NASA’s New Horizons Reaches a Rare Space Milestone

From NASA (duh)

Apr 15, 2021

Now 50 times as far from the Sun as Earth, History-Making Pluto Explorer Photographs Voyager 1’s Location from the Kuiper Belt

New Horizons

Artist’s impression of NASA’s New Horizons spacecraft, en route to a January 2019 encounter with Kuiper Belt object 2014 MU69.Credits: NASA/JHUAPL/SwRI

In the weeks following its launch in early 2006, when NASA’s New Horizons was still close to home, it took just minutes to transmit a command to the spacecraft, and hear back that the onboard computer received and was ready to carry out the instructions.

Scale of the Solar System

Here’s one way to imagine just how far 50 AU is: Think of the solar system laid out on a neighborhood street; the Sun is one house to the left of “home” (or Earth), Mars would be the next house to the right, and Jupiter would be just four houses to the right. New Horizons would be 50 houses down the street, 17 houses beyond Pluto! 

As New Horizons crossed the solar system, and its distance from Earth jumped from millions to billions of miles, that time between contacts grew from a few minutes to several hours. And on April 18 at 12:42 UTC (or April 17 at 8:42 p.m. EDT), New Horizons will reach a rare deep-space milepost — 50 astronomical units from the Sun, or 50 times farther from the Sun than Earth is. 

New Horizons is just the fifth spacecraft to reach this great distance, following the legendary Voyagers 1 and 2 and their predecessors, Pioneers 10 and 11. It’s almost 5 billion miles (7.5 billion kilometers) away; a remote region where one of those radioed commands, even traveling at the speed of light, needs seven hours to reach the far flung spacecraft. Then add seven more hours before its control team on Earth finds out if the message was received.   

“It’s hard to imagine something so far away,” said Alice Bowman, the New Horizons mission 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 received our instructions. This went from almost instantaneous to now being on the order of 14 hours. It makes the extreme distance real.” 

To mark the occasion, New Horizons recently photographed the star field where one of its long-distance cousins, Voyager 1, appears from New Horizons’ unique perch 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 due to NASA’s radio tracking.

Voyager in space

Hello, Voyager! From the distant Kuiper Belt at the solar system’s frontier, on Christmas Day, Dec. 25, 2020, NASA’s New Horizons spacecraft pointed its Long Range Reconnaissance Imager in the direction of the Voyager 1 spacecraft, whose location is marked with the yellow circle. Voyager 1, the farthest human-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 11.2 billion miles (18 billion kilometers) 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 of the objects in the image are stars, but several of them, with a fuzzy appearance, are distant galaxies. New Horizons reaches the 50 AU mark on April 18, 2021, and will join Voyagers 1 and 2 in interstellar space in the 2040s.Credits: NASA/Johns Hopkins APL/Southwest Research Institute

“That’s a hauntingly beautiful image to me,” said Alan Stern, New Horizons principal investigator from the Southwest Research Institute in Boulder, Colorado. 

“Looking back at the flight of New Horizons from Earth to 50 AU almost seems in some way like a dream,” he continued. “Flying a spacecraft across our entire solar system to explore Pluto and the Kuiper Belt had never been done before New Horizons. Most of us on the team have been a part of this mission since it was just an idea, and during that time our kids have grown up, and our parents, and we ourselves, have grown older. But most importantly, we made many scientific discoveries, inspired countless STEM careers, and even made a little history.”

New Horizons was practically designed to make history. Dispatched at 36,400 miles per hour (58,500 kilometers per hour) on Jan. 19, 2006, New Horizons was and is still the fastest human-made object ever launched from Earth. Its gravity-assist flyby of Jupiter in February 2007 not only shaved about three years from its voyage to Pluto, but allowed it to make the best views ever of Jupiter’s faint ring, and capture the first movie of a volcano erupting anywhere in the solar system except Earth. 

New Horizons successfully pulled off the first exploration of the Pluto system in July 2015, followed by the farthest flyby in history – and first close-up look at a Kuiper Belt object (KBO) — with its flight past Arrokoth on New Year’s day 2019. From its unique perch in the Kuiper Belt, New Horizons is making observations that can’t be made from anywhere else; even the stars look different from the spacecraft’s point of view

spacecraft around the Kuiper Belt diagram

Currently exploring the Kuiper Belt beyond Pluto, New Horizons is just one of five spacecraft to reach 50 astronomical units – 50 times the distance between the Sun and Earth – on its way out of the solar system and, eventually, into interstellar space.Credits: NASA/Johns Hopkins APL/Southwest Research Institute

New Horizons team members use giant telescopes like the Japanese Subaru observatory to scan the skies for another potential (and long-shot) KBO flyby target, New Horizons itself remains healthy, collecting data on the solar wind and space environment in the Kuiper Belt, other Kuiper Belt objects, and distant planets like Uranus and Neptune. This summer, the mission team will transmit a software upgrade to boost New Horizons’ scientific capabilities. For future exploration, the spacecraft’s nuclear battery should provide enough power to keep New Horizons operating until the late-2030s. 

Last Updated: Apr 16, 2021

Editor: Tricia Talbert

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April 17, 2021 2:28 am

What’s NASA doing meddling around in space ?

They should stick to their core task of altering data to suit the political agenda.

Last edited 21 days ago by saveenergy
John in Oz
Reply to  saveenergy
April 17, 2021 6:46 pm

I heard yesterday that SpaceX has the contract to land (insert preferred anthropomorphic descriptor) on the moon again with NASA seemingly the junior partner.

April 17, 2021 3:26 am

We need another postcard. The faint blue dot with better resolution.

Reply to  tygrus
April 17, 2021 10:07 am

it’s a blue dot with gray CO2 smudge that is all your fault these days .. get with the program or they ship you off to the re-education camp.

Bryan A
Reply to  tygrus
April 17, 2021 10:27 am

Postcards from the Edge are the best

April 17, 2021 3:46 am

These aircraft have expanded our horizons, actually redefining what the outer limits of our solar system is as they have shown how much further the suns influence projects into interstellar space than was previously known.

Now I have a question. Which of the satellites comes closest to penetrating the leading edge of the heliosphere. Or IOW is travelling in a line closest to the Suns direction of movement (trajectory?) as it orbits in the Milky Way? And which has a trajectory which takes it closest to passing between the tails of the heliosphere or IOW moving in the opposite direction of the solar systems orbit?

Reply to  rah
April 17, 2021 5:23 am

Sometimes wish there was an edit function. Spacecraft not aircraft! Duh!

Reply to  rah
April 17, 2021 6:08 am

There is an edit function. Place curser at bottom right and wait for the su=ynbol to appear, click and you get the edit button to click.

Reply to  RickWill
April 17, 2021 7:01 am

What I get is a comment link button.

Bryan A
Reply to  rah
April 17, 2021 10:29 am

Comment link should be upper right infinity symbol and edit should be Gear symbol lower right

Reply to  RickWill
April 17, 2021 11:21 am

Thanks to all. I finally found the edit icon.

John Dueker
Reply to  rah
April 17, 2021 6:04 am

I believe both Voyages are beyond the heliosphere. Data can be found at and I’m told the cosmic ray data (watch out for the difference in scales) shows they are in interstellar space.Another article concurs.

I find it daunting that it’s been traveling for 43 years at 38,026 mph and it hasn’t even traveled a light day. Space is big!

Sal Minella
Reply to  John Dueker
April 17, 2021 6:25 am

It has traveled seven light-hours in 14 years. Impressive! At this rate (50 years/light-day, 18250 years/light-year) we could actually position a spacecraft to get a real picture of the Milky Way in about 1,825,000,000 years.

I guess I’ll have to settle for an artists rendition.

John Dueker
April 17, 2021 5:55 am

I might be missing a qualification but , “Dispatched at 36,400 miles per hour (58,500 kilometers per hour) on Jan. 19, 2006, New Horizons was and is still the fastest human-made object ever launched from Earth.”

Yet the Voyage 1 data says it’s velocity is 38,026.77 mph,

Which one wins the speed contest?

Reply to  John Dueker
April 17, 2021 6:41 am

I don’t know but each have velocity which have not been constant. Decelerated by the sun’s gravity. Sped up when getting close to a planet, then slows down to loose some of the advantage while they leave the planet’s gravity. Then back to that small decay because the sun’s gravity is still trying to pull them back ever so slightly. I’m sure you can search internet/wiki for more details.

Reply to  tygrus
April 17, 2021 6:50 am

I think I read that without the ability to use other planets gravity to “slingshot” these craft to higher velocities, they would not be able to leave the solar system.

Reply to  rah
April 17, 2021 9:27 am

They could with a rocket engine and an adequate fuel supply.

Reply to  AndyHce
April 17, 2021 10:48 am

No such thing in existence I understand.

Reply to  rah
April 17, 2021 9:56 am

Wikipedia graphs velocity profiles for Voyager1/2 and New Horizons

V1 and NH left Jupiter at about same speed 22 km/s, but NH being directed for Pluto encounter it lost speed while V1 just continued on a ballistic path and slowed down more gradually

Currently V1 is going about 17 km/s (38,000 mi/hr) and NH is going about 13.5 km/s (30,000 mi/hr).

I’m not clear if the graphs show true speed or radial speed (i.e. how fast it is moving away from the sun). However based on the trajectories shown in this article, at the great distance they are at now the spacecraft are both moving more or less along a radial trajectory, so maybe that is a moot point.

Reply to  menace
April 17, 2021 10:03 am

Correction V1 had velocity of 22 km/s after Saturn encounter not Jupiter so that explains most of the velocity difference now

Reply to  John Dueker
April 17, 2021 10:15 am

The moment you take on a gravity assist your speed isn’t from the launch … so it is correct.

Both those object are crawling if you compare them Parker Solar Probe check out it’s speed by a search and using your criteria it wins by a country mile.

Tom in Florida
Reply to  John Dueker
April 17, 2021 12:18 pm

Be careful to see that the speeds is not mixed up. The speed is shown as relative to the Sun or the Earth, both are numbers available.

Reply to  Tom in Florida
April 17, 2021 6:52 pm

Your answer is stupid the milky way galaxy is moving at 210 km/sec at our distance (so you and the probe have that as your underlying speed of 756,000Km/hour). Do you want to account for that as well and you could round you and the two probes doing the same speed 🙂

Generally we report speeds relative to the dominant gravitational force that a body is under otherwise it all gets stupid.

Last edited 20 days ago by LdB
April 17, 2021 6:30 am

Great craft !

April 17, 2021 10:08 am

This is science processed in the near-frame, without the colored assumptions/assertions (e.g. models, signal fidelity) that prejudice other scientific enterprises. Patience is a virtue.

Stephen Richards
April 17, 2021 11:11 am

When NASA are just so brilliant at this science why do they allow GISS to destroy it

Reply to  Stephen Richards
April 17, 2021 2:46 pm

How many blocks away is GISS from the Madoff building?

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