| Techniques pioneered by the European Space | | | | pitch of siren on a fast moving vehicle, as it first |
| Agency (ESA) for use on Mars, are set to have a | | | | moves towards you then away from you. |
| very down to earth use here on planet Earth and | | | | This new study is meeting with success and opens |
| beyond to the Icy moon Europa circling the Gas Giant | | | | the doors for even more precise instruments that |
| Planet, Jupiter. As well as Europa, another Ice moon | | | | could work around Earth. A satellite fitted with this |
| "Titan", the biggest of Saturn's Moons, is also a | | | | type of radar could accurately estimate the ice sheet |
| target for study. | | | | thickness of the Antarctic and other ice covered |
| ESA's Mars Express has aboard some pioneering | | | | regions. The data coming back would reveal the |
| radar experiment currently investigating the Red | | | | three-dimensional internal structure of the ice sheets, |
| Planet and searching for any evidence of sub-surface | | | | the contours of the underlying terrain and give |
| reservoirs of water and ice. This technology holds | | | | information right down to the bedrock. Watching how |
| great promise for subsurface oceans under the icy | | | | this changes over time will give climate scientists |
| crusts of Europa and Titan as well. In our experience | | | | invaluable data. Currently, expensive and difficult |
| to date, liquid water = Life! | | | | drilling programs largely do work such as this. |
| However the technology used by Mars express | | | | As we all hear in the news day after day, melting ice |
| cannot be used directly here on earth, as the | | | | from the Polar Regions are set to have a huge |
| frequency of 5 Mhz used for Mars would quickly | | | | impact on climate change. The most recent example |
| interfere with radio communications. Experiments are | | | | of this is the evidence of a potential large scale break |
| currently underway to adapt the technology for use | | | | up of the Ross Ice Shelf in Antarctica. Not only could |
| at 435 Mhz where the radar will not cause disruption | | | | this work make a real difference to our |
| to earth based communications. | | | | understanding of the effects of climate change here |
| So what are these experiments all about? In a boost | | | | on the lovely blue green planet we call home, it could |
| for earth science research, funded by ESA's General | | | | unlock the doors to the search for life in our own |
| Studies Program, a new study, which has been | | | | solar system. |
| dubbed the Advanced Concept for RAdar Sounder | | | | The ACRAS study is set to conclude in October this |
| (ACRAS) is underway. This technique has been | | | | year and although a fully-fledged earth based satellite |
| proposed once before by ESA in the late 90's, | | | | mission is a long way off yet. Florence Heliere, the |
| however at that time the technology was not | | | | ESA study officer says, "We hope to conduct an |
| available to filter out false signals. These false signals | | | | airborne test of the technique." Source: ESA. |
| come firstly from the earths Ionosphere and then | | | | So as you go out to gaze up at the night sky, |
| secondly from terrain outside the radar's target area. | | | | looking at the prominent planets Mars and Saturn in |
| ACRAS appears to have found a way around this | | | | the early evening and Jupiter late in the evening. |
| problem by the use of multiple radar beams, in this | | | | Spare a thought for the hardworking scientists who |
| case 3 beams, each with slightly different properties, | | | | have made it possible for this pioneering work to be |
| using the principles of the Doppler effect. The | | | | done. |
| Doppler effect is best demonstrated by the changing | | | | |