These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters …

6 days ago · Comet 3I/ATLAS, the third interstellar object ever detected, reached its closest point to Earth overnight from Thursday to Friday (Dec. 18 to 19), and it remains in a good viewing …

Dec 17, 2025 · Comet 3I/ATLAS will approach within 168 million miles (270 million kilometers) of Earth when it makes its close flyby on Dec. 19. You can watch comet 3I/ATLAS's flyby live …

6 days ago · Interstellar comet 3I/ATLAS will make its closest approach to Earth on Friday. New X-ray images could shed light on its composition.

5 days ago · Today is one astronomers, stargazers and alien conspiracy theorists have been waiting for: interstellar comet 3I/ATLAS is as close to Earth as ever.

Dec 3, 2025 · 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 …

Nov 29, 2025 · Comet, a small body orbiting the Sun with a substantial fraction of its composition made up of volatile ices. Comets are among the most-spectacular objects in the sky, with their …

Aug 26, 2025 · 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. Wanderers of the Solar …

Nov 2, 2025 · A comet is a small, icy body that orbits the Sun and releases gas and dust when heated. Each comet has a frozen nucleus (ice, rock, organic material), a glowing coma that …

Apr 24, 2025 · Each comet has a frozen part, called a nucleus, often a few miles across. The nucleus contains icy chunks, frozen gases with bits of embedded dust. A comet warms up as it …