[ad_1]
Although the ground beneath our feet is solid and reassuring (most of the time), nothing in this Universe lasts forever.
One day our Sun will die, ejecting much of its mass before its core shrinks into a white dwarf, gradually releasing heat until it is just a piece of cold, dark, dead rock, a thousand trillion years later.
But the rest of the solar system will be long gone. According to new simulations, it will only take 100 billion years for all of the remaining planets to cross the galaxy, leaving the dying Sun far behind.
Astronomers and physicists have been trying to figure out the ultimate fate of the solar system for at least hundreds of years.
“Understanding the long-term dynamic stability of the solar system is one of the oldest activities in astrophysics, dating back to Newton himself, who hypothesized that mutual interactions between planets would eventually make the system unstable.” , wrote astronomers Jon Zink of the University of California, Los Angeles, Konstantin Batygin of Caltech and Fred Adams of the University of Michigan in their new article.
But it’s much trickier than it looks. The greater the number of bodies involved in a dynamic system, interacting with each other, the more complicated this system becomes and the more difficult it is to predict. This is called the N-body problem.
Due to this complexity, it is impossible to make deterministic predictions of the orbits of objects in the solar system beyond certain time scales. Beyond about five to 10 million years, certainty goes out the window.
But, if we can figure out what will happen to our solar system, that will tell us something about how the Universe might evolve, on timescales much longer than its current age of 13.8 billion years. .
In 1999, astronomers predicted that the solar system would slowly collapse over a period of at least a billion trillion – or 10 ^ 18, or a quintillion – of years. This is the time it would take, they calculated, for the orbital resonances of Jupiter and Saturn to decouple Uranus.
According to Zink’s team, however, this calculation left out some important influences that could disrupt the solar system earlier.
First, there is the sun.
In about 5 billion years, as it dies, the Sun will transform into a red giant, engulfing Mercury, Venus, and Earth. Then, it will eject nearly half of its mass, carried into space by stellar winds; the remaining white dwarf will only represent about 54% of the current solar mass.
This mass loss will loosen the Sun’s gravitational hold on the remaining planets, Mars, and the outer gas and ice giants, Jupiter, Saturn, Uranus and Neptune.
Second, as the solar system revolves around the galactic center, other stars are expected to come close enough to disrupt the orbits of the planets, about once every 23 million years.
“Taking into account the loss of stellar mass and the inflation of the orbits of the outer planets, these meetings will become more influential,” the researchers wrote.
“With sufficient time, some of these flyovers come close enough to disassociate – or destabilize – the remaining planets.”
With these additional influences factored into their calculations, the team ran 10 N-body simulations for the outer planets (excluding Mars to save on computational costs, as its influence should be negligible), using the powerful cluster. Shared Hoffman2. These simulations were divided into two phases: until the end of the mass loss of the Sun and the phase which follows.
While 10 simulations isn’t a solid statistical sample, the team found that a similar scenario played out every time.
Once the Sun has completed its evolution into a white dwarf, the outer planets have a larger orbit, but remain relatively stable. Jupiter and Saturn, however, are captured in a stable 5: 2 resonance – for every five times Jupiter orbits the Sun, Saturn orbits twice (this eventual resonance has been proposed several times, most notably by Isaac Newton himself) .
These enlarged orbits, as well as the characteristics of planetary resonance, make the system more sensitive to disturbances due to the passage of stars.
After 30 billion years, such stellar disturbances throw these stable orbits into chaotic orbits, causing rapid planet loss. All but one of the planets escape their orbits, fleeing into the galaxy as rogue planets.
This last lonely planet remains for another 50 billion years, but its fate is sealed. Finally, she too is stunned by the gravitational influence of passing stars. Ultimately, 100 billion years after the Sun turned into a white dwarf, the solar system no longer exists.
That’s a much shorter timeframe than that proposed in 1999. And, the researchers carefully note, it depends on current observations of the local galactic environment and stellar flyby estimates, both of which may change. It is therefore by no means set in stone.
Even if estimates of the timeline for the Solar System’s demise change, however, it is still several billion years away. The likelihood of humanity surviving long enough to see it is slim.
Sleep well!
The research was published in The astronomical journal.
[ad_2]
Source link