Musk Outlines The Questionable Reason He Wants To Get To Mars So Badly, NASA Astronaut Responds

Musk has spoken previously about having Mars as a backup planet for humanity, in case of an existential threat such as World War III.

“It’s important to get a self-sustaining base on Mars because it’s far enough away from earth that [in the event of a war] it’s more likely to survive than a moon base,” Musk said in 2018, per The Guardian, adding, “if there’s a third world war we want to make sure there’s enough of a seed of human civilization somewhere else to bring it back and shorten the length of the dark ages.”

In a new interview, he explained another reason why he believes humanity should head to the Red Planet. As many have pointed out, it isn’t exactly a pressing concern.

“One of the benefits of Mars is life insurance for life collectively,” Musk said in an interview with Fox News. “So eventually all life on Earth will be destroyed by the Sun. The Sun is gradually expanding, so we do at some point need to be a multi-planet civilization because Earth will be incinerated.”

“It’s an undisputed fact,” he added of the disputed hypothesis, “and I don’t think there’s anyone who would disagree with that.”

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What is true is that, according to our best models of the evolution of stars, the Sun will eventually swell up as it fuses hydrogen and helium in its core.

“When a main sequence star less than eight times the Sun’s mass runs out of hydrogen in its core, it starts to collapse because the energy produced by fusion is the only force fighting gravity’s tendency to pull matter together,” NASA explains. “But squeezing the core also increases its temperature and pressure, so much so that its helium starts to fuse into carbon, which also releases energy. Hydrogen fusion begins moving into the star’s outer layers, causing them to expand. The result is a red giant.”

During this red giant phase, its radius is predicted to swell to around 1-2 Astronomical Units (AU), with one AU being the distance from the Earth to the Sun. If the Earth were to remain in its current orbit (or really, move away from the Sun at its current rate) it is possible that it would be engulfed. But at 1.5 AU, Mars may join it, or else become an uninhabitable hot world rather than an uninhabitable cold world. What’s more, it is not entirely certain that either planet would be devoured during this phase, billions of years in the future.

“We do not currently have a consensus whether Earth could avoid being engulfed by the red giant sun in 6 billion years,” Dr Keming Zhang, from the University of California San Diego, explained in a statement after an Earth-sized planet was found orbiting a white dwarf, the remnant of a red giant star. 

“In any case, planet Earth will only be habitable for around another billion years, at which point Earth’s oceans would be vaporized by runaway greenhouse effect – long before the risk of getting swallowed by the red giant.”

“Whether life can survive on Earth through that (red giant) period is unknown. But certainly, the most important thing is that Earth isn’t swallowed by the Sun when it becomes a red giant,” Jessica Lu, associate professor and chair of astronomy at UC Berkeley, added. “This system that Keming’s found is an example of a planet – probably an Earth-like planet originally on a similar orbit to Earth – that survived its host star’s red giant phase.”

Musk acknowledged that it is a long-term project to make Mars self-sustainable as a life insurance policy, and would not be complete any time soon.

“We have several hundred million years, so don’t hold your breath, it’ll be ok, but if Earth has been around for 4.5 billion years, which is what the fossil record suggests, then Earth only has about 10 percent more life in it before it gets so hot that life is impossible,” he added.

“We’re headed there. We have a long way to go, because it’s not about just landing on Mars and doing flags and footprints, it’s about creating a self-sustaining city on Mars, with the fundamental fork in the road of destiny being that Mars is sufficiently self-sustaining and can grow by itself if the resupply ships from Earth stopped coming for any reason. Whether that is because civilization died with a bang or a whimper. But if the resupply ships are necessary for Mars to survive, then we have not created life insurance for life collectively.”

Nevertheless, X users were quick to point out that a focus on keeping Earth habitable might form a better life insurance policy than planning for a potential threat a billion years in the future. You don’t spend time perusing brochures for life at the bottom of the Atlantic Ocean, for example, while your house burns down around you.

“Earth to Elon: If we’re incinerated, so is Mars,” former NASA astronaut and current senator Mark Kelly said in response on X. “I’m all for exploring Mars, but this isn’t the rationale for it.”