300 articles
International Asteroid Warning Network
The International Asteroid Warning Network (IAWN) is a UN-endorsed, NASA-coordinated collaboration of asteroid astronomers, created in 2013 after the Chelyabinsk airburst, that tracks hazardous near-Earth objects and issues impact warnings.
Io (moon)
Io, also known as Jupiter I, is the innermost of Jupiter's Galilean moons and the most volcanically active world in the solar system, with about 400 active volcanoes.
Io (Ἰώ)
Io is Jupiter's innermost Galilean moon, slightly larger than Earth's Moon, and the most volcanically active body in the Solar System, with roughly 400 active volcanoes.
Iron and nickel vapor in comets
Iron and nickel vapor in comets refers to neutral iron and nickel atoms found in cometary atmospheres, first widely detected in about twenty comets with the VLT in 2021.
JPL Small-Body Database
The JPL Small-Body Database (SBDB) is a NASA database maintained by the Jet Propulsion Laboratory covering orbital data for nearly one million known asteroids and comets.
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the solar system, a gas giant with 115 known moons and a day of 9.9 hours.
Jupiter's dilute core
Jupiter's dilute core is an interior structure in which heavy elements are dissolved into the planet's hydrogen and helium envelope, revealed by NASA's Juno spacecraft.
Jupiter's polar cyclones
Jupiter's polar cyclones are clusters of large, long-lived storms at the planet's poles: eight circumpolar cyclones in the north and five in the south, discovered by NASA's Juno spacecraft in 2016.
Kamoʻoalewa
Kamoʻoalewa, minor planet 469219, is a roughly 18-meter near-Earth asteroid in a quasi-satellite orbit around Earth, discovered in 2016 in Hawaii and targeted by China's Tianwen-2 sample-return mission.
Kepler-1625b I
Kepler-1625b I is a candidate exomoon of the Jupiter-sized planet Kepler-1625b, 8,000 light-years away in Cygnus, claimed in 2018 and disputed since, with no moon confirmed.
Kepler-90i
Kepler-90i is a hot, rocky exoplanet, the eighth planet around the Sun-like star Kepler-90, discovered in December 2017 by a neural network searching archived Kepler data.
Kerberos
Kerberos (S/2011 (134340) 1, P4) is a small moon of Pluto discovered by Hubble in 2011, orbiting between Nix and Hydra with a 32.17-day period, a double-lobed ~19 km body of bright water ice.
Khalanasy Vallis
Khalanasy Vallis, an IAU-approved 1997 valley (vallis) on Venus, 320 km across, centered at 51S 168.5E, named for an Azeri river mermaid; one of 72 named Venusian valles.
Kore
Kore, also designated Jupiter XLIX and provisionally S/2003 J 14, is a small retrograde moon of Jupiter in the Pasiphae group, discovered in 2003 at Mauna Kea and named by the IAU in 2007.
Kūmsong Vallis
Kūmsong Vallis (Kumsong Vallis), a 700 km valley system on Venus centered at -59.00°, 152.50°E, IAU-approved in 1997, named with the Korean word for the planet Venus.
Life on Mars
Life on Mars is the scientific question of whether life exists or ever existed on Mars; none has been confirmed, though organic molecules and potential biosignatures have been found.
Life on Titan
Life on Titan, also called Titanian life, is a hypothesized possibility studied in astrobiology: Saturn's moon Titan has liquid methane lakes and a possible subsurface ocean.
Life on Venus
Life on Venus, also known as habitability of Venus, is the scientific question of whether life exists or ever existed there, focusing on microbial life in the clouds.
List of asteroid close approaches to Earth
The list of asteroid close approaches to Earth catalogs near-Earth objects passing within 0.05 au of Earth; the closest on record, in 2025, passed about 230 km up.
List of minor planets
The list of minor planets, also called the Minor Planet Catalogue, is the official International Astronomical Union catalog of numbered asteroids and other small bodies orbiting the Sun.
List of minor planets: 1–1000
The list of minor planets 1–1000 covers the first thousand asteroids numbered by the International Astronomical Union, from Ceres, discovered in 1801, to minor planet (1000), announced in 1923.
List of minor planets: 10001–11000
The list of minor planets 10001–11000 covers 1,000 consecutively numbered asteroids with permanent numbers from the Minor Planet Center, each paired with its provisional discovery designation.
List of minor planets: 15001–16000
The list of minor planets 15001–16000 catalogs 1,000 consecutively numbered minor planets, discovered between 1940 and 2000, with entries for designations, discovery circumstances, and Sun distance.
List of minor planets: 16001–17000
The list of minor planets 16001–17000 is a partial catalog of numbered minor planets, objects whose orbits were confirmed and numbered sequentially by the Minor Planet Center.
List of minor planets: 20001–21000
The list of minor planets 20001–21000 is a segment of the Minor Planet Center's catalog of 1,000 numbered small Solar System bodies, mostly discovered during 1991–1994 surveys.
List of minor planets: 21001–22000
The list of minor planets 21001–22000 covers one thousand consecutively numbered minor planets in the Minor Planet Center's catalog, including both named and unnamed bodies.
List of minor planets: 24001–25000
The list of minor planets 24001–25000 covers 1,000 numbered minor planets cataloged by the Minor Planet Center, numbered by orbit reliability rather than discovery date.
List of minor planets: 25001–26000
The list of minor planets 25001–26000 covers 1,000 sequential catalog numbers assigned by the Minor Planet Center once orbits are well determined, roughly in discovery order.
List of minor planets: 27001–28000
The list of minor planets 27001–28000 is a catalog block of 1,000 numbered asteroids, mostly discovered in 1998 and 1999 and dominated by the LINEAR automated survey.
List of minor planets: 28001–29000
The list of minor planets 28001–29000 is a segment of the Minor Planet Center's catalog of 1,000 small bodies, mostly discovered in late 1997, largely by LINEAR in Socorro, New Mexico.