A star dims.
A planet crossing its star blocks a fraction of the light. Repeated dips can reveal its size and orbit.
NASA · transit methodWORLDS AROUND OTHER STARS
Exoplanets.
Signals become worlds.
We rarely see these planets directly. We find them in the small, repeatable changes they cause in a star’s light and motion.
SCHEMATIC SIGNAL
A repeatable dimming.
Light received from the starA star moves.
The gravity of an orbiting planet makes its star shift towards and away from us. Spectra record that motion.
NASA · radial velocityA world separates.
Advanced instruments can suppress starlight and isolate the much fainter glow of a planet.
NASA · direct imagingWHAT WE KNOW / WHAT REMAINS OPEN
What can we learn after detecting a planet?
Atmospheres, clouds and climates require further observations. Every method reveals a different part of the same system.
Read the NASA overview