NASA Exoplanet Archive 23 August 2026
We never see
the planets.
A planet does not have to shine to be found. It only has to cross its star and leave a trace in the light, smaller than a breath.
Cut the light01 / a measurable absence
A planet announces itself through missing light.
When a world moves between us and its star, the light dips for a while. From the size of the dip, astronomers learn the planet's size relative to the star. We do not see the surface. We see its small eclipse.
Earth's signal would be almost impossible to feel with the eye: 0.0084% of the Sun's light, about 84 parts per million. A good detector can keep the trace, repeated on every orbit, until a tiny fall begins to look like an object.
The same planet can cast a much larger shadow on a small star. That is why TRAPPIST-1 b, at only 1.116 Earth radii, has a reported depth of 0.7378% in the archive: its star is 0.1192 solar radii across.
02 / exposure room
Make your own shadow.
Choose the planet's size and the star behind it. The strip below shows what an observer would measure.
The dip is enlarged visually so you can see it. The number stays to scale.
Earth is 1 R⊕; Jupiter is about 11.2 R⊕.
Earth crossing a Sun-sized star.
03 / plates found
In the archive, shadows have names.
Choose a real planet. The figure comes from NASA's table, not from an illustration made for this page.
How much light disappears?
From the 4,513 planets with a reported transit depth. The thresholds are not a continuous scale.
Most signals sit between 0.01% and 0.1%. Only 238 fall below 0.01%.
Who caught the shadows?
The discovery facility associated with each transiting planet in the archive.
See a few values in a table
| Planet | Depth | Period | Discovery |
|---|---|---|---|
| Kepler-37 b | 0.00122% | 13.37 days | Kepler, 2013 |
| Kepler-186 f | 0.04666% | 129.94 days | Kepler, 2014 |
| TOI-700 d | 0.0613% | 37.42 days | TESS, 2020 |
| TRAPPIST-1 b | 0.7378% | 1.51 days | La Silla, 2016 |
| WD 1856+534 b | 56.65% | 1.41 days | TESS, 2020 |
04 / reading the plate
A shadow does not say everything. It says something exact.
Transit depth is the relative fall in flux when a planet crosses its star. The calculator uses the geometric approximation `(planet R / star R)²`. Archive values are reported or calculated in the literature collected by NASA and can include details the approximation does not see.
NASA Exoplanet Archive, Planetary Systems Composite Parameters table, accessed 23 August 2026.
6,354 confirmed planets. The archive records a transit for 4,731. The depth distribution uses 4,513 reported values; the 218 missing values stay outside the chart.
A planet can be found by another method and later have a transit observed. A transit is not a photograph of the planet and cannot, by itself, tell us whether a world has an atmosphere or water.