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Tesla Roadster Elon Musk Launched Into Space Has 6 Percent Chance of Hitting Earth In the Next Million Years (sciencemag.org)
sciencehabit shares a report from Science Magazine: SpaceX CEO Elon Musk grabbed the world's attention last week after launching his Tesla Roadster into space. But his publicity stunt has a half-life way beyond even what he could imagine -- the Roadster should continue to orbit through the solar system, perhaps slightly battered by micrometeorites, for a few tens of millions of years. Now, a group of researchers specializing in orbital dynamics has analyzed the car's orbit for the next few million years. And although it's impossible to map it out precisely, there is a small chance that one day it could return and crash into Earth. But don't panic: That chance is just 6% over a million years, and it would likely burn up as it entered the atmosphere.
Hanno Rein of the University of Toronto in Canada and his colleagues regularly model the motions of planets and exoplanets. "We have all the software ready, and when we saw the launch last week we thought, 'Let's see what happens.' So we ran the [Tesla's] orbit forward for several million years," he says. The Falcon Heavy rocket from SpaceX propelled the car out toward Mars, but the sun's gravity will bring it swinging in again some months from now in an elliptical orbit, so it will repeatedly cross the orbits of Mars, Earth, and Venus until it sustains a fatal accident. The Roadster's first close encounter with Earth will be in 2091 -- the first of many in the millennia to come.
Hanno Rein of the University of Toronto in Canada and his colleagues regularly model the motions of planets and exoplanets. "We have all the software ready, and when we saw the launch last week we thought, 'Let's see what happens.' So we ran the [Tesla's] orbit forward for several million years," he says. The Falcon Heavy rocket from SpaceX propelled the car out toward Mars, but the sun's gravity will bring it swinging in again some months from now in an elliptical orbit, so it will repeatedly cross the orbits of Mars, Earth, and Venus until it sustains a fatal accident. The Roadster's first close encounter with Earth will be in 2091 -- the first of many in the millennia to come.
"Space junk" is only a problem in Earth orbit, where it has a significant chance of colliding with other important objects. The smaller, scattered debris left behind by launches or collisions is the real problem, as it's harder to track. When the Chinese intentionally blew up one of their own satellites in an anti-satellite missile test around a decade ago, it caused a real uproar, because they intentionally created thousands of pieces of debris that would be a problem for many decades to come.
This solar-orbiting Roadster is not any sort of real problem worth complaining about, unless you just want to grump about something.
Irony: Agile development has too much intertia to be abandoned now.
So far, we've discovered 15,000 rocks in orbits crossing close to Earth ("Near Earth Objects"), and the best estimate is that we've found about one quarter of the ones larger than 140 meters in diameter.
Wheelbase of a Tesla roadster is about four meters.
For every Tesla roadster in Earth-crossing orbit-- one--there are a million rocks that are at least that big.
There are a lot of asteroids. But, fortunately (quoting Douglas Adams), space is big. Really big.
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