Vol. Science · Astronomy · Worlds around other stars
Exoplanets
Planets beyond our solar system — usually orbiting another star in the Milky Way. NASA’s public archive now lists more than 6,000 confirmed worlds (the tally keeps rising), plus thousands of candidates still waiting on follow-up. This desk is a literacy schematic: how we find them, and a handful of famous confirmed examples. Pair with the nearest-stars yardstick — Proxima b is the closest known exoplanet, still about four light-years out.
Educational cartoon, not an ephemeris and not a dump of the NASA Exoplanet Archive. Orbits are scaled to fit; planet sizes are exaggerated. Figures are rounded from NASA Science / NASA Exoplanet Archive public pages. Habitable-zone rings are order-of-magnitude Goldilocks bands for that stellar type — liquid-water possibility, not a life detection.
Interactive · Discovery methods
Tap a method · cartoon of the signal
Interactive · Notable confirmed worlds
Star at center · gold ring ≈ habitable zone · sizes exaggerated
Glossary · starter terms
Exoplanet
A planet outside our solar system. Most confirmed cases orbit another star; a few are free-floating (rogue) or circle pulsars.
Confirmed vs candidate
A candidate is a likely signal that still needs follow-up. Confirmed worlds have passed extra checks so a false positive (eclipsing binary, starspot, noise) is unlikely.
Transit
Planet crosses the star’s disk and the light curve dips. Depth hints at radius; repeat dips give the period. Alignment is required — we miss most systems this way.
Radial velocity
The star wobbles toward and away from us. Spectral lines shift blue then red. That gives a minimum mass (m sin i) and the period.
Habitable zone
The Goldilocks band where a rocky planet could hold liquid water. Red-dwarf zones hug the star; Sun-like zones sit near 1 AU. Climate and atmosphere still decide.
Hot Jupiter
A gas giant on a few-day orbit — 51 Pegasi b’s class. Common in early RV samples because they tug hard and transit often. Not like our Jupiter.
Mini-Neptune / super-Earth
Worlds between Earth and Neptune in size. Super-Earths are often rocky-ish; mini-Neptunes keep thick envelopes. The galaxy is full of them; our solar system is not.
Naming
Host designation + a lowercase letter. The first planet found is b (the star is the unspoken A). Earth as an exoplanet would be Sun d.
Kepler / TESS / JWST
Kepler surveyed one deep field; TESS watches bright nearby dwarfs. JWST does not hunt thousands of new planets — it reads atmospheres of worlds we already have.
Educational schematic. Discovery-method cartoons follow NASA Science exoplanet facts. World cards use rounded public values from NASA Solar System / Exoplanet pages and the NASA Exoplanet Archive — not a precision catalog and not NASA imagery. “More than 6,000 confirmed” is NASA’s 2025–2026 public tally language; check the archive for today’s integer.