There are more stars in the universe than grains of sand on all of Earth's beaches

The Sun makes up 99.86% of all mass in the solar system

The Sun constitutes 99.86% of the solar system's total mass

Neutron stars are so dense that a teaspoon of their material would weigh about 6 billion tons

A teaspoon of neutron star matter equals approximately 6 billion tons

What is the estimated number of galaxies in the observable universe, and what factors contribute to the uncertainty in this estimation?

Approximately 2 trillion galaxies, with uncertainty due to observational limits and cosmic variance

Pi has been calculated to over 100 trillion digits — but 39 digits is enough to measure the observable universe to the width of a hydrogen atom

Pi's 39-digit approximation measures universe's width to hydrogen atom's size

A single teaspoon of soil contains more microorganisms than people on Earth

"One teaspoon of soil hosts more microbes than Earth's human population."

The footprints on the Moon will last millions of years — there's no wind or water to erode them

Moon's lack of atmosphere and liquid water preserves footprints indefinitely