Megan Knapp

LeBlasting Off

3/7/2019

Could Lebron James jump fast enough to escape small celestial bodies?

Ethan Gower / For The Post

I’m sure that you, dear reader, have often stopped to wonder: Can LeBron James jump off of an asteroid and not return? Could he jump off of anything? Most likely yes. With an astounding vertical of one meter, LeBron produces approximately 1100 joules when he jumps. That gives him a velocity of about 4 and a half meters per second as he leaves the surface. Earth’s escape velocity is 11 kilometers per second, so whether or not he can jump from “anything” is tentatively no.

Ceres, the largest asteroid, has a gravity less than three percent that of Earth. Here, LeBron’s leap reaches 37 meters (120 feet), but with an escape velocity of 500 meters per second, No. 23 (RIP) still remains grounded. That is also the case for asteroids Bennu and Ryugu, though Dactyl — moon of asteroid Ida, which requires 18 meters per second — should be small enough to leap from though I was unable to find mass data. Dactyl is tiny at under a mile at its longest axis. Even its orbit remains undefined, something I’m doubtful a 113 kilogram person shoving off its surface could constrain.

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Riley Scott | ILLUSTRATION

Now back to the original question: Can LeBron jump off of an asteroid? That would depend on your definition of asteroid. The effective cutoff, in terms of gravitational influence, is an object about a kilometer across. Asteroid Itokawa is about one third of that diameter and is more like a conglomerate of boulders and rubble than the solid rocky asteroids mentioned above. With an escape velocity of less than one meter per second, LeBron could easily generate enough speed to escape the surface.

Is there anything else? As far as things visited by spacecraft, not many. 67P/Churyumov-Gerasimenko is a dumbbell-shaped comet with an orbit that takes it out to Jupiter’s orbit and then back toward the Sun. As a comet nears the star, its icy body heats up and sublimates, liberating ice and debris that streams behind in the signature tail of a comet. Being effectively a large snowball, it has a very low surface gravity and LeBron can overcome its escape velocity with a brisk walk.

Having checked the requirements for all Plutonian moons – all woefully unmet, even on smallest Styx – the last notable object LeBron could leave is rather famous. In the 18th century, an astronomer by the name of Edmund Halley (like “valley”) was able to calculate and refine the recurrence of an ancient comet and determined, correctly, that it was the same comet as seen for millennia. Though he died before its return, Halley’s Comet has since bore his name.

Halley’s Comet is 100 times more massive than 67P/C-G, however its escape velocity is not that much greater. At an estimated 2 meters per second, LeBron could leap off the comet with ease. However, during Halley’s next closest approach, LeBron will be in his late 70s. I think he could still do it.

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