NASA’s New Horizons probe has woken up in good health nearly 6 billion miles away beyond Pluto after spending nearly a year in hibernation.
Traveling such vast distances between our solar system’s most remote objects means New Horizons often cruises for months at a time with little to do other than passively collect data. During these periods, the probe goes into a hibernation mode in which its instruments still collect data, but most other systems power down.
New Horizons entered just such a hibernation period last August, and has now woken up in “good health”, according to a NASA statement. The spacecraft is 5.9 billion miles (9.5 billion kilometers) from Earth, so far away that it takes around 9 hours for its radio signals to reach us. Now that it’s awake, New Horizons will begin transmitting the data it has collected over the last 321 days and letting its controllers on the ground know how its systems are faring in the cold, dark reaches of deep space.
So far, the probe appears to be in perfect health. “Every status report through this hibernation period was ‘green,’ meaning all was well aboard New Horizons each and every week,” said Alice Bowman, the New Horizons mission operations manager at the Johns Hopkins Applied Physics Laboratory (APL) in the NASA statement.
New Horizons is the first and only flyby spacecraft to conduct a flyby of the Pluto system, which it did in 2015. Four years later, the plucky probe studied the most distant object ever explored in our solar system, the snowman-shaped planetesimal Arrokoth, while it was one billion miles (1.6 billion kilometers) past Pluto.
Since then, the long-distance voyager has been probing the edge of our sun’s influence and studying objects in the Kuiper Belt, the cold, donut-shaped ring of icy objects that circles the outer solar system beyond Neptune.
New Horizons is currently speeding away from Earth at a rate of 300 million miles (483 million km) per year, according to NASA.
Three weeks from now, New Horizons will begin conducting a study of hydrogen in the outer heliosphere, the region of space influenced by the stream of charged particles blowing outward from the sun, known as the solar wind.
The data the probe is collecting at the farthest reaches of our solar system is the first of its kind. It could help scientists understand what happens at the boundary between the sun’s region of influence and interstellar space, known as the “termination shock.”
Only two spacecraft have crossed this boundary before, NASA’s twin Voyager probes. However, those far-flung explorers weren’t equipped with the same scientific instruments as New Horizons, which enable it to conduct more sensitive measurements of this distant region of the solar system.
“The data from the termination shock encounter will be a treasure trove for space physicists worldwide who are eager to understand how this vast boundary works,” Pontus Brandt, New Horizons project scientist at APL, previously told Space.com. “All these discoveries from pioneering missions like Voyager and New Horizons teach us how little we know about what lies beyond.”