Hi I’m Evan from Chicago IL. I’m studying HOD & Econ and am very eager to learn more about the solar system in this class. Here is a picture of me and my brother in Paris because I like to travel, and a hyperlink to vandy’s website because I love my school.
Hi guys! This is my intro post for my blog, “Reigen’s Guide to the Galaxy.” My name is Brian though, not Reigen. I’m a junior majoring in Mechanical Engineering, and I’m looking forward to blogging about space. Here’s a picture of me writing this blog post. And here’s a link to some coolmathgames.
If you’re in my 2021 Solar System class, please put a comment here showing that you’ve found my blog and that you’re following it :) Please include your first name and last name initial. Note that you MUST be logged in to your own WordPress blog when commenting or else you’re doing it wrong!
Also make sure you have bookmarked the big class blog aggregator: Astro2110 – The Solar System. From there, you can follow everyone or specific classmates if you like (when I post them).
Jupiter is the largest planet in our solar system. In my opinion it is also one of the most interesting. One of the interesting features on Jupiter is its Great Red Spot. The Great Red Spot is a churning, red hurricane that is twice the size of Earth. It was first discovered in 1831, so the storm has existed for at least 150 years if not longer. The storm is located in the southern hemisphere of the planet and has wind speeds that can reach up to 270-425 mph. The long li fog this storm can be attributed to the non-solid nature of Jupiter’s surface. Unfortunately, it seems as if the storm is shrinking. The Great Red Spot is currently a third of the size it was in the 1800s. Some think the storm shrinks and then grows again. Others are saying that the storm may one day shrink to the point that it disappears.
Where are the aliens? This is the question the Fermi paradox attempts to answers. The paradox revolves around the lack of confirmed evidence of extraterrestrial life and the high calculated probability that life beyond Earth exists. The Fermi paradox is named after physicist Enrico Fermi. The argument raised by Fermi was formalized by Michael Hart. The basic parts of the argument are the the aliens choose to never come to Earth, advanced civilizations have risen too recently for the aliens to have reached us, aliens have visited before but we did not observe them, and that aliens do not come because of a physical obstacle.
After traveling 94 million miles into deep space, the journey of NASA’s Kepler space telescope was finally completed in October of 2018. Operational since 2009, the telescope was able to detect a total of 2,681 exoplanets before running out of fuel. The archival data retrieved by Kepler will have immense value as it is continued to be analyzed by astronomers. Notably, this data has led to an astonishing discovery just this week.
Astronomers have identified an exoplanet 300 light-years away that has various promising Earth-like qualities. The planet is named Kepler-1649c. As we learned in class, both size and distance from a star impacts the habitability of any planet. Earth is the correct size and distance from the Sun to support liquid water and life. Kepler-1649c is only 1.06 times the size of Earth and receives 75% of the light compared to what Earth gets from the Sun. It orbits a red dwarf star which is much smaller and cooler than our star and therefore, must orbit much closer than we do to the Sun. A complete orbit of Kepler-1649c only takes about 19.5 Earth days.
There are still many things we do not know about this potentially habitable Earth-like planet. Due to barriers inherent to exoplanet detection methods, we do not know the composition of the atmosphere. This could impact the assumed temperature of the planet’s surface and reduce its ability to sustain life.
Further, the information gathered by the Kepler telescope is not absolute. Kepler-1649c was initially written off as a false positive by a computer program. It is only now that scientists have recombed through some of the data to discover this planet. Additionally, scientists suspect that there is another candidate planet in the same solar system. By analyzing orbital resonances, it is theorized that there might be a slightly closer planet that is also in the habitable zone of the star.
To conclude, missions like Kepler and TESS (Transiting Exoplanet Survey Satellite) provide vital data that can be analyzed to discover promising planets even after they have stopped transmitting. Thomas Zurbuchen, associate administrator at NASA’s Science Mission Directorate says that Kepler-1649c “gives us even greater hope that a second Earth lies among the stars, waiting to be found.”
Humans often wonder if we are the only ones out here. This seems a reasonable thing to ponder considering the numerous number of stars and planets in our galaxy and in the entire universe. Our natural interest in outer civilization similar to that of humankind is part of the reason why topics such as aliens and UFO sightings easily grab the attention of the public. For example, in September 2019, people tried to raid the military base known as Area 51 in hopes of finding secretly kept aliens. Although this event was done as a joke, it clearly shows the public’s interest in extraterrestrial civilization.
In the search for extraterrestrial intelligence (known as SETI), an astronomer named Frank Drake formed an equation to estimate the number of civilizations in the Milky Way Galaxy. The simplified version of this equation is shown below.
N_HP is the number of planets in the galaxy that could potentially have life, f_life is the fraction of these planets that actually contain life, f_civ is the fraction of planets that contain life that have civilizations that were capable of interstellar communication at some point in time, f_now is the fraction of such planets that have a civilization in the present moment
This equation cannot be used to actually calculate tangible numbers, but we can use the fact that most civilizations fade away soon after reaching the intelligence level that allows them to make interstellar communication to reach a reasonable conclusion. This fact implies that f_now is extremely small (very close to zero), and allows us to conclude that we are really the only civilization that is intelligent AND active at the moment.
This conclusion, however, is just based on one simplified equation and not sophisticated enough accommodate for all other factors we know about extraterrestrial life. We may be missing something big because we haven’t reached a certain intelligence level yet, and it would be interesting to see how further advancements in technology affects the search for extraterrestrial intelligence.
The Fermi Paradox addresses the famous question: are we alone? Statistically, it’s extremely unlikely that Earth hosts the only life in the universe. Most of the universe is (by current knowledge) unreachable to humans. But let’s look at our own galaxy. Many estimates say there should be at least a hundred thousand civilizations in the Milky Way. If we move forward with the assumption that we are not the only life in our own galaxy — I personally don’t consider that a real possibility — that leaves two possibilities. One is that numerous civilizations do in fact exist, but none of them have spread across the galaxy yet. Each civilization is confined to their local planet, or even solar system. Another explanation is that a galactic civilization does exist, but they have not revealed themselves to us, whether it be because they aren’t aware of us or because they’ve decided not to.
Obviously, I don’t have the answer. But I do think it’s likely that one or the other is true. The diameter of the Milky Way has been estimated to be about 100,000 light years. If we are trying to detect another civilization, we’ll have to observe them somehow. There are two challenges here that could easily explain why we haven’t. First, whatever we observe is really the past. If we are looking at a solar system 50,000 light years away, we are seeing what that system looked like 50,000 years ago. So if a civilization there somehow developed spontaneously tomorrow, we wouldn’t see them for 50,000 years (unless they manage to travel closer to us). The second challenge is that we don’t really know what we’re looking for. We know what life looks like here on Earth. Well, we think we do — in reality, estimates are that we’ve discovered 10% of the species that exist in the ocean. But life elsewhere in the galaxy will almost certainly look different than what it does here; life will evolve under different conditions that those on Earth. All we really know to look for is something that seems out of the ordinary.
I do think a galactic civilization could reasonably exist. But can we reasonably expect them to see us? The industrial revolution is a relatively new thing in the history of life on Earth. Any signs “they” might be looking for, unless they have telescopes powerful enough to see the surface of Earth from a different solar system, will only have appeared within the last hundred or two years. These hypothetical outside observers would have to be incredibly close to our solar system to notice; an observer 300 light years away will see a pre-industrial revolution world. Unless they’ve detected one of our spacecraft (which, again, are within our solar system, so may be undetectable unless we have very close neighbors), they probably don’t know we’re here.
My personal opinion is that until we advance as a civilization to the point of interstellar travel, we will be functionally alone in the galaxy. If and when that happens, I believe we will discover other civilizations and they will discover us, but until then all we have is each other.
We all love hearing stories about aliens and extraterrestrials. But what if I told you that there is a probabilistic equation that is used by scientists to estimate the amount of active and communicative extraterrestrial civilizations there are in the Milky Way. It is called the Drake Equation and it was made by Frank Drake in 1961. In actuality, the Drake equation is not fact. It does not hold true because we do not know if extraterrestrials exist in the Milky Way. It is just an approximation and many of the values are subject to conjecture. Moreover, it was created to encourage scientific dialogue at a SETI meeting about the possibility of extraterrestrial intelligence, which is a subject that I personally think the scientific community needs to dedicate more time to. Drake has said that the meeting estimated that there are between 1,000 and 100,000,000 civilizations in the Milky Way galaxy. Moreover, if you plug in the minimum numbers the equation states there are a minimum 10, and if you plug in the maximum numbers the equation states there are a maximum of 100,000,000. This equation is not factual, but it definitely is a great place to start and something that propelled the scientific community to think more about extraterrestrial civilizations.
Sources: https://informationisbeautiful.net/visualizations/the-drake-equation/ and ch.24 of Bennett – The Cosmic Perspective
