Three billion years ago, Earth was a very different place.
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 ...January 26, 2001 • Posted by: Shige Abe • Report issue
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 ...January 23, 2001 • Posted by: Shige Abe • Report issue
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 ...January 22, 2001 • Posted by: Shige Abe • Report issue
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 ...January 18, 2001 • Posted by: Shige Abe • Report issue
(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 ...January 16, 2001 • Posted by: Shige Abe • Report issue
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 ...January 09, 2001 • Posted by: Shige Abe • Report issue
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 ...January 08, 2001 • Posted by: Shige Abe • Report issue
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 ...January 04, 2001 • Posted by: Shige Abe • Report issue
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 ...December 28, 2000 • Posted by: Shige Abe • Report issue
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 ...December 21, 2000 • Posted by: Shige Abe • Report issue
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 ...December 19, 2000 • Posted by: Shige Abe • Report issue
By simulating the conditions of hydrothermal vents in the lab, researchers at the Geophysical Laboratory of the Carnegie Institution of Washington (CIW) have created pyruvic acid, an organic chemical vital for cellular metabolism. CIW is one of eleven Lead Teams participating in the NASA Astrobiology Institute (NAI).
Hydrothermal vents were first discovered in 1977. Similar to geysers like Yellowstone Park’s Old Faithful, these hot underwater vents spew out mixtures of chemicals and nutrients for bacteria while maintaining near-volcanic heat temperatures. With the sampling of these vents, scientists have also discovered that life thrives there, despite the elevated temperatures and extremely ...December 18, 2000 • Posted by: Shige Abe • Report issue
Text based on NASA/JPL Press Release
In what ultimately may be their most significant discovery yet, Mars scientists say high-resolution pictures showing layers of sedimentary rock paint a portrait of an ancient Mars that long ago may have featured numerous lakes and shallow seas.
“We see distinct, thick layers of rock within craters and other depressions for which a number of lines of evidence indicate that they may have formed in lakes or shallow seas. We have never before had this type of irrefutable evidence that sedimentary rocks are widespread on Mars,” said Dr. Michael Malin, principal investigator ...December 14, 2000 • Posted by: Shige Abe • Report issue
Text based on NASA/JPL Press Release
In what could turn out to be a landmark discovery in the history of Mars exploration, imaging scientists using data from NASA’s Mars Global Surveyor spacecraft have observed features that suggest there may be current sources of liquid water at or near the surface of the red planet.
The images show the smallest features ever observed from martian orbit — the size of an SUV. NASA scientists compare the features to those left by flash floods on Earth.
“We see features that look like gullies formed by flowing water and the deposits ...December 12, 2000 • Posted by: Shige Abe • Report issue
Mars used to be a very wet place. A host of clues remain from that earlier time, indications that Mars was perhaps once host to great rivers, lakes and perhaps even an ocean. But the clues are contradictory. They don’t fit together in a coherent whole. Little wonder, then, that the fate of water on Mars is such a hotly debated topic.
The reason for the intense interest on water on Mars is simple: Without water, there can be no life as we know it. If it has been 3.5 billion years since liquid water was present on Mars ...December 11, 2000 • Posted by: Shige Abe • Report issue