Jupiter Was Once Close To Becoming Another Sun

Jupiter almost became another star in the solar system. An expert said if the planet just gained an extra weight in the past, a nuclear fusion could occur and turn it into a small, red dwarf.

Jupiter ranks as the biggest planet in the solar system. Combining the masses of all its neighboring planets will not even reach the half of the mass of the gas giant.

“You could eliminate every single planet in the solar system except Jupiter, and you would basically still have…the solar system,” Paul Sutter, an astrophysicist at Ohio State University, said in an article posted on Universe Today. “I’m not trying to make you feel insignificant, but the mass of the Earth is just a rounding error when adding up all the stuff orbiting the Sun.”

But with the right changes in its size, Jupiter may not look like the gentle giant we know today. Sutter said the planet was once “on the edge of becoming the Sun’s smaller sibling.” 

If it continued to grow nearly 80 times bigger than it is, Jupiter would be heavy enough to start nuclear fusion of hydrogen. That is because of the higher pressure and temperatures in its core. 

“Now I get that ‘80 times’ sounds like a big deal,” Sutter said. “If you were 80 times bigger than you are now, that would be a slightly concerning medical issue. But in the astronomy world that’s peanuts.”

He explained that planets could grow as fast as how the novel coronavirus moved across the world in a matter of days. Jupiter was born when a small clump of rocks and ices, about 5 to 10 times the mass of the Earth, moved so fast and led to its exponential growth. 

Sutter said that the Sun could also help Jupiter become another star. If the gas around the young Sun collapsed during the formation of the solar system, the planet at its right size may ignite and light up as a second star. 

It may look great to have two stars in the solar system, but Sutter noted Earth may not be able to support life in its location. Planets that orbit in binary star systems are unlikely to get the right temperatures to maintain water, which plays an important role in the existence of life.

Jupiter ALMA image showing the distribution of ammonia gas below Jupiter's cloud deck. ALMA (ESO/NAOJ/NRAO), I de Pater/UC Berkeley et al.; NRAO/AUI NSF, S. Dagnello

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