Artist’s impression of NASA’s New Horizons spacecraft, en route to a January 2019 encounter with the object of the 2014 Kuiper belt MU69. Credit: NASA
In the weeks following its launch in early 2006, when NASANew Horizons was still close to home, it took a few minutes to transfer an instruction to the spacecraft and hear back that the on-board computer had received the instructions and was ready to execute.
When New Horizons crossed the solar system, and the distance from Earth jumped from millions to millions of miles, the time between contacts grew from a few minutes to a few hours. And on April 17 at 12:42 UTC (or April 17 at 08:42 EDT) New Horizons reached a rare depth milestone – 50 astronomical units from the sun, or 50 times farther from the sun than the earth is.
Scale of the solar system
Here is one way to imagine how far 50 AE is: Think of the solar system located in a neighborhood; the sun is one house to the left of ‘house’ (or Earth), March would be the next house on the right, and Jupiter would be just four houses on the right. New Horizons would be 50 houses down the street, 17 houses out there Pluto!
New Horizons is only the fifth spacecraft to reach this great distance, following the legendary Voyagers 1 and 2 and their predecessors, Pioneers 10 and 11. It is almost 7 billion kilometers away; a remote region where one of the radio commands is needed, even at the speed of light seven o’clock to reach the distant spacecraft. Then add another seven hours before his control team on earth finds out if the message has been received.
“It’s hard to think of something like that,” said Alice Bowman, the New Horizons operations manager at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. ‘One thing that makes this distance tangible is how long it takes for us on earth to confirm that the spacecraft has received our instructions. It went from almost instantaneous until now in the order of 14 hours. It makes the extreme distance real. ”
To celebrate the occasion, New Horizons recently photographed the star field where one of its long-distance cousins, Voyager 1, appears from the unique seat of New Horizons in the Kuiper Belt. Never before has a spacecraft in the Kuiper belt photographed the location of an even more distant spacecraft, now in interstellar space. Although Voyager 1 is far too faint to be seen directly in the image, its location is known precisely because of NASA’s radio tracking.
Hello, Voyager! From the distant Kuiper belt at the boundary of the solar system, on Christmas Day, December 25, 2020, NASA’s New Horizons spacecraft pointed its Long Range Reconnaissance Imager in the direction of the Voyager 1 spacecraft, whose location with the yellow circle marked. Voyager 1, the farthest man-made object and first spacecraft to actually leave the solar system, is more than 152 astronomical units (AU) from the sun – about 14.1 billion miles or 22.9 billion kilometers – and was 18 billion kilometers (11.2 billion miles)) from New Horizons when this image was taken. Voyager 1 itself is about 1 trillion times too faint to be visible in this image. Most objects in the image are stars, but several of them, with a vague appearance, are distant galaxies. New Horizons reaches the 50 AU point on April 18, 2021 and will join Voyagers 1 and 2 in interstellar space in the 2040s. Credit: NASA / Johns Hopkins APL / Southwest Research Institute
“It’s a ghostly image to me,” said Alan Stern, lead researcher at New Horizons at the Southwest Research Institute in Boulder, Colorado.
“Looking back at the flight of New Horizons from Earth to 50 AU seems almost in a way like a dream,” he continued. ‘Flying a spacecraft over our entire solar system to explore Pluto and the Kuiper Belt’s had never been done before New Horizons. Most of us in the team were part of this mission as it was just an idea, and during that time our children grew up, and our parents, and ourselves, grew older. But most importantly, we’ve made a lot of scientific discoveries, inspired numerous STEM careers, and even made some history. ”
New Horizons is practically designed to make history. New Horizons was sent on January 19, 2006 at 36,400 miles per hour (58,500 kilometers per hour) and was still the fastest man-made object ever launched from Earth. Jupiter’s gravity assistance in February 2007 not only shaved off about three years of its journey to Pluto, but also created the best view of Jupiter’s faint ring and captured the first film of a volcano erupting anywhere in the solar system. except the earth.
New Horizons is currently just one of five spacecraft that explore the Kuiper belt past Pluto and reach 50 astronomical units – 50 times the distance between the sun and the earth – on their way out of the solar system and eventually into interstellar space. Credit: NASA / Johns Hopkins APL / Southwest Research Institute
New Horizons successfully launched the first reconnaissance of the Pluto system in July 2015, followed by the farthest flight in history – and the first close-up of a Kuiper Belt object (KBO) – with its flight past Arrokoth on New Year’s Day 2019. From its unique seat in the Kuiper Belt, New Horizons makes observations that can be made nowhere else; even the stars look different from the point of view of the spacecraft.
Artist conception of New Horizons spacecraft. Credit: Johns Hopkins University Applied Physics Laboratory / Southwestern Research Institute
New Horizons team members use giant telescopes like the Japanese Subaru Observatory to scan the sky for another potential (and long-range) CBO flight target. New Horizons itself stays healthy and collects data on the solar wind and space environment in the Kuiper Belt, other Kuiper Belt objects, and distant planets such as Uranus and Neptune. This summer, the mission team will launch a software upgrade to advance the scientific capabilities of New Horizons. For future exploration, the spacecraft’s nuclear battery should provide enough power to keep New Horizons running until the late 2030s.