Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ESA to search for life, but not as we know it

19.09.2002


This week, astrobiologists are discussing what ESA`s Huygens spaceprobe might discover when it parachutes to the surface of Saturn`s mysterious moon, Titan, in 2005. Titan possesses a rich atmosphere of organic molecules, which Huygens will analyse. Recently some scientists have begun to think that, by redefining life, in broader terms, what we may find on Titan may be life. If this is the case, it certainly will not be life as we know it...



Titan is an astrobiologist`s dream laboratory. Its atmosphere is composed of nitrogen and methane gas. Ultraviolet light from the Sun can break the methane molecules apart, leading to the formation of complex organic molecules by which scientists mean molecules containing carbon. Carbon compounds are the first step towards life, as we know it on Earth. Life, itself, is based on extremely complicated carbon molecules such as DNA. Some scientists believe the composition of Titan`s atmosphere closely resembles that of early Earth, before life began on our planet.
Huygens`s investigations may reveal how life began on Earth. Jean-Pierre Lebreton, ESA`s Project Scientist for Huygens says, "One of the key questions we hope to address is how complex the organic molecules have grown in Titan`s atmosphere."

However, organic molecules are still a long way from life itself. So, what defines life? What is the difference between the living and the non-living? Scientists are still unsure. No satisfactory definition has been found so far. Any attempt to define life`s characteristics either excludes some types of life or includes some inanimate objects. When looking for an appropriate definition of life, there is one property all scientists seem to agree on: all life needs energy to sustain its metabolism.



For example, plants use sunlight, while animals extract energy from organic molecules in the food they eat. This happens not only in these higher-level organisms, but also in the simplest forms of life on Earth, microbes. Microbes are single-cell organisms that capture their life-energy from a dizzying array of inorganic chemical reactions. Such chemical metabolisms are so different from those in the animals and plants of Earth, that astrobiologists now wonder if life could arise in any place that can sustain a rich network of chemical reactions, such as on Titan. Moreover, on Earth, microbes have adapted to the extreme environmental conditions. Scientists therefore now ask, "Could life arise on Titan?"

By all standards, Titan is an extreme and hostile environment to life, as we know it. Any life on Titan would have to be totally different from all Earthly forms. Lebreton says, "The conditions on Titan are not adequate for the kind of life we understand today. It is very cold and there is no liquid water but we should be ready for surprises." Identifying life is tricky, especially when you are unsure what to look for. Huygens`s geological and environmental investigations, and Cassini`s mapping from orbit, might record chemical anomalies or curious geological structures that warrant further investigation as possible life indicators.

Another chemically puzzling place is the planet Venus. Similarly to Titan, Venus is a world that scientists would traditionally call hostile to life, as we understand it. However, there is something odd in its clouds. Venus`s chemically laden atmosphere displays some curious phenomena, such as the planet`s ability to absorb ultraviolet radiation. Scientists cannot explain this. Some speculate that perhaps microbes in the atmosphere are responsible. If ESA`s Venus Express is given the final go-ahead later this year, it might help solve the mystery.

For centuries, scientists have struggled to define life. Space investigations present the best chance for astrobiologists to find the missing link in our understanding of what separates the living from the non-living. When we know that, we will finally have defined life here on Earth.

Jean-Pierre Lebreton | alfa
Further information:
http://www.esa.int

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>