Hello, friends! I’ve been going through some stuff recently, which limits my time for writing. But since writing is so important to me, I’ve been making time to write these short and simple blog posts on my #1 favorite facts about each planet of the Solar System. Today, it’s time for my #1 favorite fact about Saturn.
This may surprise you, but my favorite fact about Saturn has nothing to do with Saturn’s rings. It has to do with Saturn’s moons. When astrobiologists (scientists who search for and study potential signs of alien life) talk about the Solar System, not one but two Saturnian moons get mentioned over and over again. Their names are Enceladus and Titan.
Let’s talk about Titan first. Titan is covered with this weird sludge of organic chemicals. It’s important to note that in chemistry, the word organic does not necessarily have anything to do with organisms. Organic simply means carbon-based. However, when you find a world like Titan that’s just drenched in this organic chemical sludge, one can’t help but wonder….
Meanwhile, Enceladus has an ocean of liquid water hidden beneath its surface. What’s happening in that subsurface ocean? Are the conditions right for life down there? We don’t know. However, rather conveniently, there are cryovolcanoes clustered around Enceladus’s south pole. These cryovolcanoes spew water, salt, and traces of organic chemicals up from the ocean and out into space. Again, the presence of organic chemicals does not necessarily mean organisms are also present. And yet, given everything we know about Enceladus so far, one can’t help but wonder….
The search for alien life is hard, in large part because we’re not 100% sure what we’re looking for. Alien life could be wildly different from any sort of life we know here on Earth. Still, we know enough to have strong suspicions about both Titan and Enceladus, which means that exploring Saturn is a rare two-for-one deal in our ongoing search for alien life.
Thank you, friends, for reading. Next time, I’ll share my #1 favorite fact about the planet Uranus.
Today, I’d like to tell you a little about my 6th grade science teacher. Oh, I remember him well! Just not for the best of reasons. For the purposes of this blog post, let’s call him Mr. M.
So one day, Mr. M. was teaching us about the formation of the Solar System, about how the planets of our Solar System were created from a cloud of dust and gas swirling round and round the Sun. During this lesson, Mr. M. told us that our Solar System is unique. He told us that science had not yet discovered any other planets orbiting any other stars, and he hazarded to guess that science never would. He said that maybe there are no other planets out there for science to find.
Imagine that! In the whole big, wide universe, there are only nine planets (Pluto was still considered a planet at the time). And furthermore, the only nine planets in the entire universe all happen to be orbiting the same star! That sounds pretty silly today, with over 6100 confirmed exoplanet discoveries now in the books. It was also a silly thing to say at the time. This would have been in 1996. The first two exoplanets were discovered in 1992, orbiting a pulsar. A third exoplanet was discovered in 1994, orbiting that same pulsar. And then 51 Pegasi b, the first exoplanet discovered orbiting a sun-like star, was discovered in October of 1995.
So not only would science prove Mr. M. wrong—it already had.
I think about Mr. M. whenever someone tells me we’ll never discover alien life. I think about Mr. M. whenever someone tells me that maybe there’s no alien life out there for us to find.
Frankly, I think about Mr. M. every time someone claims science will never do this or never explain that. I may not have learned much in my 6th grade science class, but that class did help me learn one thing: there’s a long history of science proving people like Mr. M. wrong.
P.S.: Mr. M. also told us the Internet was just a fad and everyone would forget about it in a few years. Again, this was in 1996.
The art in today’s post is my own original work. If you like my art, please consider visiting the I-Love-Space store on RedBubble. Even if you don’t buy anything, just visiting and clicking the “like” button on some of my work helps me a lot (and if you do decide to buy something, that obviously helps me even more!). Thank you!
Right now, there’s an interstellar object passing through our Solar System. Astronomers have named this object 3I/ATLAS, and in my last post I explained how 3I/ATLAS is just a comet and NOT an alien spacecraft. But let’s pretend for a moment that an alien spaceship were traveling through the Solar System, perhaps on some sort of survey mission. What would the aliens see when they turn their scientific instruments toward Earth? How much would they learn about us and our planet?
Much depends on how technologically advanced we imagine these aliens to be, of course, but we humans have been observing Earth from space for decades now. We know some things are pretty obvious about our planet, even when viewed from a great distance away. For a start, the aliens would notice that Earth has an abnormally large moon. They’d also notice that Earth has oceans. The glint of sunlight reflecting off water would give that away. And then there’s oxygen. The spectrographic fingerprints of oxygen are all over Earth’s atmosphere.
Do these aliens breathe oxygen like we do? Maybe, maybe not. Either way, Earth’s oxygen-rich atmosphere would make the aliens stop and think, “Huh, that’s weird.” Most planets don’t have atmospheres like that. Even weirder, though, the aliens would also detect traces of methane in our atmosphere. Methane is an easily oxidized chemical, so you’d think all that oxygen would oxidize any atmospheric methane out of existence pretty quick. Something must keep replenishing the methane as quickly as oxygen destroys it. Something alive, perhaps? It’s hard to guess if the aliens would reach that conclusion yet.
As the aliens draw nearer, they’d soon notice this odd green stuff covering much of Earth’s landmasses. To say that in a more technobabbly way, the extraterrestrials would detect a chemical substance with a strong reflection spectrum in green light (and an even stronger reflection spectrum in infrared). You and I know what all that green stuff is, but would the aliens figure it out? Do they have plants back home? Do their plants contain chlorophyll and perform photosynthesis like ours do? Hard to say, but Earth’s green stuff would at least make the aliens think, “Huh, that’s also weird.”
A few more things our hypothetical aliens would notice: a substantial ozone layer, continents shaped by recent (or possibly ongoing) tectonic activity, a complex hydrological cycle with water existing as a solid, a liquid, and a gas… oh, and radio emissions. Lots and lots of narrow-band, amplitude modulated radio emissions, which cannot possibly be a natural phenomenon.
The idea that aliens many lightyears away are watching I Love Lucy, The Brady Bunch, or The Dick Van Dyke Show is probably false. As radio/television broadcasts propagate through space, those signals grow weaker and eventually blend into the background radiation. But for the purposes of this blog post, we’re imagining that an alien spaceship is right here in the Solar System with us. They’re close enough to pick up our broadcasts. At that point, the aliens wouldn’t just think, “Huh, weird.” They’d be forced to conclude not only that life exists on Earth but that intelligent life exists on Earth (unless they start watching our news or listening to our talk radio; if they do that, they might second guess the “intelligent” part).
How much more could the aliens learn about us? Again, it depends on how technologically advanced these aliens are. Consider the stuff I listed in this blog post to be the bare minimum of what they’d know.
WHAT TO LEARN MORE?
This blog post is based off several research papers, which are listed below. Detecting life on a planet—even a planet teeming with life, like Earth—is more of a challenge than you might realize. If that’s a topic you want to learn more about, please check out some of the papers below, especially the first one (the one written by Carl Sagan).
The art in today’s post is my own original work. I didn’t take it from the Internet or ask an A.I. to generate it. If you like my art, please consider visiting my store on RedBubble. Shopping on RedBubble is a great way to support artists (like me!) so that we can keep doing what we do. Thank you!
