:INFO
Terrestrial around K2-137
It is 0.64 times Earth's radius, closest in size to Mars. A year there lasts 4.3 hours.

:COUNTER
4.3 hours: one full year, start to finish

:STATS
[icon:TARGET] Radius | 0.64 Earth radii
[icon:CLOCK] One year | 4.3 hours
[icon:STAR] Host star | K2-137 at 3697 K
[icon:USERS] Distance | 322 light-years
[icon:TRENDING_DOWN] Starlight blocked | 0.041% at each transit

:PATH
What the dip tells you
How deep the star dims fixes the planet's size relative to it.

:CHECKLIST
Known and unknown, as the archive has it
[ ] A measured radius. Yes.
[ ] A measured mass. No.
[ ] A density, the one clue to composition. No.
[ ] An orbital distance. No.
[ ] An observed temperature. No.
[ ] An eccentricity, so the orbit shape is known. No.

:NOTE
The detection is a shadow crossing a disc. Shadows have no weight, which is the whole reason the mass column is empty.

:NOTE
Found by K2 in 2017, the second life of the Kepler spacecraft after two of its reaction wheels failed and it could no longer hold a fixed stare.

:LINK
https://exoplanetarchive.ipac.caltech.edu/overview/K2-137%20b
NASA Exoplanet Archive: source data, including the values not used here