Eventually, increasing solar brightness could disrupt Earth’s climate and reduce the conditions needed for oxygen-producing life.
That means this isn’t something humans need to worry about in our lifetimes—or even remotely close to them.
What Happens to the Sun?
The more dramatic part comes much later.
The Sun is currently a middle-aged star. In roughly five billion years, it is expected to enter its red-giant phase after exhausting much of the hydrogen fuel in its core.
As the Sun expands, the inner planets could face extreme conditions, with Mercury and Venus expected to be engulfed and Earth potentially suffering the same fate depending on how the Sun’s evolution affects its orbit.
So when Musk talks about humanity eventually needing another home, he is referring to an unimaginably distant astronomical problem—not an impending apocalypse.
Why Mars Comes Into the Conversation
Musk has frequently described Mars as a kind of long-term “life
