New Horizons
What is New Horizons?
Probes & telescopes· Launched 2006-01-19 – Pluto flyby 2015-07-14 (heliophysics beyond the Kuiper belt). The NASA probe that took the first close-up pictures of Pluto, including its heart-shaped plain, in 2015. It passed 60 AU from the Sun in October 2024 and now studies conditions at the outer edge of the solar system.
Mission timeline
Spacecraft specs
| Launch | 2006-01-19 |
|---|---|
| Pluto flyby | 2015-07-14 |
| Distance | ~66 AU (as of Oct 2026) |
| Mission phase | heliophysics of the outer heliosphere (passed 60 AU in Oct 2024) |
Figures are representative approximations. Distances that change over time are extrapolated from 2026-01-01. Source: compiled from NASA and IAU public data.
New Horizons' dust counter and a wider Kuiper belt
New Horizons carries a dust detector built by university students. It is called the Venetia Burney Student Dust Counter, after the 11-year-old girl who suggested the name Pluto in 1930. Since launch it has been counting the tiny grains of dust that strike the spacecraft.
The Kuiper belt is a ring of icy bodies beyond Neptune. When these bodies collide they make dust, so counting dust gives a clue to how far out the bodies extend. Scientists expected the dust to thin out beyond about 50 AU. Results published in 2024, however, showed no drop even at 55 AU.
Scientists see two possibilities. Either the Kuiper belt reaches farther out than anyone knew, or the pressure of sunlight is pushing dust outward. Ground-based telescopes have also reported candidate objects between 60 and 80 AU, so where the solar system's disc really ends has become an open question again.
The mission in depth
New Horizons was launched on 19 January 2006 on an Atlas V rocket. It left Earth at 16.26 km/s, faster than any spacecraft before it, and still needed nine and a half years to reach Pluto. In 2007 it passed Jupiter and used the planet's gravity to gain about 4 km/s more.
On 14 July 2015 the probe flew past Pluto just once. It had no fuel to stop and orbit, so that single day was all it had. Its pictures showed a wide, heart-shaped plain called Sputnik Planitia and mountains of water ice 3,500 m high. The nitrogen ice of the plain slowly churns, so the surface is young enough to have almost no craters.
The spacecraft carries some of the ashes of Clyde Tombaugh, who discovered Pluto in 1930. He found it by flipping between two photographs taken days apart and spotting a dot that had moved. Eighty-five years later, his ashes flew past the world he found.
In January 2019 New Horizons passed Arrokoth, a small Kuiper belt object shaped like a snowman made of two joined lumps. It became the most distant object ever visited by a spacecraft. In October 2024 the probe passed 60 AU from the Sun, nearly twice its distance at the Pluto flyby, and it now measures the solar wind and dust at the outer edge of the solar system.
Frequently asked
- When did New Horizons launch?
- New Horizons was launched on 2006-01-19.
- How far is New Horizons from Earth?
- The distance of New Horizons is ~66 AU (as of Oct 2026).
- In one line, what is New Horizons?
- Probes & telescopes — The NASA probe that took the first close-up pictures of Pluto, including its heart-shaped plain, in 2015.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.