Beware the Hidden Moons of Pluto
On: 12/01/2011 Views: 69
With nearly two-thirds of its journey complete, the New Horizons spacecraft is still alive and well but when the spacecraft reaches Pluto in July 2015, it may find the region more hazardous than anticipated with the discovery of several moons around Pluto — and the potential for other, hidden moons too small and faint to detect — that increase the risks during the probe's flyby. Pluto's first known moon, Charon, was discovered in 1978, Hubble Space Telescope discovered two more in 2005, and in July a fourth moon was located, leading scientists to believe there may be more. The main problem is debris because the small moons are under constant bombardment from the Kuiper Belt, but the moons' low gravity prevents the chunks of rock from being captured so they are caught in orbit around Pluto, where they could pose a serious threat to New Horizons. "The most likely problem we would encounter is to be hit by something that is large enough to instantly destroy the spacecraft," says New Horizons principal investigator Alan Stern. Experts recently convened to analyze the hazards and determined the need for a good "safe haven bailout trajectory," or SHBOT — an orbit that New Horizons could shift into that would keep it away from the most likely danger zones. "There is no wounded here," adds Stern, "only dead or alive."