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 | 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 …
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.
Stardust | JPL | NASA
On July 23, 1995, an unusually bright comet outside of Jupiter's orbit (7.15 AU!) was discovered independently by Alan Hale, New Mexico and Thomas Bopp, Arizona. The new comet, designated …
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).
Occasionally, giant molecular clouds, stars passing nearby, or tidal interactions with the Milky Way’s disc disturb the orbit of one of these bodies in the outer region of the Oort Cloud, causing the object to …
In Depth | Our Solar System – NASA Solar System Exploration
The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, …
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.
Pluto By the Numbers - NASA Solar System Exploration
Oct 21, 2025 · SURFACE AREA The outer or uppermost part of a planet, moon, asteroid, comet or other body. 6,427,806 square miles 196,936,994 square miles