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  1. Looking for Life, Astrobiologists Dive Deep


    A team of interdisciplinary astrobiologists from NASA and other agencies is homing in on recognizing the microbial biosignatures for life, making it easier someday to identify life on other planets.

    A scientific paper analyzing the team’s research results, titled “Modern Freshwater Microbialite Analogues for Ancient Dendritic Reef Structures,” was published in the journal Nature on October 5. The paper focuses on the study of mounded microbialite deposits – layers of living and non-living organisms – found at Pavilion Lake in Canada.
    Microbialites are organic sedimentary mineral deposits covered by a thin layer of microbes that become entombed in the ...

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  1. Jovian Moons


    Our moon, while celebrated in song and literature for its beauty, does not harbor life. With no atmosphere and little known water, conditions on our moon are not adequate to support life as we understand it. There are, however, a total of 61 moons orbiting the 9 planets in our solar system and some of them have atmospheres, organic molecules, water, or heat energy – the conditions necessary for life to exist.

    The larger moons of Jupiter, for instance, have some of the qualities that would make life possible. These moons – Europa, Io, Callisto, and Ganymede – are called ...

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  1. Scientists Find Clues That Life Began in Deep Space


    Text based on a NASA Ames Research Center press release

    Duplicating the harsh conditions of cold interstellar space in their laboratory, NASA scientists have created primitive cells that mimic the membranous structures found in all living things. These chemical compounds may have played a part in the origin of life.

    This breakthrough by scientists at NASA Ames Research Center in California’s Silicon Valley is important because some scientists believe that the delivery – by comets, meteorites and interplanetary dust – of similar organic compounds born in interstellar space might have “kick-started” life on Earth.

    “Scientists believe the molecules needed to ...

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  1. Without Jupiter, Home Alone


    To a biologist, the ingredients needed to form life include water, heat and organic chemicals. But some in the astrophysics and astronomy community argue that life, at least advanced life, may require an additional component: a Jupiter-sized planet in the solar neighborhood.

    “A long-period Jupiter may be a prerequisite for advanced life,” said Dr. Alan Boss, a researcher in planetary formation. Boss, who works at the Carnegie Institution of Washington, is a member of the NASA Astrobiology Institute (NAI).

    In our own solar system, Jupiter, with its enormous gravitational field, plays an important protective role. By deflecting comets and ...

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  1. Mars Ocean Hypothesis Hits the Shore


    To test the hypothesis that oceans once covered much of the northern hemisphere of Mars, scientists at Malin Space Science Systems (MSSS) of San Diego, CA, have used high resolution images of Mars taken with the Mars Orbiter Camera (MOC) on Mars Global Surveyor.

    “The ocean hypothesis is very important, because the existence of large bodies of liquid water in the Martian past would have had a tremendous impact on ancient Martian climate and implications for the search for evidence of past life on the planet,” said Dr. Kenneth Edgett, a staff scientist at MSSS.

    Features in earlier Mars ...

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  1. The Greening of the Red Planet


    Although Mars may once have been warm and wet, the red planet today is a frozen wasteland. Most scientists agree that it’s highly unlikely that any living creature, even a microbe, could survive for long on the very surface of the planet.

    When the first humans travel to Mars to explore the red planet up close, they will have to grow their food in airtight, heated greenhouses. The Martian atmosphere is far too cold and dry for edible plants to grow in the open air. But if humans ever hope to establish long-term colonies on their planetary neighbor, they will ...

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  1. Thawing Mars


    To say that Mars is a chilly place is a bit of an understatement. The mean annual temperature on the red planet is minus 55 degrees Celsius. It is far too cold for human habitation. Which explains why those who believe that humanity one day will establish colonies on Mars take very seriously the problem of how to warm the planet up.

    Humans won’t be building thriving communities on Mars any time soon. But that hasn’t stopped scientists from trying to figure out how the task of turning up the Martian thermostat might be accomplished. At a recent NASA-sponsored ...

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  1. Astrobiologists Find Evidence of Early Life on Land


    Text based on a NASA/Ames press release.

    Scientists with NASA’s Astrobiology Institute (NAI) have discovered fossilized remnants of microbial mats that developed on land between 2.6 billion and 2.7 billion years ago in the Eastern Transvaal district of South Africa.

    This significant discovery presents the strongest evidence to date that life on land occurred at a much earlier stage in Earth’s history than was previously believed by most scientists. It also suggests that an ozone shield and an oxygen-rich atmosphere existed on Earth 2.6 billion years ago, both necessary conditions for life on land to ...

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  1. The Dance of the Giant Planets


    (Text based on a NASA/Ames press release.)

    A team of planet hunters January 9th announced a discovery that will help researchers better understand planet migration and how planets’ gravitational pulls influence each other. The discovery was announced at the American Astronomical Society meeting in San Diego.

    The planet sleuths from the University of California at Berkeley, NASA and other institutions discovered the planetary pair locked in what appears to be “resonant” orbits, moving in synch around the star with orbital periods of 60 and 30 days. Because of the 2-to-1 ratio, the inner planet goes around the star twice ...

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  1. Terrestrial Powerhouses


    As the electric spark important for all cellular life, one remarkable protein, among others — called bacteriorhodopsin— converts light into metabolic energy. This process has always been something of a mystery, but after 30 years of investigations this protein has finally revealed some of its secrets. As reported in the August 10 issue of Nature, three pieces of this biological puzzle are now starting to fit together.

    Bacteriorhodopsin is an intensely purple-colored protein found in microbes that live in extreme environments such as salt marshes and salt lakes. This light-sensitive protein provides chemical energy to these microbes—sometimes called Halobacteria. It ...

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  1. Kepler Planet-Finding Mission Selected for Discovery Program


    NASA has selected for further study a proposal from Ames Research Center to search for Earth-size planets around stars beyond our solar system.

    The Kepler mission, which will use a space telescope specifically designed to search for habitable planets, is one of three candidates for NASA’s next Discovery Program mission. If selected, Kepler will be launched in 2005.

    “The Kepler mission will, for the first time, enable humans to search our galaxy for Earth-size or even smaller planets,” said principal investigator William Borucki of Ames. The mission could find habitable planets in Earth-like orbits within 4 years of ...

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  1. Martian Micromagnets


    The case for ancient life on Mars looks better than ever after scientists announced last week that they had discovered magnetic crystals inside a Martian meteorite — crystals that, here on Earth, are produced only by microscopic life forms.

    The magnetic compound, called magnetite or Fe3O4, is common enough on our planet. It is present, for example, in household video and audio tapes. But only certain types of terrestrial bacteria, which can assemble the crystals atom by atom, produce magnetite structures that are chemically pure and free from defects.

    Scientists have found just such crystals deep inside the Allan Hills ...

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  1. More Distant Planets Discovered


    Imagine a single month in which eight new worlds outside our solar system could be discovered. This summer two separate findings were announced by the University of Texas at Austin’s McDonald Observatory and by the European Southern Observatory, thus raising to over 50 the number of planetary candidates to probe in future studies.

    Astronomers at the McDonald Observatory discovered a planet orbiting the star epsilon Eridani, a solar system only 10.5 light-years away from Earth. Relatively speaking, this star is a close neighbor, being the tenth closest star to our Sun. Epsilon Eridani is the fifth brightest star in ...

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  1. Evidence of Ocean on Jupiter's Moon Ganymede


    Text based on NASA/JPL Press Release

    Add Jupiter’s moon Ganymede, which is bigger than two of the solar system’s nine planets, to the growing list of worlds with evidence of liquid water under the surface.

    A thick layer of melted, salty water somewhere beneath Ganymede’s icy crust would be the best way to explain some of the magnetic readings taken by NASA’s Galileo spacecraft during close approaches to Ganymede in May 2000 and earlier, according to one new report.

    In addition, the types of minerals on parts of Ganymede’s surface suggest that, in the past, salty water may ...

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  1. Titanic Moon: Orange Soup From Saturnian Turn


    Titan is Saturn’s biggest moon. A little larger than the planet Mercury, it is also one of the biggest moons in the solar system (only Jupiter’s moon Ganymede is larger). The astronomer Carl Sagan described Titan as, “one of the most fascinating and instructive worlds illustrating prebiological organic chemistry.” Sagan stated that, on Titan, we could see the synthesis of complex organic molecules happening right before our eyes.

    That’s because the orange haze that completely surrounds Titan is an organic chemistry experiment in action. Cosmic rays, ultraviolet light from the sun, and charged particles trapped by Saturn’s magnetic field ...

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Astrobiology Magazine