Close encounter as Nasa spacecraft survives flypast of stellar object
An unmanned Nasa spacecraft yesterday sent a signal back to Earth that it had made it through a risky flyby of the most distant planetary object yet studied, the US space agency said.
“We have a healthy spacecraft,” said Alice Bowman, missions operations manager for the New Horizons probe, which zipped by Ultima Thule at 9.33am UAE time on New Year’s Day. “We have just accomplished the most distant flyby.”
The “phone home” signals took about 10 hours to reach Earth after the manoeuvre, which was performed 6.4 billion kilometres away.
Ms Bowman said the images and data sent back would “help us understand the origins of our Solar System”.
The New Horizons probe reached the Kuiper Belt in the uncharted heart of the “third zone” on schedule.
Scientists confirmed its whereabouts through Nasa’s Deep Space Network.
The belt contains icy bodies and fragments from the Solar System’s creation – including Ultima Thule, a cool mass shaped like a giant peanut, which will be photographed by the probe’s seven onboard instruments.
Nasa said scientists had not discovered Ultima Thule when the probe was launched in 2006 on a 6.4-billion-kilometre journey to study the dwarf planet Pluto and its five moons, making the mission unique in that respect. In 2014, astronomers found Thule using the Hubble Space Telescope and selected it for New Horizon’s extended mission in 2015.
“Anything’s possible out there in this very unknown region,” John Spencer, deputy project scientist for New Horizons, said on Monday.
After trekking 1.6bn kilometres beyond Pluto into the belt, New Horizons will now seek clues about the formation of the solar system and its planets.
As the probe flies 3,500km above Thule’s surface, scientists hope it will detect the chemical composition of its atmosphere and terrain in what Nasa says will be the closest observation of a body so remote.
“We are straining the capabilities of this spacecraft,” New Horizons principal investigator Alan Stern said at the Johns Hopkins Applied Physics Laboratory. “There are no second chances for New Horizons.”
While the mission is the farthest close encounter of an object in our Solar System, Nasa’s Voyager 1 and Voyager 2 deep-space probes – launched in 1977 – have reached greater distances on their missions to survey extrasolar bodies. The first is about 21.7bn kilometres from Earth and the second more than 17.8bn kilometres. Both are still operational.