Skip navigation

So now arises the question that most people that let their minds float off into the infinite folds of the blanket of possibility often find themselves confronting: is there extraterrestrial life in the universe?

 

In finding myself wondering this same question and pondering different possibilities as well, I became quite interested when I recently came across a poster on campus here at UND that was in fact titled “Life in the Universe.” The poster was for a lecture by Dr. Lawrence Rudnick from the University of Minnesota. The title of the lecture and the buitiful cluster of solar systems picture behind it were easily enough to provoke me to come. The lecture was very interesting and pointed out a lot of different things I think should be mentioned. The rest of this post will consist of different ideas, facts, and methods about space exploration and potential life in the universe.

What are the requirements for life? In other words, what do scientists and astronomers look for on other planets in order for them to conclude that there could be life there whether it is microbial life or intelligent life.

 

-The obvious necessity for life, as we know it, is water. Many planets that we know of actually have water on them. As far as we know however, life forms must have water in the liquid form or be able to change the water to liquid form in order to use it in natural processes. Our bodies at birth are made up of about 78% water and his water needs to be in liquid form, obviously, otherwise many of our essential life processes would not work and we would not receive the proper nutrients to all of our body parts. So, this is why astronomers and scientists team up and search for life on potential life-bearing planets.

 

– It should also be noted that astronomers have found many planets and even moons with water on them, including Mars and Jupiter’s moon, Europa. However Europa is nearly a solid sheet of ice on the surface. The interesting thing is that scientists speculate that there is a vast ocean of liquid water underneath this surface due to the constant tug and pull of this moon orbiting around Jupiter. This strain causes the underlayer of the surface to be liquid while the outer layer is ice since that atmoshphere of the planet provids very cold temperatures. Possible exploration of this moon in the future is very possible and scientists are eager to determine what this vast ocean contains. Also, Mars at one point in time did have liquid water on it but over time it has lost its atmosphere and now there only exists on polar cap of ice on Mars. This spot can be seen as a large white circle on the end of top of the planet surrounding by a sea of red.

 

-Another requirement scientists consider for life to be possible is the distance of a planet to that planet’s sun. This distance needs to be close to 1 AU. An AU (astronomical unit) is a unit of measurement used in situations where the mile it too small and the light-year is too large. It is set as the distance from Earth to our sun. I do not know exactly how leniant this distance is in order for scientists to consider life but it should be near 1 AU. This distance is crucial because a given temperature range and amount of light and heat is believed to be need to sustain life. This AU distance is believed to be that distance. This makes sense because if a planet is too close to the sun, temperatures may be too hot and not only will the life forms burn but the liquid water will also turn to gaseous water. If the planet is too far the opposite is obvious.

 

-Along with temperature, the nature of the planet’s atmosphere is also considered. However, it is easiest for scientists and astronomers to assess all of the now possible 494 planets that we have discovered as of 2 weeks ago as having potential to sustain life or not by deciding if they have liquid water present on them, but more so how close they are to the sun. Even a very distant solar system can be sized up easily by this criteria with a good telescope. However another criteria that scientists keep in mind is the size of the planet, because a planet needs to be of a certain size unless it possesses other unique properties, to be able to create a large enough amount of pressure (near 1 atmoshpere) on its surface. 1 atmoshpere is the amount of pressure of the earth’s atmosphere on a particle at sea level on the earth. This value is necessary so that the planet can actually keep its atmosphere. As stated before this is what occurred on Mars. The planet is too small and it lost its atmosphere, by that its liquid water, and then by that its ability to carry life. Not only pressure of the atmosphere are necessary to know but other facts as well such as amount of elements, relative temperature ranges, how acidic or basic the atmosphere is (For instance acid rain on earth is a large contributor to weakening trees and plants to death. it also has a negative effect on fish and other aquatic life forms as well.). Earth is a very “mild” planet. This means that for instance on a scale of 0 to 100 where 0 is zeroand 100 maximum, the average temperature, atmospheric pressure, amount of oxygen relative to other gaseous elements, acidic/basic compounds, and on and on of all other properties of the earth would be at a value of about 50 +- (plus or minus) 10 for different catergories, relative to all the other planets we know of so far.

 

So with all of these criterion, and the technology we have today for finding other planets, what is the likelihood that we will soon find a planet with the possibility of sustaining life? Who knows? However, at the exponential rate that we are making new astronomical discoveries, I would speculate that the day we find this planet is coming soon. And by soon I mean within the next decade. How cool is that?

 

Note: Dr. Rudnick said that when he was first starting to teach I believe in 1987 or so, there was one other confirmed planet outside of our solar system. He also said that soon after that, that one planet was decided to actually not be a planet and that it was a mistake. So in about 30 years or so, technology has provided us with the ability to discover nearly 500 neighboring planets outside of our own solar system! And most of these planets have not even been searched for the criterion listed above necessary to posses life!

 

Fun fact: Another fun note Dr. Rudnick touched upon was that human beings have accurately teleported tiny particles, tiny as in atoms. And by teleporter I mean yes, the thing you saw on Star Trek and various other Sci-Fi futuristic films where a person gets “beamed” onto a space ship from across the galaxy nearly instantly. However, Dr. Rudnick also stated that as far as we know, teleportation is not possible with humans because we simply do not know how to reassemble the atoms of the thing being teleported. That is why it has only been done on an atomic level!

Advertisements

Naturally in answering this question one would need to first find a planet that has an atmosphere and conditions sufficient enough to sustain our existence. Simply put we need a high concentration of oxygen in the air, a smaller amount of atmospheric pressure but greater than the moon’s, sunlight, reasonable temperature ranges (-80 F to 110F which kind of particular by the way. For instance, Mar’s temperature ranges from a high of about 32 F to a low of about -200 F!), and of course water. Those things are a given. What I would like to point out here is the possibility of mankind even reaching such a planet, and about how many planets there are in our universe as we know it.


Now put these two things into perspective:


-it would take 23 years 105 days to reach the furthermost planet of our solar system, Pluto. Even yet, it is 4.3 light-years to the nearest solar system to us, Proxima Centauri, within our Milky Way galaxy. Now this is not 4.3 years but rather 4.3 years for one particle of light to go from the Earth to this solar system (the speed of light is 670,616,629 mph!) Also, remember that a light-year is the distance a particle of light travels in one Earth year (it is necessary to specify Earth year because every planet completes one full revolution, that is the time it takes to revolve around the sun, at different times and different days and thus each planet would have its own year. For example Jupiter’s year is 11.86 Earth years and Mercury’s is 88 Earth days). But all this means that if a man left the Earth and wanted to fly to the Proxima Centauri solar system, it would take him 4.3 years to just get there if he traveled at the speed of light. Unfortunately we don’t even have the technology to do that and even if we did, according to Einstein’s equation E=mc^2 where c is the speed of light, anyone who travels at or beyond the speed of light will turn into some pure form of energy! But I won’t delve into that matter. So back to being on-track, the fastest speed any type of craft made by mankind has traveled in space so far is only 47,000 mph. At that rate it would take a person 60,691.6 years to get to the nearest solar system, Proxima Centauri!!


-for this next batch of numbers I think it is necessary to give you a little bit of general information juuust in case you don’t know but I’m sure you’re all as interested as I am in space and therefore you’ll laugh at me when I say this: there is a chain of “boundaries,” or subgroups so to speak, of the bodies existing in our universe and this is it: moons/orbiting material around planets<planets<the solar system (with the star, like our sun, at the center)<galaxy<universe. This means that the body on the left-hand side of the less than or equal to sign lies within the body on the right-hand side of this sign. (Note: is is very possible to have galaxies within a galaxy). Now onto the goods, it has been estimated that there are approximately 125 Billion galaxies in our universe as we know it. There are roughly 100 billion stars in our galaxy, the Milky Way. Assuming each of those stars is the center of about 9 orbiting planets like our solar system and also assuming that each of the 125 billion galaxies in our universe are exactly like our galaxy, there would be approximately 1.125X10^18 planets in our universe (keep in mind my example of how many blades of grass there were, roughly, on the Earth)! Of course all the galaxies are not like ours and all of the solar systems do not consist of 9 planets, some may have more or less or none at all but the general idea is present. There are so many other planets out there or possible hospitable places that it’s scary.


Not only this, but most planets have moons that orbit around them. Granted these moons are generally not enormous like Jupiter, but they do certainly have the potential to possess a friendly atmosphere for several millions of people. If each of these planets or bodies in space had lets say even an average of two moons, think of how many more potential bodies in space there are to support life for us or perhaps other organisms!


So, what are the possibilities? Actually, I would think a better question would be what aren’t the possibilities? Is there somewhere in the universe that may be habitable by human beings? Could we ever possess the technology to even get there? Also, is it possible that there may be other life forms out there if there are approximately 1.125X10^18 other “planets” in the universe plus their moons? How could anyone ever say absolutely not with 100% certainty?  Let’s be serious here, the possibilities are limitless…


Does this put you in the mood to watch Armageddon or some crazy Sci-Fi movie? Or perhaps it may hurt your brain, if so, my apologies!

(Note: some of these numbers were pulled form websites such as wikipedia and their validity is up to the viewers discretion although many would argue wikipedia is quite accurate.)

Ok so I am sure you have been told or even lectured that space is gargantuan, actually, I think that it’s so big that there should be a new word made up for it just to describe how big it is. I guess I’ll take my own challenge and call it “spacratic”; so the universe is spacratic. But for more meaningful purposes I am writing this entry for those people that would enjoy the wholesomeness and comfort of numbers and statistics better than words to better illustrate this beautiful yet exotic realm of limitless possibilities we call space…

 

Put these two things into perspective:

 

-the nearest galaxy to Earth, Andromeda, is 2.5 million light-years away and keep in mind           one light year is 5.87 trillion miles (thats 235,728 times the earth’s circumference, not diameter).

-the universe is estimated to be 156 Billion light-years wide (since the earth’s diameter is 7,926 miles which is 1.35X10^-9 light-years, that would be 1.157X10^20 Earths placed one after the other from one end of the spacratic universe to the other!). Just to compare there are roughly, only 1X10^13 blades of grass on the whole Earth (If you think that’s half the number of Earth’s sorry but you’re wrong; half the number of Earths would still be 5.785X10^19 Earth’s!!)! Keep in mind this is merely across the universe. Now consider the universe being three dimensional and basically a sphere of the previous number as its diameter. Yes, do the calculation and you will find the volume of the universe to be simply “spacratic.” Try 8.10X10^59 Earths!!!

 

Does this make you wonder how much potential the universe has for things? Things like exploration, potential new home planets, perhaps even other life? I know it does for me. Perhaps these numbers simply don’t mean anything to you because they are incomprehensible. If so, I would encourage you to stay tuned for more interesting facts but more representations of those numbers that may be more meaningful in terms of things that we can wrap our minds around.

 

One more fun fact: 1.125X10^18, the number of planets approximately in our universe, is 1.125 exa planets. A common amount of a lot storage space now in computers is 1 terabyte. 1 exabyte is 1 million times bigger than a terabyte! Imagine that kind of storage space. That’s 9.536X10^11 movies!!)

 

(Note: some of these numbers were pulled form websites such as wikipedia and their validity is up to the viewers discretion although many would argue wikipedia is quite accurate.)