Why Did Jupiter Become a Planet and Not a Star?

Jupiter is made of the same material and is bigger than some stars, so why didn’t it ever become one?

Transcript

00:00 When we think about stars, supermassive balls of white fusion gas are probably what come

00:07 to mind.

00:08 But they aren't all so big.

00:09 In fact, in the Milky Way galaxy, Red Dwarf EBLM J0555-57AB is barely bigger than Saturn,

00:17 and it's actually smaller than Jupiter.

00:19 So you might be asking yourself, why didn't Jupiter ever turn into a star?

00:23 Jupiter after all is made of the same stuff that stars are made of, hydrogen and helium.

00:28 But the biggest factor is its density.

00:30 Sure, Jupiter may have the mass of 2.5 times the rest of our solar system's planets combined,

00:35 but its density is only around 1.33 grams per cubic centimeter.

00:39 And yeah, the sun's mass may only be 1.41 grams per cubic centimeter, but while Jupiter

00:44 is big on a planetary scale, it's only .0001 times the mass of our sun.

00:50 Stars form when the core of a future star is pressed so hard under the gravity of its

00:53 own mass that thermonuclear fusion occurs, and Jupiter, while big, just doesn't have

00:58 enough mass.

00:59 So rather than being a failed star like some may say, Jupiter is more likely the leftover

01:03 gases from the birth of our own solar system's sun.

01:06 (upbeat music)

01:09 (upbeat music)