object

Moon

The Moon is Earth's natural satellite, studied for its geological and gravitational interactions.
22 related articles · 1 who worked here

Description

The Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. It formed about 4.5 billion years ago, likely from debris ejected into orbit after a collision between Earth and a Mars-sized body. Its surface is covered with impact craters, and the dark areas — the lunar maria — are solidified basaltic lava plains. The lack of atmosphere leads to extreme temperature variations: from +127°C during the day to -173°C at night.

History

Ancient civilizations worshipped the Moon and used its phases for calendars. In 1609, Galileo Galilei used a telescope to sketch lunar mountains and craters, disproving the idea of perfect celestial spheres. In 1665, Robert Hooke in 'Micrographia' described lunar craters in detail and suggested their impact origin. The space race began in the 20th century: in 1959, Luna 2 reached the surface, and in 1969, Apollo 11 made the first manned landing. Analysis of returned samples revealed a striking similarity to Earth rocks, strengthening the impact hypothesis. Modern missions like LRO and Chang'e continue to map the Moon and search for water ice in polar craters.

How it works

The motion of the Moon is described by Kepler's laws and the law of universal gravitation. The orbit is perturbed by the Sun and planets, leading to librations that allow us to see slightly more than half the surface. The main feature is tidal locking: due to tidal forces, the Moon always faces Earth with the same side, as its rotation period around its axis equals its orbital period. This results from the dissipation of tidal friction energy. The Moon's gravitational influence on Earth causes tides, which slow Earth's rotation and transfer orbital momentum to the Moon, increasing its distance.

In practice

Stabilizes Earth's rotation axis, causing tides that affect navigation, coastal ecosystems and potentially used for tidal energy.

Fun fact

From Earth, only one side of the Moon is visible due to tidal locking (gravitational synchronization of rotation), but that doesn't mean the far side is always dark — day and night alternate there just like on the visible side. The first images of the far side were taken by the Soviet probe Luna 3 in 1959.

Concept graph →

Related articles · 43

High Energy2026-08-051 minarXiv:2608.04658express
Moon Shadows Cast by Giant Cosmic Rays
Cosmic rays aren't rays in the usual sense: they're fast particles bombarding Earth from all directions. Mostly they're protons and atomic nuclei. Their energies vary widely, from modest to fantastically huge. When such a particle heads our way and the Moon or Sun gets in its path, it gets absorbed.
Exoplanets2026-08-051 minarXiv:2608.04512express
Tides Steal Moons from Close-In Planets
The birth of a moon is a cosmic car crash. Two young planets collide, and a cloud of scorching debris swirls around the surviving world. From this disk, like clay on a potter's wheel, a satellite gradually takes shape. That's probably how our Moon came to be.
High Energy2026-08-051 minarXiv:2608.04658express
Moon Shadows Cast by Giant Cosmic Rays
Cosmic rays aren't rays in the usual sense: they're fast particles bombarding Earth from all directions. Mostly they're protons and atomic nuclei. Their energies vary widely, from modest to fantastically huge. When such a particle heads our way and the Moon or Sun gets in its path, it gets absorbed.
Exoplanets2026-07-112 minarXiv:2607.10403express
Lunar muons could illuminate subsurface voids
The Moon is an airless sphere of dense rocky grit called regolith. When fast particles from space slam into it, muons are born in the soil — unstable relatives of electrons, but two hundred times heavier. Most fly downward and fade away in the depths. But those that pop upward into the vacuum can travel tens of kilometers before decaying.
Waltz of Invisible Moons: The First Spectroscopic Find
The gravitational dances of celestial bodies long remained silent to astronomers. We learned to catch the shadows of planets against stars with the transit method — a breakthrough that delivered thousands of worlds thanks to William Borucki and his Kepler telescope.
Galaxies2026-07-063 minarXiv:2607.05502
The Mystery of Fragile Satellites: Dark Matter Under Tidal Assault
Dwarf galaxies orbiting the Milky Way look as if they’ve survived a gravitational storm. Their stellar bodies are stretched, scattered by tidal tails, and heated from within.
Exoplanets2026-06-241 minarXiv:2606.26026express
Cosmic Collisions: How to Witness the Birth of Planets
The birth of planets resembles the workings of a cosmic forge. Rocky blocks collide and fuse together. A powerful impact strikes a spark — material heats to white-hot and glows like cooling metal. Computer simulations show: the flash is visible from days to years, peaking at a tenth of the sun's light.
Exoplanets2026-06-231 minarXiv:2606.24028express
Moon Dust May Reveal Alien Technologies
The Moon is a natural archive that has been collecting cosmic dust for billions of years. Among the microscopic grains that arrived from distant stars, there could be techno-specks — particles created by alien civilizations.
Exoplanets2026-06-211 minarXiv:2606.22547express
Striped Ocean: How Rotation Reshapes Heat on Icy Moons
In the deep oceans of icy moons, water is not still. Warm plumes rise from the rocky seafloor, but the planet's rotation twists them into long, slanted rolls stretched along the rotation axis. Previously, this process could not be included in global models: it was too complex.
Exoplanets2026-06-181 minarXiv:2606.20398express
Why the Moon Is a Copy of Earth? The Fluidity Clue
Young Earth was a boiling sphere of liquid rock, while Theia, which crashed into it, had had time to cool and solidify. It’s like dropping a chunk of cold butter into a pot of soup: the soup splashes out, but the butter barely moves. Similarly, Earth’s interior spewed into space, forming a cloud of cosmic dust and debris.
Exoplanets2026-06-171 minarXiv:2606.19575express
The Earth may survive when the Sun becomes a giant
In 5 billion years, the Sun, having exhausted its fuel, will start to swell, turning into a red giant. Like a balloon losing air, the star will weaken its gravitational grip, and Earth — a grain of sand on an invisible thread — will drift to a more distant orbit.
Shattered Inkwell: Impact Downpour 800 Million Years Ago
Eight hundred million years ago, in the main asteroid belt, a giant inkwell shattered. The parent body, over a hundred kilometers in diameter, made of primitive carbonaceous chondrites, suddenly broke apart near the J3:1 resonance with Jupiter.
Neptune's False Note: Nereid — Not an Interloper, but a Last Survivor
Among the hundreds of moons in the Solar System, Nereid dances the most desperate dance: diving toward Neptune as close as 1.4 million kilometers, then soaring away to 9.7 million — all within less than an Earth year. An eccentricity of 0.75 — the brand of a captured wanderer.
Exoplanets2026-05-131 minarXiv:2605.13960express
Moon Bell: How Gravitational Waves Unveil Lunar Secrets
Back in the 1960s, physicist Joseph Weber tried to catch gravitational waves using aluminum cylinders: they were supposed to tremble like tuning forks from the ripples of spacetime.
Space Physics2026-04-202 minarXiv:2604.17825express
How to Measure the Electric Wind Behind the Moon
The Moon isn't just hanging in the sky: it leaves behind a long tail of disturbed solar wind. The stream of charged particles from the Sun flows around the rocky sphere, and behind it forms a zone where particles are almost absent. But this emptiness is not simple: electric fields arise in it that push apart the remaining electrons and ions.
Exoplanets2026-04-132 minarXiv:2604.11911express
A Lava World with a Cool Face
A hot skillet on the stove glows in the dark, but if you cover it with a lid, the heat escapes more slowly and the surface doesn't look as bright. That's roughly the situation on planet HD 3167 b: it always shows the same face to its star, and the dayside is heated to temperatures that melt rock.
Exoplanets2026-04-062 minarXiv:2604.05235express
Moons of Distant Planets: What's Keeping Us from Seeing Them
The light from a distant star is never steady. It shimmers like heat over hot asphalt. When astronomers pointed JWST at the star TOI 700, they saw this shimmer especially clearly: every 16 minutes, the brightness changed by a tiny fraction, just 46 parts per million.For comparison: if you placed a light bulb a kilometer away, this change would be…
Exoplanets2026-04-031 minarXiv:2604.03049express
Seven Planets March in Lockstep
Every 1151 years, seven planets of the Solar System, from Mercury to Neptune, find themselves at almost the same points in their orbits. Their positions scatter by less than a degree, as if the celestial mechanism is wound to the same tune. This rhythm was discovered by comparing planetary positions over 2600 years using precise tables of celestial motion.
Instrumentation2026-04-021 minarXiv:2604.01927express
Europa's Ice Under Electron Fire
Europa's surface is an icy armor continuously bombarded by charged particles from Jupiter's magnetosphere. Electrons slam into the ice's crystal lattice, lose energy, and kick off chemical reactions. Until now, there was no tool to show how deep such bombardment pierces the ice.
Exoplanets2026-04-011 minarXiv:2604.00604express
Tilted Rings of Small Planets
Around distant icy bodies the size of a city, circling beyond Neptune, rings of dust and ice have been found. Small moons often whirl nearby. Mathematical analysis shows that a moon's gravity rocks the ring like a swing, making it tilt.
Exoplanets2026-03-252 minarXiv:2603.24323express
A Lunar Meteorite Teaches Us to Map the Moon
Light reflected from a rock carries its composition. Just split that light into colors, like a rainbow, and look carefully for missing shades. That's how hyperspectral imaging works: the camera takes hundreds of pictures of the same spot, each in a very narrow wavelength range. Minerals absorb light differently, and these 'dips' in the spectrum reveal what we're looking at.
Cosmology2026-03-051 minarXiv:2603.04841express
A Lunar Detector Will Hear What Dark Energy Sounds Like
Until now, dark energy has been studied like a car engine — only by the acceleration the Universe's expansion gains.
Stellar2026-02-112 minarXiv:2602.11227express
The Sun's Tidal Rhythms
The Sun is not a calm sphere but a boiling cauldron that follows its own rhythms. Roughly every 11 years, its activity peaks: more dark spots appear on its surface, and streams of charged particles fly into space. But hidden within this grand cycle is a shorter one — about 1.7 years.
Exoplanets2026-02-091 minarXiv:2602.09281express
Saturn's Rings: Trace of a Cosmic Collision
Saturn's system 300 million years ago resembled a crowded dance floor. The most massive moon, Titan, began to migrate, and this movement threw its neighbors off balance. One moon crashed into Titan; the debris swirled into a vortex, gathering into Hyperion.
Quantum Physics2026-02-061 minarXiv:2602.06352express
A Laser from the Moon's Eternal Shadow
At the bottom of lunar craters, where sunlight never reaches, an eternal cold reigns — about minus 240 degrees Celsius. In these icy pockets, known as permanently shadowed regions, plans are underway to install a mirror resonator made of monolithic silicon.
Exoplanets2026-02-051 minarXiv:2602.05378express
Rogue Moons: Warmth Without a Star
Rogue planets, ejected from star systems, may harbor life on their moons. A moon of such a planet can preserve heat and liquid water for billions of years. The whole secret lies in a reliable "blanket" and an internal "stove." The stove is tidal forces: they squeeze and stretch the moon's interior, heating it up like kneading clay.
General Relativity2026-01-231 minarXiv:2601.16567express
The Moon as a Gravitational Wave Detector
Gravitational waves are ripples in spacetime curvature that imperceptibly stretch and squeeze everything around. But the Moon, like a bell, catches these waves: as a gravitational wave passes through it, it makes our satellite vibrate.
Space Physics2026-01-211 minarXiv:2601.14719express
Lunar Oxygen: Breathing Without Earth
Lunar dust looks like gray sand, but there's not a breath of air in it. Oxygen is there — tightly bound in the rocks, like sugar in caramel. To get it out, you need to break chemical bonds, and scientists are looking for the simplest way. In the lab, they took artificial lunar soil made from samples from the Apollo missions and China's Chang'e.
Exoplanets2026-01-131 minarXiv:2601.08306express
Titan's Age: Icy Moon Turns Out Younger Than Thought
Titan, discovered by Christiaan Huygens in 1655, resembles a canvas that is constantly being repainted. Impacts from cosmic dust and asteroids leave crater marks on it. But an invisible artist, the moon's own forces, time and again covers everything with a fresh layer, erasing old strokes.
Exoplanets2026-01-121 minarXiv:2601.07159express
The Climate Swings of Ancient Mars
For a long time, the climate of ancient Mars remained a mystery: the beds of dried-up rivers spoke of water, but models couldn't explain how it got there — after all, 4 billion years ago the Sun shone 30% dimmer. New research shows that the planet swayed, as if on a swing, between long glaciations and short wet epochs.
Exoplanets2026-01-111 minarXiv:2601.07080express
Lava Oceans on Exoplanets: Tidal Heating and Stone Waves
An exoplanet — a planet outside our solar system — follows a slightly elongated orbit. With each revolution, it swings closer to its parent star and then farther away.
Stellar2026-01-071 minarXiv:2601.03539express
Dance of the Invisible Giants: Gaia Finds a 'Desert' of Brown Dwarfs
Sun-like stars rarely spin alone. Many of them dance with invisible partners — brown dwarfs: objects bigger than planets but too lightweight for steady stellar burning. In their cores, hydrogen fusion flickers, only to fade fast, never matching the stability of the Sun.
Exoplanets2025-12-261 minarXiv:2512.22375express
The Moon Assembled from a Swarm of Earth's Fragments
When countless asteroids pummeled the young Earth, they tore chunks from its mantle. These fragments spiraled in a cosmic disk around the planet and, like a snowball in a blizzard, fused into the Moon.
Exoplanets2025-11-251 minarXiv:2511.19946express
The Moon Is Older Than Its Rocks: Why 4.35 Billion Years?
Lunar rocks brought a puzzle: their age is 4.35 billion years, but the Moon itself should have appeared 150 million years earlier. The missing time is hidden in tidal heating. When the Moon hung closer to Earth, Earth's gravity acted like tireless hands: it constantly kneaded and bent the satellite.
Exoplanets2025-11-061 minarXiv:2511.04067express
The Moon — a Giant Gravitational Bell
The Moon is not just a rocky sphere, but a giant bell. Passing through it, gravitational waves cause it to vibrate almost imperceptibly. This tremor was predicted by Einstein, and Weber was the first to try to hear it with Earth-based detectors.
Exoplanets2025-11-051 minarXiv:2511.03392express
Warm Moons of Rogue Planets
The planet's gravity rhythmically squeezes and kneads the moon like dough: from this constant 'kneading', the interior heats up, and oceans of water can persist under the icy crust for ages. In the Galaxy, there are plenty of rogue planets, thrown out by supernova explosions.
Exoplanets2025-11-021 minarXiv:2511.00952express
Lunar Heating: How Tides Prolonged Earth's Magma Ocean
After the Moon's birth, Earth resembled a sizzling lump of dough: a continuous liquid magma and a dense shroud of gases. The Moon acted like a giant spoon, constantly kneading this lump with its gravity. Friction generated heat, delaying cooling.
Exoplanets2025-10-141 minarXiv:2510.12388express
Icy Wanderer Chiron Encircled by Rings and a Disk
Only by passing in front of a star did Chiron reveal its secret. Three icy hoops encircle the 200-kilometer body — a hybrid of comet and asteroid. Previously, they were only hinted at by spectra of reflected light and brightness fluctuations.
Exoplanets2025-10-111 minarXiv:2510.10344express
Can the Moon have its own moon?
The Moon can have its own tiny moon — like a nesting doll, but in space. The outer doll is a planet, the middle one is a moon, the inner one is a small moon-satellite, or submoon. Ньютон showed that all bodies attract each other, and gravity holds them together.