Month: January 2020

When we think about cannibalism, we think of humans eating other people, which is quite a disturbing visual to have in the brain. However, when we take the concept of “cannibalism” to the galactic scale, the result is much less disturbing and honestly quite hauntingly beautiful. But first, what exactly is galactic cannibalism? This interesting cosmic phenomenon is when two galaxies collide and one galaxy absorbs the other. As we all know, galaxies have gravity. When these galaxies collide with one another, the gravitational pull of both galaxies tug at each other. (Picture two galaxies with gigantic arms pulling each other in for a lovely hug).

Let’s take a look at our very own galaxy, the Milky Way. It’s a spiral galaxy, comprised of a disk and halo. It has more than 200 billion stars, and is approximately 100,000 light years in diameter. Many stars in the disk are young (relatively speaking, of course) and were probably formed within the Milky Way. On the other hand, stars in the halo are old. That age gap doesn’t exactly line up, so what happened? According to astronomers, these ancient stars were most like “eaten” by the Milky Way, through the process of galactic cannibalism. Due to its large gravitational force, the Milky Way was able to overpower a smaller, weaker galaxy and absorb the stars.

Out galaxy isn’t exactly done with galactic cannibalism, though. At this very moment, we are hurtling through space towards our neighbor, the Andromeda galaxy. Andromeda is huge, so it’s likely that we will be the ones to get sucked into Andromeda’s galactic pull and combine together to form a galactic behemoth.

A question to ask might be, “How do we know we are moving towards Andromeda?” The answer lies with something called redshift, which means that light from an object is increasing in wavelength, and thus moving away from us. In 1910, Edwin Hubble was atop Mt. Wilson studying the motion of astronomical objects, when he determined that most objects outside our galaxy were redshifted. This helped later astrophysicists understand our place in the sky; Edwin helped prove that the universe was expanding. However, it’s important to keep in mind that objects in space move very slowly. Galactic cannibalism between the Milky Way and Andromeda won’t happen for another 4.5 billion years, and if humanity survives long enough to witness the event, the stars in the galaxies are so far apart there will be very little interaction. Even so, it’s an interesting phenomenon to know about and who knows, maybe in 4.5 billion years empirical evidence will prove me wrong.

Pretty much everything in the universe is in the shape of a sphere. Why? Simply, because gravity pulls everything inward. Gravity pulls from all sides, and eventually that force will even out and cause the resulting object to be a ball. However, there may technically be another shape that wouldn’t actually break the laws of physics, and that shape is a… donut. Yes, a donut (or a toroid) shaped planet could actually exist! However, there would be some physics that needs to be overcome in order to reach that point. Like I previously mentioned, planets are spherical because gravity pulls it inward. To get the hole at the center of a donut shaped planet, an equal outward force must be applied. One such force is centrifugal force, such as the force experienced on a merry-go-round, but that means the planet would have to be spinning extremely fast. This high speed would compensate for the outward force.

This type of planet is hypothetical, of course, but there are scientists that are studying it. Simon Lock, a graduate student from Harvard University, and Sarah Stewart, professor at UC Davis, have named this intergalactic donut a “synestia“.  They also say that Earth was once a synestia. Currently, the theory for planetary formation starts with a protoplanetary disk left over from star formation, and the material congregates and eventually forms larger bodies. When two large bodies collide, they cool and become spherical. However, the pair of researchers asked the question, “What if the resulting body spun extremely quickly?” Take the generic example of two figure skaters. Figure skaters are often used in physics classes because they demonstrate the concept of angular momentum very well. When a figure skater is spinning rapidly with her hands close to her, she can extend her arms to slow down. When a pair of figure skaters are spinning, they can join together and add their angular momentums. Replace the figure skaters with planets, and this is the core of what Lock and Stewart wanted to study. According to Stewart, “We looked at the statistics of giant impacts, and we found that they can form a completely new structure.”

Furthermore, this paved the way for a new explanation on how the Moon originated. When Earth was (hypothetically) a synestia, the Moon was simultaneously forming inside of it. According to Stewart, “The moon is chemically almost the same as the Earth, but with some differences. This is the first model that can match the pattern of the moon’s composition.” The problem with studying synestias is that they don’t last very long. They’re thought to last only hundreds of years, which is very short in astronomical terms. For that reason, it’s hard to detect them in the observable universe. However, scientists are hopeful, and maybe one day we can alter the current theory of planetary formation to add synestias!

When we explore the world of science fiction, we are often taken to Mars, the Moon, and other planetary bodies. Stories such as War of the Worlds and The First Men in the Moon take us on a journey not limited by the surface of the Earth. However, in the past they were just stories, but in the future, they could be reality. Of course, we’re probably not going to be invaded by Martians or little green men any time soon, but there is a chance for us colonizing these places. When we think of intergalactic bases and civilizations, we think of super high-tech buildings and machines with flying cars and such, but reality might be a bit more… biological. In a field known as synthetic biology, where life itself is being converted into technology, NASA scientists are imaging a way for fungi to be our future home on the Moon. In the myco-architecture project, NASA biologists will engineer fungi to grow into livable habitats on these interstellar rocky surfaces. Known as mycelium, these multicellular fungi can grow into macro-sized structures, which we know as mushrooms. Mycelium produces incredibly small molecules and does it with such precision it’s invisible to the human eye. As the mycelium grows, scientists intervene right before it starts the mushroom stage and can puppeteer the fungi to build specific things. And some of these things are incredibly useful to us today. The fast growing fibers produce many of the luxuries that we use, from leather to scaffolding for growing organs.

However, it’s important to remember that mycelium, like all plants and fungi, are living organisms. Enter cyanobacteria, which converts water and carbon dioxide into oxygen and food. When put together, a space habitat is constructed! The outer layer is made from water ice, tapped from resources on the planet/moon. This serves as protection from radiation. The second layer is where the cyanobacteria comes in, taking that water and producing oxygen for both the astronauts and the mycelia. The mycelia’s final layer is the one that grows into a home, fit with structural integrity.

The harsh and formidable environments on the Moon and Mars means that we have to think outside of our comfort zone if we want to live there. Unlike the floating cities and flying cars seen in science fiction, we might have to look a little bit more organically if we want to survive in such harsh locations.

One of the biggest mysteries that plague our minds is the universe. The universe is so vast and grand, and so far out of our reach. We must be content with staying on our little blue rock, floating through the fabric of space, desperately trying to peer out into the darkness and get a grasp of the cosmos. However, in the past few decades, massive strides in the field of astronomy have been taken and we now know more than we ever did before. One of the things that we understand now that wasn’t understood centuries ago was how the universe came to be. Through a theory known as the Big Bang (no, not the show), scientists have come up with a leading explanation for the birth of the universe. Now, there currently aren’t any instruments that let astrophysicists physically see back to the universe’s birth, but through a model called the Cosmic Microwave Background, which is thought to be leftover radiation from the Big Bang.

The radiation cannot be seen by the naked eye, but it is everywhere. Astronomers use specific tools to see the radiation, and as a result can “see” the expansion of the universe. The Big Bang theory is widely accepted, but there are astronomers who believe in other explanations.

According to NASA, if a snapshot were captured one second after the Big Bang, there would be a 10-billion degree sea of atomic particles, such as protons, neutrons, and electrons. The universe would start to cool, combining these atomic particles and starting the slow progress to get to where we are today. The afterglow of the Big Bang, the photons that existed then, are the very same photons that we observe today in the Cosmic Microwave Background. In 2013, the European Space Agency’s Planck satellite mapped the sky, revealing the universe to be about 13.82 billion years old, which was older than previously thought.

The Big Bang Theory was proposed by Georges LeMaitre in 1927, and was soon expanded upon by Edwin Hubble. Hubble discovered that other galaxies were moving away from us at high speeds. Hubble wasn’t aware of LeMaitre’s work at the time, but their two theories collided and supported each other. Hubble’s work with astronomy is astounding, and will forever shape the way we view the cosmos. It is through scientists like LeMaitre and Hubble that we begin to unravel the mysteries of the cosmos, and as the future draws closer, we will slowly start inching our way to understanding our role in the vast universe.

When we think of space, and the various organizations that associate with space, the National Aeronautics and Space Administration, or NASA, is probably one that immediately jumps to mind. NASA’s vision, as stated on their website, is “To discover and expand knowledge for the benefit of humanity.” People like me eagerly follow NASA and their missions, for there is the idea that every day, we are closer to revealing the secrets of the universe. In a recent update, NASA has revealed the next location in our Solar System that is to be explored: Titan, Saturn’s largest moon. Furthermore, it’s the only moon in the Solar System that has clouds and a planet-like atmosphere. Because Titan has an orange haze surrounding it, people don’t usually associate the moon with potential signs of life, as orange isn’t a color commonly associated with organic life forms, but according to an article by Astrobiology Magazine, there might be potential for biomolecules to form. See, Titan is extraordinary in that it has lakes, rivers, and seas. These bodies of water contain liquid hydrocarbons such as methane and ethane. Furthermore, underneath the crust, an ocean made up of water lies unexplored. It could be a place for life to potentially exist.

In 2019, NASA announced a new mission, named Dragonfly, that will fly to Saturn’s exciting moon and collect samples. According to their website, Dragonfly will launch in 2026 and arrive in 2034, traversing across the moon looking for chemicals that will help scientists unlock the secrets of this moon. Dragonfly exists off the backbone of the Cassini mission, which explored Saturn and finally crashed into the planet’s atmosphere on September 15, 2017. Using 13 years of data, Dragonfly can choose a calm spot on Titan to land, and look for scientifically interesting targets. The thing is, life as we think of it cannot exist on the planet’s surface, because it is so far from the Sun. The moon shivers at an astounding -290 degrees Fahrenheit, and also has a surface pressure 50 percent higher than that on Earth. Be as that may, Titan’s organic molecules still excite scientists. The atmosphere on the moon is dominated by nitrogen, methane, and oxygen, all important compounds in the building blocks of life.

2034 seems so far away, but it’s only 14 years. Those following the exciting new research and data will receive answers in the blink of an eye. Here’s to hoping that the next decade will be the harbinger of the next chapter in space exploration!