Will Our Solar System be Habitable When The Sun Becomes a Red Giant?

-- jeff | August 30, 2020

Question:

FACT: In 7.6 billion years, the sun will reach its maximum size and will shine 3,000 times brighter.
QUESTION: Could people still live in this solar system after the sun has got to this point on pluto or the dwarf planet called Farout that is farther?

-- jeff

Answer:

Possibly, but Earth will not be habitable.  Details can be found in a very nice Phys.org article which describes the evolutionary changes that our Sun will go through and how that affects the planets in our Solar System.  When the Sun becomes a Red Giant its habitable zone will move from a small range around Earth’s orbit to a range from 49.4 to 71.4 astronomical units, placing it well into the Kuiper Belt.  Many of the now icy worlds in the Kuiper Belt will melt, allowing liquid water to exist, an ingredient to making them habitable.

-- Jeff Mangum