Human Feet Leapfrog On Comet
Imagination became reality early this week, when a mechanical space traveller called the Philae probe plunked down on its target, a comet with a much less romantic nomenclature—67P—some 310 million miles from Earth. European Space Agency (ESA) scientists went gaga when the landing was confirmed. Spacecraft have crashed into comets before, but this is the first soft or controlled landing, in history. Success doesn’t come too easily, this probe too met with some glitch. ESA scientists said at a news conference that after leaving the mother ship Rosetta and descending, Philae may have bounced, rather than gently settled, on the surface of the comet. Comet 67P has a very weak gravity, so anchoring harpoons were designed to shoot into the comet to fix the spacecraft to the surface. They failed to fire and Philae is not firmly secure, ESA said. Rosetta took off from Earth 10 years ago carrying Philae and travelled 6.4 billion miles before arriving in early August at the comet. The Philae lander separated from the orbiting Rosetta around 3:30 a.m. (European Time) and landed on the comet seven hours later. The lander weighs about 220 pounds and is the size of a domestic washing machine. The target comet is only four kilometers, or 2.5 miles, in diameter. Shortly after landing was confirmed, the probe tweeted: “Touchdown! My new address: 67P!” Later, it tweeted again: “I’m on the surface but my harpoons did not fire.”
Philae is equipped with an array of experiments to photograph and test the surface of Comet 67P as well as to find out what happens when the roasting effect of the sun drives off gas and dust. Built by a European consortium, led by the German Aerospace Research Institute, the landing probe has nine experiments. Sensors on the lander will measure the density and thermal properties of the surface, gas analyzers will help detect and identify any complex organic chemicals that might be present, while other tests will measure the magnetic field and interaction between the comet and solar wind. The major impact of this space odyssey will be on our capability of meeting and diverting any asteroid or comet before it becomes a danger for Earth.
By Nilabh Krishna