A composite of 25 images of the Sun, showing solar outburst/activity over a 365 day period. Without the right amount of nuclear fusion, which is made possible through quantum mechanics, none of what we recognize as life on Earth would be possible. (NASA / SOLAR DYNAMICS OBSERVATORY / ATMOSPHERIC IMAGING ASSEMBLY / S. WIESSINGER; POST-PROCESSING BY E. SIEGEL)

Our Sun Is Lighter Than Ever, And The Problem Is Getting Worse

Stars don’t stay the same throughout their life, and the Sun is no exception. Here’s what’s going on.

Here on Earth, the ingredients for life to survive, thrive, evolve, and sustain itself on our world have all coexisted without fail for billions of years. In addition to all the atoms and molecules our planet possesses, our world also has the right conditions for liquid water on its surface, owing to our atmosphere and being at just the right distance from our Sun.

Yet if the Sun were either significantly cooler or hotter, that habitability would come to an abrupt end. All the ingredients we could conceive of wouldn’t change the simple fact: without the right energy input from our Sun, life would be an impossibility. Our Sun contains 99.8% of the Solar System’s mass, but gets lighter every day. When enough time goes by, its changes will render Earth uninhabitable. Here’s how it’s changing.

Artist’s impression of a young star surrounded by a protoplanetary disk. There are many unknown properties about protoplanetary disks around Sun-like stars, but the general picture of a dusty disk with heavy elements distributed through it is certainly what gave rise to our planets. (ESO/L. CALÇADA)

When our Solar System first formed, a large clump of mass began gravitationally attracting more and more matter to it, forming a growing proto-star. Surrounding it, a…