In Depth | 1P/Halley – NASA Solar System Exploration
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 …
In Depth | Oumuamua – NASA Solar System Exploration
No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width. The most elongated objects we have seen to date are no more than three …
Asteroids, Comets & Meteors - NASA Solar System Exploration
Asteroids and comets – and the meteors that sometimes come from them – are leftovers from the formation of our solar system 4.6 billion years ago.
In Depth | Perseids – NASA Solar System Exploration
The pieces of space debris that interact with our atmosphere to create the Perseids originate from comet 109P/Swift-Tuttle. Swift-Tuttle takes 133 years to orbit the Sun once.
In Depth | 2P/Encke – NASA Solar System Exploration
Overview Comet 2P/Encke is a small comet. Its nucleus measures approximately 2.98 miles (4.8 kilometers) in diameter, which is about a third of the size of the object hypothesized to have led to …
Planet Compare – NASA Solar System Exploration
Oct 21, 2025 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
C/1995 O1 (Hale-Bopp) - NASA Solar System Exploration
Comet Hale-Bopp (C/1995 O1) was discovered on 23 July 1995 by two independent observers, Alan Hale (Cloudcroft, N.M.) and Thomas Bopp (Stanfield, AZ), and is showing potential of putting on a …
In Depth | 21P/Giacobini-Zinner – NASA Solar System Exploration
Comet Giacobini-Zinner was discovered on Dec. 20, 1900 by Michel Giacobini at the Nice Observatory in France. The comet was later recovered by Ernst Zinner in 1913 (October 23).
Comet Shoemaker-Levy 9 - NASA Solar System Exploration
May 19, 2025 · Comet Shoemaker-Levy 9 was discovered by Carolyn and Gene Shoemaker and David Levy in a photograph taken on Mar. 18, 1993, with the 0.4-meter Schmidt telescope at Mt. Palomar.
Pluto By the Numbers - NASA Solar System Exploration
Oct 21, 2025 · The distance from the center of an object to its equator. The outer or uppermost part of a planet, moon, asteroid, comet or other body. The gravitational acceleration experienced at its surface …