CQR Search for Life on New Planets
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Published by CQ Press, an Imprint of SAGE Publications, Inc. www.cqresearcher.com Search for Life On New Planets Are distant worlds habitable? ith increasing frequency, scientists are finding evidence that planets and moons throughout the universe could be hospitable to life. W Nearly 1,800 planets orbiting stars other than the sun have been confirmed since 1995, including more than 700 in February alone. Scientists now conclude that the Milky Way galaxy alone contains a trillion planets, and many believe microbial life, if not intelligent life, exists beyond Earth. Still, finding extrater - The Allen Telescope Array, in Northern California, is restrial life poses enormous challenges. Adequate instruments for now made up of 42 dishes that scan space for radio signals possibly sent by civilizations from distant observation and sufficient scientific understanding don’t yet exist to planets or moons. Initially funded by Microsoft co- founder Paul Allen, the privately operated array is envisioned to include 350 dishes when, and if, determine whether distant planets — or even potentially habitable funds are raised for its completion. moons in our own solar system — harbor life. Moreover, scientists are split on whether sending robots or humans to explore distant I THIS REPORT worlds is more effective. The biggest challenge for space science, N THE ISSUES ....................531 however, may be Washington budget-cutting, which has made it dif - S BACKGROUND ................538 ficult to ensure stable, long-term funding for large scientific projects. I CHRONOLOGY ................539 D AT ISSUE ........................545 E CQ Researcher • June 20, 2014 • www.cqresearcher.com CURRENT SITUATION ........546 Volume 24, Number 23 • Pages 529-552 OUTLOOK ......................547 RECIPIENT OF SOCIETY OF PROFESSIONAL JOURNALISTS AWARD FOR BIBLIOGRAPHY ................550 EXCELLENCE N AMERICAN BAR ASSOCIATION SILVER GAVEL AWARD THE NEXT STEP ..............551 SEARCH FOR LIFE ON NEW PLANETS June 20, 2014 THE ISSUES Tally of Exoplanets Volume 24, Number 23 533 Rises to Nearly 1,800 MANAGING EDITOR: Thomas J. Billitteri • Is complex life rare in the Scientists find hundreds of [email protected] 531 universe? distant planets each year. • Should the search for ASSISTANT MANAGING EDITORS: Maryann extraterrestrial life focus on Missions to Mars Haggerty, [email protected], 535 Kathy Koch , [email protected] Earthlike planets? Scientists have been studying • Should the search for life the “red” planet for more SENIOR CONTRIBUTING EDITOR: rely on robotic missions? than 50 years. Thomas J. Colin [email protected] The Search for Habitable 537 CONTRIBUTING WRITERS: Brian Beary, BACKGROUND Planets Marcia Clemmitt, Sarah Glazer, Kenneth Jost, NASA lays out its goals for Reed Karaim, Peter Katel , Robert Kiener, exploration in coming Barbara Mantel, Tom Price, Jennifer Weeks Scientific Groundwork decades. 538 The Cold War drove the SENIOR PROJECT EDITOR: Olu B. Davis space race. Chronology EDITORIAL ASSISTANT: Ethan McLeod 539 Key events since 1953. 542 Viking and After FACT CHECKERS: Eva P. Dasher, Unmanned craft have explored SETI Scientists Scan the Michelle Harris, Nancie Majkowski Mars and other planets. 540 Universe INTERN: Kaya Yurieff Private funds finance search New Hopes for intelligence. 544 Astrobiology drew increased interest as scientists discovered Planet Studies Give planets in other solar systems. 542 Earthlings a Cosmic Perspective An Imprint of SAGE Publications, Inc. CURRENT SITUATION “We’ve learned what we really don’t know.” VICE PRESIDENT AND EDITORIAL DIRECTOR, HIGHER EDUCATION GROUP: 546 Remarkable Discoveries At Issue: Michele Sordi NASA’s robots continue to find 545 Is asteroid retrieval a good planets that might harbor life. EXECUTIVE DIRECTOR, ONLINE LIBRARY AND step toward a human Mars REFERENCE PUBLISHING: mission? 547 Webb Telescope Problems Todd Baldwin Budget, timetable have Copyright © 2014 CQ Press, an Imprint of SAGE Pub - delayed other missions. FOR FURTHER RESEARCH lications, Inc. 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POST MAST ER: Send ad dress chang es to CQ Re search er , 2300 N St., N.W., Suite 800, Cover: SETI Institute Wash ing ton, DC 20037. 530 CQ Researcher Search for Life On New Planets BY MARCIA CLEMMITT The increasingly frequent THE ISSUES discovery of evidence that many moons and planets could arlier this month, as - support at least microbial life tronomers announced touches one of humanity’s most E the discovery of a sur - persistent questions: Are we prise in the skies: the heav - alone in the universe? iest rocky planet ever ob - The public’s fascination with served — 17 times the mass life elsewhere in the universe of the Earth. Until now, sci - is clear “any time data or pic - entists had thought that all tures show signs of water,” says such massive planets would Linda Billings, a research pro - be made of gas or ice, like fessor at the George Washing - Jupiter and Neptune in our ton University School of Media solar system. and Public Affairs who fre - The new planet, though, quently has consulted for the has such a small diameter in National Aeronautics and Space relation to its mass that it Administration (NASA). “All the must consist mainly of dense headlines scream, ‘Life on Ence - rock, the researchers said. ladus!’ The public discussion Scientists currently think immediately turns to life.” life is more likely to devel - In some ways, that fascina - op on planets with hard sur - tion with life in space is un - faces, so the discovery “in - alloyed good news for NASA. creases the number of planets NASA science missions such k y out there which could be r as the Kepler space telescope, t S potentially habitable,” said re - launched in 2009 to search for d e search team member Dimitar T exoplanets, and the Cassini / L Sasselov, a professor at the P Saturn orbiter, launched joint - J Harvard-Smithsonian Center / ly in 1997 with the European A S for Astrophysics, in Cam - A Space Agency and Italy’s space 1 N bridge, Mass. Complex patterns cover the icy surface of Jupiter’s agency, are almost wholly re - The big, rocky planet, which moon Europa in an image created with data acquired by sponsible for the data and ob - is 560 light years away, circling NASA’s Galileo spacecraft in the 1990s. Flyby NASA servations on which a current a star in the constellation Draco, missions since 2004 have shown that some moons flood of findings is based. is not the only such find to including Europa contain evidence of water and NASA essentially invented geologic activity, making them possibly habitable. make headlines recently. * Many scientists believe that microbial life, if not astrobiology — the interdis - The pace of discovery of intelligent beings, exists beyond Earth. ciplinary scientific field that confirmed exoplanets — studies the origin, nature, dis - planets orbiting stars other tribution and future of life than the sun — has greatly accelerated: In April, scientists reported spotting across the universe. Since its found - Of the almost 1,800 exoplanets found an Earth-sized planet orbiting at the ing in 1958, the agency has funded a since the first one was discovered in right distance from its star to have liquid sometimes- controversial group of sci - 1995, 715 were just added to the list water — another sign of potential habit - entists whose work has shaped the now- in February. 2 (See graph, p. 533. ) ability — in a solar system 490 light mainstream field. Today those efforts years away. 3 Other scientists found are paying off in new discoveries. evidence of a lake the size of Lake * A light year is a unit used for astronomical dis - But findings suggesting that life tances. One light year is the distance light can Superior under the ice near the south may exist in many more places than travel in a vacuum in one year — a little less pole of Saturn’s moon Enceladus, in - previously thought create their own than 6 trillion miles. The sun is about eight light creasing the chance that Enceladus too challenges. Scientists still have neither minutes from Earth. might harbor life. 4 adequate observational instruments nor www.cqresearcher.com June 20, 2014 531 SEARCH FOR LIFE ON NEW PLANETS “We should allow ourselves . as Moons May Contain Water — and Life broadly as possible, to think of life as Moons once thought to be quiet and lifeless are now known to contain being as capable as possible, and get signs of water and geologic activity.