Comet facts that are worth knowing

COMET

A comet is a very small solar system body composed primarily of ices with minor amounts of dust and rock.

"Comet" is derived from the Latin "cometes," which is derived from the Greek "kometes," which means "long-haired."

A comet is made up of four parts: a nucleus, a coma, a dust tail, and an ion tail.

A comet's nucleus is made of ice and rocky material and can range in size from a few hundred metres to 100 kilometres (62 miles).

The coma is the cloud of gases that forms around the nucleus as the coma heats up. These gases are typically a blend of water vapour, ammonia, and carbon dioxide.

A comet's dust tail is made up of gases and tiny dust particles that are blown away from the nucleus as the comet heats up. A comet's dust tail is its most visible feature.

The ion tail is a stream of ionised gases blown directly away from the Sun by the comet's interaction with the solar wind.

When a comet's ices are heated by the Sun, they begin to sublimate. The solar wind blows a mixture of ice crystals and dust away from the comet nucleus, forming a pair of tails. When we look at comets from Earth, we usually see the dust tail.

Comet tails can be more than one million kilometres (600,000 miles) long.

There are several types of comets. Periodic and non-periodic are the most common.

Periodic comets, also known as short-period comets, have orbital periods of less than 200 years.

Non-periodic comets such as Hale-Bopp (C/1995 O1), Hyakutake (C/1996 B2), McNaught (C2006 P1), and Lovejoy (C/2011 W3) are well-known. These flared brightly in our skies before fading away.

Furthermore, Comet Shoemaker-Levy 9 (D/1993 F2) was discovered after it had broken up following a close encounter with Jupiter.

The most famous comet in history is the periodic comet Halley (1P/Halley). Every 76 years, it returns to the inner solar system. 2P/Encke, which appears every 3.3 years, and 9P/Tempel (Tempel 2), which was visited by the Deep Impact and Stardust probes and makes perihelion around the Sun every 5.5 years, are two other well-known periodic comets.

Edmond Halley discovered the comet observed in 1531, 1607, and 1682 in 1705 while studying the orbits of several known comets. The comet was named after Halley as a result of his discovery. Halley's Comet appears every 75 to 76 years.

While the coma around Halley's Comet can span up to 100,000 km, the nucleus is only about 15 km (9.3 miles) long, 8 km (5 miles) wide, and 8 km (5 miles) thick.

Comet

Comet Hale-Bopp was possibly the most widely observed comet of the twentieth century, and it was one of the brightest seen in decades. On July 23, 1995, it was discovered at a great distance from the Sun, raising hopes that the comet would brighten significantly by the time it passed close to Earth. It was visible to the naked eye for an unprecedented 18 months, more than twice as long as the previous record-holder, the Great Comet of 1811.

Comets, like planets, orbit the Sun in elliptical orbits. A comet's path, on the other hand, is far more elliptical than that of any planet.

Perihelion is the closest point in a comet's orbit to the Sun. The most distant point is referred to as "aphelion."

Comets have two tails: a dust tail that can be seen with the naked eye and a plasma tail that can be photographed but is difficult to see with the naked eye.

Comets are also known as "dirty snowballs" or "cosmic snowballs." This is due to the fact that they are mostly made up of ice, rock, gas, and dust.

There are currently over 3,000 known comets.