Categories: Cosmology

Asteroids Crashing Into Dead Stars are Helping Explain Where the Universe’s Missing Lithium Went

What happened to all the lithium? The question has stumped astronomers for decades. While cosmologists have successfully predicted the abundance of the other light elements from the Big Bang, lithium has always come up short. Now, a team of astronomers may have found the reason: lithium-rich asteroids are smashing into white dwarves.

As amazing as it sounds, we can use nuclear theory to understand the conditions of the universe when it was only a dozen minutes old. In that inferno, the lightest elements – hydrogen, helium, and lithium – got their start. Astronomers have been able to compare the predicted abundances of those elements to what they see throughout the universe, and everything matches up…except lithium.

It’s called the “cosmological lithium problem” because that’s exactly what it is. We know that this story of the Big Bang is largely correct, so where did all the lithium do?

Wherever it is, it’s not in stars or interstellar gas clouds – we checked there.

And now a new survey by a team of astronomers with University of North Carolina Chapel Hill, University of Montreal and Los Alamos National Laboratory think they have the answer: white dwarves.

Using the Southern Astrophysical Research Telescope, the astronomers observed two very old white dwarf systems, whose planets formed over 9 billion years ago. Those planets are long gone, destroyed when their parent stars turned into white dwarfs.

But then pieces of those planets crashed into the white dwarfs, where the astronomers found signs of much more lithium than normal.

So potentially the missing lithium of the universe is bound up in planets and asteroids, and can only make itself visible to astronomers when those objects end up crashing into their parent stars. Only more observations will tell, and maybe we’ll finally find all that lithium.

Paul M. Sutter

Astrophysicist, Author, Host | pmsutter.com

Recent Posts

Stellar Winds Coming From Other Stars Measured for the First Time

An international research team led by the University of Vienna has made a major breakthrough.…

1 day ago

Neutron Stars Could be Heating Up From Dark Matter Annihilation

Astronomers have an intriguing idea for searching for dark matter, measuring the effect of particle…

1 day ago

The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star

After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst…

2 days ago

Formation-Flying Spacecraft Could Probe the Solar System for New Physics

It's an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge…

2 days ago

Watch a Satellite Reaction Wheel Melt in a Simulated Orbital Re-Entry

Most satellites share the same fate at the end of their lives. Their orbits decay,…

2 days ago

NASA is Building an Electrodynamic Shield to Deal with all that Dust on the Moon and Mars

Exploration of the Moon or other dusty environments comes with challenges. The lunar surface is…

3 days ago