Illustration of types and morphologies of galaxies. Top left to right: Spiral, Barred Spiral, Irregular; Bottom left to right: Lenticular, Peculiar, Elliptical. These types fall into a system used by astronomers to divide galaxies into groups based on their visual appearance.
Galaxies are cosmic Islands of stars, gas, dust and dark matter. They span across very long distances and they are held together by gravity. There are multiple types of Galaxies as shown in the the photo above. The word galaxy is derived from the greek word “galaxias”. It means milky, which is a direct reference to the Milky way Galaxy. The Hubble deep field estimates that there are about 125 billion galaxies in the observable universe. That is a huge amount considering how vast a single galaxy is on its own. The Milky way Galaxy itself is about 100, 000 light years long itself. That comparison helps me understand how big the universe really is.
Kuiper Belt in relation to Pluto and Neptune’s Orbit.
The Kuiper Belt is a region in the solar system beyond the orbit of Neptune as shown in the photo above. Although they have only scratched the surface, there has been about 2,000 objects discovered so far in the Kuiper belt. It is said to be filled with bits of rock and ice, along with comets and dwarf planets. Among those dwarf planets includes Pluto, Eris, Makemake, and Haumea. Comets also exist with in the Kuiper Belt. It is said that comets from the Kuiper belt comets can orbit the Sun in less than 200 years. They also travel in about the same plan as the rest of the objects orbiting the sun. The belt is named after Gerard Kuiper, who speculated about objects beyond Pluto in a paper in 1951.
Pluto’s beloved carotid glacier, Tombaugh Regio, has been the apple of astronomers’ eyes ever since New Horizons made its fly-by in 2015. This fly-by gave us the highest resolution images of Pluto we’ve ever been able to capture, and in these new photos, a particular feature on the dwarf planet’s surface rose to a meteoric notoriety. This region, also known as Sputnik Regio, is theorized to have formed rapidly after an impactor struck the dwarf planet’s surface, and ice filled the basin left by the crater.
Tombaugh Regio is an expanse of nitrogen ice, spanning 990 miles in diameter. That’s over 22% the circumference of the entire dwarf planet itself! This distance is equivalent to more than the length of Tennessee, two times over–a pretty impressive plane for a world that would only be the size of a popcorn kernel if the Earth were scaled down to the size of an nickel.
Pluto’s heart has a specific role as well on this little world, it controls the dwarf planet’s atmospheric circulation. Because of the cycle of evaporation and condensation of the nitrogen ice, winds are set in a direction opposite to the planet’s spin, a phenomenon known as retro-rotation.
You have likely heard of the asteroid belt located between Mars and Jupiter, but did you know we also have the Kuiper belt? It’s approximately 20 AU (astronomical units) wide and is located beyond Neptune. Several dwarf planets such as Pluto, Makemake, Haumea, and Eris are all located here. Unlike asteroids which are mostly composed of rock and metal, Kuiper belt objects (KBOs) are primarily made of frozen gases like nitrogen, ammonia, and methane. Although these objects may appear to all be the same, they can actually be categorized into three major groups: classical, resonance, and scattered.
Classical KBOs
Classical KBOs make up the majority of KBOs discovered so far. These were named “classical” because they most closely resemble what astronomers predicted objects in the Kuiper belt would look like. They are all located between 42-48 AU from the Sun and have somewhat circular orbits. Their orbits are also relatively close to the ecliptic, which is the plane that the rest of the planets orbit on.
Resonance KBOs
Resonance KBOs are named after their close association with Neptune; their orbits follow a pattern that is controlled by Neptune’s orbit. These are separated into four categories: 1:1, 2:1, 3:2, and 4:3. These numbers describe a ratio of Neptune orbits to KBO orbits. Our favorite dwarf planet Pluto is actually located in this category and is in a 3:2 resonance with Neptune. This means that for every three orbits of Neptune, Pluto orbits the Sun twice. Roughly a quarter of all KBOs follow this 3:2 resonance, and they are a subcategory known as plutinos.
Scattered KBOs
Scattered KBOs are located the furthest from the Sun and are comprised of objects that have been scattered by Neptune. They have extremely elliptical orbits and high inclinations. KBOs in this category are also the hardest to find because they are often too far away to be detected using current observational methods. Eris is the largest known member of this group.
Although located at the outer edge, the Kuiper belt contains many interesting objects that can help us learn more about the formation of our solar system.
Did you ever wonder how spaceships and shuttles have the power to take off and travel through that big black expanse we call space? Or ever thought about how these rockets survived with the limited technology we had in the 1950s, 60s and 70s during the Space Race? Well the answer has to do with the same power source from Doc Brown’s time-traveling DeLorean in the movie “Back to the Future”.
Nuclear fuel turns blue during refueling from Plutonium-238
Just like the sci-fi car, spacecrafts use plutonium for power. In the 1950s scientists and engineers developed nuclear batteries called radioisotope thermoelectric generators (RTGs) and powered them through plutonium-238 to enable spacecrafts to explore the reaches of space. Plutonium was chosen as the main power source because of its longevity and its properties of having a high heat density and emitting alpha particles. This makes it both much lighter and safer to handle than most other radioactive compounds and elements. Plutonium-238 is then converted into electrical power that operates the computers that run the craft. It also assists in the creation of power for deep space travel that would not be possible without it. Is this still efficient today? Or is there a better source of energy now? Let me know in the comments below!
The Cassini orbiter, initially launched on October 15, 1997, traveled seven years with the objective to relay observations of Saturn and its satellites. Attached to this spacecraft was also the Huygens probe, designed to enter the atmosphere and land on the surface of Titan, Saturn’s largest moon. On January 14, 2005, Huygens executed its mission; descending into Titan’s atmosphere and landing on its surface through a series of parachutes. Before the descent little was known about the surface of Titan because of atmospheric haze that shrouded the entire moon. However, images sent back to the Cassini spacecraft during Huygens’s fall and landing revealed much about Titan’s atmosphere and surface. Through the probe’s descent, much of the atmospheric composition and weather patterns could be inferred. It was observed that Titan had a much heavier atmosphere than expected due to concentrated levels of dust particles. Wind and weathering pattern could also be inferred as Huygens parachuted to the surface and was carried by winds. From this, it was concluded that winds circulated worldwide from north to south. However, the more surprising imagery came when the probe reached Titan’s surface as it revealed, through a slight haze, geography similar to earth. Present on the surface was evidence of liquid erosion, believed to have been produced through running liquid methane, that had carved out channels along Titan’s surface. Resulting in larger evidence of lakes and oceans. Also, in the final landing spot of Huygens, there were clear depictions of rounded and errored rocks that express characteristics of a previous river bed.
That’s right, there exists a planet that appears to be one giant diamond. 55 Cancri e was discovered in 2004, orbiting a nearby star in our galaxy. This star is actually visible to the naked eye in the night sky and is a part of the constellation Cancer. Based on its mass, radius, and host star’s composition, it is now believed that this star is made up of mainly carbon (along with iron, silicon carbine, and potentially silicates). This carbon is in the form of diamond and graphite, making at least one third of the planet’s mass pure diamond. This is the first “diamond planet” to be found around a sun-like star, making it a very interesting discovery. This type of planet is extremely different from Earth, which has an oxygen rich interior and very little carbon. 55 Cancri e is a super-Earth, meaning it is twice as wide but with a mass eight times greater. It also orbits its host star in just 18 hours, as opposed to Earth’s 365 days. The reason for this speedy orbit is its close proximity to its star, making the planet so hot it would not be able to sustain life. Unfortunately, we will likely not be living on a huge diamond any time soon. Personally, I think that would have been very cool, though it would have likely made diamonds worth effectively nothing. Regardless, the next time you see a massive celebrity engagement ring, just know that it’s nothing compared to 55 Cancri e. If they were really cool, they’d find a way to buy a whole diamond planet.
More insight into the Space Force’s history and purpose
At first glance, I thought the newest branch of the US Military, Donald Trump’s “Space Force”, was going to be tasked with things such as dealing with more existential threats from Space, such as a life ending asteroid or something. While I was confused as to why this would warrant a 6th branch of the military, I did think it was a worthy problem to research. This assumption proved naive, after learning that it is actually just a consolidation of the Defense Department’s orbit-focused operations. In hindsight it’s quite obvious that this branch was meant to begin developing space-based warfare, but I somewhat optimistically hoped it wasn’t the case. Nonetheless, my thoughts on it are mixed. Spending $15 billion dollars a year on this new (hypothetical) type of warfare seems advantageous if other countries are developing similar programs, so we aren’t left behind. It’s hard to reconcile spending this much money on a, again, hypothetical version of war when there are concrete things that could use that kind of money today, from underfunded schools to climate change prevention. This being said, $15 billion is just a drop in the bucket of the trillions our government spends in a year, and it is definitely not significant enough and an expense to lead to any real issues.
While my opinion on the Space Force as a concept is up in the air, the one aspect I definitely don’t like is how it is essentially a new wave of American Imperialism. In a doctrine published by the branch, they stated their goal is “the control and exploitation of the space domain” for “the prosperity and security of the United States.” This just seems like an extension of American overreach and entitlement, as the ways they would accomplish these goals would be through increased surveillance of foreign, sovereign states. The Space Force could be a source of immense patriotism and scientific advancements, but it is stained by this American need to impose on a global scale. At the same time, I am really curious to see what they develop, and the implications this new branch has on, not only international relations, but the capabilities of science and technology. Hopefully in the coming years I can come to take pride in the Space Force, but for now I will continue being wary of it.
The rings of the Jovian planets are absolutely stunning, almost making you wish Earth had a few of its own! Every Jovian planet has its own group of rings to stare at.
Saturn is quite famous for its bright, illustrious seven rings. These rings are named A-G in the order they were discovered. Surprisingly, data from the Cassini spacecraft suggest that the rings may be relatively young, only about 100 million years old. I couldn’t even imagine what Saturn would look like without its rings.
Jupiter has a 4 sets of massive rings that surround it. Jupiter’s rings are incredibly faint and composed of tiny dust, making it hard to observe. When observed from infrared light, the rings are seen to have a reddish color.
On August 24, 2006, the International Astronomical Union changed Pluto’s status from planet to dwarf planet. This caused an outrage amongst the public. Memes were created and shared expressing Pluto’s sadness at its “demotion” from planetary status. Textbooks had to be changed and the general public was oddly passionate over an object in space’s official title. Nevertheless, people were unhappy and felt as though Pluto was being treated unfairly. While I understand feeling emotionally attached to a floating object in space billions of miles away from us, it is important to understand why this change was made. Firstly, when Pluto was discovered and classified as a planet, it was considered to be odd. It has a much more eccentric orbit than any of the other planets. In the following years, more and more Kuiper Belt objects were discovered, and the question had to be asked: where was the cut off going to be for classifying a world as a planet? The IAU then created an executive committee to meet and officially define “planet.” Eventually, they voted and decided that there would be three categories of worlds in the solar system, two of which being planets and dwarf planets. From then on, Pluto and all similar Kuiper Belt worlds would be considered dwarf planets. Technically, Pluto and its neighbors are considered dwarf planets because they only meet two of the three criteria of being a full-sized planet. It is in orbit around the sun and has enough mass to have a nearly round shape, but it is not massive enough to “clear its neighborhood.” This means that it does not have enough gravitational force to have no other worlds of comparable size in its vicinity in space. It is for this reason that Pluto is officially considered a dwarf planet. Despite your personal beliefs, I think Pluto is quite happy with its dwarf planet status, as it is still a very intriguing world with much left to be discovered.
