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exoplanet-archive [orbits|sky|charts] planetThe catalogue is a snapshot of the NASA Exoplanet Archive stored on this site.
The page opens on a planet from the catalogue. Press Random, use ← →, click a dot in any view, or choose one from the Find list.
The Planet tab shows size, mass, orbit, temperature, starlight, its star, an Earth-likeness score with the points behind it, bars that compare it with Earth, and how long a probe would need to get there.
Orbits draws the whole system to scale around its star with the habitable zone in green. Click a planet in the diagram to switch to it.
Find searches names, stars, methods and types, with quick filters (Earth-like, habitable zone, Super-Earths, gas giants, nearest, newest), type chips, method, year and distance. Every view follows your filters.
Sky map places every planet in the sky. Charts plot mass, orbit and starlight against radius, discoveries per year and distance. Hover for a name, click to open it, and share the link of a planet.
An exoplanet is a planet orbiting a star other than the Sun. This explorer loads the confirmed planets from the NASA Exoplanet Archive and gives each one a simple, unofficial habitability score, so you can quickly find the worlds that are closest to Earth in size, temperature and orbit.
An exoplanet is any planet that orbits a star outside our solar system. The first confirmed exoplanet around a Sun-like star, 51 Pegasi b, was discovered in 1995. The NASA Exoplanet Archive now lists more than 6,000 confirmed exoplanets, found with space telescopes such as Kepler and TESS and with ground-based observatories; the counter at the top of this page shows the current number. They range from rocky worlds smaller than Earth to gas giants many times larger than Jupiter.
The habitability score (0–100) is this app's own simplified estimate, not an official NASA metric. It adds four parts: 35 points if the planet is in its star's habitable zone, up to 25 points for a radius close to Earth's, up to 25 points for an equilibrium temperature between 200 and 320 K, and up to 15 points for a host star between 3,800 and 7,000 K. Scores of 70 and up are labelled High, 40–69 Moderate, 20–39 Low and below 20 Very Low. Missing measurements simply earn no points, and real habitability also depends on atmosphere, magnetic field and much more that the score cannot see.
The main methods are: Transit (watching a star dim slightly as a planet crosses in front, used by Kepler and TESS), Radial Velocity (measuring the star's wobble caused by a planet's gravity), Direct Imaging (photographing the planet directly, which is very difficult) and Microlensing (a foreground star and planet bending the light of a background star). Transit is by far the most productive method, with roughly three quarters of all confirmed planets. The Discovery Methods panel counts every method in the loaded catalogue.
The habitable zone (or "Goldilocks zone") is the region around a star where a planet's surface temperature could allow liquid water to exist: not too hot, not too cold. It depends on the star's luminosity: for our Sun a commonly used conservative estimate is roughly 0.95–1.37 AU, and for a cool red dwarf such as TRAPPIST-1 it lies much closer in. This app counts a planet as in the zone when it receives between 0.25 and 1.75 times Earth's insolation; when insolation is missing it estimates the zone from the star's radius and temperature. Being in the habitable zone doesn't guarantee life: it's a necessary but not sufficient condition.
Several candidates score highly: Kepler-442b (1.34× Earth radius, a 112-day orbit in the habitable zone of a K-type star), Kepler-452b (often called "Earth's cousin", about 1.6× Earth radius with a 385-day orbit around a Sun-like G-type star) and TRAPPIST-1e (0.92× Earth radius, in the habitable zone of an ultracool dwarf star about 40 light-years away). Sort by Habitability ↓ to see the top scorers. The Earth-like filter shows terrestrial planets (up to 1.6 R⊕) with a score of 40 or more, so slightly larger worlds such as Kepler-452b appear under Super-Earths instead.
From the NASA Exoplanet Archive, run by Caltech/IPAC. The page shows a snapshot of its public pscomppars table, one row per confirmed planet, with radius, mass, orbital period, distance from the star, temperature, starlight, eccentricity, density, position in the sky, the host star's temperature, size and mass, and how and when the planet was found. The snapshot is dated on the About tab and stored on this site, so the page does not depend on NASA's servers or on any proxy, and it never shows made-up planets. The archive is updated several times a month, so very recent discoveries can be missing until the snapshot is refreshed.
Types are assigned by radius, in Earth radii: Terrestrial under 1.6, Super-Earth 1.6 to 2.5, Sub-Neptune 2.5 to 4, Neptune-like 4 to 8 and Gas Giant above 8 (Jupiter is 11.2). A gas giant orbiting in under ten days is a Hot Jupiter. When only a mass is known the radius is estimated from it, and planets with neither are marked Unknown. These are rules of thumb: the real boundaries between rocky and gassy planets are fuzzy.
Roughly half of the planet masses in the NASA catalogue (3,035 of 6,451) are not measured at all: when only a transit gives a radius, NASA fills in a mass from a mass–radius relationship. Those values follow a smooth curve by construction, so this page marks them as estimates, leaves them out of the mass chart and shows no density for them. Planets found with the radial velocity method only have a minimum mass (M sin i), because the tilt of their orbit is unknown, and they have no measured radius either, so the radius shown for them is a model value: it is marked as an estimate, earns no size points in the Earth-likeness score and is left out of the charts. The page spots such radii by checking whether they sit within 1% of a mass–radius formula, which catches about 1,600 planets and may occasionally flag a real measurement that happens to match.
The selected planet's whole system around its star, with orbits on a square-root distance scale so tight and wide systems both fit, the habitable zone in green and the orbits of Mercury, Earth and Jupiter as a reference. Planet speeds are sped up so you can watch them move.
Every planet at its position in our sky, flattened onto one map. The dense clump is the field watched by the Kepler telescope; TESS has since covered the whole sky.
Mass and radius, orbit length and radius, the starlight a planet receives, discoveries per year by method, and distance. All of them follow your filters, so you can see where, say, only the habitable-zone planets sit.
There is no account, and nothing you search or click is sent anywhere. The page loads the catalogue from this site, its font from Google Fonts and page statistics from SimpleAnalytics, and it makes no other network requests. It stores nothing in your browser. The address of the page gets a planet and a view parameter so you can share what you are looking at.