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ANTIMATTER SPACECRAFT
A piece of antimatter the size of an aspirin could power a spacecraft over distances of hundreds of light years. The Moon could be minutes away and Mars a matter of days.
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What is antimatter?
You might not think that we have very much in common with stars. Yet we are made from the same building blocks - protons, neutrons and electrons. Take an electron - any electron - from your body. It will be identical to an electron in the rings of Saturn, or an electron from the heart of the Sun. In other words, we are all made of the same type of matter.
In 1928, the physicist Paul Dirac suggested that particles of matter have alter egos called antiparticles. Antiparticles have the same mass but opposite electric charges. When matter and antimatter meet, the fireworks start - particle and antiparticle destroy each other, and all their mass is converted to energy. If we could harness this energy, we could have the most efficient fuel possible.
What's the matter with antimatter?
There is a big problem with using antimatter. It takes more energy to make antiparticles than antiparticles produce when they are destroyed. Because of this, only 10 billionths of a gram is produced globally per year. This paltry amount isn't even enough to heat a cup of coffee, let alone travel to another planet.
In addition to this, there's also the tricky problem of storage. How do you contain antimatter when it explodes as soon as it comes in contact with matter?
These technical difficulties mean that we won't be jetting off in antimatter rockets in the foreseeable future. Researchers at NASA's Marshall Flight Centre are hoping that the technology will be ready in 30-40 years time. In the meantime, we have found a more practical application for antimatter in the world of medicine. It is used used inside PET scanners, which diagnose diseases such as cancer, epilepsy and coronary artery disease.
Most space scientists think that our best bet for escaping the Solar System is either by jetting off in a nuclear rocket, or setting sail in a Sun-driven spacecraft.
