Before I begin, I’m a bit of backyard astronomer (when I can actually see the night sky), I don’t have an academic career in physics or astronomy. But not all information need be learned in a professor’s presence. That said, if I’ve made any grand mistakes or misunderstanding of the observations below, you are encouraged to clarify for me. Except if you want covert me into a believer of organized religion. However, I’m certainly open to a discussion of spirituality. At any rate, this isn’t even a post about religion, spirituality, or philosophy. It’s science, which has room for the former.
I’m a bit of a space-nut. There’s something about feeling insignificantly small that comforts me. Astronomers estimate that there are 200-400 billion stars in the Milky Way Galaxy. The Milky Way is one of 100-200 billion galaxies in the Universe. Our Sun is just one star in one galaxy. So, it begs the question, one of the greatest unanswered question of mankind-
Are we alone?
I believe that is highly improbable that we are. When I say “we”, I mean that as in any form of life, not just intelligent life. I would hazard a guess that life is common in the Universe. Intelligent life- maybe not too common. Hell, sometimes I question the intelligence of members of our own species. (Woman wins $3M lawsuit against Ferrero- claims she thought Nutella was healthy).
It used to be widely believed that solar energy was a required condition for life. Then deep-sea exploration revealed thriving ecosystems completely devoid of sunlight. Based on what scientists now understand, to harbor life you need:
- the elements needed for metabolism and reproduction;
- an energy source;
- suitable environmental conditions; and
- the presence of liquid water.
Chemical elements found on Earth are found elsewhere in the Universe. The Universe is flooded with stars, some of which are supplying planets with energy. Some of these planets could even be Earth-like- the Kepler mission is on the search for Earth-sized planets in or near habitable zones right now. But what about water? For that, we may need look no further than our own Solar System.
Images from the Mars Reconnaissance Orbiter suggests that there is flowing water on the red planet. The spacecraft has been orbiting Mars since 2006, going through Mars’ seasons. In the warmer Martian seasons, it captured images of brown streaks on the landscape. In the colder months, the streaks were gone.
“The best explanation for these observations so far is the flow of briny water,” said Alfred McEwen (Nice name!!) of the University of Arizona, the principal investigator using the ship’s high-resolution camera system.
“We expect water on Mars to be briny, to be salty, because we know that the surface is salty from all of the past landers and rovers,” said McEwen. “Furthermore, the salt serves to depress the freezing point of the water, so in places where it’s below freezing, we see this activity, it is still plausible for that to be salty water.”
It’s believed that underneath the icy crust the Jovian moon Europa contains a layer of liquid water. That belief has spurred calls to send a probe there – the JUpiter ICy moon Explorer (JUICE), proposed to launch in 2022, and to reach Jupiter in 2030.
The Drake Equation
And that’s just in our Solar System. The Milky Way is so vast that I have a hard time believing any kind of life can only exist on Earth. If you believe a step further, that there is life with which we can communicate, there’s an equation to help you estimate the number of civilizations in the Milky Way Galaxy. It’s called the Drake equation. I’m not nearly smart enough to use it, but here it is anyway.
- N = the number of civilizations in the Milky Way with which we can communicate,
- R* = the average rate of star formation per year in our galaxy;
- fp = the fraction of those stars that have planets;
- ne = the average number of planets that can potentially support life per star that has planets;
- fℓ = the fraction of the above that actually go on to develop life at some point;
- fi = the fraction of the above that actually go on to develop intelligent life;
- fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space;
- L = the length of time for which such civilizations release detectable signals into space.
My head hurts.
Search for Extraterrestrial Intelligence
What if there is intelligent life out there? That’s a question probably most of us ask, and a question some seek to answer at the SETI (Search for Extraterrestrial Intelligence) Institute, among others. Messages have been signaled out to space, hoping to pique the interest of some S-M-R-T aliens out there. No one has answered the call. 🙁
IMO, that’s a good thing! If an alien civilization were advanced enough to travel lightyears away from their planet to Earth, then they for sure are advanced enough to, pardon my French, fuck shit up here, right? So be afraid. Be very afraid.
Are we an untouched planet?
I have a rather whimsical fantasy that Earth is an untouched planet, like those uncontacted tribes in South America. What if advanced alien civilizations did know about us and our Solar System but purposely kept their distance because making contact would be devastating to us Earthlings? I daydream that they use signals we don’t use, which is why we can’t find them, kind of like the loneliest whale in the world.
It’s a thought! Could make for a good sci-fi movie. 😉