An even grander Grand Canyon

Posted on April 6, 2023 by reachforthestarsbysam

Have you ever seen the Grand Canyon? Well take that image and toss it out because it’s not even close to the size of the canyon we’re talking about here!

An inside scoop on this canyon is supported by the image above, found at Business Insider!

The New Horizon’s mission has been one of the most exciting planetary explorations in recent history, as it dove deep into the outer solar system to explore and collect data on Pluto and its surrounding satellites. One of the most interesting parts about Pluto is that it is in a binary system with its largest moon, Charon, so when the New Horizons spacecraft went to study Pluto, it was also able to explore Charon and its properties. Similar to Pluto, Charon is made of ice and rock particles that condensed at the formation of the solar system, but as ice naturally does, it expanded. As Dr. Alan Stern mentioned in his talk on Pluto and the New Horizons mission, Charon expanded much like water that freezes in a glass expands, and when the water expands further than the capacity of the glass, the glass cracks. Something very similar happened with Charon: it expanded so far that the surface had to expand to relieve some of the pressure, which caused there to be a massive canyon on Charon’s surface (pictured above!). This canyon is nearly double the length of the Grand Canyon of the United States, and nearly 5 times as deep!

Information found here, and supplemented by the information given in a talk by Dr. Alan Stern!

Posted in Class | Tagged , , , , , , | Comments Off on An even grander Grand Canyon

Blog 6 – Planet Nine

Posted on April 6, 2023 by Melanie Marszal

Unfortunately, “Planet Nine” does not refer to Pluto. However, its potential existence could explain the interesting movement of some objects in the Kuiper Belt.

Researchers at Caltech have found mathematical evidence of a large planet far out in our Solar System, which has been named Planet Nine. This hypothetical planet would be about the same size as Neptune and have about 10 times the mass of Earth. Its orbit would be very elliptical and about 20 times further from the Sun than Neptune on average.

Scientists believe there may be a large planet out in the Solar System due to the peculiar clustering of some Kuiper Belt objects that have been observed. This clustering seems like it could be caused by the gravity of a large planet, Planet Nine. Below is an illustration of the orbits of the clustered Kuiper Belt objects in question as well as the hypothetical orbit of Planet Nine.

An image from polispace of the orbits of Kuiper Belt objects along with Planet Nine.

Scientists hope to find concrete evidence of a planet out in the far reaches of our Solar System, but have yet to detect anything. It is possible that Planet Nine is not a planet at all, but instead a type of black hole. It is also possible that Planet Nine is made of dark matter. Some scientists think the key to finding it may be to look instead for moons or other matter orbiting around the planet rather than the planet itself. Regardless of what Planet Nine may be or if it even exists, astronomers will continue to search. Do you think we will find Planet Nine?

Posted in Class, Observables | Tagged , , , , | Comments Off on Blog 6 – Planet Nine

Blog 5 – Pluto

Posted on April 5, 2023 by Melanie Marszal

Many of us may remember back when we were younger and Pluto was still considered to be one of the nine planets in our Solar System. What happened? Below I will explain the reasons Pluto is no longer considered to be a 9th planet as well as some arguments for why it should be.

Anti-planet:

The International Astronomical Union (IAU) has three criteria that are required for an object to be considered a planet:

  1. It is in orbit around the Sun.
  2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
  3. It has “cleared the neighborhood” around its orbit.

Pluto meets the first two criteria, but struggles with the third. Since there are many other large objects in the Kuiper Belt where Pluto is found, Pluto is not considered to be gravitationally dominant in its orbit. For this reason, Pluto is considered to be a dwarf planet instead.

Pro-planet:

Although the IAU downgraded Pluto to a dwarf planet, some astronomers and planetary scientists disagree with the IAU’s criteria for being a planet. One planetary scientist argued that a planet should be defined by its intrinsic properties over its orbit. Pluto is a complex and active body, with oceans, moons, a multilayer atmosphere and more. Another scientist pointed out that since there are so many asteroids everywhere in our solar system, other planets also technically have not “cleared their neighborhoods.”

What do you think? Should Pluto be considered a planet? Why or why not?

Image of Pluto from NASA‘s New Horizons spacecraft.
Posted in Class, Dwarf Planets | Tagged , , , , | Comments Off on Blog 5 – Pluto

The Planets Inspiring Art

Posted on March 8, 2023 by 88bw
This is the front cover of Gustav Holst’s first edition of his staple work, The Planets.

Planets have always been a large source of inspiration for classical music composers, and there is probably no larger example than Gustav Holst’s Planets Suite. This work’s popularity has also reached the masses, and his music is known to have significantly influenced John Williams in his compositions for his film scores. What I find interesting about this suite is that it only has seven movements for seven planets; the missing eighth planet is actually Earth. Lately with the focus on climate change and the survival of our planet, many more composers are writing with a focus on planet Earth. It is intriguing to see the artistic inspirations shift from other planets during Holst’s time (1874-1934) to our own planet’s beauties in contemporary art.

In addition to music, the recent conjunction of Jupiter and Venus along with exam 1’s connection to Shakespeare writing made me wonder if planet conjunctions ever inspired any romantic poems in the field of literature. I did find this poem from William Cullen Bryant (1794-1878) and his experience with the same Jupiter-Venus conjunction of his lifetime. These works of art remind me about my motivation for learning about the solar system; it has been fun to learn about the concrete science and histories of the celestial bodies that have induced so much wonder and inexplicable beauty among humans.

Posted in Class, Historical, Observables | Tagged , , , | Comments Off on The Planets Inspiring Art

Kessler Syndrome and The Future of Satellite Use

Posted on March 8, 2023 by 88bw
This image from Wikipedia demonstrates the mass of satellites that orbit Earth in low Earth orbit.

The topic of spacecraft in our solar system made me curious about the use of satellites in our exploration of space. Although we hear more about the telescopes and imaging systems that we send far beyond Earth’s vicinity, the only low Earth orbit (LEO) satellite that I hear often about is the ISS. I wanted to learn more about the number of satellites and the frequency that we send one into orbit.

With a few quick searches, I found that the alarming rate of increase in satellite count has already been a concern for astronomers, even since the 1970s; Donald Kessler specified that larger numbers of satellites inevitably comes with growing amounts of space debris, and space debris could induce more collisions resulting in a positive feedback loop for more and more space “trash.” In fact, this concern reared its ugly head as recently as 2021, when an old Soviet satellite’s destruction led to the formation of a large debris cloud. There are even some worries that this debris could collide with the stately ISS. With such trends that do not bode well for the introduction of new satellites in the coming years, I am wondering if the realization of technological advancements will be hindered due to logistical hurdles in sending new spacecraft into an already crowded LEO.

Posted in Class, Science, SolarSystem | Tagged , | Comments Off on Kessler Syndrome and The Future of Satellite Use

Star Formation

Posted on March 8, 2023 by niqretnuh

When I was a kid, I thought stars were mysterious, distant, beautiful little things in the sky. I often pictured them as little beacons far out into the universe where the “spacemans” – a cute figment of my imagination – use to locate themselves once they get lost in the dark. A polar opposite of the tranquil stars, I thought, was the fiery Sun. I always imagined the Sun to be a giant ball of red fire – a fire-breathing dragon perhaps. I was completely shocked the first time I was told that they are actually the same thing – that both the Sun and the stars were spheres of extremely hot and dense gas emitting extremely hot light.

In their initial formation, the prototypes of stars accrete matter, faster and faster as its mass increases and gravitational forces become stronger. Gravity pulls matter closer to its center and the dense core begins to get hotter and hotter – at some point the inner pressure of the star cannot counter the gravitational force, and the protostar collapses. In this process, the core gets even denser until it is hot enough to perform hydrogen fusion, at which point the heat pressure inside the star is enough to counter the effect of gravitational collapse, and the star officially enters its main-sequence life stage.

Depending on its mass, the star can evolve into different astronomical bodies after it uses up its hydrogen. For small mass stars (like our sun), it will become hot enough to perform helium fusion but not more than that. When its core turns into a carbon ball, the star will officially be dead. Its outer layer will be carried out by stellar wind and become a planetary nebula where the matter will be reused, and its carbon core will be exposed, called a white dwarf.

For high mass stars, the star will continue to fuse heavier elements after helium – all the way until iron, where fusion does not create more energy anymore. The star will collapse and form a big explosion – supernova – and either turn into a neutron star or a black hole.

Posted in Class | Tagged , , | Comments Off on Star Formation

The Λ-CDM Model

Posted on March 8, 2023 by dromalley
The Λ-CDM Model of Cosmology

As this blog post presents me with much more freedom in topic, I’ve decided to discuss the most widely accepted theory for the origin and evolution of our universe: the Λ-CDM model. This model, named for the cosmological constant Λ which governs the accelerating expansion of space-time and for Cold Dark Matter, lays out a model of the universal from the Big Bang through now which aligns very closely with observations. Under the Λ-CDM model, about 68% of the mass-energy of the universe (Einstein showed how the two are linked) is accounted for by dark energy, which causes the acceleration of expansion. The next largest portion (~27%) is comprised of Cold Dark Matter, which interacts with other particles only through gravity and cannot be detected by other means. Finally, about 5% of our universe is Baryonic Matter, which makes up the various stars and galaxies which fill the night sky. The Λ-CDM model also provides explanations for various phenomena we see in the modern universe, such as the formation of galaxies around dark matter haloes which formed first and attracted baryonic matter around them. While there are certainly still areas of cosmology to explore, the Λ-CDM model is believed to be largely correct, and allows astronomers to make accurate predictions about the universe around them.

Posted in Class, Universe | Tagged , , , | Comments Off on The Λ-CDM Model

The Unimaginable Nature of Space-Time

Posted on March 8, 2023 by jackdoyle25

Most depictions of the space-time continuum display it as a two-dimensional plane in three-dimensional space. In such a model, objects make indents in the plane based on their gravity, with more massive objects having larger indents. This model is helpful to display how gravity works, but it doesn’t capture the whole picture.

The Sun makes an indentation in the space-time continuum, and the Earth’s motion is guided by the resulting curve.

The planar model of space-time is useful, but as we know, celestial objects do not lie on a two-dimensional plane. A more accurate model would depict objects as making indentations in three-dimensional space.

It is at this point that we need to somewhat abandon any hope of visualizing the space-time continuum. Take a moment to imagine for yourself what an indentation in three-dimensional space would look like. Most will have a great deal more difficulty imagining such a phenomenon than the planar model.

For another example, suppose that a circle in two dimensions corresponds to a sphere in three dimensions. It follows that a four-dimensional shape must exist that corresponds to a sphere. However, in our three-dimensional perception, the sphere has nowhere else to expand; it has no more observable dimensions to grow into.

This emphasizes an important but often overlooked feature of astronomy: observation has its limits because human perception is limited. Though the origins of astronomy, and indeed much of current astronomical study, is based on observation, the study of space-time is a more conceptual science. In order to reach the heights of astronomical study, it is thus necessary to let go of our reliance on perception, as astronomers are studying phenomena they are not capable of perceiving.

Posted in Class, Physics | Tagged , , , | Comments Off on The Unimaginable Nature of Space-Time

What would happen if an asteroid struck present-day Earth?

Posted on March 8, 2023 by Myles7235

We normally only see asteroids striking Earth in science fiction (what a relief!). NASA actually has an observatory whose sole purpose is to track both asteroids and comets and that appear like they might come close to Earth. During December of 2022, there were 5 asteroids that were placed on watch. Two of these asteroids were the size of a commercial jet. Luckily, all of these asteroids flew straight by Earth. In that same year, an asteroid thought to be this size of the New York City’s Empire State Building flew by Earth as well.

Although we haven’t witnessed a large asteroid hit Earth recently, the most famous asteroid hit Earth about 66 million years ago. The asteroid left a crater the size of a mountain near the cost of the Yucatan Peninsula in Mexico. It is believed that his asteroid caused massive tsunamis and was able able to block off sunlight from the amount of water and dust it flung into the air. This is the famous asteroid that is thought to have caused the extinction of the dinosaurs.

There are low chances of an asteroid hitting Earth. NASA has stated that all most of the asteroids that they have tracked have a low chance of actually making impact. In order for an asteroid to do significant damage to Earth, it would have to be at least the size of a house. If this type of asteroid were to hit Earth, concrete buildings and wooden structures around the impact site would be flattened. This would be enough to cause significant damage to a city. We may not have encountered asteroids that appear to hit Earth, but that doesn’t mean that there are unknown asteroids out there that could make their impact on our planet.

You can find out more about asteroids here

Posted in Class, Small SS Objects | Tagged , , , | Comments Off on What would happen if an asteroid struck present-day Earth?

Nuclear Fusion

Posted on March 8, 2023 by niqretnuh

At noon on a hot summer’s day, have you ever wondered how the Sun acquires so much energy that the light coming from it, 150 million kilometers away, can bring so much heat that it even burns your eyes and skin? The answer lies in hydrogen fusion happening in the Sun’s core.

In its initial formation, stars gather enough hydrogen molecules that their center becomes incredibly dense and hot. At extreme high temperatures – about 100 million degrees Kelvin, entirely unimaginable by humans – hydrogen fusion becomes possible. This fusion, how our Sun is able to create a constant source of energy that is the basis of life on our planet, is called a “proton-proton chain” reaction. Four hydrogen atoms fuse together into one helium (with two protons), 2 hydrogen atoms, neutrinos. In this process, a microscopic amount of mass is lost, and converted into an enormous amount of energy. The amount of energy released can be predicted by Einstein’s formula E = mc^2, where E stands for energy released, m stands for the lost mass, and c represents the speed of light (3 * 10^8 m / s).

Nuclear fusion is very difficult to replicate on Earth, since we cannot easily create the amount of heat required to allow such actions. Nuclear fission, on the other hand, can be done much easier. In this reaction, a heavy element is split into several different elements and protons, releasing a large amount of energy – we use this principle for inventions such as nuclear power plants or atomic bombs. Using nuclear fission technology, we were able to create hydrogen fusion on Earth – hydrogen bomb – and we could achieve it because it is powered by an atomic nuclear-fission bomb. The atomic bomb creates a high enough temperature for nuclear fusion.

Posted in Class, Sun | Tagged , , , | Comments Off on Nuclear Fusion