Astronomy

Articles about stars, planets, space and the universe.

Articles in this category: 1040 Updated: April 29, 2026 Page 9 / 22

Himalia (moon)

Himalia: Jupiter’s largest irregular prograde moon

Himalia group

Hinotori (satellite)

Hinotori (satellite): Japan's 1981 solar X-ray mission

Hipparcos

History of astronomy

History of Astronomy: From Ancient Skywatching to Modern Astrophysics

Hiten (spacecraft)

Hiten (MUSES-A) — Japan's first lunar probe

Hoag's object

Hoag's Object — a nearly perfect ring galaxy

Hohmann transfer orbit

Horologium (constellation)

Horologium (constellation) — the Clock of the Southern Sky

Horsehead nebula

Horsehead Nebula (Barnard 33): dark cloud in the Orion Molecular Cloud Complex

HR 4729

HR 5171

HR 5171 (V766 Centauri): a massive yellow hypergiant

HR 6819

Hubble Deep Field

Hubble Extreme Deep Field

Hubble Space Telescope

Hubble Ultra-Deep Field

Hubble Ultra Deep Field

Hubble's law

Hyades (star cluster)

Hyakutake

Comet Hyakutake (C/1996 B2)

Hydra (constellation)

Hydra (moon)

Hydrus

Hyperbolic trajectory

Hypergiant

Hypergiant (luminosity class 0): enormous, unstable stars

Hyperion (moon)

Hyperion (moon of Saturn)

Hyrrokkin (moon)

Iapetus (moon)

Iapetus: Saturn's Two‑Faced Moon

IC 10

IC 10 — irregular starburst galaxy in Cassiopeia

IC 2118

IC 418

Ice giant

Icy moon

Ijiraq (moon)

Ijiraq — an irregular moon of Saturn

Impact event

Impact event: collisions between space objects and planets

Indian Space Research Organisation

Indus (constellation)

Inflation (cosmology)

Cosmic Inflation (cosmology)

Infrared telescope

Infrared Telescope: Observing the Heat of the Universe

Inner moons of Jupiter

Intercalation (timekeeping)

Intercalation (timekeeping): adding days, months and seconds to calendars

International Astronomical Union