I’ve always been passionate about space, in wavering degrees. When I was little, I had posters in my bedroom of Saturn’s moons and watched a lot of Star Trek with my grandmother. As I got older, other interests took precedence and my penchant for planetary studies was surely put on the back burner, where it would stay for a while.
Then, Voyager 1 crossed into interstellar space. All of a sudden, my love of space was reborn, quickly shooting back into the forefront of my intellectual pursuits like a quasar. Couple that with the airing of Cosmos: A Space-Time Odyssey on FOX and now I am soaking up information about space like a sponge.
That being said, let’s head to Mars for our topic of the day.
Earlier in the year, this guy — Curiosity — was just hanging out at Gale Crater. It made a startling discovery. Gale Crater contained an ancient freshwater lake that could have been hospitable for microbial life. This information rocked the scientific community, since they’ve already learned that nutrients exist on the planet and that, at one time, Mars had a magnetic field that protected the planet from cosmic and Solar radiation. While this information doesn’t conclusively prove that life ever existed on Mars, it makes a very strong case that, at least, microbial life had a solid chance.
That being said, I believe there is life on other planets.
When we look at the known universe, there are billions and billions of planets circling billions and billions of stars. That means there are billions and billions of galaxies. Keep in mind that the phrase ‘the known universe’ means only the parts of it we have discovered. That means there are portions of the universe we have not been able to observe yet because the light generated by those stars have not made to Earth.
Our planet is situated in our solar system, which itself is closer to outer edge of our galaxy than it is to the supermassive black hole at the center. Our star, the Sun, is host to eight planets that revolve around it, harmoniously influenced by the Sun’s gravity. Our planet is third from the Sun, in a region known as a “Goldilocks zone”, named after the literary character. A Goldilocks zone is a region of star system where liquid water could form. It’s not too close, thus not too hot, and not too far, thus not too cold.
Mars is also within our Sun’s Goldilocks zone.
The principle is simple — conditions have to be perfect for life to exist, even in our own micro-scale existence. Certain conditions have to be met for women to become pregnant, for certain plants to thrive, and other biological reactions on our planet. Life is systematic. Furthermore, we know that biological life needs water — or some equivalency, under certain conditions, but we’ll get to that later — in order to sustain itself. Think about what happens to water when it’s heated. It turns into a gas. When water is chilled, it turns into ice. So, for water to retain it’s liquid consistency, conditions have to be “just right.”
Now, we know that our star is just one of billions that exist in the Milky Way. We know that the vast majority of those stars have planetary bodies orbiting them. Around each of those stars is another Goldilocks zone, and if a planetary body exists within that zone, with a magnetic field, and liquid water, then conditions are right for microbial life to begin.
Now, let’s put it on an intergalactic scale. Each galaxy that exists — which there are over one-hundred billion — contains more stars and more planets. For the sake of simplicity, let’s say every galaxy outside of ours contains ten billion stars (which is probably a low estimate). Using simple multiplication, we can extrapolate that there are, at least, a sextillion (1,000,000,000,000,000,000,000) Goldilocks zones in the observable universe. At least, within this example. The number could actually be higher, for all we know.
At one time, we liked to think of life as a crap-shoot, that the chance of these perfect conditions forming were mathematically near-impossible. But, that’s not necessarily the case anymore. Through extensive research and testing, we have discovered that the only factors needed to give life a chance at forming is a safe distance from a star and liquid water. This is, essentially, the “primordial soup.”