Astrobiology and Space Exploration (Winter 2010) - Download free content from Stanford. Carl Sagan Center. How many planets exists that might support life? Indeed, what is required for life to exist? How does life start? How does it evolve, and what fabulous creatures can evolution produce? How often do intelligent creatures appear in the giant tapestry of life? It is exactly these questions that are being addressed by the scientists of the Carl Sagan Center for the Study of Life in the Universe. Directed by Dr. David Morrison, the center brings together leading researchers in astrobiology, the study of life in the universe.
Our team focuses on a wide set of disciplines ranging from observing and modeling the precursors of life in the depths of outer space to studies of Earth and its rich biological history. Carl Sagan Center Projects and the Drake Equation Each Carl Sagan Center research project is related in some way to understanding the origins of life or the extent to which life may be present beyond Earth. Carl Sagan Center Funding. Homepage | setiQuest. The Universe in 3D: Planet & Star Size Comparison. Discovery of "Arsenic-bug" Expands Definition of Life. Discovery of "Arsenic-bug" Expands Definition of Life Dec. 2, 2010: NASA-supported researchers have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism, which lives in California's Mono Lake, substitutes arsenic for phosphorus in the backbone of its DNA and other cellular components.
"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it. " This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth.
The research is published in this week's edition of Science Express. The research team included scientists from the U.S. Editor: Dr. New Bacterial Life-Form Discovered in NASA and ESA Spacecraft Clean Rooms. High atop a platform inside a clean room at the European Space Agency’s (ESA) launch site in South America, scientists painstakingly searched for microbes near the Ariane 5 rocket due to launch the Herschel space telescope in May 2009. Only very unusual organisms can survive the repeated sterilization procedures in clean rooms, not to mention the severe lack of nutrients available.
But the scientists’ careful inspection was fruitful, turning up a type of bacteria that had been seen only once before. Two years earlier this same bug had surfaced 4,000 kilometers away in the clean room at NASA’s Kennedy Space Center in Florida where engineers were preparing the Mars lander Phoenix for launch. The researchers named the bacterium Tersicoccus phoenicis. Scientists go to all this trouble for the purpose of “planetary protection”—which usually means protecting other planets from contamination by microbes originating on Earth.
Icy Worlds Projects. The Center for SETI Research. SETI, the Search for Extraterrestrial Intelligence, is an exploratory science that seeks evidence of life in the universe by looking for some signature of its technology. Our current understanding of life’s origin on Earth suggests that given a suitable environment and sufficient time, life will develop on other planets. Whether evolution will give rise to intelligent, technological civilizations is open to speculation. However, such a civilization could be detected across interstellar distances, and may actually offer our best opportunity for discovering extraterrestrial life in the near future. Finding evidence of other technological civilizations however, requires significant effort. Currently the Center for SETI Research develops signal-processing technology and uses it to search for signals from advanced technological civilizations in our galaxy. Work at the Center is divided into two areas: Research and Development, and Projects.
Titan. Titan is Saturn's largest moon. It is surrounded by a thick, golden haze, and only certain kinds of telescopes and cameras can see through the haze to the surface. Titan is of great interest to scientists because it has flowing liquids on its surface and a dense, complex atmosphere. 10 Need-To-Know Things About Titan If the sun were as tall as a typical front door, Earth would be the size of a nickel and Titan would be the size of a pea.Titan is a moon that orbits the planet Saturn. Saturn is the sixth planet from the sun at a distance of about 1.4 billion km (886 million miles) or 9.5 AU.One day on Titan (the time it takes for Titan to rotate or spin once) takes about 16 Earth days. The length of Titan's day is the same as the amount of time it takes Titan to orbit Saturn. Read More About Titan. Europa. Planets: The planet count in our solar system has gone as high as 15 before new discoveries prompted a fine tuning of the definition of a planet. The most recent change was in 2006 when scientists reclassified Pluto as a new kind of object - a dwarf planet.
Dwarf Planets: This new class of worlds helps us categorize objects that orbit the Sun but aren't quite the same as the rocky planets and gas giants in our solar system. There could be hundreds more of these small worlds far out there waiting to be discovered. Moons: This count includes only the moons orbiting the eight planets in our solar system. Asteroids: New asteroids are discovered on an almost daily basis. Comets: Orbiting spacecraft such as SOHO have raised this tally in recent years by catching the comets as they plunge toward the Sun - and sometimes vaporize. Calculating the odds of intelligent alien life - Jill Tarter. Visualizing the possibility of intelligent life in the Milky Way. The Drake Equation. "What do we need to know about to discover life in space? " How can we estimate the number of technological civilizations that might exist among the stars? While working as a radio astronomer at the National Radio Astronomy Observatory in Green Bank, West Virginia, Dr.
Frank Drake conceived an approach to bound the terms involved in estimating the number of technological civilizations that may exist in our galaxy. The Drake Equation, as it has become known, was first presented by Drake in 1961 and identifies specific factors thought to play a role in the development of such civilizations. Although there is no unique solution to this equation, it is a generally accepted tool used by the scientific community to examine these factors.-- Frank Drake, 1961 Where, N = The number of civilizations in The Milky Way Galaxy whose electromagnetic emissions are detectable.
R* = The rate of formation of stars suitable for the development of intelligent life. Big Picture Science. Monday 16 December 2013 We all may prefer the goldilocks zone – not too hot, not too cold. But most of the universe is bitterly cold. We can learn a lot about it if we’re willing to brave a temperature drop. A chilly Arctic island is the closest thing to Mars-on-Earth for scientists who want to go to the Red Planet. Meanwhile, the ice sheet at the South Pole is ideal for catching neutrinos – ghostly particles that may reveal secrets about the nature of the universe.
Comet ISON is comet ice-off after its passage close to the Sun, but it’s still giving us the word on solar system’s earliest years. Also, scientists discover the coldest spot on Earth. Francis Halzen – Physicist, University of Wisconsin-Madison, principal investigator of The IceCube Neutrino Observatory Ted Scambos – Glaciologist, lead scientist, National Snow and Ice Data Center, University of Colorado Pascal Lee – Planetary scientist, SETI Institute, director, NASA Haughton-Mars Project, and co-founder of the Mars Institute.
A needle in countless haystacks: Finding habitable worlds - Ariel Anbar. S Kepler Telescope Discovers First Earth-Size Planet in 'Habitable Zone' The artistic concept of Kepler-186f is the result of scientists and artists collaborating to imagine the appearance of these distant worlds. Image credit: NASA Ames/SETI Institute/JPL-Caltech› Full image and caption April 17, 2014 Using NASA's Kepler Space Telescope, astronomers have discovered the first Earth-size planet orbiting a star in the "habitable zone" -- the range of distance from a star where liquid water might pool on the surface of an orbiting planet. The discovery of Kepler-186f confirms that planets the size of Earth exist in the habitable zone of stars other than our sun.
While planets have previously been found in the habitable zone, they are all at least 40 percent larger in size than Earth, and understanding their makeup is challenging. "The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth," said Paul Hertz, NASA's Astrophysics Division director at the agency's headquarters in Washington. Scientists Find Evidence of Water in Meteorite, Reviving Debate Over Life on Mars. This scanning electron microscope image of a polished thin section of a meteorite from Mars shows tunnels and curved microtunnels.
Image Credit: NASA› Full image and caption February 27, 2014 A team of scientists at NASA's Johnson Space Center in Houston and the Jet Propulsion Laboratory in Pasadena, Calif., has found evidence of past water movement throughout a Martian meteorite, reviving debate in the scientific community over life on Mars. In 1996, a group of scientists at Johnson led by David McKay, Everett Gibson and Kathie Thomas-Keprta published an article in Science announcing the discovery of biogenic evidence in the Allan Hills 84001(ALH84001) meteorite.
In this new study, Gibson and his colleagues focused on structures deep within a 30-pound (13.7-kilogram) Martian meteorite known as Yamato 000593 (Y000593). The team's findings have been published in the February issue of the journal Astrobiology. "This is no smoking gun," said JPL's White. Mars Exploration Rover Mission: Science. Goal 1: Determine Whether Life Ever Arose on Mars From the tiniest bacterium to the largest tree, all life as we know it requires water. Though we don't yet know if life ever existed on Mars, within weeks of arriving, NASA's Mars Exploration Rover Opportunity discovered that the plains of Meridiani were once a water-soaked place. While analyzing rocks and soils on Mars, the robotic geologist, equipped with a toolbox of scientific instruments, found hard spheres the size of peppercorns. Sometimes the spheres, nicknamed "blueberries," were loosely scattered across the surface; other times, they were anchored within individual rock layers.
After weeks of meticulous measurements, Opportunity demonstrated that the spheres consisted primarily of the mineral hematite. On Earth, hematite generally -- though not always -- forms in the presence of water. Water provides the oxygen atoms that bind with iron atoms in the mineral.