Title: Finding Life on Other Worlds - Science in the News
Headings: Finding Life on Other Worlds
Finding Life on Other Worlds
Finding the Pieces of the Puzzle
Looking in the Neighborhood
Current and Future Missions
For more information:

Content: For example, scientists have generated two new DNA bases that could have evolved alongside the four found in Earth’s organisms. The possible forms of life that could develop from these same starting blocks are hard to fathom. To simplify the search for extraterrestrial life, the main compound of interest has been liquid water, given how vital is was for the development of life on Earth. In our own solar system, both planets and their moons have been investigated using spacecraft that either study from afar or land directly on the surface. Outside the solar system, the Kepler telescope looks for evidence of other planets by searching for dimming stars as planets pass in front of them. Using this technique, Kepler has identified over 2,400 exoplanets (planets around other stars). The atmosphere of these exoplanets is inferred from spectroscopy, where compounds in the atmosphere block specific wavelengths of light as the planet passes in front of its star. Several of these identified planets are about the size of Earth, and reside in the zone around their star where liquid water could be present based on their stars’ heat output. Looking in the Neighborhood
Due to its proximity, the planet that has been most closely researched for signs of life is Mars, which has been studied using orbiting satellites and rovers, and probably humans themselves in the near future. Though Venus is closer on average to Earth than Mars is, Venus’s 800 degree Fahrenheit acid-laden atmosphere makes it far less likely to sustain life, making Mars our closest plausible planetary neighbor with signs of life.