Three billion years ago, Earth was a very different place.
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Bugs From Hell
Deep, very deep, beneath the surface of Earth a microbial community dines and thrives. Slowly, but tenaciously, these deep dwellers feed on gases seeping into rock fissures and divide – maybe once every thousand years – to make more of themselves. Geochemists and microbiologists are delving into the details of extreme biochemistry deep within the Earth, where chemical and metabolic processes go at glacial pace, and life appears to be completely disconnected from the photosynthesis-based biological cycles that dominate surface life.
“There is a huge biomass inside the Earth,” says David Boone, a microbiologist at Portland State University in ...
January 23, 2002 • Posted by: Shige Abe • Report issue
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In Search of E.T.'s Breath
If “E.T.” is out there, whether in the form of intelligent beings or much simpler organisms, we may soon be hot on its trail. For the first time in history, the dream of searching for signs of life in other solar systems belongs not only on the philosopher’s wish list, but on the list of doable and planned human endeavors.
Momentum is gaining rapidly. Only 6 years ago, the first planet around another Sun-like star was discovered by scientists using Doppler Detection — a method that reveals Saturn-sized (or larger) planets close to their parent suns. Today, we ...
January 18, 2002 • Posted by: Shige Abe • Report issue
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Living on Fool’s Gold
A bright red river meanders through the countryside of southwestern Spain, its water acidic enough to eat through metal. Such an image brings to mind the worst excesses of industrial pollution, and scientists long assumed that a local copper mine had contaminated the Tinto River.
Mining activity at the Tinto River dates back at least 5,000 years, and while it has altered the river it is not solely responsible for the river’s conditions. Acid rock drainage is a natural process that occurs when water, oxygen, and bacteria interact with sulfide minerals, producing highly acidic solutions. The Tinto River ...
January 16, 2002 • Posted by: Shige Abe • Report issue
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Life Without Volcanic Heat
An 18-story undersea vent off the Atlantic, near what has been called the ‘Lost City’, has recently revealed itself as ripe with exotic microbial life. From the University of Washington oceanography team, led by Deborah Kelley, recent reports in Nature magazine point to a new way to build such towering vents from what is nearly 100% limestone.
Previous deep-sea finds of hot vents have not reached beyond 8-stories (80 feet) and also proved rich in a mix of black minerals (mainly iron-sulfides). But the new vent found atop the seafloor mountain Atlantis Massif, is nearly 10 stories taller. Not piled ...
January 11, 2002 • Posted by: Shige Abe • Report issue
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Evidence of Bacteria on Europa?
Jupiter’s moon Europa is thought to be one of the most likely abodes for microscopic life in our solar system. The ice-covered world may have liquid water, energy, and organic compounds – all three of the ingredients necessary for life to survive.
Streaks of reddish-brown color highlight cracks in Europa’s outer layer of ice. Some scientists have speculated that microorganisms suspended in Europa’s ice may be the cause of these colorations. To test this theory, planetary geologist Brad Dalton of the NASA Ames Research Center compared the infrared (IR) signature of Europa’s ice with the IR signature of microorganisms living ...
January 09, 2002 • Posted by: Shige Abe • Report issue
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Jurassic Spark: Early Ancestor of Mammals Found
Based on an American Association for the Advancement of Science press release
What is nearly 200 million years old, furry, weighed less than a paper clip and scurried beneath the feet of dinosaurs? A team of fossil-finders, led by researchers at Pittsburgh’s Carnegie Museum of Natural History, suggest the answer may include one of your relatives – a distant cousin of modern mammals.
Classified as a new species, the newly discovered miniature mammal is the closest known relative to living mammals. It displays crucial mammalian features – a large brain and detached ear bones – yet it is forty million ...
January 02, 2002 • Posted by: Shige Abe • Report issue
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The Oldest Life on Land
Until recently, scientists believed that life on Earth did not emerge onto land until 1.2 billion years ago. In October 1999, Dr. Hiroshi Ohmoto of the NASA Astrobiology Institute pushed back that date a billion years by discovering 2.3 billion-year-old rock formations called laterites. Now, the discovery of 2.6 billion-year-old fossilized microbial mats intermixed with soil has pushed back that date even further.
A team of scientists discovered the fossils in core samples taken from a mine in South Africa, which contained a layer of iron-rich soil combined with fossilized microorganisms. This mat-like layer was sandwiched between ...
December 28, 2001 • Posted by: Shige Abe • Report issue
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One-Handed Life
(Based on a press release from The Scripps Research Institute)
Scientists at The Skaggs Institute for Chemical Biology, a part of The Scripps Research Institute (TSRI) in Southern California, published a paper in the February 15, 2001, issue of Nature that suggests a possible answer to how one of the early steps necessary for the origins of life arose.
Principal Investigator M. Reza Ghadiri, Ph.D., Professor of Chemistry at TSRI and a member of the NASA Astrobiology Institute, has created a biological polymer that can discriminate between two types of building blocks, taking those that are similar and building ...
December 26, 2001 • Posted by: Shige Abe • Report issue
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Earth's Oldest Mineral Grains Suggest an Early Start for Life
Scientists are drawing a portrait of how Earth looked soon after it formed 4.56 billion years ago, based on clues within the oldest mineral grains ever found.
Tiny zircons (zirconium silicate crystals) deposited in ancient stream deposits appear to indicate that Earth developed continents and water — perhaps even oceans and environments in which microbial life could emerge — 4.3 billion to 4.4 billion years ago.
The findings by two research groups, one in Australia and the other in the US, indicate “liquid water stabilizes early on Earth-type planets,” said geologist Stephen Mojzsis, a member of ...
December 24, 2001 • Posted by: Shige Abe • Report issue
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The Heat Is On: Asteroid Belt Found Around Nearby Star
When unusually warm dust was first discovered (1991) around a nearby star, called zeta Leporis, infrared astronomers begun hunting in detail for the heat source. According to the latest research at UCLA, what the star may be undergoing is asteroid and planet formation similar to that of our own early solar system. For infrared astronomers the warm particle halo may reveal more than just a hot cloud. It may reveal a dusty disk that resembles an asteroid belt.
Michael Jura and Catherine Chen reported their most recent findings at the annual meeting of the American Astronomical Society.
“We chose to ...
December 19, 2001 • Posted by: Shige Abe • Report issue
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The First Sulfur Eaters
Some of the oldest rocks on Earth can be found amid the spiky grass and orange-red dust of Northwestern Australia. While most rocks have been altered over time through geological processes, the Australian rocks have remained relatively unchanged since their inception 3.47 billion years ago. Earlier this year, Yanan Shen of Harvard University, Donald Canfield of Odense University in Denmark, and Roger Buick of the University of Washington announced they found evidence for life in the ancient Australian rocks.
The scientists found indications of a type of bacteria that consume sulfate and produce sulfide as a waste product. Sulfate-reducing ...
December 17, 2001 • Posted by: Shige Abe • Report issue
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Test-Tube RNA
Based on an MIT Whitehead Institute press release
A new RNA enzyme, or ribozyme, synthesized by David Bartel, Wendy Johnson and colleagues at MIT’s Whitehead Institute for Biomedical Research, opens a door to create a path for the earliest evolution to have happened without either DNA or proteins in the primordial soup. Since first described in the journal Science, the Whitehead ribozyme, or RNA catalyst, has filled in the picture of early chemical evolution and how life might have arisen.
As highlighted in Sydney Altman’s 1989 Nobel laureate address entitled “RNA World”: “If very primitive life on Earth ...
December 14, 2001 • Posted by: Shige Abe • Report issue
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NASA’s Global Surveyor Sees Possible Climate Change on Mars
Based on a Jet Propulsion Laboratory press release
The planet Mars we know today is a cold, dry, desert world, but suppose the martian climate is changing even now, year to year and decade to decade?
New observations by NASA’s Mars Global Surveyor spacecraft are expanding understanding of the martian climate and may indicate the climate is changing significantly even today. This suggests even larger climate changes have occurred during the planet’s recent history and may again in its future. The observations were made during a full martian year, 687 Earth days.
If this is so, Mars might someday ...
December 10, 2001 • Posted by: Shige Abe • Report issue
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Atmosphere of an Extrasolar Planet Detected for the First Time
Astronomers have made the first direct detection and chemical analysis of an atmosphere of a planet that exists outside our solar system.
The planet – HD 209458b – orbits a yellow, Sun-like star that lies 150 light-years away. The star HD 209458 is in the constellation Pegasus, and can be seen with an amateur telescope.
As the planet passes in front of – or “transits” – its parent star, light rays from the star pass through the planet’s atmosphere. Using NASA’s Hubble Space Telescope, the astronomers analyzed the spectrum of this light and detected the presence of sodium in the ...
December 05, 2001 • Posted by: Shige Abe • Report issue
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Doubts About ALH84001: The JSC Mars Meteorite Team Responds
Buseck et al. have “rediscovered” an anaytical method developed in 1947 by Dennis Gabor for defining the morphology of crystals using electron microscopy. Unfortunately, the Buseck et al. paper adds nothing to further the understanding of the issue of life on Mars. It demonstrates that these authors fail to understand the work of Thomas-Keprta et al, 2001 who used a transmission electron microscope to image individual microscopic particles at multiple angles and orientations. From this, the 3-D morphology of the particles could be reconstructed. The technique used by Buseck et al. also uses a transmission electron microscope to image microscopic ...
December 03, 2001 • Posted by: Shige Abe • Report issue