Latest data from Venus Express

The latest issue of the journal 'Nature' gives a special focus to the European Space Agency's Venus Express mission, which has major contributions from UCL.

It has long been recognised that Earth and Venus share certain characteristics, but the latest results from Venus Express reveal more detail about the process at work that have made Venus - often dubbed 'Earth's evil twin' - evolve so differently to Earth.

The spacecraft was launched in November 2005 and entered planetary orbit in April 2006. This issue of 'Nature' features nine papers from project scientists, providing the most comprehensive and detailed picture of the planet to date.

Professor Andrew Coates (UCL Mullard Space Laboratory) is lead co-investigator of the electron spectrometer on the craft, and co-author on one of the papers (by Barabash et al, on 'The loss of ions from Venus through the plasma wake').

He said: "One of the evolutionary differences that has made Venus the Earth's 'evil twin' is that present-day Venus lacks a magnetic shield. This means that its atmosphere feels the onslaught of the solar wind and cosmic radiation, and has done for billions of years. We already know that Venus is a dry planet as the surface is so hot, but what we've found now is that Venus is still getting dryer. It loses hydrogen, helium and oxygen through its wake at a rate faster than escapes from Mars."

He added: "These are all lost forever in the flowing solar wind. The ratio of hydrogen to oxygen being lost here is close to double, as we'd expect for water. The boundaries of the wake, where the bulk of this loss occurs, are found using data from our electron spectrometer."

Ian Pearson, Minister for Science and Innovation, commented: "These latest results from Venus Express are providing a real insight into the extreme climatic processes at work on a planet that is very similar to our own. Understanding the influencing factors of global warming on Venus could help us in mitigating the threat here on Earth. British scientists and engineers are also playing a leading role in this very important European mission, thereby further demonstrating both the contribution, and the continuing strength, of the UK space industry."

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Image: Venus' southern hemisphere in the ultraviolet Credits: ESA © 2007 MPS/DLR-PF/IDA