 | | | | |
| | | | | |
|
| Europe goes to Mars About Mars Express About Mars Meet the team Multimedia VideoTalkMars Express imagesMars Express videosHRSC videosAnimation in 11 languagesDownload wallpapersDownload screensavers3D Flash 'model'Make a modelServices Comments
| | | | | | | | Article Images |  |
Mars and Venus are surprisingly similar
5 March 2008
| | Mars, Earth and Venus are immersed in a flow of plasma, an ionised and highly variable gas originating from the Sun, called the solar wind.
While Earth has a planetary magnetic field, which can deviate the flow of solar wind, Venus (and Mars) don’t. Gases in the upper atmospheres of these planets are ionised and can thus interact with the solar wind.
Venus is as large as Earth and it is difficult for its atmosphere to escape due to the planet’s gravity. The solar wind is the best source of energy to accelerate the upper atmosphere’s charged particles, giving them enough energy to escape. This is why Venus loses its atmosphere due to interaction with the solar wind.
To understand this phenomenon, the key questions that the instruments studying plasma on Venus Express must answer are: what and how much of the atmosphere is lost, and where is it lost?
Right now, solar activity is at its minimum in the 11-year cycle, making the solar wind weaker than average. The critical question now is how solar wind interacts with Venus when solar activity is low.
Credits: ESA (Animation by C. Carreau) | |  |  | |
| | | | | An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a six-month journey, and has been investigating the planet since early 2004.
Credits: ESA - D. Ducros | | | | |
| | | | | Venus Express is studying largely unknown phenomena in the Venusian atmosphere like never before. Its suite of instruments is also digging into the interaction between the solar wind and the planetary environment. In addition, the mission is gathering glimpses of the planet's surface, which is strictly coupled with its dense atmosphere.
Credits: ESA (Image by AOES Medialab) | | | | |
| |
| | Looking at Mars Mars Express highlights  Water on MarsRelated articles Mars Express one of three orbiters preparing for Phoenix landingIce clouds put Mars in the shadeMars Express watches a dust storm engulf MarsMars Express - 5000 orbits and countingMars and the search for traces of life Looking at Venus ESApod: Venus Express Related articles The light and dark of VenusVenus Express seeks out gases below the cloudsVenus Express educational filmInterviews: the martian water cycle and climateLifting the Venusian veil, two years since launch
|
HI-RES MOV (Size: 
HI-RES JPEG (Size: 
HI-RES JPEG (Size: