Asteroids and nucleotides | blog VIII

Posted on May 1, 2022 by clviggiano
NASA

Just five days ago, researchers identified the last two nucleotide bases in asteroid samples that had previously been unrecognized. Professor and researcher Yasuhiro Oba at Hokkaido University in Japan, alongside a team of scientists, successfully identified the missing cytosine and thymine nucleases. Unlike the other bases, Cyt. and Thy. have very delicate structures, making them more difficult to distinguish in meteorite samples. This discovery confirms the presence of all five nucleotides on asteroids, which are the bases of DNA and RNA—the bases of life. Organizations and science magazines that have reported on Oba’s findings are suggesting that this discovery revealed the ‘blueprint’ of life. 

Of course, there are many more questions remaining than there are answers to satisfy them. One of the main uncertainties is how exactly the nucleotides were transferred from their source asteroids to Earth. There are two hypotheses to explain this transference. One suggests that meteorites directly introduce them to Earth’s surface through impacts with the planet. The other delivery is attributed to meteoric smoke, which is a vaporized form of solid matter that then condenses at low altitudes in gaseous atmospheres; this particle smoke occurs when the meteorite enters and burns in the atmosphere. This theory posits that the nucleotides are carried via this meteoric smoke, which then is deposited on Earth’s surface as the particles settle. These hypotheses are not mutually exclusive, and may even occur as two phases of a meteorite’s contact with Earth. Right now, the specifics of how these nucleotides are transferred from asteroids to Earth are not the most important part of this discovery. Rather, it is the newfound confirmation that the building blocks of organic life can and do form in space.

Universe Today
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Bracewell “Messanger” Probes

Posted on May 1, 2022 by josephmaquino9
Figure 1. Depiction of the hypothetical Bracewell probe.

In 1960, Ronald Bracewell made public his idea of a “Bracewell probe” that was capable of both identifying and exchanging information with intelligent alien civilizations. These probes would be sent toward different star systems and place themselves within a near-circular orbit in a star’s habitable zone. Using solar energy from the star, the probe would power its electronics and continuously scan for narrow-band radio transmissions within the star system. Should any transmission be identified, the Bracewell probe will locate the source of the signal and send the original signal back in hopes of gaining attention and establishing further discussion between the probe and civilization.

There are several advantages of having a probe with the described characteristics. First, placing a probe direction in a star system allows for a more powerful signal to be transmitted as opposed to transmitting from Earth (being light-years away). This means that the signal would be much more noticeable for advanced civilizations that are capable of detecting these signals. Another advantage is that this probe could remain in orbit around the star of interest for a long period of time. If initial broadcasts from the probe generated no response, new messages across a variety of frequencies could be emitted to increase the odds of contacting these civilizations. Finally, placing a probe directly in a star system allows for near real-time communication. This eliminates the issue of sending and receiving messages that are several years old.

Perhaps the Bracewell probe is our answer for locating other advanced civilizations; however, two main obstacles exist with current technology. One issue is that we currently do not have the propulsion methods for getting these probes to a location in a reasonable amount of time. There have been advancements with nuclear fusion propulsion units, but these units have not been fully developed. With current propulsion methods, fuel would be exhausted long before we would attain speeds that would get us to these star systems in a timely manner. The second problem is that the probe requires a high degree of artificial intelligence. Even though real-time conversations can occur between the probe and an advanced civilization, it will take a while for this information to be relayed back to Earth. Therefore, the probe must be capable of carrying a conversation without having human input. When these problems are addressed, finding extraterrestrial life can become a reality.

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Acidophiles, pH, and life on Venus | blog VII

Posted on May 1, 2022 by clviggiano

The pH scale is used to gauge the acidity and ranges from 0-14, with lower values being more acidic and higher values being more alkali. 7 is the neutral level between the two. Substances like battery or stomach acids have pHs around 0 or 1; water and blood are around 7, with drain cleaner or bleach being the most alkali at a pH of 14. Everything on Earth with a measurable pH falls somewhere on this scale. However, these limits do not apply in our solar system. The clouds that comprise Venus’ atmosphere are made mostly of sulfuric acid, ranging from concentrations of 75-96% in different areas and elevations. Their pH falls below the Earth scale to an incredible -1.2. To date, this is the most acidic substance ever discovered, and reflects the extremity of extraterrestrial conditions. 

Acidophiles on Earth favor conditions with pH values under 5, making oceanic volcanic vents and sulfur springs suitable homes for these microorganisms. However, it seems they grow most successfully when the pH is approximately 3. This raises the question—to what extremes could life survive? Is an environment of -1.2 pH too acidic even for acidophiles? Could even this harsh planet support some kind of life? For the moment, these questions remain unanswered. Yet the presence of acidophiles on Earth raises it as a very real possibility. 

On a final note, achieving a calculated negative pH level is actually quite simple; it occurs when the hydrogen ion concentration of the substance reaches a molarity greater than 1. However, testing whether the substance actually has a negative pH is incredibly difficult. There is no litmus paper or method to confirm that the calculation matches the true pH. This being said, the true acidity of Venus’ clouds is not known with certainty, but is simply a calculated value. It is possible that solar pH levels are much higher or lower than currently-known values.

Sulfuric acid clouds on Venus. JAXA/ISAS/AKATSUKI PROJECT TEAM.
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KB’s Astronomical Review

Posted on April 30, 2022 by Karan Bhardwaj

Over the course of the semester, I have significantly improved my understanding of space, the stars within, and the 8 planets of our solar system. It was particularly interesting to me discussing the formation of the solar system, as I had no idea there were so many unique events that shaped our solar system to be how it is today. (For example, the Moon being made out of Earth’s crust that was blown away.)

When I look at a picture of space, or look up into the sky, I now wonder what solar systems the stars above hold, when we will reach them, and if they’ll respond to the radio communications humans have sent out. Additionally, I wonder if the gold plaque’s sent out into space will ever be recovered, by either humans or aliens.

Looking into the future, I am excited for what the future holds. Specifically, future probes to the solar system. I distinctly recall looking at the Mission Juno ‘time until destination’ multiple times while I was in high school, and reading about the mission in our textbook was extraordinary. For the future, I hope that we are able to send out many, many probes that bring back information that leads to more answers about the universe.

Jupiter’s South Pole, as seen from Mission Juno.
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The Fermi Paradox & Possible Implications

Posted on April 30, 2022 by Karan Bhardwaj

Are we alone? This sentence, likely thought by many humans around the world and throughout history in hundreds of languages, brings forth a profound question. Also known as the Fermi Paradox, the search for intelligent extraterrestrial life has captured many minds. If life is so plentiful here on Earth, and there are so many habitable planets in the universe, where are all the aliens? The Fermi Paradox, known colloquially as “Where are all the aliens?” has many implications of its meaning, of which, a few I discuss below:

  1. Self-destruction
    • Known as a “Great Filter”, an unrealized blockage towards space expansion may be the inability to leave our own planet. In our current times, much is driven by scarcity: food, water, and shelter to begin, and anything else a human can “need” next. This scarcity is likely to, and certainly has in the past, brought about conflict – destruction that has only gotten more advanced. A reason that we do not see alien spaceships flying around our solar system may be due to the fact that there are no aliens capable, and this is because they all destroyed themselves in this scarcity driven conflict. For humans to be able to completely solve the problem of scarcity by mining asteroids, or mining other planets, we must first be able to live with and thrive in our current means.
  2. Type 3+ civilizations
    • To make things even more ominous, another implication of the Fermi Paradox may be a civilization that is type 3 or above. This type of civilization would be able to travel across its galaxy within its species lifetime, and has complete control of its galactic sphere. A civilization this advanced may simply wait until an alien species is on the brink of becoming a “type 3 civilization”, and then exterminating the species. This would ensure that no other alien species is able to cause any harm to the extremely advanced civilization.
    • Another way of looking at this would be the example of a rainforest. Imagine a Toucan living in the rainforest. Humans regularly harvest wood from rainforests, leaving the Toucans with nothing. To a Toucan, a tree is likely all it needs in life: it may find food if the free has fruit, a tree can certainly support a Toucan’s family, and a tree was where it was born, so it may harbor sentimental value. Like humans coming into the rainforest, aliens could come and harvest the water, rare earth metals, or other resource present on Earth key to human survival. Similarly to the Toucan, we would be left without this resource, and likely perish, and similar to the Toucan, we would not be able to do anything about it.
  3. The Limits of Technology
    • If the previous two implications aren’t the ones holding aliens back, it may be the limits of technology. Until we reach the limits, we will never know where they are, but there are some large issues with intersteller travel:
      • Distance
        • Traveling hundreds of thousands of lightyears may be possible for light, but it is traveling at the speed of light. Traversing these incredible distances is impossible for any rockets currently developed.
      • Length of Life
        • Aliens, like humans, may have a lifespan that is far too short for space voyages. For this reason, space travel may be impossible, as our bodies begin to break down far sooner than we reach our destination.
A magnetoplasmadynamic thruster design. These rockets are some of the fastest things humans have developed, being able to travel at speeds of over 100 km/s.
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Barophiles

Posted on April 30, 2022 by solarelizabeth
“extreme barophile bacteria“

The barophiles we have found are tiny organisms, usually bacteria, living in areas with intense pressure. They are found on ocean floors where pressure can reach about 400 atm. For reference, the atmospheric pressure at sea level is 1 atm. Some barophiles known as obligate barophiles cannot survive in low pressures. The barophile Halomonas salaria cannot survive in pressures less than 1000 atm. Though barophiles can withstand and thrive in immense pressure, they have their evolutionary shortcomings. For example, UV rays can kill them because they are unable to repair their DNA. 

Studying extremophiles made me think about how each organism has different specialties. Barophiles can live at the sea floor but cannot withstand ultraviolet radiation at all. Cheetahs are extremely fast but cannot program. Humans are communicative and advanced but would be essentially helpless in the wild without their innovation and intelligence- they’re not fast and they don’t have sharp teeth! Not every species is strong in the same areas yet our differences help us survive in our unique environments and sometimes even coexist.

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The Hubble Space Telescope turns 32!

Posted on April 30, 2022 by gcomartin
Hickson Compact Group 40

On April 24, 2022, the Hubble Space Telescope celebrated its 32nd birthday. To commemorate the celebration of the most famed telescope man has ever seen, the team behind the telescope released an image of Hickson Compact Group 40, the shot containing 5 whole galaxies, taken by Hubble late last year. Nearly all of the galaxies have sources of radio waves at their cores, potential evidence that a huge black hole resides at each galaxy’s center. Nasa has said that the galaxies are gravitational impacting one another, with the galaxies so clustered together that they could fit within a span of space only twice as far across as our own Galaxy, the Milky Way. On Hubble’s special day, the scientists at NASA were quick to point out that this beautiful shot was only one of 1.5 million snapshots taken by the telescope, each of which is stored at the Space Telescope Science Institute in Baltimore, Maryland. It is safe to say that Hubble, for 32 years now, has been a national and public treasure.

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Bracewellvon Neumann Probes

Posted on April 30, 2022 by solarelizabeth
Bracewellvon Neumann Probes

Human space travel is slow and each mission must be meticulously planned. What if there were a way we could learn more about the universe more efficiently? John Von Neumann, in charge of computing the design of a bomb, wondered how else he could use his computing skills. He developed the idea of self-reproducing automation. These machines would use material from their surroundings to create copies of themselves. The idea was that the machines would resemble reproducing cells. Though hypothetical, von Neuman’s idea sparked discussions about using these machines to colonize the galaxy. It’s interesting to consider the implications of this idea if it came to life. Do you all think these machines would replicate indefinitely or break down? When would they develop “mutations?” This idea seems revolutionary and efficient but not without strong considerations. What if the machines mutated and caused harm? What if they destroyed small moons or other worlds? These probes would be super cool but could have serious consequences if out of control. Perhaps they could be programmed to self-destruct in this case.

*I have hyperlinks but they won’t show up for some reason

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Blog#8 Final Thoughts regarding Drake equation 

Posted on April 29, 2022 by Irene

Throughout this semester of study, I have been convinced that life on Earth is unique. Although we have only studied the solar system in-depth, the volcanic IO, the freezing Pluto, and the variety of planets and moons with different extremes of weather have furthered my awareness of how unique Earth’s conditions are. Even though planets can have the same geological activity as Earth, the river is flowing with methane and the air is sulfur. Henceforth, when we started the last lesson with the Drake equation to estimate a living planet, the variables I predicted were very pessimistic: I estimated that the probability of life was about 0.00001. This predicts that there are only 2*10^-6 planets with life in the entire universe. 

Drake Equation. Cr. Britannica

I didn’t think anything was wrong, but a question in the handout made me realize how terribly wrong I was. “How many planets are actually known to be having a life?” The answer is obviously one: the Earth. That is, if I extrapolate backward based on this answer, my extremely pessimistic variable prediction must be wrong. I then recalculate the drake equation based on the data from the solar system and came up with 600 planets that could have life. This answer is amazing to me! Indeed, though the requirement for life-form might be extremely strict, the Universe has infinite numbers of stars and planets and it is destined to have aline lives. Now the question becomes: where are they and will human beings be able to make contact with them? What will happen if an encounter happens? 

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How the Creators of “Interstellar” Came up with what a Black Hole Should Look Like

Posted on April 29, 2022 by timmyshaheen
A Real Life Image of a Black Hole (Shutterstock)
“Interstellar” Black Hole (Warner Bros.)

As Christopher Nolan was creating “Interstellar,” he wanted to make sure that the film was as scientifically accurate as possible, so he hired a theoretical physicist named Kip Thorne to help. The largest contribution that he had to the creation of the film was his help rendering the stunning black hole. It was Thorne that did the calculations to prove that the particles captured by the black hole would emit light due to their high temperatures. Additionally, he reasoned that black holes should have an accretion disk that surrounded them as they formed, much like the ones that stars have. This is the reasoning for the ring of light surrounding the black hole.

I personally think that it is amazing, the creators of the film were able to not only show their viewers a visually stunning object, but also make sure that it is scientifically accurate. Some of the stunning shots that they created can be found here.

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