We are very lucky here on Earth, we have a powerful magnetic field, known as the magnetosphere surrounding us and our atmosphere, protecting us from the worst that the Sun can throw at us. Other planets in our Solar System ain’t so lucky. Poor old Mars has been damaged beyond repair by the constant erosion by the solar wind, dragging most of its atmosphere into space. Now, Earth’s planetary sister, Venus, is showing signs of atmospheric leakage… where will it end?
European Space Agency (ESA) scientists working with the Mars Express and Venus Express missions have found common ground. Both Express missions are very similar, allowing a unique opportunity for researchers to directly compare two planets. One instrument in particular is creating a special stir.
The Analyser of Space Plasmas and Energetic Atoms (ASPERA), on both spacecraft, has spotted that the planets are losing their atmospheres at an astonishing rate. Neither have a protective magnetosphere to deflect solar wind particles, so the solar wind is continually wearing away at Venus and Mars. The Sun is even smothering the two planets with its own magnetic field, creating a long, comet-like tail of atmospheric particles trail behind.
This is the first chance for ESA scientists to carry out comparative planetology (directly comparing two planets) on both Mars and Venus using identical spacecraft. This is a wonderful opportunity to understand the stages of planetary evolution, and perhaps help us understand the dynamics behind our own planets future.