Results for “what is comets” · retrieved September 22, 2026
Comets are ancient, icy objects that orbit the Sun and develop glowing heads and long tails when they get close to solar heat.
Comets are ancient, icy bodies that orbit the Sun, often described as cosmic snowballs or dirty snowballs. They are remnants from the formation of the solar system approximately 4.6 billion years ago. At their core is a solid nucleus made of ice, dust, and rocky material. As a comet approaches the Sun, it heats up, causing its ices to sublimate and release gas and dust. This creates a large, fuzzy atmosphere called a coma and often two distinct tails: a dust tail and an ion (gas) tail, both of which point away from the Sun. Comets typically originate in distant regions like the Kuiper Belt or the Oort Cloud and travel in highly elliptical orbits.
Answer details
The Nucleus
The nucleus is the solid, frozen heart of a comet, typically a few kilometers wide and composed of ice, dust, and rocky material.
Coma and Tails
As a comet nears the Sun, it develops a coma, a large atmosphere of gas and dust, and two types of tails: a dust tail and an ion (gas) tail, both pointing away from the Sun.
Origin and Orbit
Most comets originate in the distant Kuiper Belt or Oort Cloud and follow highly elliptical orbits that bring them into the inner solar system.
Solar System History
Comets are considered leftovers from the formation of the solar system 4.6 billion years ago and may have provided water and organic compounds to early Earth.
Sources 8
About this answerComets
Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles. There are likely billions of comets orbiting our Sun in the Kuiper Belt and even more distant Oor
Publication date not supplied
Comet
A comet is an icy, small Solar System body or interstellar object that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or coma surrounding the nucleus, and sometimes a tail of gas and dust gas blown out from the coma. These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of
Publication date not supplied
Comet - Nucleus, Tail, Orbit | Britannica
Telescopic observations from Earth and spacecraft missions to comets have revealed much about their nuclei. Cometary nuclei are small solid bodies, typically only a few kilometres in diameter and composed of roughly equal parts of volatile ices, fine silicate dust, and organic materials. The ices are dominated by water ice (about 80 percent of the total ices) but also include carbon monoxide, carbon dioxide, formaldehyde, and methanol. The silica
Publication date not supplied
What Is a Comet?
The Short Answer: Comets are large objects made of dust and ice that orbit the Sun. Best known for their long, streaming tails, these ancient objects are leftovers from the formation of the solar system 4.6 billion years ago....Comets, such as the comet ISON pictured here, are thought to hold material from the time when the Sun and planets were forming. They are like giant, frozen time capsules in our solar system. Credit: NASA/MSFC/Aaron Kingery
Publication date not supplied
Comet Facts
Comets are leftovers from the dawn of our solar system around 4.6 billion years ago, and consist mostly of ice coated with dark organic material. They have been referred to as "dirty snowballs." They may yield important clues about the formation of our solar system. Comets may have brought water and organic compounds, the building blocks of life, to the early Earth and other parts of the solar system. Comets Home about Comet Facts Contents...W
November 15, 2017
ESA - Comets: an overview
With a name derived from the Greek komētēs, meaning a 'long-haired' star, comets are ancient celestial icebergs of the Solar System. Each comet is roughly 4600 million years old and formed at the same time as the Sun, Earth and the other planets....The defining characteristic of a comet is its tail – the long 'hair' to which the Greeks referred. Tails come in two main types, ion (or plasma) and dust. When sunlight evaporates the ice on the comet’
Publication date not supplied
What is a comet? | BBC Sky at Night Magazine
Comets, the least predictable Solar System visitors, can be one of its great highlights....Simply put, a comet is a large body of ice and dust orbiting the Sun, sometimes seen as a bright object in the sky with a long tail streaming behind it....The heart of a comet is its nucleus, a core of ice laced with rock and dust, a few kilometres wide....Comets travel in huge elliptical orbits, briefly visiting the inner Solar System at one end before tra
August 26, 2025
Comets - Learn the facts
LOCATION: The distant Kuiper Belt and Oort Cloud regions of the solar system...DISTANCE FROM THE SUN: 55 million miles (89 million kilometers) up to 100,000 astronomical units (or 100,000 times the distance between the Earth and the Sun)...GRAVITY: Almost nonexistent...Leave your spaceship on the launch pad for this mission. If there's any heavenly body that’s best seen from Earth’s surface, it’s a comet. These leftovers from the formation of our
Publication date not supplied
Keep exploring
Related on this site
This page was prepared by Seeked from live retrieval on September 22, 2026 and is not continuously updated. Run a fresh search for the latest, or to inspect each source.