Fantastic Four #18, by writer Ryan North and artist Carlos Gómez, features the heroic quartet taking on a group of asteroids. As they zip through an array of far-fetched, super-powered methods of channeling away the explosive energy falling to earth, diverting them, and getting an assist (and then an anti-assist) from their son Franklin, the family demonstrates some of the challenges that various asteroid mitigation strategists have considered over the years.
For instance, forming a force field around the blast zone and then fanning the explosion away — probably not a viable technique. Nor is getting a super stretchy guy to form himself into a dome and bounce the asteroids back into space (though it is darkly funny to see Mr. Fantastic turned into Swiss cheese).
Marvel Comics
Deflecting them onto another trajectory is the best option, if you can manage to do it, and most plans for preventing planetary destruction focus on that method. The earlier an Earth-bound asteroid is detected, the less momentum’s required to divert it, so the first step is developing tools that scan the solar system for potentially dangerous objects. If astronomers determine a rocky body is on its way, there are a few ways it could possibly be diverted.
Setting off nuclear warheads could nudge it, but that also risks breaking the object up. Landing a rocket on it that would push it onto a different path could work as well. There are even suggestions along the lines of landing mirrors on the Sun-facing side of the asteroid and letting solar radiation do the pushing. The best approach might vary depending on how much time we have before impact, and what sort of object was heading our way.
In Fantastic Four #18 though, astronomers had no chance at early detection because the asteroids were, somehow, invisible. They don’t understand how or why, and it doesn’t comport with our understanding of planetary science that heavy, massive objects in the solar system could be transparent, but surprisingly, it isn’t that far afield of some problems that astrophysicists face. Namely, dark matter — a substance of unknown provenance that affects luminous matter through gravity, but doesn’t leave visible traces.
Our best guesses about dark matter’s nature have coalesced around evidence that it’s made up of diffuse, non-interactive, massive particles. The fact that it doesn’t emit or reflect light means that it can’t form electromagnetic bonds, like those that hold “normal” matter together. So our belief is that dark matter consists of one or more hitherto unknown particles, mostly inhabiting the outer halos of galaxies. (This is typically the point when someone wonders something along the lines of “maybe gravity works differently than we thought,” or “what if it’s black holes,” or any number of a dozen other options, and please allow me to assure you: whatever idea you’ve had, we’ve thought of it already.)
Although, this wasn’t always our best guess. After evidence began mounting that matter was missing in the 1970’s, astrophysicists proposed a variety of possible explanations, including the idea that it was hiding as dark but conventional objects. The term MACHOs (“MAssive Compact Halo Objects”) was coined to describe dense things (like planets, black holes, dim red/brown dwarfs) floating through space outside of planetary systems.
Fortunately, despite being “invisible,” there are ways you can measure the occurrence of these sorts of things. To account for the missing matter in the galaxy, there would need to be enough MACHOs that they’d sometimes pass in front of stars, from our point of view. So if you pick a handful of stars, and constantly monitor their luminosity, you should notice the brightness change occasionally, when a MACHO passes in front of it.
These objects won’t block the light of the background star — in fact, they’d momentarily increase it, behaving as a gravitational magnifying glass. This is known as “microlensing,” and multiple studies have been performed, extrapolating the number of possible MACHOS by monitoring a set of stars for sharp increases in brightness. What have they found? There are none.
Marvel Comics
Well, not none. There are a few, but not enough to explain the missing dark matter. There are some dark objects in the galaxy, likely very dim dwarf stars and stellar remnants, but there would have to be several times more of them to explain the gravitational effects of dark matter that we observe in other ways.
The invisible asteroids in Fantastic Four would be too small to cause observable microlensing. The rocks that turned Mr. Fantastic into Swiss cheese could have been our missing dark matter if there were enough of them, but there would have to be a lot. And they would have to be very invisible. And we wouldn’t have any future-seeing Marvel characters to let us know they were coming.
AIPT Science is co-presented by AIPT and the New York City Skeptics.
You must be logged in to post a comment.