Welcome to my blog post on my astronomy wonder project! My question is “What would happen if the sun suddenly disappeared? If given time to prepare could we survive?” Throughout this project, I broke down my question into a few different ideas as we cannot fully answer this question because it isn’t really possible so a good portion of it is hypothetical. I looked at “What would happen to the earth if the sun disappeared?“, “Could we survive the freeze and if so how?” and “Could we preserve plant life?” I hope you enjoy!
So the first big thing we need to figure out is whether or not the earth itself could survive without the sun. The sun, being a huge object with a huge gravitational pull disappearing would be very problematic. We would be sent flying through space at whatever direction we were currently moving and wouldn’t ever stop unless we collided with another big object. The biggest problem right off the bat would be whether or not we pull or get pulled to another planet in our solar system. If that were to happen we would basically be doomed, but if not we probably wouldn’t have to worry about that for thousands of years. But lets say we get over that first hurdle, what would it look like from earth, everything on earth would suddenly go dark and we wouldn’t be able to see a thing but luckily (or unluckily) our planet retains heat pretty well so we wouldn’t die instantly. After about a few days the temperature would drop to around 100 degrees below zero and after a few weeks it would drop to about a few degrees above absolute zero and by that point, anything above ground is basically doomed. Even if we were to find a way to survive on the surface, the atmosphere would freeze and fall to earth which would cause us to be completely exposed to the radiation in space. Evidently, it all looks pretty grim, in our current state we would be completely wiped out by the end of the week, the only organisms with a chance at survival would be the microorganisms living deep below the surface of the earth thanks to the heat of earths core.
So it is pretty obvious that without any kind of preparation we would be wiped out pretty fast. So let’s say that we knew for a fact that at some point in the next 100 years the sun was going to vanish from existence, (which isn’t possible) could we survive? As for the heat, if we were to build some kind of underground sci-fi dome with geothermal heating and nuclear fusion cores for both heating and electricity we could likely at least survive the freeze for at least a couple hundred years which probably would be enough time to figure out ways to elongate our survival.
Now that we know that we could avoid freezing to death, we need to consider how we would live in our domes. A big problem for us would be the loss of plant life. Without plants, we lose the base of all ecosystems on earth, and equally important, the loss of oxygen. Therefore, we would need to figure out whether or not we could grow plants without the sun and whether or not we can even contain them. Luckily, we do have some experience with bio domes, although they still use the sun. Biosphere 2, a bio dome located in Arizona was used for an experiment in which a group of people were tasked with living inside the facility, completely isolated from the outside world. There was no exchange of atmosphere (except sunlight) or water with the outside world. The experiment was largely a failure. The dome wasn’t efficient enough to compensate for the amount of oxygen needed. Many pollinating insects died due to the amount of CO2 and the filtration systems became clogged and condensation from the plants made everything really humid. Oxygen levels in the facility dropped over time and after 16 months the oxygen levels dropped to the equivalent of an altitude of 13,400 feet above sea level. However, even though that experiment was a failure, we learned a lot from it. Later studies found that the reason for the lack of oxygen was mostly because of the soil used. The group running the experiment used rich soil to give their crops a good chance of survival but turns out, rich soil is full of oxygen consuming microbes which largely caused the problem. After looking over the experiment, scientists have determined that with careful refining they will be able to make this idea work sometime in the near future. As for the filtration, NASA has put a priority on Bio filtration systems that use plants, fungi and microorganisms to keep the water and air in closed ecosystems clean. Although as of right now the technology is not ready for space and therefore, life on an earth without the sun but will likely be ready sometime in the future.
But one big problem still remains, without the sun plants cannot photosynthesize, or can they? Thanks to testing within the ISS, we have learnt that plants are much more resourceful then we thought. For example, scientists have always assumed that the roots of plants always grow downwards thanks to earths gravity. But we have learnt that this is not the case. Plants are still able to grow their roots in lower gravity which may not be super important for our scenario, but it shows that plants are adaptive enough to survive within different conditions. Luckily, we are already able to use UV lights as a replacement for the sun, therefore the growth of plants for food on an earth with no sun could work.
Although we may be able to grow food without the sun, a large scale bio dome would need a lot of food and a lot of oxygen. Fortunately, scientists have found a way to make the photosynthesizing process a lot more efficient. Currently, the problem with photosynthesis is that in its current state it only uses about 1% of the sunlight the plants receive. The reason for this is that plants use an enzyme called RuBisCo to grow. RuBisCo first emerged about 3.5 billion years ago when the atmosphere didn’t have as much oxygen floating around, so now it has some trouble differentiating between CO2 and oxygen molecules. Scientists are now experimenting with the RuBisCo enzyme to make it so that plants can differentiate between the molecules better in order to grow and expel oxygen better. We have already managed to make this idea work with simple plants like tobacco, we could also make this work with food crops like wheat, soy etc. and by extension maybe even trees. Scientists have also figured out how to disable/lower a plants “sun shield” that would normally stop the plant from overloading on sunlight but luckily that wouldn’t be an issue with artificial sunlight. This all means that in the near future, we may be able to make more efficient plants (and trees) that could photosynthesize better under artificial sunlight and therefore, produce more food and oxygen.
So given all of this information, it is safe to say that if the sun disappeared in the next few years we would be doomed. However most of the problems that we would face in our hypothetical scenario could be dealt with given a decade or two. Now you may be wondering, “Given that the idea of the sun disappearing is impossible, why is this information important?” The truth is that even though that may be true, we can use this information to help future astronauts colonize different planets. Not all planets have just the right amount of everything like our earth, but we may be able to use these different technologies to widen our candidates for colonization.
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