Did you know that we know less about the universe than we do about what we don’t know? It’s true! Dark energy is one of the biggest mysteries out there. We know it’s responsible for about 68% of the universe’s expansion, but we have no idea what it is or why it’s even there! Is it a new kind of energy? A mysterious force field? Something else entirely? Who knows?
Dark matter comprises approximately 27% of the total mass energy of the universe. Despite its significant impact, we still know very little about what dark matter actually is. One prevailing theory is that it is composed of particles that are weakly interacting with regular matter and electromagnetism, such as WIMPs (Weakly Interacting Massive Particles). However, numerous experiments designed to detect these particles have so far come up empty-handed, leaving scientists to search for alternative explanations.
The expansive Kuiper Belt, located beyond Neptune’s orbit, has intrigued astronomers as it offers insights into the early stages of our solar system’s formation. Home to numerous icy celestial bodies known as Kuiper Belt Objects (KBOs), this region presents crucial information for understanding the development and composition of our cosmic environment.
KBOs, encompassing dwarf planets like Pluto and Eris, are invaluable for exploring the nature of the protoplanetary disk from which they originated over 4.5 billion years ago. By studying the chemical attributes of these relatively unaltered objects, scientists can unravel the mysteries of the ancient solar system and refine existing theoretical models of its emergence.
Additionally, KBOs have transformed our perception of planetary migration due to their distinct orbital distributions and characteristics. Gravitational forces between KBOs and the outer planets, especially Neptune, are thought to have prompted significant orbital alterations over time. Investigating the interactions among KBOs and their contribution to the Kuiper Belt’s intricate dynamics can reveal previously unknown aspects of solar system evolution, emphasizing the importance of these icy celestial bodies in our continuous pursuit of cosmic understanding.
Since its unveiling in 1930, Pluto has occupied a special role in our exploration and understanding of the solar system. Although it no longer retains its status as the ninth planet, this mysterious celestial object has piqued the interest of astronomers, researchers, and the wider public through its elaborate geological features and ever-evolving atmosphere.
In 2015, the New Horizons mission yielded a wealth of unexpected findings about Pluto’s terrain, necessitating a reexamination of our previous assumptions about icy astronomical bodies. For example, the identification of Sputnik Planitia—a sprawling plain of nitrogen ice with distinct polygonal patterns—has led scientists to theorize that the region may be indicative of convection taking place beneath the surface, powered by the internal heat generated within Pluto. Furthermore, the detection of vast mountain ranges like Tenzing Montes and Hillary Montes, which are believed to consist of water-ice bedrock, has prompted a reevaluation of our conceptions of geological processes occurring on relatively small celestial bodies.
Among the most fascinating outcomes of the New Horizons mission is the suggestion of a hidden ocean beneath Pluto’s icy exterior. The presence of extensional faults and cryovolcanic features implies that the planet’s internal makeup may have experienced tectonic movements, driven by the heat generated from the decay of radioactive elements. This notion points to the potential existence of an underground liquid water ocean, providing fertile ground for new research possibilities concerning the habitability of distant celestial bodies.
Despite its thin nature, Pluto’s atmosphere has revealed a remarkable complexity. Observations of discrete layers of atmospheric haze with diverse particle sizes, accompanied by a blue hue resulting from sunlight scattering off these particles, have encouraged scientists to reexamine the photochemical processes at play within Pluto’s delicate atmospheric layers. As our comprehension of Pluto continues to expand, this enigmatic dwarf planet exemplifies the vast diversity and untapped potential for discovery that exists in the outer reaches of our solar system.
Despite comprising almost a third of the asteroid belt’s total mass, Ceres is often left out of dwarf planet discussions. However, Ceres is actually pretty unique and could potentially support life in the future. Because of its relative closeness compared to the likes of Pluto, it was the first dwarf planet to be visited by a spacecraft, called Dawn. While Ceres looks like many asteroids, especially those called C-type asteroids, Ceres contains much more water than anticipated. In fact, it could possibly be almost 25% water, which is more than available on Earth. It also contains ammonia on its surface which is characteristic of objects outside of the ice line. In these ways, Ceres is much more similar to a Kuiper Belt object than an asteroid belt one. There are plenty of theories suggested to explain how these characteristics formed in the asteroid belt, but some scientists believe Ceres actually originated outside the orbit of Saturn. During the early solar system formation, it could have migrated to its current location as giant planets shifted. Learn more about the migration theory here.
Another unique factor separating Ceres from other asteroids is evidence that Ceres was geologically active despite its small size. Ceres could not generate heat like other terrestrial planets or through tidal friction like many giant moons. Instead, it is thought that Ceres was initially cold, and the radioactive decay of elements like uranium and thorium heated the planet up for a period of time before cooling again. This process is called radiogenic heating, and its natural instability would produce unique features across the surface of Ceres. For example, there is a large plateau on one hemisphere with localized fractures that were lacking on the other hemisphere. Physicists simulated this with a model of localized instability on one hemisphere, and the fractures match those observed by the Dawn spacecraft. Read more about the model here.
This geological activity could have created ice volcanoes which could produce the water vapor found in its thin atmosphere. Additionally, layers of ice could shift and erase large craters while perhaps even a layer of water ice exists below the crust. Because of this, some astronomers are hoping for a rover mission to Ceres to take samples and gather information about the possibility of sustaining life not so far away from home.
An artist’s rendition of Cere’s possible layers is shown below.
After analyzing Moon samples taken over two years ago, scientists have discovered glass beads of water on the surface of the Moon. The Chinese probe, Chang’e 5, took soil samples from the lunar surface as part of China’s first sample-return mission. These glass beads are thought to be across the entire surface of the Moon and hold potentially 600 trillion pounds in just the top 40ft of the surface. Although it was widely thought that the Moon contains water, it was previously unknown how much of it still existed.
This discovery also raises the question of how these beads formed, and scientists analyzing the samples have a theory. When asteroids collide with the moon, pieces of the lunar surface are launched into the atmosphere and heated. Under these intense circumstances, silicate particles from the asteroids combine to create tiny glass beads. Water is thought to have formed in the beads through interactions with solar wind. Hydrogen atoms, which match the type released from the Sun, combine with oxygen in the beads to form water molecules. These beads can then release water back into the surface.
This suggests that the moon has an active water cycle and vast amounts of water stored under the surface. Possibly in the future with more lunar explorations and missions, water will not have to be transported. Water weighs over 8 pounds to the gallon which makes it particularly expensive rocket cargo and often the limiting factor for manned missions. Lunar exploration or settlement could be sustainable, and future explorers could possibly extract the water, use it, and recycle it, without needing shipments from Earth. Read more about the finding here.
Glass beads from a lunar sample. Source: Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences
Would you want to try a glass of water from the Moon?
Titan is Saturn’s largest moon and the second largest moon in the solar system behind Ganymede. It is shrouded in a thick, yellow atmosphere and has standing bodies of liquid on its surface. It is the only place besides Earth(that we know of) that has an atmospheric cycle of precipitation and evaporation. One day on Titan is 15 Earth days and 22 hours long, and one year is about 29 Earth years.
The average temperature on Titan’s surface is -290 degrees Fahrenheit. Due to these extremely cold temperatures, water ice forms the crust of the planet in much the same way that rock forms Earth’s crust. Titan’s surface is shaped by the flow of methane and ethane, both of which are in the liquid state due to Titan’s extremely cold temperature. These liquids form features we are very familiar with from Earth, such as rivers and lakes. Titan is also thought to have icy volcanism. This would be liquid water erupting as a kind of extremely cold lava equivalent.
Titan’s atmosphere is comprised primarily of nitrogen, much like Earth’s, but extends about ten times further into space due to Titan’s lower gravity. There is also evidence of organic compounds both in Titan’s atmosphere and on its surface. These are thought to be formed when UV from the sun splits particles apart in Titan’s upper atmosphere, which then reform and can fall to the surface. On the surface, these particles form structures reminiscent of sand dunes on Earth.
July 20th, 1969. We landed on the moon. But did we really?
There are many conspiracies on if we really landed on the moon or not. People claim many reasons which prove that the moon landing never actually occurred. Shadows in the moon landing photos are not parallel which shows that they were fake. The astronauts would not have been able to survive Earth’s radiation field. There are no stars in the pictures of astronauts on the moon. The flag set on the moon was waving, but theres no wind on the moon. If we really did land on the moon, way haven’t we been back?
All of these claims are believable, but why aren’t they true. Each of these claims have been debunked by astronomers and researchers, which can be found here.
Even though all of these claims have so called be “debunked”, do we really believe these explanations, or are the questions of if we really landed on the moon still being contemplated. That is completely to up to you. For me, I think I need to see another moon landing in order to truly believe this. But while you are still contemplating if this achievement really happened or not, maybe this video of the new Apollo 11 landing site being pictured will help skew your decision.
There is a theory concerning the orbit of celestial bodies which has been proposed that would explain the extinction of the dinosaurs.
The theory rests on the idea that our sun is part of an astronomical dynamic called a binary system. A binary system resembles the mechanics of satellite and planetary orbital behaviors but it diverges in that it involves the tango of two stars.
The nickname of the sun’s hypothetical companion is Nemesis, dubbed in this fashion for the chaos it causes as it approaches the center of the solar system. Theoretically, it has an orbital period of approximately 26 million years, which is similar to the incidence of mass extinctions like those that ended the reign of reptilians.
When Nemesis transitions toward its perihelion, it is said to pass through The Ort Cloud— a sphere of icy space scraps that surround the solar system. In doing so, it disrupts the potion in its path, sending tons of comets and other junk hurdling toward the inner planets, causing many of them to impact Earth. The period of such destruction would be thought to last around a hundred thousand years or so.
Unfortunately, there hasn’t been any concrete evidence to support this quite interesting astrophysical hypothesis. But even if the theory did turn out to be true, hopefully, the rapid progression of science and technology would help us to combat the consequent destruction of its return.
Neutron stars are the collapsed cores of massive stars of 10-25 solar masses. They are formed when these supergiant stars collapse under their own gravity and undergo a supernova explosion, which compresses the star’s core to the extremely high density of atomic nuclei. In fact, they are called neutron stars because the extreme forces within a neutron star cause the protons and electrons present in normal matter to combine, producing neutrons. Neutron stars are composed almost entirely of neutrons.
Illustration of a neutron star–stellar corpses. (Source)
Aside from black holes, neutron stars are the smallest and densest currently known class of stellar objects, with radii on the order of 10 km and masses of around 1.4 solar masses. This is like compressing twice the mass of the Sun into an object the size of a small city. Also, a teaspoon of neutron star material would weigh around 1 billion tons on Earth!
What keeps neutron stars from collapsing further is neutron degeneracy pressure. As a star collapses, it eventually reaches a point where it cannot collapse any further due to the Pauli exclusion principle. The principle states that no two fermions (a category of quantum particles that includes protons, neutrons, quarks, and leptons) can occupy the same quantum state. The interior of a neutron star is so densely packed that there is physically no room for additional particles. This causes an outward pressure against the collapse of additional material. Thus, equilibrium is maintained between the inward force of gravity and the outward force of the neutron degeneracy pressure. It takes immense gravity, caused by an immense mass, to overcome the neutron degeneracy pressure, which is what happens when the mass of a neutron star exceeds the Tolman-Oppenheimer-Volkoff limit and the neutron star collapses into a denser form.
The inward force of gravity is counteracted by the outward force of neutron degeneracy pressure in a neutron star. (Source)
The most likely denser form is a black hole. However, at even more extreme temperature and pressure conditions, it is hypothesized that when the neutron degeneracy pressure is overcome, the object might not become a black hole, but might establish a new equilibrium. In this scenario, the neutrons would merge together and dissolve into a sea of their constituent quarks. This would represent an entirely different, ultra-dense phase of matter–quark matter. A new equilibrium would be reached–one between the inward force of gravity and the outward force of quark degeneracy pressure, which is analogous to neutron degeneracy pressure. This stellar object would be called a quark star, and is considered an intermediate stellar category between neutron stars and black holes. Alternatively, it is possible that quark matter exists in the inner cores of some neutron stars.
To take this one step further, or perhaps, stranger, we must discuss the different types of quarks. There are six types of quarks: up, down, charm, strange, top, and bottom. Normal matter is composed of up and down quarks, since they are stable at the temperature and pressure conditions of the majority of the universe. For example, protons are made of two up quarks and a down quark, and neutrons are made of two down quarks and an up quark. The other four quarks are unstable at normal pressure and temperature conditions and will decay into up and down quarks. However, under the intense pressures at the interior of a quark star, it is strange quarks that would be the most stable, so up and down quarks may transform into strange quarks and form strange matter.
Thus, we have a new variation of quark star: the hypothetical strange star, composed of up, down, and strange quarks. It is possible that we have already detected such objects–astronomers have found stellar objects that appear to be neutron star adjacent, but are a bit unusual. For example, the star at the center of the supernova remnant HESS J1731-347 seems like it should be a neutron star, but its mass is only 0.77 solar masses–significantly lower than the minimum neutron star mass predicted by theory. Is there a gap in our understanding of neutron stars? Are we looking at a strange star? Are we looking at something completely different? More research is necessary, but the idea of stars composed of forms of matter entirely unknown on Earth is an exciting possibility!
Comets are Kuiper Belt objects composed of chunks of rock and various ices. For the majority of their orbits they are a long way away from the Sun and don’t have the characteristic tail that we are used to seeing. However, as the comet dives back into the inner solar system, the radiation from the sun causes the tail of gas and dust to form in the wake of the comet’s passage. These tails can stretch for millions of miles behind the comet, and when one of these tails cross over Earth’s orbit it can cause meteor showers on Earth.
There are currently 3,865 known comets, but astronomers estimate that there are billions in orbit within the Kuiper Belt and Oort Cloud. As I touched on above, these objects would not have the long, bright tails that we associate with comets due to their great distance from the Sun, which makes them much harder to see. This, coupled with our small number of missions to the outer solar system, accounts for the small number of comets we have discovered relative to the total estimated amount.
There are two main types of comets: short period and long period. Short period comets come from the Kuiper Belt and typically have predictable orbits, due the fact that we have seen them come by before. These have orbits that are typically less than 200 years long. A well known example would be Halley’s comet, which has an orbital period of about 75 years. Long period comets are thought to come from the Oort Cloud and are much less predictable than short period comets. Part of this unpredictability comes from the fact that these comets can come from any direction; not just the plane of the solar system. The larger factor however, is that these orbits can last up to 30 million years due to the extreme distances they travel. This makes it extremely hard to predict when they will come through the inner solar system, and therefore probably poses the largest risk of unforeseen impact with Earth.
