Averting Armageddon
The European Space Agency (ESA) has launched a project that could prevent mankind from suffering the same fate as the dinosaurs. The recent discovery of asteroid 2002NT7, a near earth object (NEO) measuring two kilometres in diameter, again led some commentators to predict the end of the world. Fortunately, closer study of the object by scientists suggests that Armageddon will be postponed for now, but it appears that the ESA have decided to take no risks. They have asked academics and industry to come up with proposals on how we can learn more about NEOs, and how to safeguard the earth from the threat that they pose. An expert ESA panel has selected six winners and, after a period of preliminary study, they may decide to develop one or more of the ideas into a full programme. As panellist Andrés Gálvez explains, 'the six winning proposals were selected because the mission concepts would help to answer essential questions on the NEO threat such as: how many are there, what is their size and mass, are they compact bodies or loose rock aggregates? This information, as well as other data, is needed before adequate mitigation procedures can be developed.' The winning proposals include: - Don Quijote: Two spacecraft (Hidalgo and Sancho) would intercept the NEO, and whilst one deliberately collides with it at high speed, the other observes the result and relays information on the objects internal structure back to earth. - Simone: A fleet of low-cost small satellites that rendezvous with multiple NEOs to characterise the population and provide first-hand information on the objects. - Ishtar: A new technology called radar tomography is used to scan the interior structure of the solid asteroid, and thus assess the danger it poses to earth. The feasibility studies on these ideas should be completed by 2003, when a decision on further development will be made. This delay in implementing Europe's first NEO protection programme shouldn't overly worry the population, however; collisions of the type that wiped out the dinosaurs are estimated to occur only once every hundred million years.