Which exoplanet has the strongest surface gravity?

Among worlds small enough to have a surface, with a mass and size that agree, Kepler-123 b has the strongest surface gravity known: 6.4 times Earth's. Everything about Kepler-123 b

Strongest surface gravity known
Kepler-123 b
6.4x Earth gravity · 3,332 ly
The top 25
#WorldSurface gravityDistance
★ 1Kepler-123 b6.4x Earth gravity3,332 ly
2Kepler-287 c6.2x Earth gravity2,726 ly
3TOI-1853 b6.1x Earth gravity538 ly
4Kepler-462 b6.0x Earth gravity1,946 ly
5Kepler-297 b5.9x Earth gravity2,257 ly
6Kepler-282 e5.8x Earth gravity4,363 ly
7Kepler-277 c5.7x Earth gravity3,185 ly
8TOI-332 b5.6x Earth gravity727 ly
9Kepler-32 d5.5x Earth gravity1,056 ly
10Kepler-145 b5.3x Earth gravity1,849 ly
11Kepler-338 b5.1x Earth gravity1,803 ly
12TOI-1696 b5.1x Earth gravity212 ly
13TOI-1174 b4.9x Earth gravity309 ly
14Kepler-58 b4.6x Earth gravity3,161 ly
15Kepler-411 b4.4x Earth gravity501 ly
16Kepler-215 d4.1x Earth gravity1,585 ly
17Kepler-122 e4.1x Earth gravity3,351 ly
18Kepler-189 c4.0x Earth gravity1,929 ly
19WASP-84 c4.0x Earth gravity328 ly
20HD 22946 d3.9x Earth gravity205 ly
21Kepler-279 d3.9x Earth gravity3,384 ly
22Kepler-62 d3.7x Earth gravity981 ly
23Kepler-84 c3.6x Earth gravity3,340 ly
24KOI-94 b3.6x Earth gravity1,556 ly
25Kepler-53 c3.6x Earth gravity4,456 ly

Showing the top 25 of 1,951 that qualify.

How we know

Gravity is computed from mass and size, and this record only admits worlds where those two numbers are physically consistent: together they must imply a density in the rock-to-iron range. That gate matters because the raw table is full of minimum masses sitting on tiny radii, implying impossible densities and gravities that were never real. Where a mass is a minimum (the m·sin i method), the gravity is a floor and reads "at least".

For comparison, Mars pulls at 0.38 g and our Moon at 0.17 g. What could unseat this record: a newly weighed super-Earth whose measured mass and radius both check out; mass measurements improve every year.

Common questions

Which exoplanet has the strongest surface gravity?

Among worlds small enough to have a surface, with a mass and size that agree, Kepler-123 b has the strongest surface gravity known: 6.4 times Earth's.

Where would you weigh the most?

On Kepler-123 b, among the worlds with solid ground and a mass and size that agree with each other. Its surface gravity is 6.4x Earth gravity, so a person weighing 150 pounds on Earth would weigh a good deal more there and would find walking genuinely hard work.

Why are gas giants not at the top of this list?

Because there is nowhere to stand on one. A giant's quoted surface gravity is measured at the top of its clouds, an arbitrary altitude in an atmosphere thousands of kilometres deep, so it is not a surface gravity in any sense you could experience.

How is surface gravity calculated?

From mass and radius alone: gravity scales with mass and falls off with the square of the radius. That makes it only as reliable as those two numbers, which is why this ranking requires a mass and a radius that together imply a physically possible density.

Keep exploring: all records · the worst places to visit · what would you weigh there?