You are here

More Hydrogen

May 29, 2016

Hydrogen is the most abundant element in the universe — it accounts for more than 90 percent of all the normal matter. It also accounts for more than 90 percent of the matter that makes up the Sun and most other stars.

Here on Earth, though, it’s seldom found in its pure form. Instead, it’s combined with other elements to make water and other compounds. As a result, it wasn’t “discovered” until 250 years ago.

All that hydrogen was forged in the Big Bang. As the universe expanded and cooled, energy was converted to matter — the first subatomic particles. These then merged to form protons — the nuclei of hydrogen atoms. Some of those nuclei linked up to form helium, so the early universe consisted almost entirely of hydrogen and helium.

Over time, clouds of these gases collapsed to form stars. Nuclear reactions in the hearts of the stars forged more elements. And stellar explosions forged even more. So stars that formed later, such as the Sun, incorporated a smidgen of these newly formed elements.

Even so, their main ingredients are still hydrogen and helium. The Sun “burns” almost 700 million tons of hydrogen every second. These nuclear reactions produce helium, plus the energy that makes the Sun shine.

That process has been going on for four and a half billion years. Yet despite its prodigious rate of consumption, the Sun contains so much hydrogen that it won’t run out anytime soon. It’ll continue to shine for billions of years more.


Script by Damond Benningfield

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.