How many planets are there in our galaxy? That’s a tricky question to answer. Are there other planets that support life? That’s exactly what the Kepler mission hopes to discover.
NASA launched the Kepler space telescope, designed to find habitable planets, in 2009. So far it has discovered five new Earth-sized planets beyond our solar System. These planets are hotter than the Earth -much too hot for life as we know it. The Kepler team predict that they will need at least three years to find an Earth-like planet.The simplest requirement for a planet to have life is for there to be liquid water so the distance from the planet’s sun and therefore temperature are important. There also needs to be the correct amount of air. If a planet is as small as Mars (half the size of Earth) its weak gravity means that it can’t hold on to air molecules. If a planet is Neptune sized (four times bigger than Earth) it has very strong gravity and too much air. So size
matters too. The cost of the mission is approximately six hundred million dollars. It is scheduled to observe until 2013 but this could be extended. Will we be sad if we discover we are alone in our galaxy or happy if we find that we share it with other life forms?
B. Choose the correct answers.
1. What is the passage about?
A. Planets in our solar System
B. The difference between Earth and other planets
C. Space exploration to find habitable planets
D. NASA’s missions to explore the outer planets
2. The Kepler space telescope is looking for__________
A. new planets in our galaxy
B. life on other planets
C. liquid water on other planets
D. Earth-sized planets in the solar System
3. Kepler has found five planets that__________.
A. has water and air
B. are similar to Earth
C. are not too far away from the Earth
D. are not in our solar System
4. The Kepler team predict that they will need__________ to find an Earth-like planet.
A. three years and possibly longer
B. as much as three years
C. no more than three years
D. approximately three years
5. What are the primary factors that make a planet habitable?
A. Liquid water and living things
B. Size and distance from the Sun
C. Hot temperature and weak gravity
D. Strong gravity and too much air
6. How much does the Kepler mission cost?
A. Exactly $600 million
B. About $600 million
C. More than $600 million
D. Less than $600 million
7. Which of the following statements is NOT true?
A. The planet can support life if it has water and air.
B. A very small planet will not have enough air.
C. Earth is four times as big as Neptune.
D. Kepler mission is scheduled to end in 2013.
