Space Encyclopedia
🌎 Exoplanets
Overview
An exoplanet is a planet orbiting a star other than the Sun. The first confirmed exoplanet around a sun-like star was discovered in 1995; today more than 5,700 have been confirmed. The Kepler and TESS missions revealed that planets are the rule, not the exception.
Key facts
- •Confirmed exoplanets (2024): 5,700+
- •First discovered around a sun-like star: 51 Pegasi b (1995)
- •Detection methods: transit, radial velocity, direct imaging, microlensing
- •Closest exoplanet: Proxima Centauri b, 4.24 light-years
- •Habitable-zone candidates: dozens known
Why it matters
Exoplanet research is how we place our Solar System — and Earth itself — in cosmic context. Are Earth-like planets common? Do they have magnetic fields and atmospheres like ours? These questions drive JWST and future missions.
Explore related on this site
Frequently asked questions
Can we see exoplanets directly?
Very rarely. Most are found indirectly — by the tiny dip in starlight when they transit their star, or the tiny wobble they induce in the star's motion. JWST has directly imaged a small number.
Is there another Earth?
Not yet confirmed. Several rocky planets in habitable zones (Kepler-452b, TRAPPIST-1e, Proxima b) are candidates, but we don't yet know whether they have Earth-like atmospheres or water.
More encyclopedia topics
Cosmic Explorer Navigation Matrix
Automated internal linking across every layer of the tracker — no orphan pages.
🌌 Broader Cosmic Context
🪐 Related Space Phenomena & Objects
- Space Weather Tracker — Home DashboardLive global overview
- Live Space Weather Command DashboardReal-time metrics
- Space Weather 101 — The Complete Beginner's GuideLearn the science