Will Earth ever leave the solar system?
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A short story by Liu Cixinwandering earth (opens in new tab)‘ (first published in the Chinese magazine Science Fiction World in July 2000), Cixin depicts a scenario that the planetary leaders agree to pursue. earth out of solar system escape from a dire situation solar flare It is expected to destroy all terrestrial planets.
Of course, this story is based in the realm of fiction, but could Earth really leave the solar system?
“It’s very unlikely,” said Matteo Seriotti, an aerospace engineer and space systems expert. engineering A lecturer at the University of Glasgow in the UK told Live Science via email.
However, as Ceriotti explained, “unlikely” does not mean “impossible,” but implies that it is theoretically possible.
“Earth could be pushed out of orbit by the action of huge interstellar objects flying through interstellar space, entering the solar system, and passing close to Earth,” he said.
Related: What if the Earth was a Super Earth?
“In this close encounter, known as a ‘flyby’, the Earth and the object exchange energy and momentum, and the Earth’s orbit is disrupted. An escape trajectory that points the Earth out of the solar system if the object is fast, large, and close enough. “
Timothy Davis, a senior lecturer in physics and astronomy at Cardiff University in England, agrees that the Earth could theoretically be expelled from the solar system, and has his own hypothesis on how this might happen. I have.
“The planet, as it exists today, is in a stable orbit around the Earth. SunHowever, when the Sun comes close to another star, gravity The interaction of these bodies could disrupt these orbits and cause Earth to be ejected from our solar system,” Davis told Live Science in an email.
However, Davis says that while this scenario is feasible, it is highly doubtful that it will come true, at least in the foreseeable future.
“Stellar encounters like this are extremely rare,” Davis said. “For example, the star Gliese 710, astronomically speaking, is expected to come very close to the Sun in about a million years, but even this flyby is unlikely to disturb the planet.”
While it is unlikely that an external force will force the Earth out of the solar system any time soon, could humans build machines that could move the Earth to the point where it would eventually be ejected?
“The energy required to pull the Earth out of orbit and out of the solar system is so enormous, equivalent to detonating a megaton of nuclear bombs all at once, which is unlikely,” Davis said. .
Such an event is unlikely, but what would happen if Earth were to leave our solar system? What would be the effects if our home planet were permanently expelled into the depths of space? ?
“Earth flies into interstellar space until it is captured or swallowed by another star or black hole,” Ceriotti said, adding that Earth’s departure from the solar system probably means many, if not all, of the planets. He added that it would lead to destruction. life.
“It is unlikely that the atmosphere will remain. The Earth’s global climate is very delicate due to the delicate balance between radiation from the Sun and the energy dissipated into deep space. If this were to change, the temperature would instantly ,” said Serriotti.
Related: Why isn’t the Earth perfectly round?
Davis agreed that it would not survive this cataclysm that would push most life on Earth away from the solar system.
“If Earth leaves the solar system, it is very likely that most of life as we know it will disappear. Almost all the energy used by life on Earth comes directly from the Sun ( photosynthetic plants), or indirectly (eg, herbivores eat plants and carnivores eat herbivores).
“In this scenario, the farther the Earth is from the Sun, the lower its distance. temperature will be It eventually freezes completely. The only natural heat source left is the decay of radioactive elements in the Earth’s crust left over from the formation of the solar system,” Davis said.
Davis explained that while some lives may drag on, they will eventually be doomed. We might be able to make a living from the energy, but complex life could be wiped out entirely.This radiant heat is only capable of sustaining a temperature of about minus 230 degrees Celsius. [Celsius, or minus 382 degrees Fahrenheit]At these temperatures, most of the atmosphere would also freeze, making Earth a dead ice world hurtling between the stars,” Davis said.
Looking far into the future, Seriotti added that our solar system would eventually be so badly disturbed that the Earth would be knocked out or completely destroyed.
“We predict that our galaxy is on its way to colliding with Andromeda. [our nearest neighbouring galaxy] In about 4.5 billion years.Such a massive collision of millions of stars is likely to wreak havoc on our solar system, Ceriotti predicts.
So while Earth will eventually leave the solar system in some form or another, it’s not something to worry about for billions of years yet.
Originally published in Live Science.
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