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The search for extraterrestrial life:

There is life on Mars, there may be life on Europa, Ganymede and maybe Io, but is there life on other planets around other stars? As time goes by, it becomes more and more likely. This page will keep you updated on the latest discoveries.

In this page:

European Mars Probe to land a miniature mass spectrometer on Mars soon:

BBC News Online reports on May 24 2002 that the British Mars lander project du to land on Mars next year to search for past or present life on Mars received an important and welcome grant of £2.6 milions. The money comes from the Wellcome Trust, the medical research charity which has funded a large portion of the Human Genome Project.

The cash will go towards developing a miniature mass spectrometer, one of the instruments the Beagle 2 lander will need to search for signs of past or present life. The director of the Wellcome Trust says that building the instrument could lead to extremely useful medical spin-offs.

"The whole point is how the instrument could be developed further," Professor Colin Pillinger, head of the Planetary and Science Reseach Institute at the UK's Open University, told BBC News Online. "It will be small, robust, light and automated. It could be sterilised and we may in the end be able to build something that could turn into a personal mass spectrometer," he said.

Mass spectrometers are sensitive instruments used to discover what a sample of material is made of. The Beagle 2 lander will analyse samples from the Martian surface and radio the results back to Earth.

Beagle 2 will ride aboard Europe's Mars Express probe, due to lift off from the Baikonur spaceport in Kazakhstan on 23 May, 2003. The instrument will take up a third of the space in the tiny Beagle 2 lander and will weigh about five kilograms. A conventional version of the same thing measures two by two by three metres and weighs the best part of a tonne.

The background of this European research is that the US Viking probe detected life on Mars in 1977, but the results of the experiments were dismissed because the mass spectrometer aboard Viking detected no organic matter on Mars, and because it was considered that Mars conditions are unsuitable for life. Later, it was discovered that the Viking spectrometer has been unable to find organic matter on Earth also, and though this fact has not been advertised much, European exobiologists are aware of that. It has also been discovered that the conditions on Mars may not be that hard for adapted microbial life forms to develop, and that life on Earth does thrive in several different types of very extreme conditions.

See the Mars section of my site for more information on that topic.

Life-like cell membramnes created in simulated space environment, January 2001:

In a simulated deep-space environment, researchers have created small structures that look like cell walls in living organisms and show early signs of the ability to convert sunlight into chemical energy.

This adds to growing evidence suggesting that interstellar clouds of gas have the enclosed ingredients for life, which can dump into a hospitable planet with water. NASA scientists and others involved in the work said it implies that the recipe for life is not unique to Earth.

First written up in a 1999 magazine article, the work involves creating quinones, substances that help produce photosynthesis in plants and helped build the lab-created membranes that resemble cell walls. A more academically respected version of the article comes in the January 30, 2001, issue of Proceedings of the National Academy of Science.

This new work was designed to explore what sorts of compounds might exist in comets and other space debris, to determine what other building blocks for life they might have brought to Earth. The result is stunning.

Scientists at NASA's Ames Research Center and the University of California Santa Cruz duplicated the conditions of interstellar clouds of gas and dust, which are the birthplaces of stars. They combined ordinary chemicals common on Earth and in space, including water, ammonia, carbon monoxide and methanol, and chilled the mix to near absolute zero (minus 441 degrees Fahrenheit or minus 253 degrees Celsius).

"Instead of finding a handful of molecules only slightly more complicated than the starting compounds, hundreds of new compounds are produced in every mixed ice we have studied," said NASA's Scott Sandford. "We are finding that the types of compounds produced in these ices are strikingly similar to many of those brought to Earth today by in-falling meteorites and their smaller cousins, the interplanetary dust particles."

The chemicals froze into thin bits of ice. Then, just as a star floods an interstellar cloud with ultraviolet radiation, the researchers zapped their chemical soup with UV rays.

The icy mix transformed into more complex chemical compounds, as expected. But what happened next was a surprise.

When dipped in water, these compounds assembled themselves into membranes similar to those that protect living cells. While the structures are not alive, they show that chemical reactions in space are more complex than traditionally expected.

"This is an enormous step forward in our thinking from not too many years ago, when most scientists believed the chemistry in space was very, very simple," said Louis Allamandola, a NASA astrochemist who led the research team. "The astonishing thing here is that not only is it far more complex than imaginable a short while ago, the chemicals are actually very similar, and in some cases exactly the same as used in living systems today."

This does not mean that life exists in space. But these complex molecules might serve as sort of a ready mix of ingredients for life when delivered to a planet with the right conditions.

Allamandola said the experiment shows that the molecules needed to produce cell membranes, and thus life, are everywhere. "This discovery implies that life could be everywhere in the universe," he said.

Benzene detected in space, January 2001:

A team of Spanish astronomers has made the first detection of interstellar rings of carbon, the type of molecules upon which Earth's life is based.

The team led by José Cernicharo of Instituto de Estructura de la Materia, CSIC, used the European Space Agency's Infrared Space Observatory (ISO) to find benzene, the ring molecule par excellence. They think benzene is produced by stars at a specific stage of evolution.

They chose a typical red giant star to start the search. But it did not work: the star did have carbon-based molecules, such as acetylene, but not ringed molecules. So the astronomers turned to an even older star, a protoplanetary nebula, a star that is about to die via becoming a white dwarf star surrounded by a beautiful cloud of glowing dust and gas. They focused on the protoplanetary nebula CRL618.

As published in the January 10 issue of The Astrophysical Journal, they found benzene in the surroundings of the CRL618 protoplanetary nebula. The authors think that there could be a few molecules of benzene per cubic centimeter, a value considered to be high, although the estimated density of molecules of all kinds in the area observed is 10 million per cubic centimeter.

Benzene is an essential chemical step towards the synthesis of more complex organic molecules. It is made of six atoms of carbon chained together to form a ring, plus six atoms of hydrogen, one per carbon.

Astronomers expected to find these ringed molecules in space, where long strings of carbon atoms have been detected. Moreover, it had been postulated that certain compounds of yet unknown nature, that are known to be very abundant in space, are actually aromatic hydrocarbons. Cernicharo said: "It seems that carbon-rich protoplanetary nebulae are the best organic chemistry factories in space."

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This page was last updated on July 27, 2002.