In about 5 billion years, hydrogen fusion in our star will decrease dramatically due to the near exhaustion of the supply of hydrogen. The Sun will begin fusing helium in its core, and begin moving into its red giant phase.
Estimates indicate that the Sun will expand approximately one astronomical unit, the mean distance from the Sun to the Earth. This means that Mercury, Venus, and Earth itself will likely be enveloped by the Sun.
Read Also: Top Reasons Why You Should Eat A Lot Of Onions
The following artist’s representation of the future looks very bleak for the planets of our solar system. The small dots located near the red giant can be thought of as planets in the process of destruction.
As the surface of the sun continues to expand, the earth will have been long since rendered a lifeless chunk of rocky debris, with no oceans and no atmosphere. This is illustrated below:
The Sun gave Earth the spark of life, and will take it away by fire.
The habitable zone, the Goldilocks zone of the Sun will gradually move farther away as the red giant expansion continues. Once the sun has expanded to its maximum size, there is some uncertainty as to the fate of Jupiter, which would be much closer to the Sun than it is today. It could lose vast quantities of its mass because it is a gas giant. However, gas giant exoplanets have been observed quite near their red giant stellar hosts, and they are holding themselves together, so the future of Jupiter is somewhat uncertain, as well as that of Saturn.
Jupiter will be in a habitable zone. Examine the following illustration to see the significant changes which will take place during the Sun’s evolution to a red giant.
