Will Life Exist in the Solar System After the Death of the Sun?

(Image credit: Greg Wyatt)The Sun is ~4.6 billion years old. Within ~5 billion years, the hydrogen fuel in its core will run out, and the Sun will begin expanding into a red giant star. In ~6.5 billion years, the helium in its core will ignite and the Sun will settle into a helium-burning phase lasting ~100 million years. In ~7.5 billion years, the helium will be exhausted, and the Sun will enter the asymptotic giant branch, and its envelope will swell to near Earth’s orbit.(Image credit: Greg Wyatt)Most of the outer layers of the Sun will be shed off over a few hundred thousand years, so that in ~8 billion years the ejected gas will create an extended planetary nebula. The exposed hot core, a dense carbon-oxygen white dwarf, will carry about 0.55 solar masses. This massive remnant of the Sun will settle to a size comparable to that of the Earth.As a result of this predictable evolution, the solar system will become a ghostly remnant of its former self once the age of the Universe will exceed 14.6 billion years. Its transformation will follow the following stages.(Image credit: Greg Wyatt)During the red giant phase, the Sun will engulf and completely incinerate the inner solar system. Mercury and Venus will be swallowed first. Earth will likely be engulfed as well, in which case the Moon will crash on Earth’s. surface as a result of drag on the puffed-up stellar envelope. The mass loss from the Sun will initially weaken the Sun’s gravity and push Earth out to about 1.7 times the current Earth-Sun separation, namely, 1.7 AU. But the bloated Sun will also drag Earth’s orbit inward, and the most detailed models find that Earth will be pulled in and be vaporized. Even if Earth narrowly escapes being swallowed, its oceans will boil, its atmosphere will be ripped away, and its surface will melt into a sea of lava, leaving behind a scorched, lifeless rock.(Image credit: Greg Wyatt)The white dwarf remnant will start with a surface temperature over 100,000 degrees Kelvin and