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Entering orbit…
Habitability
62/ 100
Habitable
LHS 1903 e rendered in TerraForge from its measured mass, orbit and star

LHS 1903 e

Also written LHS 1903e

Water-Rich116 light years awayFound 2026
Mass
5.79 × Earth
Radius
1.73 × Earth
Gravity
1.93 g
Surface (est.)
346 K
Year
29.3 days
From Earth
116 ly
Mass
5.79 × Earth
Radius
1.73 × Earth
Gravity
1.93 g
Surface (est.)
346 K
Year
29.3 days
From Earth
116 ly

LHS 1903 system

Type
M-type (Red Dwarf)
Spectral type
M
Temperature
3,664 K
Radius
0.539 ☉
Mass
0.538 ☉
Planets
4
Luminosity
0.0474 ☉

Published by the NASA Exoplanet Archive. This world’s temperature and habitability score are computed from this star’s measured luminosity, not from a stand-in for its class.

Habitable zone

Star and planets drawn to scale: the star is 34 times as wide as LHS 1903 e, so only its edge is in view. Orbits spaced as in the star system view.

Water-Rich, likely · its density could also fit a sub-Neptune

LHS 1903 e, from the NASA Exoplanet Archive (found 2026). Measured: 5.79 Earth masses, 0.151 AU, a 3664 K M-type star. Composition inferred from a measured bulk density of 1.12x Earth's at this size, suggesting roughly 12% water/ice by mass, with an assumed 24-hour day — rotation cannot be measured for exoplanets.

Surface. Vast oceans covering most of the surface, scattered islands or archipelagos

✓ Conditions could support life. This planet’s modelled conditions could support biological processes: stable temperatures, liquid water and the chemistry life as we know it needs. That makes life possible, not present.

Water-Rich
Life possibleMagnetic FieldExtreme Activity
LHS 1903 e has abundant oxygen (31.0%) and hydrogen (13.6%), creating extensive water coverage while in the habitable temperature zone.
Water worlds have deep global oceans covering most or all of their surface. They form when planets have high water content and orbit in the habitable zone.
Classification Criteria:
✓ Oxygen: 31.0% + Hydrogen: 13.6% (water-forming elements)✓ Temperature: 346K (habitable range)✓ Distance: 0.15 AU (habitable zone)

Reading LHS 1903 e’s atmosphere

Dominant elements: O, Si, H, Fe, N, CThis is what a telescope would measure while LHS 1903 e crosses in front of its star: starlight passes through the atmosphere and spreads into a rainbow band. Each dark line marks a wavelength the atmosphere absorbed.Every element absorbs its own signature wavelengths — hydrogen always darkens the same two spots, calcium another pair, and so on. Astronomers match the lines in a real spectrum against a library of these signatures to say what an atmosphere is made of, light-years away, without ever visiting. A deeper line generally means more of that element is present.LHS 1903 e sits about 116 light-years away, found by the transit method. Most catalogued distances trace back to parallax: as Earth orbits the Sun, a nearby star appears to shift very slightly against the distant background stars, and the size of that shift gives its distance directly.
Habitability ScoreHabitable
62
Contributing Factors
temperature35
Hot - near boiling, only heat-loving microbes would thrive
atmosphere100

Nitrogen and oxygen with water vapor, mild greenhouse effect

Nitrogen-oxygen atmosphere - breathable and protective
water90
Good water content
magnetic Field100
Magnetic field provides radiation protection
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution

Physical Properties

Mass
5.79x Earth (3.46e+25 kg)
Radius
1.80x Earth (11,440 km)
This planet: 1.80× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.80x Earth (17.6 m/s²)
Surface Temperature
346 K (73 °C / 164 °F)
Rotation Period
24.0 hours/day
This planet: 24 h/dayEarth: 24 h/day

Elemental Composition

A dark ringed planet hanging over the horizon of a rocky moon, its rings lit by a distant sun

New: Stand on Your Moons 🌒

A planet's surface view isn't the only ground any more. Press the surface button on a planet with moons and it asks where to stand: the planet itself, or any moon still in orbit, each tagged with what it became — ocean, ice, carbon, volcanic. Every moon gets its own ground and sky from its own physics: airless rock under a black sky, ice cracked by geysers over a hidden sea, sulfur plains shaking with eruptions, or orange haze you can't see the sun through. And hanging over the horizon, there's the planet you built.

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