Blog Blog 8: Culminating Blog!

Posted on April 29, 2024 by Jonas Kobza

Overall, this class has greatly improved my knowledge of space and the solar system.  I learned some useful (and fun) skills such as finding the north star, and the increased perspective I now have on both the solar system and the universe will be invaluable as we explore and travel more into space. I have learned the importance of being well informed about topics in space, as they often have parallels to things happening here on the Earth. I remember reading the first article by Neil Degrasse Tyson at the beginning of the textbook, talking about the importance of looking into space. He says: “The cosmic perspective enables us to grasp, in the same thought, the large and the small.” The importance of this class goes beyond the coolness of looking at Jupiter’s moons through a telescope or learning about Pluto, it’s about putting our world into perspective, and to that end, this class has accomplished this goal. Next semester, I am taking astrophysics to close out my physics minor. I am eager to learn more about our universe.

Picture of Earth from Saturn. Source: European Space Agency
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Light Has Momentum?

Posted on April 29, 2024 by John Newell

How is that possible – And how can we take advantage?

We know that light has no mass. And, according to classical mechanics, momentum is given by 1/2mv^2; in other words, according to classical mechanics, light cannot have momentum. But, as we know, light is different — and oh so interesting! By virtue of energy transfer, light creates the phenomenon of radiation pressure, which results in momentum being exerted on objects which are struck by the photons. The upshot of all of this is, that with clever engineering, and a massive surface for which the photons to strike, we can actually propel a spacecraft using only light! A square sail with sides 800m long can result in a force of 5N. This might seem incredibly small, but over time, a force as tiny as this can result in sufficiently accumulated acceleration to reach, surprisingly, incredible speeds. We will need to get creative to explore the universe. Solar sails might be the beginning of something truly incredible.

Solar Sail, Scientific American
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Our Neighbor?: The Andromeda Galaxy

Posted on April 29, 2024 by Garrett

Image of the Andromeda Galaxy 1888

For this blog I wanted to talk about The Andromeda Galaxy. Other than it being the closest galaxy to our Milky Way I really didn’t know much about it. The Andromeda galaxy was first photographed in 1888 by Issac Roberts (picture above). Andromeda is located over 2 million light-years away. It is set to collide with the Milky Way in 4.5 billion years. I wonder what happens when two galaxies collide? The Andromeda galaxy is significantly larger than the Milky Way, cotanting about one trillion stars, compared to the 100-400 billion in the Milky Way. Andromeda is thought to have a colossal black hole in the center, much like the Milky Way’s Sagittarius A*. I actually did not know our galaxy had a blackhole at the center of it until now! Another cool thing is that observations of Andromeda have provided evidence for the existence of dark matter. The galaxy’s rotational speed indicates that there is a lot more mass present than what we can see, presumed to be dark matter. As of now we can’t observe the planets within the Andromeda galaxy, due to technological limitations, but I wonder if there are any habitable Earth-like planets there and if so how many? Even if we could, we would be observing them 2 million years in the past, so probably best to search for life a little bit closer to home.

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Blog 7: Space Propulsion

Posted on April 29, 2024 by Jonas Kobza

Though designing and building a rocket is a very complex endeavor, most people have a pretty good idea of what makes them fly: Burn a whole lot of fuel to produce thrust. This method does a great job of getting a rocket up to a high speed, relative to our planet and the solar system. However, these rockets are nowhere near the speed needed to travel to other planets. The problem is that rockets need tons of fuel in order to generate enough thrust to get going really fast, but this fuel is heavy, and heavier things accelerate slower. 

There have been several proposed solutions to this problem, and all of them are pretty crazy. First, scientists have proposed creating a ship that produces thrust by detonating small nuclear bombs behind the spacecraft; these bombs would push the spaceship, which is shielded by a protective plate, forward. The scientists that proposed this design calculated that if one million bombs are detonated behind a ship, it could get to alpha centauri in about one century, which is pretty quick relative to the speeds we can produce now. Another idea is to use antimatter annihilation, which converts all of an atom’s atomic mass into energy. This would produce a vast amount of energy, but the technology required is more in the realm of science fiction rather than reality at this point. The general takeaway is: If were going to get to another star in less than thousands of years, we need to find some new crazy sources of energy.

Artists rendering of an antimatter engine. Source: Medium
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Are We Living in a Black Hole???

Posted on April 29, 2024 by Justin Kim

While this question seems ridiculous, we shouldn’t dismiss the theory outright. Maybe there are lessons to be extracted out of this thought experiment. Or maybe our universe truly exists within a black hole.

The theory is called Schwarzschild cosmology which posits that our universe lies within the black hold of a larger parent universe. The theory opens the door for an infinite number of universes. The problem with testing the theory however is the limitations of the laws of physics. We know that nothing that goes beyond a black hole’s event horizon can come back, not even light. This means that all relevant data from within a black hole could never make it out to any observer outside of the black hole’s event horizon. We do know what phenomena would be experienced if our universe was in a black hole such as the slowing of time and stretching of matter which we do not seem to experience. This may mean that the black hole that we reside in is so large that these distortions are unnoticeable by humans, even with the most finely tuned instruments. It can generally be agreed upon that with our current understandings of physics and our level of technological development, we will never be able to answer this question concretely- just as we cannot answer whether or not we are living in a simulation. These considerations seem far fetched but our inability to answer them with confidence should humble us. The vastness of the universe has become much more evident to me. We learned about how the New Horizons mission took nine years to finally reach Pluto and that is just within our own solar system. It is fascinating to think about the distances beyond our solar system and even beyond our own universe.

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The Search for Extraterrestrial Life

Posted on April 29, 2024 by Jack Abrams
The Drake Equation

One of the most exhilarating topics in astronomy to me is the search for extraterrestrial life. The Drake Equation is one way to estimate the number of active and communicative extraterrestrial civilizations in the Milky Way. This equation was formulated in 1961 by Frank Drake to stimulate intellectual discussion about the factors that influence extraterrestrial life development. The equation contains several variables such as the rate of stars suitable for development of intelligent life, the number of stars that have planetary systems, and the number of planets per star system that could have an environment suitable for life, among others. 

Additionally, the Seager Equation, proposed by Dr. Sara Seager, is a parallel version of the Drake equation to estimate the number of habitable planets in the universe. THe equation contains variables such as planets with biosignature gasses and factors in the star’s type and planetary atmosphere to predict whether a planet is hospitable for life. Therefore the Drake equation could be used to estimate the number of civilizations on other planets that are similar to our human civilization, whereas the Seager Equation could approximate the number of extraterrestrial life such as microbes or extremophiles!

NASA’s missions, like the Kepler Space Telescope and the James Webb Space Telescope are designed to find planets in the habitable zone of their stars and use the principles laid out by these two equations to prioritize what star systems they observe. Looking forward, the continued advancement in exoplanet research and astrobiology will bring us closer than ever to answering the question if we are alone in the universe. I am very hopeful that we will be able to find extraterrestrial life in my lifetime, but for now this search will undoubtedly inspire my continued interest in the cosmos.

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Blog 8: Culmination of the Course

Posted on April 29, 2024 by Seth Creech

Picture: Potentially viable planets visualization

ASTRO 2110 was my fourth astronomy class that I have taken here at Vanderbilt, and it was also one of my favorites. Astronomy is seen by many as interesting but irrelevant, so it was nice getting a deeper understanding of the most relevant parts of the universe to us by focusing on the Solar System. I enjoyed learning about planets and their moons in a more accurate and in-depth way than I did in middle and high school, and I feel much more well-versed in topics that are related to our Solar System.

My favorite topic that we discussed was looking at our discovery methods for other planets. I loved looking at the graphs of starlight over time, as it felt like a puzzle that I was solving to find the types of planets and the size of their orbit. Even though it was relatively simple, it was fun to think about the fact that it is not that much more complicated for scientists, they just have to collect the information that I just got from the graph.

Since I am minoring in Astronomy, I will be taking Astrophysics next semester. I am very excited to take some of the principles from this class and put them to mathematical use in that course. It will be very interesting to see similar topics in even more depth than what we did in this class.

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Space Weather

Posted on April 29, 2024 by Ayden Harris

Space weather is an interesting topic that has not been discussed much. We know that the temperature in space is ~3 degrees Kelvin, however, we don’t consider space weather to be important because it is hard for us to visualize weather in space. Space weather is primarily affected by the interplanetary magnetic fields carried by solar wind plasma and solar winds. These can cause geomagnetic storms, geomagnetically induced currents on Earth’s surface, and Auroraes.

Although these doesn’t affect most people here on Earth, it can still have a negative effect on some of us. For instance, these space weather events can damage electronics on board spacecrafts, as that is what happened to the Galaxy 15 spacecraft (a telecommunications spacecraft) which caused us to lose communication. In some cases, this can threaten the lives of astronauts if something goes awry.

So even though space weather seems trivial, as we begin to further explore space, it will become more of a problem, and luckily we have devices now that can predict future solar events so we can better prepare for them.

Solar Winds visualized

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Goldilocks Planet

Posted on April 29, 2024 by Ayden Harris

Looking for another habitable planet outside of Earth has drawn the attention of scientists for years. Initially scientists believed that as long as a planet orbits a star in a habitable zone that the could be a potential planet for humans to colonize on. However, over the years that list has gotten more extensive. So, distance matters. So does an active molten core with volcanism, plate tectonics, a magnetic field, it can’t be too close or too far from a gas giant (a gas giant can either cause asteroids to hit the planet, but can also prevent it as well), circular orbit (so conditions on the planet are consistent throughout the revolution), not too fast or slow of a rotation rate. These are just some of the necessary conditions for making a planet habitable. These conditions also don’t include the factors that make a star system habitable, which makes it a longer list, such as it can’t be too close to a supernovae or other cosmic explosions.

                  There have been a few planets that have met a lot of the qualifications for a habitable planet, however, scientists have differing factors about what makes a planet habitable, so there is no consensus whether there are any planets that are currently potentially habitable. We must keep looking throughout the Milky Way to see if we can find the ‘goldilocks’ planet.

An extrasolar planet example

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Strain 121: Surviving Beyond Boiling

Posted on April 29, 2024 by Garrett

Image of Strain 121

For my blog post I wanted to learn more about extremophiles. One extremophile I found particularly interesting was Strain 121. This single-celled organism is considered a hyperthermophile. Strain 121 can survive and reproduce at temperatures as high as 121 degrees Celsius (250 degrees Fahrenheit), which is where it gets its name. It was first discovered in 2003 near a hydrothermal vent 200 miles from the Puget Sound. Strain 121 is actually capable of surviving in temperatures up to 130 degrees Celsius (266 degrees Fahrenheit) without dying. It cannot grow at this temperature, but when it returns to a lower temperature it can start reproducing again. This means that Strain 121 can survive the sterilization process of medical equipment; however, Strain 121 poses no threat to humans as our body temperatures are actually too cold for it to grow. Since the discovery of Strain 121 scientists believe that temperatures as high as 150 degrees Celcius might be able to support microbial life. This insight broadens the scope of where we might find life beyond Earth.

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