• May 26, 2022
 Amy’s Everyday Astronomy: Your astronomy questions answered: What if Jupiter became a star?

Amy’s Everyday Astronomy: Your astronomy questions answered: What if Jupiter became a star?

Arthur C. Clarke, a man who had his finger on the pulse of the sci fi reading world. If you’ve never read any of his stuff, you’re really missing out on some great fiction writing that is rooted in real science.

One of his series of stories (The Complete Odyssey) is a set of four books (2001, 2010, 2061, and 3001) that follows the idea of aliens who are so much more advanced than humans that they seem god-like. Two of these books have been made into movies. And, in my humble opinion, 2010 is the best of those.

For those have never seen the movie, nor read the book, but plan to…. beware of spoilers ahead.

The story follows Dr. Heywood Floyd, a scientist that sent a team to investigate a large monolith found in orbit of the planet Jupiter back in 2001. The entire team was lost and now, nine years later, he is approached with a proposal to go and find out what really happened to them.

As the course of the story takes us to those answers, while delving into the politics of the cold war, the part I’m going to focus on is near the end when the monolith begins to multiply and seemingly consume the King of Planets. But rather than being taken out of existence, Jupiter ignites, becoming a star (like our own Sun, but on a much smaller scale).

Recently, on my Facebook page, I was asked “With reported lightning storms in its upper atmosphere, why hasn’t it ignited into a star??”

The truth is, Jupiter is a planet plagued with storms. I mean, everyone is familiar enough with its Great Red Spot. This is a storm (much like a hurricane here on Earth) that has been swirling for hundreds of years. But all the lightning on this giant world could not spontaneously cause the fusion process to begin, though igniting the gas within the atmosphere is possible.

Yet, having a planet that’s on fire is not nearly the same thing as the internal, plasmatic burning associated with fusion.

To put things in a different perspective, imagine having a candle and a lightbulb. You can light the candle, but it will only burn for a very finite time. How long depends greatly on wick construction and how much wax is used. Sure, you have light and some heat, but eventually it will be gone. With a lightbulb, the illumination is internal.

Electricity flows into the bulb where it is conducted into a filament that then glows. That light will shine for as long as there is a power source (given the filament is not burned out in the process). Likewise, for Jupiter to become a star, the power source would be that of fusion.

You can read in more detail about the fusion process in my article about black holes.

So, the easy answer is as I mentioned before: Jupiter simply isn’t big enough (doesn’t have the gravitational force necessary) to start the fusion process. As far as scientists know, nothing can change that fact. Jupiter will simply never ignite.

But what if it did?

The new Jupistar would be a small red dwarf star and would shine in the sky in an orange hue, like Mars but much brighter. And if Jupiter somehow began in the internal fusion process at its current size, the first thing that would happen would be a shock wave. This shock wave, caused by the spontaneous ignition, would spread out in all directions.

This would cause many of the asteroids that lie between Mars and Jupiter to be flung toward the inner part of the solar system. Given the size of some of these asteroids, this would be deadly to life on our planet.

Potentially, the extinction level event would dwarf that which killed off the dinosaurs 65 million years ago.
But let’s suppose this didn’t happen. We only get hit by tiny asteroids that cause nothing more than a glorious meteor shower, and life remains as it is now. Okay.

There would be times of the year where we were in perpetual twilight due to Jupistar rising at night. At other times of the year, when Jupistar rises in the day time, we would see our large Sun and a smaller, dimmer Sun gracing our skies.

Would this make for warmer days and nights? Probably not.

Keep in mind that the planet Jupiter is 4.2AU (AU is an Astronomical Unit that measures the distance between the Earth and the Sun) away from the Earth at its closest approach. The temperature changes would be all but undetectable, given this distance and how small Jupistar would be.

In its immediate neighborhood, however, things would change a great deal.

One of the largest moons that orbits Jupiter is Europa. This moon is covered in a thick layer of frozen water ice and it is believed that underneath that icy crust lies a liquid ocean. This moon may find itself within the habitable zone of the new Jupistar where the ice would melt and the water warm enough for detectable life to flourish.

Likewise, for Saturn’s moon, Enceladus. Though it may not be within the habitable (goldilocks) zone, the icy crust of this moon (which is not unlike Europa) could warm enough to melt and oceanic life may begin to flourish there, as well. This is provided they both survived the initial shock wave and maintained their current positions.

Still, the thought is intriguing. If Jupistar were real, and stayed its current size, we would have many other worlds to which we could travel and explore.

In fact, the idea of this has fired the imagination of one writer with Futurism who made a simulation of this very scenario back in 2014. You can see that video here.

And if you’d like to run your own “what if” scenarios on our solar system, you can download the software from universesandbox.com for just about $10.

Have fun and remember that even though Jupiter will never become a star, you should keep looking up. Because you never know what you’ll see if you just keep your eyes to the skies.


For a daily dose of Amy’s Everyday Astronomy:, like and follow her Facebook Page; to read previous articles, click here.

Amy Cooley

A native El Pasoan, Amy Cooley attended Parkland High School before beginning her studies in physics at EPCC. With her love of dark skies increasing, she transferred to New Mexico Tech University where she earned her degree in Astronomy. Moving back to El Paso in 2008, she now wants to share her love of the cosmos with the city she calls home.

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