Will the sun become red?
Andrew Mclaughlin
Updated on January 09, 2026
A red giant is a dying star in the final stages of stellar evolution. In about five billion years, our own sun will turn into a red giant, expand and engulf the inner planets — possibly even Earth.
What happens if the sun turns red?
As our star ends its life, it will swell far beyond its current size, and as it does so, it will transition into a Red Giant. During this transformation, the sun will melt our glaciers and (eventually) boil our oceans. This expanding Sun will engulf the Earth, and any life that remains along with it.Will our sun become a red giant?
In a few billion years, the sun will become a red giant so large that it will engulf our planet. But the Earth will become uninhabitable much sooner than that. After about a billion years the sun will become hot enough to boil our oceans. The sun is currently classified as a “main sequence” star.Can Earth survive with a red sun?
Even if the Earth were to survive being consumed, its new proximity to the the intense heat of this red sun would scorch our planet and make it completely impossible for life to survive. However, astronomers have noted that as the Sun expands, the orbit of the planet's is likely to change as well.How long will the sun be red?
Under these conditions, life as we know it will be unable to survive anywhere on the surface, and planet Earth will be fully transformed into another hot, dry world, just like Venus. Red Giant Phase: In 5.4 billion years from now, the sun will enter what is known as the red giant phase of its evolution.The Sun will turn into a Red Giant TWICE!
Will the Sun destroy Earth?
By that point, all life on Earth will be extinct. Finally, the most probable fate of the planet is absorption by the Sun in about 7.5 billion years, after the star has entered the red giant phase and expanded beyond the planet's current orbit.How long will the Earth last?
The upshot: Earth has at least 1.5 billion years left to support life, the researchers report this month in Geophysical Research Letters. If humans last that long, Earth would be generally uncomfortable for them, but livable in some areas just below the polar regions, Wolf suggests.How hot will it be in 2100?
Results from a wide range of climate model simulations suggest that our planet's average temperature could be between 2 and 9.7°F (1.1 to 5.4°C) warmer in 2100 than it is today. The main reason for this temperature increase is carbon dioxide and other heat-trapping “greenhouse” gases that human activities produce.How long would humans survive without the Sun?
With no sunlight, photosynthesis would stop, but that would only kill some of the plants—there are some larger trees that can survive for decades without it. Within a few days, however, the temperatures would begin to drop, and any humans left on the planet's surface would die soon after.How much longer until the Sun dies?
Astronomers estimate that the sun has about 7 billion to 8 billion years left before it sputters out and dies. One way or another, humanity may well be long gone by then.Will the Earth survive the red giant?
In about five billion years the Sun will run out of hydrogen fuel and swell into a red giant star over a thousand times its current volume before shrinking back into a white dwarf.Will the Sun burn out one day?
The sun's death rattleAll good things eventually come to an end. And one day, about 4 billion or 5 billion years from now, the sun will burn through its last gasp of hydrogen and start burning helium instead.