By Gary Thomas
Life On Mars?
Climate Models and the
Does Mars Disprove Global
Sources and Further Reading
The latest Mars rover, Curiosity, landed on the surface of
the Red Planet on 6th of August 2012 and is currently
sampling, analysing and photographing the surface of the planet. The
Mars rover has several primary goals whilst on the planet, with the
overall aim of determining whether Mars could ever have supported life.
To do this, the Curiosity rover will climb up the inside of
the 5km high Gale Crater, sampling rocks as it goes. In order to
determine whether the planet was once habitable, the past conditions of
the Martian climate must be unravelled. But how much can we learn about
our own climatic fate from our neighbour? This article aims to outline
how much information can be gained about climate change from Mars and
the dangers of predicting too much from another planet.
An artist’s impression of how the Mars rover Curiosity
looks on the surface of the red planet. Image Source: NASA
Life On Mars?
The great benefit of the Mars rover is that it will allow climate
change theory to be tested in a real world situation. However detailed
climate change models have become, it is still impossible to test the
various hypotheses on the Earth’s climate without inherent dangers.
Scientists do not want to muck about with the only atmosphere we have
just to prove a point!
There is much proof that Mars was once, if not a green planet, a
planet that once held flowing water and possibly life. The previous
Mars rover, Opportunity, discovered almost irrefutable proof
of liquid water on the planet’s surface when it discovered a thin vein
of gypsum, which must have precipitated from water. Other evidence
includes satellite photos of ancient deltas, rilles and rivers.
However, over billions of years the surface of the planet was all but
stripped of its water content, due to constant battering from solar
winds. The current Mars rover will look at how exactly Mars did lose
all its water, and how this could relate to the Earth.
and the Carbon Cycle
|The Red Planet: Quick Facts About
|Distance From the Sun:
Length of Day: 24 hours, 37 minutes
Length of Year: 687 Earth Days
Equatorial radius: 3,397 kilometers
Surface Temperture: -81 degrees F
Climate scientists are extremely excited about the Curiosity
mission, as by discovering more about the climate on Mars, models of
Earth’s climate can be refined. Often, looking at the climate of
another planet will help to consolidate existing theories by reducing
margins of error in models. It may also throw up questions that have
not been fully considered before. When looking at Venus for example,
scientists greatly refined models regarding wind, as the models they
applied to the planet did not correlate correctly.
It is hoped that similar refinements to models will be made when
searching the surface of Mars, specifically models relating to the
carbon cycle. The carbon cycle is the method by which carbon is
exchanged between the different ‘spheres’ of the planet i.e. the
hydrosphere, biosphere, geosphere, and the atmosphere. The carbon cycle
has a profound effect on the Earth’s climate, as the temperature and
climate of the planet can be altered heavily depending on the amount of
CO2 in the atmosphere, or the amount trapped in the oceans.
Since the industrial revolution, people have directly affected the
Earth’s carbon cycle by adding carbon straight into the atmosphere
which, according to the majority of climate scientists, is altering the
temperature of the planet. By looking at the carbon cycle on Mars, it
is hoped that some important questions, such as ‘where does carbon go?’
and ‘Does it ever come back again via volcanoes?’ can be answered, even
though the atmosphere of Mars is very different.
Does Mars Disprove
However, basing climate change theory on activity seen on other
bodies in the solar system can be misleading. There have been several
theories that discuss how the climate changes on other planets shows
that recent global warming is more likely to be caused by external
events rather than anthropogenic activity. In 2007 a Russian planetary
scientist, Habibullo Abdussamatov, proposed that the increasing
temperatures and melting ice on earth was being mirrored by Mars, and
therefore the cause of this was more likely to be an increase in solar
irradiance. There has also been a perceived increase in temperature on
the dwarf plant Pluto in recent years, but the suggestion that these
changes are related to temperature changes on Earth is refuted by most
Firstly, the Sun’s energy output has been consistently measured
since 1978, and there has been no measured change in this output. Even
if there was a change in the Sun’s output, this would mean that all the
moons and planets in the solar system would be experiencing similar
temperature changes, not just three.
Furthermore, it is very difficult to gain high quality temperature
data from Mars and Pluto over a long period of time. It has been
suggested that the perceived shrinking of the Martian icecap may be due
to a regional effect, increased winds (leading to a darkened surface
and hence a higher albedo) or just large natural fluctuations. The
cause of Pluto’s warming is less clear, but it may be due to a release
of methane gas from ice as Pluto moves closer to the Sun.
Brave New World- an image sent back from
Curiosity, showing the side of the Gale Crater which it will eventually
climb to the top of. Image Source: NASA
Sources and Further
can the Mars rover tell us about climate change on Earth? The
myths: Mars and Pluto are warming too New Scientist,
Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says National
Curiosity rover successfully lands on Mars, BBC News,
rover makes first colour panorama, BBC News, 09/08/2012