Where is Halley's Comet now?

A comet is a lump of ice, dust and rock. Far from the Sun it is dark and quiet. When it comes close, sunlight warms it, and gas and dust stream off to make a glowing head and a long tail.

Halley's Comet is the most famous one. It goes round the Sun about every 76 years, so most people get one chance to see it. Its orbit is a long, thin oval, and it runs the opposite way round from the planets. At its closest it comes inside the orbit of Venus. At its farthest it is 35.14 AU from the Sun, about 1.2 times as far out as Neptune.

For decades after its 1986 visit, Halley climbed slowly away from the Sun. On 8 December 2023 it stopped climbing. That was its farthest point, 1,062 days ago. Since then it has been falling back in.

Out there it moves slowly, less than half a kilometre per second towards the Sun. It speeds up the closer it gets. It will spend most of the coming decades far from us, then rush through the inner Solar System in a few months.

It is far too faint to see now. Where it is today comes from its orbit, worked out by JPL from thousands of observations made between 1835 and 1994.

Halley was last closest to the Sun on 9 February 1986. Its nearest approach to Earth came later, on the way out, and it was not one of its brighter visits.

Space made up for it. A fleet of five spacecraft from Europe, the Soviet Union and Japan flew out to meet it. On 14 March 1986 the European probe Giotto passed within 596 kilometres of the nucleus. It became one of the first spacecraft to photograph the nucleus of a comet, the solid heart hidden inside the glowing head. Dust hit the probe thousands of times, and one grain sent it spinning for a while. It survived.

People have written about this comet for more than two thousand years. In 1066 it blazed in the sky before the Battle of Hastings, and it was stitched into the Bayeux Tapestry as an omen.

For most of history nobody knew these were all the same comet. Then, in 1705, the English astronomer Edmond Halley used Isaac Newton's new laws of gravity to work out comet orbits. He saw that several comets seen in earlier centuries moved the same way, and predicted it would return in 1758. It did, after he had died. It has carried his name ever since.

Each time Halley passes the Sun, it sheds dust along its orbit. Earth crosses that trail twice a year. The tiny grains burn up high in our air as shooting stars.

In May we get the Eta Aquariids, and in October the Orionids. NASA calls both weak showers. So even now, with Halley far beyond Neptune, a little of it falls into our sky every year. See our meteor showers page for the next one.

Halley will be closest to the Sun on 28 July 2061, in 12,685 days. A child born this year will be in their thirties. JPL's orbit is based on observations up to 1994, so the exact hour may shift, but the year is secure.

A lifetime is about 73.3 years on average, and Halley takes about 76 to come round. So most people see it once, if the sky is kind. A few lucky people see it twice, once as a child and once when old. Whoever sees it in 2061 will be looking at the same comet people watched in 1066.