In 2 billion years, the Earth will be a very different place than it is today. The sun will have grown hotter and brighter, causing the Earth's oceans to boil away and the planet to become a barren wasteland.
The Sun's Evolution
The sun is a star, and like all stars, it goes through a life cycle. It is currently in its main sequence phase, where it is fusing hydrogen into helium in its core. This process releases energy in the form of light and heat.
However, the sun's core is constantly being depleted of hydrogen, and as it runs out, the sun will begin to evolve into a red giant. This will happen in about 5 billion years.
The Earth's Fate
When the sun becomes a red giant, it will expand dramatically and engulf the inner planets, including Mercury, Venus, and possibly even Earth.
Even if Earth survives the initial expansion, the sun's increased heat and radiation will render the planet uninhabitable. The oceans will boil away, the atmosphere will be stripped away, and the surface will become a scorched and barren wasteland.
Other Changes
Besides the sun's evolution, other changes will occur on Earth over the next 2 billion years.
- Plate tectonics will continue to reshape the Earth's continents.
- The Earth's magnetic field will likely weaken.
- The moon will continue to drift further away from Earth.
- The Earth's atmosphere will become thinner and less dense.
While 2 billion years is a long time, it is a blink of an eye in the cosmic timeline. The Earth's ultimate fate is tied to the sun's evolution, and it is inevitable that our planet will eventually become uninhabitable.
