NASA’s New Horizons spacecraft passed by the ice-and-rock planetoid, the tiny planet Pluto and its entourage of five moons at 7:49 a.m. EDT (1149 GMT), capping a journey of 3 billion miles (4.88 billion km) that began nine and a half years ago.
About 13 hours after its closest approach to Pluto, the last major unexplored body in the solar system, New Horizons, the pluto probe, phoned home, signalling that it had survived its 31,000 miles per hour (49,000 km per hour) blitz through the Pluto system. Managers had estimated there was a 1-in-10,000 chance a debris strike could destroy New Horizons as it soared just 7,750 miles (12,472 km) from Pluto. New Horizons made radio contact with flight controllers right on time, at the Johns Hopkins University Applied Physics Lab outside Baltimore, sparking a wave of shouts and applause from an overflow crowd gathered to watch the drama unfold. New Horizons spent more than eight hours looking back at Pluto for a series of experiments to study the planet’s atmosphere and photograph its night-side using light reflected off its primary moon Charon.
Sending back its first post-flyby signal took another 4½ hours, the time it takes radio signals, travelling at light speed, to travel the 3 billion miles (4.88 billion km) back to Earth. Already, the trickle of images and measurements relayed from New Horizons before Tuesday’s pass by Pluto has changed scientists’ understanding of this diminutive world, which is smaller than Earth’s moon. Once considered an icy, dead world, the planetoid has yielded signs of geological activity, with evidence of past and possibly present-day tectonics. Scientists have many questions about Pluto, which was still considered the solar system’s ninth planet when New Horizons was launched in 2006. Pluto was reclassified as a “dwarf planet” after the discovery of other Pluto-like spheres orbiting in the Kuiper Belt, the region beyond the eighth planet, Neptune.
It will take about 16 months for New Horizons to transmit back all the thousands of images and measurements taken during its pass by Pluto. The spacecraft will have, by then, travelled even deeper into the Kuiper Belt……
See full story on channelnewsasia.com
Image: Reuters