Oct 13, 2025 05:35 PM
https://www.livescience.com/physics-math...-habitable
EXCERPTS: The planets around white dwarf stars might provide long-term homes for alien life, but they suffer from a fatal overheating problem. Who's going to rescue them? According to new research, it's none other than Albert Einstein.
White dwarfs are the compact remnants of dead sun-like stars. They litter the universe, with the Milky Way alone home to hundreds of millions of them. And because they can stay warm for hundreds of billions of years, they are a very intriguing place to search for life.
However, research had suggested that life would probably have a tough time on a planet around a white dwarf. The habitable zone — the region where temperatures are just right to support liquid water on a planetary surface — around white dwarfs spans somewhere from a tenth to a hundredth the distance between Earth and the sun. This is fine, if a bit uncomfortable, but the problem comes when the planet is not alone.
If there's another planet in the system even somewhat nearby, its weak-but-persistent gravitational influence will pull the inner world into a highly elliptical orbit. Once there, it will stretch and squeeze from tidal heating. This happens in the icy moons of the outer solar system, which liquefies their interiors. But for a planet around a white dwarf, this same process will heat it up so much that it becomes totally uninhabitable.
Previous research had found that this was very easy to do. Even a small deviation from a perfectly circular orbit would be enough to doom a planet. But that research only considered Newtonian gravity, which is the simple formulation of gravity...
[...] In a new paper published Sept. 30 to the preprint database arXiv, researchers performed a more careful analysis of planets orbiting white dwarf stars, accounting for the effects of general relativity. While previous researchers knew that general relativity was more accurate, it’s a much more difficult theory to use, and usually doesn’t produce significant differences in planetary orbit calculations.
But the researchers found that a more accurate treatment revealed a much wider window of habitability than previously thought. This is because the precession of the inner planet's orbit "protects" it from being pulled into more elliptical paths, which, in turn, prevents runaway tidal heating, the researchers explained... (MORE - missing details)
EXCERPTS: The planets around white dwarf stars might provide long-term homes for alien life, but they suffer from a fatal overheating problem. Who's going to rescue them? According to new research, it's none other than Albert Einstein.
White dwarfs are the compact remnants of dead sun-like stars. They litter the universe, with the Milky Way alone home to hundreds of millions of them. And because they can stay warm for hundreds of billions of years, they are a very intriguing place to search for life.
However, research had suggested that life would probably have a tough time on a planet around a white dwarf. The habitable zone — the region where temperatures are just right to support liquid water on a planetary surface — around white dwarfs spans somewhere from a tenth to a hundredth the distance between Earth and the sun. This is fine, if a bit uncomfortable, but the problem comes when the planet is not alone.
If there's another planet in the system even somewhat nearby, its weak-but-persistent gravitational influence will pull the inner world into a highly elliptical orbit. Once there, it will stretch and squeeze from tidal heating. This happens in the icy moons of the outer solar system, which liquefies their interiors. But for a planet around a white dwarf, this same process will heat it up so much that it becomes totally uninhabitable.
Previous research had found that this was very easy to do. Even a small deviation from a perfectly circular orbit would be enough to doom a planet. But that research only considered Newtonian gravity, which is the simple formulation of gravity...
[...] In a new paper published Sept. 30 to the preprint database arXiv, researchers performed a more careful analysis of planets orbiting white dwarf stars, accounting for the effects of general relativity. While previous researchers knew that general relativity was more accurate, it’s a much more difficult theory to use, and usually doesn’t produce significant differences in planetary orbit calculations.
But the researchers found that a more accurate treatment revealed a much wider window of habitability than previously thought. This is because the precession of the inner planet's orbit "protects" it from being pulled into more elliptical paths, which, in turn, prevents runaway tidal heating, the researchers explained... (MORE - missing details)