Doubt cast on life on Mars – University of Greenwich Reproduces Chemical Structures Found In Meteorites

University of Greenwich

London, England

Contact:

Mr Nick Davison

0181 331 8092

dn05@gre.ac.uk

Caron Jones

Public Relations Unit

020-8331 8248

The complex chemical structures found in a meteorite from Mars, which
scientists in 1996 hailed as possible evidence of past life on the planet,
can be reproduced quite simply in any laboratory according to new
research from the University of Greenwich.

Professor Aron Vecht and researcher Terry Ireland from the university’s
School of Chemical & Life Sciences say that the special structures —
which are shaped like flowers and spheres — could have been formed on
the cold surface of Mars from minerals commonly occurring there. Their
findings cast grave doubts on the possibility of Martian life.

In a paper published today (Tuesday, August 1 2000), Vecht and Ireland
show that vaterite, a rare form of calcium carbonate found in the
meteorite, can be made easily. It occurs when carbon dioxide is bubbled
through a solution of calcium chloride in the presence of ammonia at
room temperature (about 25 degrees Celsius) — conditions that may
well have existed on Mars in the past. Other forms of calcium carbonate,
such as calcite and aragonite, can be formed at higher temperatures,
around 65 degrees Celsius.

“Any junior school laboratory in the country could replicate these results
using a very simple process,” says Professor Vecht. “It came as a great
surprise that, under the electron scanning microscope, the structures we
had made bore very great similarities to those reported in the Martian
meteorite, as these have been used as the best/only evidence for the
existence of primitive life on Mars. Our findings cast grave doubts on
the possibility of Martian life, especially as we used minerals readily
available on Mars.”

The discovery came about while the team was investigating the properties
of different forms of calcium carbonate (chalk) as part of an ongoing
research project into phosphor compounds which have luminescent
properties. The Centre for Phosphors & Display Materials at the University
of Greenwich carries out leading research on the preparation, study and
improvement of phosphors which are widely used in electronic display
and flat screen technology including TVs, computers, oscilloscopes and
medical equipment such as X-ray screens. It is hoped that the research
which led to this discovery may be extended to the investigation of fossil
structures that have been attributed to previous life forms on Earth.

ENDS

Peer reviewed publication and References

* ‘Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian
Meteorite ALH84001’, McKay et al published in Science on August 16 1996

* ‘The role of vaterite and aragonite in the formation of psuedo-biogenic
carbonate structures: Implications for Martian exobiology’, Vecht and
Ireland published in Geochimica et Cosmochimica Acta, August 2000