Anti-terror squads could soon have a new weapon at their disposal to help track down bombers - a breathalyser that can pick up signs of handling explosives. Dubbed Heartsbreath, the new device, which has been developed by Michael Phillips and his colleagues from Menssana Research in New Jersey, can detect minute traces of explosive compounds excreted on the breath of individuals who have recently handled ordnance, including dynamite, TNT and C-4. The machine was originally developed to assist in medical diagnostics, looking for volatile compounds produced by lung cancers, and in cases of heart-transplant rejection. But because explosive chemicals can be inhaled or absorbed through the skin, the developers wondered whether the machine could also pick up these chemical signatures too. The researchers admit there is some way to go before this approach becomes a front-line tool in the fight against terrorism, but they are optimistic that it could provide a rapid and sensitive wy to flush out would-be bombers, including possibly picking up signs of radiation exposure.
Sarah - Mars is the closest it's been to earth since 2003, at a distance of 43.1 million miles. That's wafer thin in space terms. Can you give people some idea of how far that is.
Lisa - Well for example, light form the sun takes eight minutes to reach us here on Earth, and light from the sun to reach Mars takes approximately a further eight minutes. So on average, Mars is approximately twice as far away from the sun as the Earth is. It's very difficult in terms of millions of miles to imagine how far that actually is.
Sarah - Yes, it's very hard to comprehend. Now, it's going to look like a bright orangey-yellow star. What's the best way to see it?
Lisa - Well obviously you can use binoculars and telescopes to see it, but Mars is actually visible with the naked eye. If you look towards the north-east and east, you will be able to see Mars very clearly on a clear night. It will look very bright compared to the rest of the stars, and it will look slightly larger, although obviously not as big as the moon.
Chris - Will you be able to pick out anything spectacular if you look at it with a normal cheap telescope?
Lisa - You may be able to see dark regions on the surface compared with the light regions, but you would have to have a very powerful telescope if you were going to distinguish anything more detailed than that. But you would be able to make out different colourings, maybe.
Chris - Mars has the tallest volcano in the entire solar system, at three times the height of Mount Everest.
Lisa - That's right.
Sarah - Do we know when it last erupted?
Lisa - As far as I'm aware, volcanic activity on Mars is no longer active. We believe that Mars has cooled sufficiently to stop volcanic activity, as it's obviously a lot further away from the sun than the earth.
Chris - For strange impacts like the Tunguska Fireball, how common are big meteorite impacts, and can they cause that much damage?
Lisa - Absolutely. Asteroid or comet impacts could make a huge crater. There are craters all over the world that can be used as evidence for past meteoric or comet impacts. Of course, if we look on the surface of the moon or Mars, there are a number of craters. The moon actually protects us to a certain extent from further impacts from asteroids or comets.
Chris - So it acts like a giant comet hoover.
Lisa - Yes, absolutely.
Chris - But how regularly do these things smash into the earth? Is it often enough to change the climate so that we can't exist, like with the dinosaurs?
Lisa - It also depends on the size of the impact as well of course. Things are entering our atmosphere and will burn up in the atmosphere before they actually reach the earth. So if an asteroid or a comet is sufficiently small when it enters the atmosphere, it will just disintegrate on entry. I don't know the exact frequency, but to have a comet hit the earth the size of the one that wiped out the dinosaurs is not a frequent occurrence.
Lisa - The question that springs to mind with these sightings is where are these UFOs coming from. That's the interesting question for me. We're searching in our own solar system to try and find life on other planets, and we are yet to find amoeba life, let alone intelligent life like our own. So the big question for me is if these UFOs really are aliens or extra terrestrial life, where are they coming from?
Chris - So maybe we haven't looked hard enough yet and we haven't developed the tools to do that.
Lisa - Absolutely. There are lots of astronomers that think that somewhere in the universe we will find life. This is not only within our own solar system, but we have now found 170 planets around others tars in our own galaxy. So there's lots of potential for life out there, but we are yet to find anything.