Carl Sagan was right about us being cosmic dust

Contributed by
Jan 27, 2018

You know how Carl Sagan said we’re made of space dust on Cosmos? He wasn’t just dreamily stargazing.


Sagan meant it literally when he said, “The cosmos is within us. We’re made of star stuff.” Cosmic dust doesn’t just float around in microgravity, but gets blown everywhere in space, and now has illuminated a new study in the journal Astrobiology that supports the idea of us and all the other life-forms on Earth being made out of star stuff.

“Floating in the Earth’s atmosphere are a variety of particles containing the telltale signs of Earth’s organic story, including microbial life and life essential molecules,” the study says. Just take a moment to process that.

Hypervelocity space dust bombards our planet every day. It swirls in the atmosphere, constantly transferring energy, disrupting and even altering light particles and molecules with at least some of the components of life. Gravitational escape is the vice versa to that. Atoms and molecules hanging out above Earth’s stratosphere are not subject to the drag and heating that get in the way at lower elevations and can blast out into space if moving at escape velocity, or the lowest velocity that makes it possible to evade gravity. Any larger particles that may contain microorganisms or at least fingerprints of our planet’s biology usually require a one-two punch to accelerate to escape velocity. Some force has to kick them into the upper atmosphere before space dust particles collide with them and send them flying into the unknown.



So what does all this really mean for us and any hypothetical alien life out there?


With so much space dust whirling in, our planet could suddenly be colonized by micro-aliens, or microbial Earthlings could be crawling on some other planet light-years away—in theory. The reality is much more complex. Space dust doesn’t exactly offer luxury travel accommodations. Think killer radiation, temperatures far below freezing, and exposure to the vacuum of space. Tardigrades and some other nearly indestructible microoganisms can survive these extremes. They can hide out in grains of rock as they travel to other worlds via cosmic dust storm.


"It has been shown in previous studies that bacteria can endure such stress," Queenie Chan, who led another study that unearthed hydrocarbons and amino acids in meteorites that had crashed to Earth, told "But they have to be protected within volatile-rich bodies, or rocks of a few centimeters which can offer a shielding effect."


This is kind of a big deal because it’s the first time scientists have ever found abundant extraterrestrial organic matter associated with liquid water, which could reveal where and how these compounds emerged from space and even the origins of life. The salt crystals in the meteorites Chan and her team found can be a haven for many organic compounds when an asteroid still has plenty of water ice. The scientists revealed carbon and amino acids through a method called—wait for it—ultra-performance liquid chromatography fluorescence detection and quadrupole time-of-flight hybrid mass spectrometry.


Findings like this can lead us to the origin of the meteorites, which likely escaped from somewhere around Jupiter, whose moon Europa may be hiding more organic compounds in its icy crust and subterranean oceans.


Could everything in our cells have originated from distant galaxies? No one knows for sure yet, but we do know Carl Sagan continues to blow minds.



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