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 Kelper mission hopes to discover. NASA launched the Kelper 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’s sun – much too hot for life as we know it. The Kelper 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 (carbon-based life like on Earth) is for there to be liquid water (not frozen or gas) 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?
Answer the questions:
What is the Kelper’s mission?
How much time will be needed to find an Earth-like planet?
What are the requirements for a planet to have life?
What is the cost of the mission? (4 points)