* Astronomy

Members Login
Post Info
TOPIC: Martian Aliens


L

Posts: 131433
Date:
RE: Martian Aliens
Permalink  
 


Looking for life on Mars? Try the salty bits

The surface of Mars is extremely cold and dry. Cosmic and solar radiation reach the surface unimpeded by the thin atmosphere, and the soil contains strong oxidants that destroy organic compounds. Fat chance for life. But it wasn't always so.
Early in its history Mars was warmer and wetter enough for the development of rivers, lakes and perhaps oceans. The atmosphere was thicker and the protective magnetic field was switched on. Mars might be uninhabitable today, but life would have been possible in the past. This is why future missions will focus on the study of ancient sediments, hoping to find fossilised evidence of life.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Title: New approaches to the exploration: planet Mars and bacterial life
Authors: Giuseppe Galletta (UniPD), Giulio Bertoloni (UniPd), Maurizio D'Alessandro (INAF-OAPD)

Planet Mars past environmental conditions were similar to the early Earth, but nowadays they are similar to those of a very cold desert, irradiated by intense solar UV light. However, some terrestrial lifeform showed the capability to adapt to very harsh environments, similar to the extreme condition of the Red Planet. In addition, recent discoveries of water in the Martian permafrost and of methane in the Martian atmosphere, have generated optimism regarding a potentially active subsurface Mars' biosphere. These findings increase the possibility of finding traces of life on a planet like Mars. However, before landing on Mars with dedicated biological experiments, it is necessary to understand the possibilities of finding life in the present Martian conditions. Finding a lifeform able to survive in Martian environment conditions may have a double meaning: increasing the hope of discovering extraterrestrial life and defining the limits for a terrestrial contamination of planet Mars. In this paper we present the Martian environment simulators LISA and mini-LISA, operating at the Astronomical Observatory of Padua, Italy. They have been designed to simulate the conditions on the surface of planet Mars (atmospheric pressure,0.6-0.9 kPa; temperature from -120 to 20 °C, Martian-like atmospheric composition and UV radiation). In particular, we describe the mini-LISA simulator, that allows to perform experiments with no time limits, by weekly refueling the liquid nitrogen reservoir. Various kind of experiments may be performed in the simulators, from inorganic chemistry to biological activity. They are offered as experimental facilities to groups interested in studying the processes that happen on the Martian surface or under its dust cover.

Read more (1253kb, PDF)

__________________


L

Posts: 131433
Date:
Permalink  
 

A plan to send live microbes to the Red Planet's largest moon risks wrecking our search for extraterrestrial life

We humans have a unique talent for contaminating pristine environments. We put millions of tonnes of pollutants into the atmosphere every year. We poison our soils, lakes, rivers and streams with chemical and radioactive waste. We spill oil into our seas. We fill the Pacific and Atlantic oceans with islands of plastic garbage visible from space. Is it any surprise that we are also contaminating pristine celestial bodies with bacterial spores?
Spacefaring nations have been sending unsterilised spacecraft to the moon, Mars, Jupiter, comets and asteroids for over 40 years. It has been estimated that about one trillion microbial spores from spacecraft are now scattered around Mars. Yet the search for life in our solar system has barely begun.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Ancient Mars More Favourable to Life than First Thought

A couple of Mars orbiters have found evidence suggesting that water prevailed throughout the Red Planet's early history. That's significant because scientists until now believed that wet conditions only prevailed in the southern reaches of Mars.
The discovery of lay minerals point to the existence of a wet environment "at thousands of sites" in the southern region of Mars, an area where rocks date back approximately four billion years old, according to a report from NASA's Jet Propulsion Lab.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

If there's life on Mars, it could be right-handed

Life may be left-handed, but it shows flashes of ambidexterity. That could complicate the search for life on other worlds, but it may also help clear up some puzzling findings from NASA's Viking Mars landers.
Many amino acids, sugars and other molecules that are important for life are chiral - they come in two forms that are mirror images of one another. Life tends to prefer one form over the other, using only right-handed glucose molecules, for example. However, bacteria appear to be less selective.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Common Mars rock can preserve microfossils after all

Life on Mars, if it ever existed, may be easier to find than previously thought. New research on terrestrial rocks suggests that a type of rock common on Mars can preserve fossilised microbial life, rather than erasing evidence of it as previously thought.
Minerals called sulphates, which form in the presence of liquid water, have been found in great abundance on Mars, including at the landing site of NASA's Opportunity rover, Meridiani Planum.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Earth Microbes May Contaminate the Search for Life on Mars

Bacteria common to spacecraft may be able to survive the harsh environs of Mars long enough to inadvertently contaminate Mars with terrestrial life according to research published in the April 2010 issue of the journal Applied and Environmental Microbiology.
Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Look for Mars life with laughing gas

Trace amounts of laughing gas, or nitrous oxide, in Mars's atmosphere could aid the search for life on the Red Planet.
Vladimir Samarkin, of the University of Georgia in Athens, and colleagues found that the nitrite-rich water of hypersaline Don Juan pond in Antarctica reacts with minerals in volcanic rock to produce nitrous oxide.
Since the geology, sub-zero temperatures and brine geochemistry of the lake closely resemble those of Mars, the researchers say the process could be an important component of the Martian nitrogen cycle.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Sulphur could contain signatures of life on Mars

New evidence indicates that signs of life on Mars might be all over the Red Planet in the form of sulphur, and the next Mars lander should be able to detect the proof.
No mission to Mars has ever found complex carbon-based molecules, from which life as we know it is built.
But sulphur is everywhere on Mars. In fact, it is more abundant there than on Earth, and it could contain one of the signatures of life.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Scientists in Aberdeen say they may be on course to finding out if there is life on Mars after discovering the remains of organisms which survived while the Earth was being bombarded by meteorites 4billion years ago.
Researchers have long thought conditions were too hostile for life on Earth immediately after the birth of the solar system.

Read more

__________________
«First  <  1 2 3 4 5  >  Last»  | Page of 5  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard