NASA’s New Horizons probe has already made history a few times since its 2006 launch. At the time, Pluto was a planet, but it had become a dwarf planet when New Horizons beamed back the first close-up photos of it in 2015. After that, the probe flew deeper into the Kuiper Belt and delivered the first images of Arrokoth. Now, it’s only the fifth human-made object to reach a distance of 50 astronomical units. In celebration, New Horizons snapped a photo of the Voyager 1 spacecraft. Well, it tried, but Voyager 1 is still way out in the lead.
New Horizons now joins the 50 AU club with Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2. It would have taken too much fuel to slow New Horizons down at Pluto, so it just kept on trucking. That gave it the opportunity to check out the fascinating Kuiper Belt Object (KBO) known as Arrokoth, which it breezed past on New Year’s Day 2019.
An astronomical unit (AU) is equal to the distance between Earth and the sun, about 93 million miles (150 million kilometers). Pluto is just shy of 30 AU away, and New Horizons made it there in only nine years. The launch in 2006 set a record for the fastest ever, and that record holds to this day. And it’s still among the fastest things we’ve ever built. It has sufficient velocity to escape the solar system, but it won’t ever overtake Voyager 1. New Horizons is moving at 13 kilometers per second, but Voyager’s multiple gravity assists accelerated it to 17 kilometers per second.
After reaching 50 AU, NASA turned New Horizon’s camera toward Voyager 1 and snapped a picture (above). You can’t see the 1977 space probe, which is about a trillion times too dim. However, it would be right in the middle, as indicated by the circle.
New Horizons is still healthy, and NASA hopes it will be able to intercept another KBO. Teams on Earth are using powerful telescopes like the Japanese Subaru observatory to scan the spacecraft’s path to see if there are any viable targets. Regardless of whether there’s another KBO in the probe’s future, it’s got a long life ahead of it. NASA will transmit updated software to New Horizons this summer to boost its scientific capabilities. Its nuclear battery should keep it transmitting until the late 2030s.