No life will survive death of Sun as Earth’s magnetosphere won’t provide protection: Study

The magnetic field of the Earth is an underrated natural miracle. It protects our environment, creates some of the most stunning scenery when auroras occur, and helps people to travel from one side of the globe to the other. Unfortunately, it will not be able to save us from the Sun's death. Dr Dimitri Veras of the University of Warwick and Dr Aline Vidotto of Trinity College Dublin have discovered this in the new research.

No life will survive the death of the sun: Research

Scientists have quite thoroughly drawn out the Sun's predicted life cycle. It will run out of the hydrogen fuel source that powers the nuclear fusion in its core once its current main sequence phase is completed, said the research. Without the fusion's pushing power, the Sun will compress and eventually heat up. That extra heat will expand its outer atmosphere to many times its current size, possibly swallowing Earth, but almost certainly destroying Venus and Mercury.

The sun will also produce a powerful, variable solar wind during its red giant phase. Normally, our magnetic field is able to prevent solar wind particles from destroying Earth's atmosphere. The magnetic field, however, has little chance of preserving the planet's atmosphere due to the increased amount of particles assaulting it as a result of the red giant's ongoing bombardment. The likelihood of life remaining on the planet decreases as it is stripped away, despite the fact that the Earth will presumably drift further away from the Sun due to the lower gravity associated with the star's smaller mass.

The habitable zone around red giants is significantly further out than the habitable zone around main sequence yellow stars, stretching well beyond Neptune's orbit. The Earth's ponderous orbital route will not allow us to arrive in time before all life on the planet's surface is cooked. As a result, we may be confident that a declining sun will be able to kill us in multiple ways.

However, after its red giant phase, the star transforms into a white dwarf, which is far more stable and emits no solar wind. However, for life to survive so far, its planet's magnetic sphere must be 100 times stronger than Jupiter's, and it must be able to migrate fast between the habitable zones of three different star types.  At least, according to Drs. Veras and Vidotto's models are the necessary qualities of a planet that can continue to support life through these periods. They did models for the winds of 11 distinct stars, each of which had a different mass.

Earth’s magnetosphere won’t provide protection anymore

Fortunately, all of this will occur billions of years from now, giving mankind ample time to devise a technological defence strategy. However, this hypothesis has ramifications for a number of exoplanets that other astronomers are now searching for. Some, including a few Jupiter-sized ones in the habitable zone of these ultra-stable stars, have previously been discovered surrounding white dwarfs. While the death throes required to form a white dwarf would have likely wiped out any previously evolved life, white dwarves are stable for billions of years, allowing life to emerge again in a much more benign environment.

Despite rare outbursts that threaten humanity's whole energy infrastructure, our own solar system is currently a pretty benign environment. As long as that doesn't happen, our magnetic field will give us plenty of time to study other white dwarfs and look for indications of life on their exoplanets after the sun dies.

Picture Credit: NASA/JPL