Blog 7 – Where did life on Earth come from?

Posted on April 26, 2023 by Melanie Marszal

Many people, myself included, may have assumed that life developed here on Earth and evolved from there. However, other promising theories suggest that life may have originated elsewhere and then traveled to Earth on meteorites. These theories are called panspermia theories.

Although space is a very harsh vacuum environment, experiments have determined that a number of organisms on Earth could survive for a while in space, such as tardigrades, the organism shown below. Tardigrades can be found alive in a variety of extreme conditions. Other organisms, mainly bacteria, were found to be able to survive under space conditions as well.

Image of a tardigrade from National Geographic

The most likely theory of where else Earth life could have originated is Mars. Scientists have found that molybdenum, an element thought to be crucial to the formation of life, was available in an oxidized form on the surface of Mars a long time ago. This element was unavailable on Earth at the time. Although the Mars theory is fascinating and cannot yet be ruled out, many scientists still agree that the most likely scenario is that life formed on Earth. Additionally, slightly more exciting but unlikely theory states that life could have been purposefully directed to Earth by another intelligent species.

Where do you think life on Earth came from?

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Political Economics of Space Exploration

Posted on April 25, 2023 by georgeboardman20

Image from NASA Press Release

I remember when I was young thinking, why haven’t we put humans on Mars yet? We have the feasibility to do so, but why? The answer comes down to the intersection between power politics and economics that often hamper, restrict and sometimes fuel the drive for space exploration. Before this class, I remember wondering why scientists keep demanding more and more rovers and explorations of Mars. I did not understand why, after one fly-by or orbit of Saturn, scientists pushed the need for more. After completing this course, I now realize the reason is simple economics and budgetary constraints placed on NASA by Congress.

Additional missions to planets arise from several reasons. One is that its not efficient to launch a probe with hundreds of specialized instruments. Later missions are thus needed to fill in data gaps missing due to simple engineering constraints. Other times, NASA mission proposals are afforded a maximum cap on their budget that prevents equipment from being installed that is otherwise feasible. This leads to a definite desire for further missions, diffusing already sparse funds from a mission designed for symbolic goals of planting the American flag on Mars.

At the same time, space exploration is heating up due to International great power competition. The Chinese lunar exploration agency aptly states that “the universe is an ocean, the moon is the Diaoyu Islands, Mars is Huangyan Island. If we don’t go there now even though we’re capable of doing so, then we will be blamed by our descendants. If others go there, then they will take over, and you won’t be able to go even if you want to. This is reason enough.” I write my final blog post on this because I intend to major in Law, History, and Society with a focus on pre-law along with a minor in Global Politics (Political Science) and (hopefully) Astronomy. This question about the future of space exploration and economic prioritization centers on competition between international powers and hopes to use pre-existing and future legal frameworks to center future colonization and exploration of space. We live in a very interesting time, and I certainly intend to pay attention to the consequences and discoveries of future astronomical discovery.

Source: Article on Space and International Politics

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Scientists Dream of Complex Life on Europa

Posted on April 25, 2023 by georgeboardman20

Images from BBC Article on Europan Life and CNET Article on Proposed NASA Rover

The search for extraterrestrial life is often focused upon deep space with distances the human mind can barely comprehend. However, evidence has been building that complex life could be present in our cosmological backyard on the icy moon of Europa. The Galileo space probe passed by Europa in the 1990s, finding compelling evidence for a 60 mile deep ocean capped off by an icy crust with fissures and later observed suspected geysers of water. In the past 20 years, evidence has built that, despite common assumptions that life needs sunlight to flourish, that Europa could be home to life and potentially even a complex ecosystem.

The reasonably scientifically accurate 2013 movie Europa Report highlights the human discovery of an octopus-like animal prowling the oceans beneath Europa. The discovery and categorization of extremophile bacterium has lent credence to the idea that life can potentially flourish in environments of extreme pressure, no sunlight, and near hot hydrothermal vents. Scientists theorize that these vents might exist if there is a rocky surface next beneath the ocean and layer of ice. Also, since water can apparently escape in geysers, it is plausible that oxygen and carbon can enter the ocean, providing ingredients for life.

The planned Europa Clipper project by NASA would aim to change that. Designed specifically with the intent to scope out the potential for life on this world, it would carry instruments not available to Galileo, “including a camera that will image most of the surface; spectrometers to understand its composition; ice-penetrating radar to map the ice shell in three dimensions and find water beneath the ice shell; and a magnetometer to characterise the ocean.” Overall, the instruments along with theoretical proposals of flying through geysers to ascertain the presence of organic compounds and potential landers lay the groundwork for at the very least some fascinating new discoveries over the next decade.

Sources include Article from BBC on Potential for Life and Business Insider Commentary on Prospects for Life on Europa

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The Universe and Me

Posted on April 23, 2023 by cuia2
We are a small and yet important part of this vast universe

     Looking back on the whole course, I felt like I learned so much about our solar system and beyond. I think it’s important to understand where you come from so you can better understand yourself and your place in the universe. Now, I definitely know more about the theory behind the formation of our solar system, the different methods we use to detect faraway planets, and why Pluto “isn’t” a planet anymore. I feel as if I don’t look at the universe any differently now, I just feel more secure about my place in the universe because I’m aware of what’s happening around me. I’ll definitely look out for news on sending astronauts to Mars and the New Horizons team.

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The Drake Equation and its Implications

Posted on April 23, 2023 by cuia2
The Drake Equation shown with images

     I’ve always wondered if there was life like humans in space, and thanks to the Drake equation, I’m now 99.9% sure there are multiple alien civilizations as advanced, if not more advanced, than us in our own galaxy. The Drake Equation hypothesizes that the number of alien civilizations that can communicate can be calculated with a variety of factors. Each factor is merely a guess, however we can make more educated guesses using the information we already have on our own solar system. It’s interesting to think about when we will be advanced enough to be able to detect extraterrestrial life, whether that could be in the distant or near future. We know for sure we’re going to send astronauts to Mars soon, and personally I think it’s only a matter of time before we are greeting aliens to Earth or visiting other alien civilizations.

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Color-Band-Filters

Posted on April 21, 2023 by Alex Diefenbach

(Rudimentary colored filters)

This semester, I was fortunate enough to get the opportunity to do undergraduate research in the realm of astronomy here at Vanderbilt.

My particular work’s main focus has been trying to find a correlation between the redshift and the luminosity of different stars observed in the universe. I created a code via Jupyter Notebook to create a graphic of a 3d graph comparing the redshift, luminosity, and the number of stars which fall into each particular point on this graph.

However, I soon learned that my work was not done yet. The data I had been analyzing was generated by a green-band filter. Basically, all of the light I was using to calculate the luminosity was only in a small section within the green area of the electromagnetic (EM) spectrum.

Basically, as we’ve seen depicted in photos in class, a lot of the time astronomers will use filters when taking photos to only let in a certain type of light, as they can potentially provide different views of these celestial bodies.

In order to get the true luminosities of these stars, I need to consider the average energy flux they put out not just in the green region, but the EM spectrum as a whole. And similar to the blackbody curves we dealt with in class, these can be somewhat non-uniform.

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Chemosynthesis

Posted on April 21, 2023 by Alex Diefenbach

(The Chemosynthetic Process)

I remember back in AP Biology in high school, my teacher briefly mentioned during the unit on autotrophs, that there are certain types of organisms who create their own energy but do it in the absence of the sun.

To me this was a complete conundrum. In every science related class, presentation or seminar that I had attended up until this point had preached that the sun was the absolute beginning of the energy supply of Earth’s ecosystems.

However, as I delved further into this topic, I learned that extremophiles are notorious for employing the process of chemosynthesis. And this made sense, considering that places like the ocean floor near hydrothermal vents are almost always devoid of sunlight. I just never had known any autotrophs existed at these depths and brutal of environments.

In short, the sulfur-oxidizing-bacteria which do this process take in water, carbon dioxide dissolved in the ocean water and hydrogen sulfide from geothermal vents and fix all of them in such a way that it creates sugars like glucose as an energy source and sulfuric acid as a waste product.

They often aren’t the only ones who benefit from this energy production however. A lot of the time, they hold mutualistic or commensal relationships with other organisms such as plants on the ocean floor, who utilize some of the sugar that they produce. In the mutualistic cases, they often return the favor by giving these bacteria a place to live and colonize. Other organisms may also garner sugar from the bacterium when they die or by ingesting them.

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Blog 8 – Changed View of Astronomy

Posted on April 21, 2023 by kevkoppa123

I’ve learned so much about the formation of star systems, planets, the physics and chemistry that sustain life, the different space missions that have pushed technology and engineering, and more. I have a much greater appreciation for missions that collect data from other planets and star systems now that I understand the level of technology, funding, coordinating, and engineering necessary to collect this data. In the past, when I heard scientists discover certain chemicals or puddles on a distant planet, I used to not care but now, I appreciate the amount of dedication to find this useful data, as it will help build our understanding for the future. In the beginning of the course, we read an essay by Neil Degresse Tyson that was very interesting. It talked about how we are very small creatures relative to the scale of the universe and that we are merely star stuff. Looking at things from this perspective is really interesting because it means everything that’s happened until now is just a random set of events that happened to occur from the Big Bang. I’m excited to learn about more astronomical discoveries in the future. 

Here’s a cool visualization of the formation of the Orion Nebula that I wouldn’t have appreciated had I not taken this course.

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Blog 7 – Astrobiology

Posted on April 21, 2023 by kevkoppa123

Astrobiology is the scientific search of life in the universe. There are three major

areas of astrobiology: studying the origin and evolution of life on Earth, finding worlds suitable for life, and finding evidence for life on other worlds. The first area teaches us about the necessary conditions for certain life to develop. Many researchers have used fossils to track the origin and evolution of life on Earth. Researchers have concluded from these studies that life on Earth rose relatively quickly 4 billion years ago, implying that life on other planets could develop relatively easily. In addition to fossils, researchers have studied extremophiles, which are a broad group of organisms that enjoy extreme preferences that could be suitable on some planets we’ve discovered. So far, however, no life has been found on any other planets. The search for life on other planets continues, as missions have been deployed to collect samples, roam worlds, and fly in the universe. 

MarsCuriosityRover-Drilling-Sol170++-2.jpg

Mars Curiousity Rover

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Cumulative Post Featuring the JUICE Launch

Posted on April 20, 2023 by sydneyastr2110

As I reflect on my blog posts this semester as well as overall topics within the class, I appreciate the time aspect. By that I mean that we have examined the past, present, and future of astronomy. My blogs included everything from the Carrington Event, a result of a large solar flare in 1859, to the total solar eclipse sweeping across North America in 2024. I picked topics based on what we had discussed in class but ended up connecting each topic to my own interests.

I learned about important astronomers and their contributions. I learned about current information about other worlds and their characteristics. I learned about what scientists hope to explore next. I learned about the diversity of the field of astronomy and its importance to past, present, and future societies.

My final post is forward-facing as it concerns one of the most recent space events, and something that was briefly mentioned in class, the launch of the JUICE spacecraft. Less than a week ago, on April 14th, the European Space Agency spacecraft was launched. Its mission is to explore the moons of Jupiter, specifically Europa, Callisto, and Ganymede, and determine the habitability of these moons. The launch had to occur within a second of the planned time for a complex maneuver, a Lunar-Earth gravity assist, to work properly. The image below shows the launch of the spacecraft attached to an Ariane 5 rocket.

Image Credit:  JODY AMIET/AFP via Getty Images, obtained here

While the launch is exciting, the spacecraft will not reach its intended destination until 2031. Once it arrives, it is expected to complete 35 flybys of the three moons. The spacecraft is certainly an impressive feat involving everything from its trip to its power supply to its instruments. You can learn more about each aspect here, which is where I learned about the mission.

This spacecraft reflects the exciting time in space travel. I am happy that I got to learn more about it through this class and hope that one day I will be involved in it.

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