The BBC ran a story today regarding the Venus Express programme, sister to the Mars Express currently in orbit around the Red Planet. ESA is to use its Venus Express satellite to observe the atmosphere around Venus and use the results to look at how our own atmosphere may be affected by the green house gasses.
Venus as you will know has run through an extreme version of climate change reported as "runaway greenhouse warming". Being closer to the sun than the earth at 108 942 109 km at aphelion it is subject to a higher degree of solar heating. It is proposed that due to the lack of tectonic plates, Venus can not generate its own magnetic field, which has lead to the overheating from the sun's solar radiation. This is turn has lead to the greenhouse gas effect observed on Venus. The atmosphere is nearly all CO2 at 96.5% with a small amount of N2 at 3.5%. This contrasts with earth's CO2 at 0.038%, O2 at 20.95% and N2 at 78.08%. Surface Pressure also vary with Venus coming in at a heavy 9.3mPa and the Earth at 101kPa.
So how can Venus help us understand our own climate change models? Published this week in Nature magazine Professor Fred Taylor, a Venus Express interdisciplinary scientist, University of Oxford, stated “It is really surprising how un-Earth-like Venus is now”. When you compare its stats you realise that once it must have been very similar. Venus has approximately the same mass as the Earth yet it is hotter, where surface temperatures can be over 400°C and the surface pressure is a hundred times that on Earth.
Dmitri Titov, Venus Express science coordinator from the Max-Planck-Institute for Solar System Research thinks that “Today’s results focus on the different science themes Venus Express is covering...An important first set of results concerns the complex dynamics and structure of Venus’s atmosphere, studied with a whole suite of instruments.” A second set of results concerns both the atmosphere’s composition and its chemistry. Venus Express has taken compositional profiles of the atmosphere around the planet, and unambiguously confirmed the presence of lightning which can have a strong effect on the composition of the atmosphere itself. A third set of results is about the processes by which the atmosphere of Venus is escaping into space. This is driven by the solar wind – a stream of electrically charged particles given out by the Sun. As the solar particles collide with electrically charged particles near Venus, they energise the gases, stripping them forever from the planet.
Professor Taylor, commented that "It is now becoming clear why the climate on Venus is so different to Earth, when the planets themselves are otherwise quite similar. "Our new data make it possible to construct a scenario in which Venus started out like the Earth - possibly including a habitable environment, billions of years ago - and then evolved to the state we see now." This model will be used to assess our own possible future if climate change continues its own upward drive.
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