What Would Happen if the Sun Lost Half Its Mass?
If the Sun lost half its mass – what outcomes could be expected?
The main consequence of such a change would be a dramatic decrease in the Sun’s gravitational pull. It would have a fundamental impact on the structure of the entire solar system. Earth’s orbit would increase in radius, and we’d find ourselves further from the Sun.
Moreover, the Sun would become cooler and redder after losing half of its mass. It would become a red dwarf. Its habitable zone would become smaller and move closer to the Sun. Earth would face extremely low temperatures, plants wouldn’t be able to photosynthesize in the dim light, and the water would likely freeze.
Planets that are now further from the Sun would completely escape the Sun’s gravitation. Jupiter, Saturn, Uranus, and Neptune would leave our system.
This colorful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER’s primary mission. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
In contrast, Mercury would be located in the theoretically habitable zone. However, being very close to the Sun would result in extreme tidal forces, leading to large variations in the sea level (if such existed there) and possibly even seismic instabilities.
This planet would likely become tidally locked. One side of Mercury would always be in daytime, and the other would be condemned to eternal darkness. It’s hence unlikely any form of life would emerge there.
Is it possible for the Sun to lose 50% of its mass rapidly?
No, it is not possible for the Sun to lose 50% of its mass rapidly. The Sun’s mass is about 1.989 × 1030 kilograms, and such a significant loss of mass would require extraordinary and currently unknown processes.
The Sun undergoes a gradual loss of mass over its lifespan through the solar wind, but losing half of its mass rapidly is not a plausible scenario based on our current understanding of stellar physics.
When do stars lose their mass extremely fast?
Stars can experience rapid mass loss during specific phases of their evolution.
For example, one common scenario is during the late stages of a massive star’s life when it undergoes a supernova explosion. A supernova is a powerful and explosive event that results in the ejection of a significant portion of the star’s mass into space.
Supernovae are classified into different types, with Type II supernovae associated with the collapse and subsequent eruption blast of massive stars. In this process, the core of the star collapses under gravity, leading to a violent explosion that expels the outer layers of the star into space. This rapid mass loss leads to the creation of heavy elements and enriches the surrounding space with these materials.
This image of the supernova remnant Cassiopeia A. Image credit: NASA/CXC/SAO/IXPE
However, not all stars undergo supernovae, and the fate of a star depends on its mass. Smaller stars, like our Sun, do not end their lives in a supernova but rather go through a more gradual process, shedding their outer layers to become planetary nebulae.
Final word
If our Sun lost rapidly half of its mass, it would lead to high orbital instabilities of the entire planetary system, with some of the planets entirely leaving the Solar system. Luckily, for our home star such a rapid loss of a large portion of its mass is not possible in hundreds of millions or even billions of years ahead.
