Dec 9, 2024 · 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.

Oct 11, 2024 · The comet hails from the Oort Cloud, which scientists think is a giant spherical shell surrounding our solar system. It is like a big, thick-walled bubble made of icy pieces of space debris the sizes of mountains and sometimes larger.

Jan 14, 2025 · A comet has two tails that get longer the closer it gets to the Sun. Both tails are always directed away from the Sun. The ion tail (blue) always points directly away from the Sun, while the dust tail (yellow) points away from the Sun in a …

Jan 22, 2025 · Asteroid and Comet Resources. Explore this page for a curated collection of resources, including activities that can be done at home, as well as videos and animations, images, handouts, and online interactives. This resource package is suitable for educators, students, and anyone interested in learning more about asteroids and comets! Learn More

On June 15, 2020, a citizen scientist spotted a never-before-seen comet in data from the Solar and Heliospheric Observatory, or SOHO — the 4,000th comet discovery in the spacecraft’s 25-year history.

Jun 7, 2000 · When a comet approaches within a few Astronomical Units (1 AU equals approximately 150 million kilometers) of the Sun, the surface of the nucleus begins to warm, and volatile material on the comet evaporates.

From Jan. 11 to 15, 2025, a bright comet surged through images from the ESA (European Space Agency) and NASA SOHO (Solar and Heliospheric Observatory) spacecraft. Called C/2024 G3 (ATLAS), the comet made its closest pass to the Sun, or perihelion, on Jan. 13, soaring a mere 8 million miles (or 9% of the average Earth-Sun distance) from our star.

Nov 3, 2024 · Halley is often called the most famous comet because it marked the first time astronomers understood comets could be repeat visitors to our night skies. Astronomers have now linked the comet’s appearances to observations dating back more than 2,000 years.

Apr 12, 2022 · This sequence shows how the nucleus of Comet C/2014 UN271 (Bernardinelli-Bernstein) was isolated from a vast shell of dust and gas surrounding the solid icy nucleus. On the left is a photo of the comet taken by the NASA Hubble Space Telescope’s Wide Field Camera 3 on January 8, 2022.

The featured image shows impressive Comet ATLAS over trees and a grass field in Sierras de Mahoma, San Jose, Uruguay about a week ago. After being prominent in the sunset skies of Earth's southern hemisphere, Comet G3 ATLAS is now fading as it moves away from the Sun, making its impressive tails increasingly hard to see. Gallery: Comet ATLAS (G3)