611 articles
(523676) 2013 UL10
(523676) 2013 UL10 is a centaur, a small outer Solar System body whose orbit lies between Jupiter and Neptune, and the first known active red centaur.
(523764) 2014 WC510
(523764) 2014 WC510 is a binary trans-Neptunian object in the Kuiper Belt, discovered in 2011 by Pan-STARRS1 and locked in a 2:3 orbital resonance with Neptune.
(614689) 2020 XL5
(614689) 2020 XL5 is a roughly 1 km near-Earth asteroid librating at Earth's L4 Lagrange point, the second known Earth Trojan, confirmed by a 2022 study.
10199 Chariklo
10199 Chariklo is the largest known Centaur, orbiting between Saturn and Uranus. Discovered in 1997, it became in 2013 the first small Solar System body found to have rings.
1437 Diomedes
1437 Diomedes is a large Jupiter Trojan asteroid, about 118 km across, discovered by Karl Reinmuth in 1937 and named after the Greek hero of the Trojan War.
1561 celestial phenomenon over Nuremberg
The 1561 celestial phenomenon over Nuremberg, also called the Nuremberg UFO sighting, was a dawn sky display described in an illustrated broadsheet printed by Hans Glaser.
1894 in science
1894 in science brought the announcement of argon, Yersin's isolation of the plague bacillus, the first effective diphtheria treatment, and Oliver Lodge's first public wireless telegraphy demonstration.
1977 in science
1977 in science was marked by the launches of the two Voyager probes to the outer planets, the publication of Carl Woese's three-branch tree of life, and the first observations of deep-sea hydrothermal vents.
2015 BZ509
2015 BZ509, asteroid 514107, named Ka'epaoka'awela, is a small Solar System body about 3 km across, the first found in a stable retrograde co-orbital resonance with Jupiter.
2015 TG387
2015 TG387, nicknamed the Goblin, is a distant trans-Neptunian object discovered in 2015, with its extreme orbit fitting patterns attributed to the hypothetical Planet Nine.
2018 LA
2018 LA was a small asteroid discovered in space on 2 June 2018 that impacted Earth's atmosphere over Botswana about eight hours later, producing the Motopi Pan meteorites.
2018 Mars global dust storm
The 2018 Mars global dust storm began in Acidalia Planitia in May 2018 and within weeks covered nearly the whole planet, ending NASA's Opportunity rover mission.
2020 CD3
2020 CD3 was a small near-Earth asteroid that became Earth's second known temporary natural satellite, or minimoon, discovered in February 2020 by the Catalina Sky Survey in Arizona.
2061: Odyssey Three
2061: Odyssey Three is a 1987 science fiction novel by Arthur C. Clarke, the third book in the Space Odyssey series following aging astronaut Heywood Floyd.
3:1 resonance
The 3:1 resonance, also called the 3:1 mean motion resonance or 3:1 Kirkwood gap, is a chaotic orbital resonance with Jupiter at about 2.5 AU.
A Princess of Mars
A Princess of Mars, also known as Under the Moons of Mars, is a 1917 science fantasy novel by Edgar Rice Burroughs, the first of his Barsoom series.
Adam Strange
Adam Strange is a DC Comics science-fiction superhero created in 1958 by Julius Schwartz, Gardner Fox, and Mike Sekowsky: an Earth archaeologist teleported to the planet Rann by the Zeta Beam.
Adrastea (moon)
Adrastea, also designated Jupiter XV, is the smallest of Jupiter's four small inner moons, discovered in Voyager images from 1979 and a principal source of the planet's main ring.
Ahuna Mons
Ahuna Mons is a 4-km-high mountain near the equator of the dwarf planet Ceres, the tallest there, formed as a cryovolcano that erupted salty, muddy brine.
Alfvén surface
The Alfvén surface is the boundary around a magnetized star where the solar wind outruns the Alfvén speed, first crossed by Parker Solar Probe in 2021.
Allende meteorite
The Allende meteorite, a carbonaceous chondrite (CV3), fell near Pueblito de Allende, Chihuahua, Mexico, in 1969; its calcium-aluminum-rich inclusions are the Solar System's oldest dated solids.
Amalthea (moon)
Amalthea is the largest of Jupiter's small inner moons, a dark red body about 270 km long that orbits closer to Jupiter than Io. It was discovered in 1892.
Analemma
An analemma is the figure-eight curve traced by the Sun's position in the sky when observed at the same mean time of day over a full year.
Ananke (moon)
Ananke, also designated Jupiter XII, is a small retrograde irregular moon of Jupiter discovered in 1951, and the largest member of the Ananke group of satellites.
Ancient astronauts
Ancient astronauts, also known as the paleocontact theory, is a pseudoscientific hypothesis that aliens visited Earth, popularized by Erich von Däniken's 1968 book Chariots of the Gods?
Apparent retrograde motion
Apparent retrograde motion, also called apparent retrograde and direct motion, is the temporary reversal of a planet's apparent direction among the stars, produced by Earth's orbital motion.
Apsis
An apsis is either extreme point of an elliptical orbit, the periapsis (closest approach) or apoapsis (farthest); around the Sun these are called perihelion and aphelion.
Arche
Arche (Jupiter XLIII, S/2002 J1) is a ~1.5 km retrograde irregular moon of Jupiter in the Carme group, discovered in 2002 by Scott S. Sheppard, orbiting 23.4 million km out in 732 days.
Asteroid belt
The asteroid belt, also called the main asteroid belt, is a torus-shaped region between the orbits of Mars and Jupiter where most known asteroids orbit the Sun.
Asteroid impact avoidance
Asteroid impact avoidance, also known as asteroid deflection or planetary defense, aims to prevent dangerous near-Earth objects from hitting Earth, demonstrated by NASA's DART mission in 2022.