Comet C/2023 A3 Tsuchinshan–ATLAS will soon fly by Earth - CNN
网页3 天之前 · CNN —. A recently discovered comet, known as C/2023 A3 Tsuchinshan–ATLAS, will make its closest approach of Earth on Saturday. Sky-gazers won’t want to miss the event since it may be the ...
Comet - Wikipedia
网页A comet is an icy, small Solar System body 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.
Comets: Facts - NASA Science
网页Comet Facts. In the distant past, people were both awed and alarmed by comets, perceiving them as long-haired stars that appeared in the sky unannounced and unpredictably. Chinese astronomers kept extensive records for centuries, including illustrations of characteristic types of comet tails, times of cometary appearances and disappearances ...
Comets: Everything you need to know | Space
网页2023年7月31日 · Comets are defined as icy bodies of frozen gases, rocks and dust left over from the formation of the solar system about 4.6 billion years ago. They orbit the sun in highly elliptical orbits that ...
Comet | Definition, Composition, & Facts | Britannica
网页2024年10月5日 · comet, a small body orbiting the Sun with a substantial fraction of its composition made up of volatile ices. When a comet comes close to the Sun, the ices sublimate (go directly from the solid to the gas phase) and form, along with entrained dust particles, a bright outflowing atmosphere around the comet nucleus known as a coma.
What Is a Comet? | NASA Space Place – NASA Science for Kids
网页2024年9月27日 · 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.
A comet not seen in 50,000 years is coming. Here's what we know - Space.com
网页2023年1月6日 · On Feb. 1, comet C/2022 E3 (ZTF) will pass to within 28 million miles (42 million km) of our planet, its first visit in 50,000 years.
Comets - NASA Science
网页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.
Comet C/2022 E3 (ZTF): The best comet of 2023 may soon be …
网页2023年1月10日 · Comet C/2022 E3 (ZTF) is now sailing through the inner solar system. Here’s everything you need to know to track this celestial visitor.
NASA’s Webb to Unlock the Mysteries of Comets and the Early …
网页2019年9月25日 · Shortly after its launch in 2021, NASA’s James Webb Space Telescope will observe three different types of comets in infrared light, which is invisible to human eyes. By learning more about comets, scientists can gain new insights into what the solar system was like billions of years ago. Webb, A Powerful Tool.