Charlie Sensenbrenner's List: Requirements for life

• arik Israelian is a spectroscopist, studying the spectrum emitted by a star to figure out what it's made of and how it might behave. It's a rare and accessible look at this discipline, which may be coming close to finding a planet friendly to life.

• bombardments of meteorites approximately four billion years ago could have helped to make the early Earth and Mars more habitable for life by modifying their atmospheres
• extreme heat causes some of the minerals and organic matter on its outer crust to be released as water and carbon dioxide before it breaks up and hits the ground
• could have made Earth's and Mars' atmospheres wetter
• each meteorite was capable of releasing up to 12 percent of the meteorites' mass as water vapour and 6 percent of the meteorites' mass as carbon dioxide when entering an atmosphere
• an ancient meteorite shower called the Late Heavy Bombardment (LHB), which occurred 4 billion years ago, where millions of rocks crashed to Earth and Mars over a period of 20 million years
• 10 billion tonnes of carbon dioxide and 10 billion tonnes of water vapour could have been delivered to the atmospheres of Earth and Mars each year.
• Mars' good fortune did not last. Unlike Earth, Mars doesn't have a magnetic field to act as a protective shield from the Sun's solar wind. As a consequence, Mars was stripped of most of its atmosphere.
• A reduction in volcanic activity also cooled the planet. This caused its liquid oceans to retreat to the poles where they became ice.

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• At 3:49 GMT today, 7 March, NASA's Kepler mission successfully launched into space from Cape Canaveral Air Force Station, Florida, aboard a United Launch Alliance Delta II. Kepler is designed to find the first Earth analogues orbiting stars at distances where water could pool on the planet's surface. Liquid water is believed to be essential for the formation of life. By the end of Kepler's three-and-one-half-year mission, it will give us a good idea of how common or rare other Earths are in our Milky Way galaxy.
• so meaningful to the human race - Kepler will help us understand if our Earth is unique or if others like it are out there.
• Kepler now has the perfect place to watch more than 100,000 stars for signs of planets,'
• We are on the verge of learning if other Earths are ubiquitous in the galaxy.'
• is the world's first mission with the ability to find true Earth analogues - planets that orbit stars like our sun in the 'habitable zone.'
• Kepler's three-and-one-half-year mission, it will give us a good idea of how common or rare other Earths are in our Milky Way galaxy
• Kepler detects planets by looking for periodic dips in the brightness of stars. Some planets pass in front of their stars as seen from our point of view on Earth; when they do, they cause their stars to dim slightly, an event Kepler can see.

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• ocky planets, possibly with conditions suitable for life, may be more common than previously thought in our galaxy, a study has found.
• New evidence suggests more than half the Sun-like stars in the Milky Way could have similar planetary systems.

• What is life? What does it mean do be alive? How is something made “living”? These are all pertinent questions when discussing the origin of life. Scientists have identified seven basic characteristics of life. For something to be described as living, that something must display all seven of these characteristics. Although many different people have many different opinions about what "living" means, the following characteristics were designated "characteristics of living things" with the consensus of the scientific community.

  • You will notice difference in how many traits there are in living things. We learned "5" in class. That doesn't mean it is the perfect answer to a tough question. The reason there are differences is that you might be able to include some of the characteristics together. For example: We have "reproduce" as a trait. This site has "reproduce" and "displays heredity" as two separate traits. We are grouping heredity as part of reproduction.