object

super earth

A rocky exoplanet with a mass higher than Earth's but substantially lower than ice giants.
82 related articles

Description

A super-Earth is a rocky exoplanet with a mass between that of Earth and the ice giants like Uranus or Neptune, typically ranging from about 1.5 to 10 Earth masses. These planets are common in the galaxy, often found in close orbits around their host stars, and they challenge our understanding of planetary formation and habitability. Super-Earths can have a wide variety of interiors, from iron-rich cores with thin mantles to water worlds with deep global oceans, depending on their formation history and distance from their star.

History

The first super-Earth was discovered in 1992 around a pulsar, but the term gained wide usage after the 2005 discovery of Gliese 876d. The Kepler mission, launched in 2009, revealed that super-Earths are among the most common planet types in the Milky Way.

How it works

Super-Earths form in the protoplanetary disk around a young star, accumulating material through collisions and gravitational attraction. Their larger mass means stronger gravity, which compresses their interiors more than Earth's, leading to denser cores and potentially thicker atmospheres. The boundary between super-Earths and mini-Neptunes is thought to be set by atmospheric loss: planets below a certain mass lose their primordial hydrogen envelopes, leaving bare rocky surfaces, while more massive ones retain thick gaseous atmospheres.

In practice

Super-Earths are prime targets in the search for habitable exoplanets, as some may have conditions suitable for liquid water, and they are studied to refine models of planetary formation and evolution.

Fun fact

Some super-Earths are so dense that they are thought to be made largely of diamond, formed from carbon-rich parent stars.

Concept graph →

Related articles · 82

Scales Where Overly Heavy Planets Tip the System
Astronomers catch distant planets by the trembling of their stars: an invisible companion tugs the star toward us and away, and its light subtly shifts in color. But that trembling tells only half the truth. If the planet's orbit is tilted to our line of sight, only part of its weight rocks the star, so telescopes reveal not the true mass but its shadow.
The Neighbor Who Wasn't Kicked Out
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Stellar2026-08-072 minarXiv:2608.07331express
The Stellar Family Tree of Planets
A star is not just a distant sun. It's a cradle for planets, and its light carries the birth story of the entire system. The chemical composition of a star is its DNA. Astronomers peer into this DNA to understand why some stars host rocky worlds like Earth, while others host gas giants.
Exoplanets2026-07-212 minarXiv:2607.19632express
Planetary Collisions and Their Hydrogen Coat
In a single star system, two teams of planets orbit. Some follow neat paths, like figure skaters on an ice rink, avoiding collisions. Others crowd together, their trajectories cross, and sooner or later a cosmic accident occurs — a giant impact.
General Relativity2026-07-201 minarXiv:2607.18405express
Dark Matter in the Embrace of Gravity
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Icy Origins: Most Hot Jupiters Come from the Cold
Among the scorching exoplanets that circle perilously close to their stars lies the secret of their birth. Nearly three decades ago, Michel Mayor and Didier Queloz discovered the first such world, and since then astronomers have been tormented by the question: how does a gas giant end up pressed against…
High Energy2026-07-081 minarXiv:2607.07668express
Strange Stars vs. Neutron Stars: A Duel in Gravitational Waves
Two ultradense spheres, each the size of a city, whirl in a dance. Their masses are less than the Sun's, but inside them is matter compressed to unimaginable limits. One sphere is a neutron star; the other is a strange star, made entirely of quarks — the elementary particles that build up protons and neutrons.
Galaxies2026-07-053 minarXiv:2607.04216
Quasi-interstellar objects: when the Solar System meets its own exiles
Remember the sensational comet 1I/‘Oumuamua — the first object to come to us from another star? Its hyperbolic trajectory left no doubt: it was a wanderer from the interstellar void. But astronomers wondered: could some of these visitors not be strangers at all, but our own, escaped from the Solar System millions of years ago?
Stellar Palimpsests: How We Read the History of Swallowed Planets
Every star is a living archive, and its spectrum a multilayered manuscript. Over billions of years, the history of the galaxy is written into it: the galactic chemical evolution of the Milky Way leaves a smooth trace in elemental abundances.
Cosmic Debt: How a Planet's Mass Locks Civilizations Forever
Every civilization is born with a gravitational debt. The home planet's mass determines the loan amount, and the Tsiolkovsky equation is the interest rate applied to each kilogram of payload. To send a probe to the stars, you have to pay with fuel, and the debt grows exponentially.
Cosmic Carving: Birth of a Bloated Neptune from a Jupiter
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Exoplanets2026-06-241 minarXiv:2606.26075express
A Mirror Planet in the Neptunian Desert
Hundreds of light-years away, there's a planet that looks like a giant mirror. LTT9779b reflects most of the light that hits it — far more than you'd expect from a Neptune-sized body. Astronomers have long debated what makes it so shiny: a thick carbon-rich haze or a layer of clouds. The James Webb Space Telescope has helped settle the debate.
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.
Exoplanets2026-06-181 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.
Exoplanets2026-06-182 minarXiv:2606.20789express
How Tidal Waves Sort Planets
A pot of boiling soup is shaken hard — the liquid sloshes, waves crash against the walls. Something similar happens inside a gas planet when it swings past its star on an elongated orbit. The star's gravity excites powerful internal waves in the planet, known as tidal fundamental modes. These waves can completely change the planet's fate.
Exoplanets2026-06-161 minarXiv:2606.18219express
Inside Uranus and Neptune Lie Oceans of Magma
Previously, Uranus and Neptune were considered ice giants because of assumed thick layers of frozen water, methane, and ammonia. New calculations paint a different picture: deep inside them hides an ocean of hot magma, which under immense pressure has absorbed a colossal amount of hydrogen.
Exoplanets2026-06-161 minarXiv:2606.18355express
The Iron Planet Isn't So Iron After All
A cosmic sprinter on a short track: that's how you might describe planet GJ 367 b. It whips around its star in just 7.7 hours. This world is slightly smaller than Earth but has a personality: it was once thought to be nearly a solid ball of iron.
Exoplanets2026-06-161 minarXiv:2606.18410express
Super-Earths and Mini-Neptunes: Two Fates
In the catalogs of exoplanets, there are many worlds with sizes between Earth and Neptune. They are divided into two groups: rocky super-Earths and gaseous mini-Neptunes. The Solar System has none of these, and scientists debate where they come from. The authors of the study looked into each planet's 'passport'—its orbit.
Popular Physics2026-06-141 minarXiv:2606.17105express
Gravitational Visitors: How Passing Planets Rewrote Earth's History
On the periphery of the Solar System lurk thousands of objects comparable in size to an exoplanet — a body of planetary mass not bound to our star. Their orbits are chaotic, and from time to time the trajectory of such a wanderer crosses Earth's path.
Cosmology2026-06-121 minarXiv:2606.14827express
Dark Matter Sways Distant Planets
Think of a baby mobile: figurines dangling on threads, twitching at even a whisper of breeze. In the same way, planets on very wide orbits barely cling to their star's gravity, and they feel the faintest gravitational drafts. Astronomers have proposed turning such planets into detectors of dark matter.
The Cosmic Forge: Why GJ 3929 b Lost Its Air
Red dwarfs are tireless blacksmiths of planetary fate. Their radiation, like a hammer, beats off gas envelopes, leaving only naked rocky cores. In the depths of the constellation Hercules, around the dim M-dwarf GJ 3929, orbits a world one-and-a-half times Earth's size, like a billet on an anvil.
Ultraviolet Trap: How TRAPPIST-1 Star Fakes Signs of Life
In the orchestra of interstellar life search, every note counts. And the score here is dictated not by man, but by a distant star. For the planet TRAPPIST-1 e, one of seven in the system of an ultracool red dwarf, the conductor's baton is harsh ultraviolet light.
Exoplanets2026-06-022 minarXiv:2606.03740express
A Watery Surprise from Young Super-Earth V1298 Tau c
Astronomers using the JWST (James Webb Space Telescope) have for the first time studied in detail the atmosphere of a young exoplanet, V1298 Tau c. This super-Earth, a planet more massive than Earth but less so than gas giants, is only 23 million years old.
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.
Exoplanets2026-05-252 minarXiv:2605.26216express
Planetary Budget Doesn't Add Up
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High Energy2026-05-212 minarXiv:2606.02593express
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For a long time, a void yawned in the family of ultra-dense remnants of dead stars. Neutron stars, swift city-sized tops, rarely weigh more than two Suns. Black holes start at about five solar masses. Between them lies a 'gap' where for decades no object could be found.
HEP Phenomenology2026-05-192 minarXiv:2605.20162express
Dark Matter Knocks on the Detector
A giant tank of ultrapure water sits deep underground in Japan. Its walls are lined with thousands of light-sensitive sensors that catch faint flashes — the traces of ghostly particles passing through the water.
High Energy2026-05-182 minarXiv:2605.18260express
Stellar Droplets from Quark Soup
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Exoplanets2026-05-061 minarXiv:2605.04840express
Mars's dense layer reveals the fate of rocky planets
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Exoplanets2026-05-041 minarXiv:2605.02243express
Atmosphere found on a small icy body beyond Neptune
Beyond Neptune, in the icy belt, astronomers watched as object (612533) 2002 XV93 momentarily occulted a distant star. Using метод прохождений (when a planet dims the star's light for a second, like a fly in front of a lamp), Уильям Боруки and Дэвид Шарбонно determined: the light not only dimmed but also shifted…
Exoplanets2026-05-022 minarXiv:2605.01390express
Chemical Portrait of an Invisible World
Light from a distant star seeps through a planet's gaseous envelope, and astronomers try to guess what that envelope is made of. That's how we study the atmospheres of worlds we can never touch. When a planet passes in front of its sun's disk, its gaseous veil briefly intercepts some of the rays.
Exoplanets2026-04-301 minarXiv:2605.00100express
Dark, Chilled Planet Without Volcanoes: JWST’s Gaze
Astronomers aimed JWST at the rocky exoplanet LHS 3844 b — a world orbiting another star, where a year lasts just 11 hours. The planet is tidally locked: one side always faces the star, with a permanent scorch of 770°C, while the night side is plunged into icy darkness.
Exoplanets2026-04-281 minarXiv:2604.25253express
Jupiter's Tail Is Wired Differently
A planet's magnetic field is like an invisible shield: it catches charged particles from the solar wind and stretches out behind the planet into a long tail, like a fluttering scarf.
Exoplanets2026-04-211 minarXiv:2604.19179express
A Planet Rolling Against the Stellar Current
The carousel spins all the horses in one direction, but one stubbornly gallops against the flow. That's exactly how the planet TOI-1710 b behaves around its star. Using the HARPS-N and GIANO-B instruments, astronomers measured its tilt at 149 degrees. That's nearly a 180-degree flip, meaning the planet orbits "backward" relative to the star's rotation.
General Relativity2026-04-141 minarXiv:2604.12787express
Planet Nine Heats Up with Dark Matter
At the edge of the solar system, far beyond Neptune's orbit, something is knocking icy chunks off their paths. Their orbits are stretched and tilted in the same way, as if an invisible hand arranged them in a pattern.
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.