1P/Halley

At a glance

Key points

It last rounded the Sun in 1986 and is due back in 2061.

• Returns every 76 years; next in 2061
• One of the darkest objects known
• Parent of the Orionid meteors

Up close

In 1986 ESA's Giotto flew within about 600 km of the nucleus and found it one of the darkest objects known, venting jets of gas and dust from a few active patches on its sunlit side.

History

Records of Halley stretch back more than 2,000 years, including its appearance in the Bayeux Tapestry. Edmond Halley predicted its 1758 return, the first proof that some comets orbit the Sun.

The 1986 armada

Five spacecraft met Halley in March 1986. The Soviet Vega 1 and Vega 2, both arriving from Venus, passed within about 8,900 and 8,000 km, and their positions of the nucleus were used to steer ESA's Giotto much closer. Japan's Suisei and Sakigake observed from farther out. Shortly before closest approach a large dust grain set Giotto wobbling and briefly cut contact; by then it had already recorded more than 2,300 images, and it recovered to keep sending data.

Waiting for 2061

Halley is now a cold, inactive nucleus about 35 AU from the Sun, beyond Neptune's orbit. It reached its farthest point in December 2023 and is falling back, due at perihelion on 28 July 2061, inside the orbit of Venus. Its period is not fixed: tugs from Jupiter and Saturn change it from one orbit to the next, and the interval from 1835 to 1910 was only 74.4 years. In 1986 it never came closer to Earth than 0.42 AU.

Missions

1. 1985–1992

   Giotto

   ESACompleted

   Imaged Halley's nucleus in 1986.

Related entries

• 67P/Churyumov–GerasimenkoThe comet Rosetta orbited
• Oort cloudThe Solar System's distant icy shell

Sources

1. ESA: Giotto approaching Comet Halley (opens in a new tab)
2. ESA: Giotto images of Comet Halley (opens in a new tab)
3. NASA Science: 1P/Halley (opens in a new tab)
4. JPL Small-Body Database: 1P/Halley (opens in a new tab)
5. NASA JPL: Horizons ephemeris system (opens in a new tab)
6. ESA: Giotto 20 years on (opens in a new tab)

Last reviewed 10 Oct 2026 against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.