will be the best place to live because it is the closest planet
to the earth and it will be easier to travel there. The temperature, gravity
and environment are not too different from earth. Another advantage is that
there is probably water there.
Before
people can live on Mars, we need more information about it. The North American
Space Agency, NASA, is planning to send more space probes to explore Mars.
Space probes are better than manned space craft because space travel over long
distances is difficult and dangerous for humans and takes a long time. There
are, of course, no people on board space probes and scientists on earth send signals
to the probes to control them. This takes a long time. When Pathfinder space
probe landed on Mars in 1997, it took 11 minutes for signals to travel to and
from Earth. Another difficulty is that the space probes do not have a lot of
energy to send their information back to Earth.
It
is important to improve communications between Mars and Earth. NASA scientists
want to have communications satellites around Mars. When they are in position,
they will help scientists to send and receive signals from the exploration
probes more easily. Cameras on the satellites will photograph Mars and also
scientists will make better maps. Communication satellites will also help NASA
with its plan fro a space probe to bring rock back from Mars.
When
more information is known about Mars, humans might be able to explore the
planet themselves. NASA scientist Chad Edwards said: “If we have to carry
everything with us, we’ll never get there.” NASA’s plan is to send unmanned
space probes first that will produce energy, water, fuel, and air on Mars.
Humans will then use these supplies during their stay there.
Ref:
Michael Harris and David Mower, World
Club Students’ Book, 2002.
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