"Mars life" with new evidence?

"Magnetic crystals" revealed traces of life, scientists mention extraterrestrials solar system biological discoveries

Beijing News weekly of the new knowledge

Meteorite ALH84001 (top) of the photo (below) shows that there may be life on it.

Figure/NASA

In 1996, the United States Air Space Agency (NASA) and the White House has posting this explosive message: in a piece of the Antarctic meteorites found on the "relic" of Mars, from where a sensation, but also led to the da Vinci Code "author ·

Dan · Brown wrote the scam of the novel. However, the news was subjected to a rebuttal, and soon no one mentioned again. 13 years, scientists have announced that he's new evidence that stone there lives on.

Martian meteorites in Antarctica

Once again become the focus of this stone in 1984, found in Antarctica Allen Hill, is named "Alan Hill (AllenHills, ALH) 84001" meteorites, scientists believe this stone is an asteroid or comet impact Mars, though from the Mars surface and into space.

It was floating in space, after 160 years around 1.3 years ago came to the Earth. This piece from the Martian crust falling rocks formed in billions of years ago, many experts believe that Mars has liquid water, and appropriate biological survival.

Shortly after the discovery of the meteorites, scientists have discovered a worm-like structure.

Scientists believe that these structures are Mars, insect fossils. Micrograph shows the meteorite has a slender body, much like life. But people's excitement didn't last long. Soon, scientists suspected meteorite is a biological pollution of the Earth. They also raised another possibility that rock surface from Mars avalanche when heat generated will be formed some mineral structure, these mineral structure be mistaken as a Microbe fossils.

Recently, NASA scientists in the past have not advanced high resolu

tion electron microscope with the assistance of a new study. This study by keprta (KathieThomas-Keprta) and is located at the Johnson Space Center in Houston's original class teams. Their findings indicate that there is life on meteorites.

In this study, the scientists focus on meteorites in a place called "magnetic crystals" small magnetic particles.

Magnetotactic bacteria into key

There are some on the Earth is called "magnetotactic bacteria" bacteria, body contains "magnetic crystals", the scientific community believe that bacteria rely on it to tell the direction.

Magnetotactic bacteria is in 1975 by Bo Lake Morris (RichardBlakemore) discovered that he called the collapse of Treponema pallidum (Spirochaetaplicatilis) bacteria found in the existence of the magnetic body. These bacteria under the microscope is always to set out on the side of the glass. Get a magnet near contains slide, bacteria to the magnet N extremely mobile. These bacteria are such conduct mainly because they can produce small, containing iron, magnetic small particles. Small and uniform particles, each particle, there are two poles. These bacteria are these small magnets into straight lines to form a magnet, they use this magnet as a compass to make your move in a direction along the Earth. Why move to extended geomagnetic? has the scientists think that magnetotactic bacteria are not very fond of oxygen, they needed from the oxygen-rich area to move to the oxygen-poor. In the water, the oxygen content as water depth increases, so magnetotactic bacteria like living on the bottom. They use magnetic compass tell which direction to yourself. In the northern hemisphere, and not only point to the North Pole, but also point to bevel, bacteria can pass along the magnetic field of the Arctic to the deep end of the movement. In the southern hemisphere, the magnetic field of the Antarctic is inclined, so in the southern hemisphere magnetotactic bacteria was "chasing the South".

If Mars Meteorite ALH84001 "" tiny magnets really and bacteria, they would form a stone on the unusual shape.

In addition, the scientists say, from chemical purity of perspective, this is more like a non-biological and geological phenomena.

United States Sierra Nevada College of PA kozlinski (DennisBazylinski) Professor review this article, submitted to the journal of the Institute of geochemistry and meteorite, "said:" I think this is a very good paper.

I think these magnetic meteorite crystals, it looks like from magnetic bacteria, which is the ancient Mars had existed as evidence of life. At first, I also suspect that this is a mistake. But now I have to admit, has no doubt. ”

However, kozlinski believes there is a big problem, these so-called "not necessarily" magnetic fossils in formed on Mars: "magnetic bacteria produce magnetic lens shape is unique, but the Mars meteorite magnetism of single crystal and bacteria on Earth created by the shape of magnetic crystals are very similar."

The "Europa" fish surfaced

Recently been broke out possible life of extraterrestrial environments is more than a Mars.

According to the United States National Geographic website reported that the United States some scientists recently discovered moons of Jupiter's Europa may far exceed the oxygen content of scientists previously estimated.

Europa-equatorial region's average temperature is about-163 ° c.

Scientists believe that the surface of the ice intro also has a liquid Ocean. In 1994, sectionPlanetologists inferred Europa has a layer to oxygen-thin atmosphere. Previously, scientists have speculated that in Europa liquid marine life may exist. Now, scientists estimate the Europa the oxygen content of the ocean, that value is the previous estimate of 100 times. United States Arizona University scientists Greenberg (RichardGreenberg) considers that, to the level of oxygen-containing, in theory, the Europa's marine life living in total reach 300 million tons of similar biological fish on Earth. He said: "is not to say that the Europa must exist on the life, but we do know that there exist to support the physical conditions of life. ”

However, now began to speculate about life on Europa evolve too early.

Want to really know the Europa on the real situation, the need for further research. Have scientists try to possible Europa depth exploration of design depth impact and wear ice robot.

Compilation/reporter Liu Zheng interns Ding Kai