Astro2110 – The Solar System | Aggregating the class blogs of Astro2110 at Vanderbilt

Miranda

Posted on April 9, 2023 by aaronxu041009

Uranus is the only planet in the Solar System that rotates on its side, with an axis tilt of 97.77 degrees. This is most likely the result of a large collision not long after the planet formed. Among Uranus’ moons, there is one in particular that has drawn my attention, one that is also likely to be drastically affected by a collision. This moon is Miranda.

Miranda is the smallest of Uranus’ five large, round moons, and is closest to the planet. Miranda has some of the most bizarre geological features in the Solar System. There are three patches unique to Miranda called “coronae”, valleys and ridges that are lightly cratered (likely younger surface!), named “Elsinore”, “Inverness”, and “Arden”. It is suspected that these patches are caused by convection in Miranda’s ice mantle, and the heat required for this convection likely came from tidal heating due to it being in an elliptical orbit.

In addition to coronae, Miranda has some of the greatest canyons in the Solar System, some being 12 times deeper than the Grand Canyon. There is also a cliff on Miranda that is twenty kilometers high. It is fascinating how a moon only 500 km in diameter could sport so many strange geological features. The reasons have to be traced back to the moon’s past.

These great canyons and high mountains on Miranda, and the “Frankenstein” look of its surface could suggest that this moon was nearly destroyed in an impact, but it survived and was hastily recombined into what it is now. Another theory is, as introduced earlier, that internal heat caused convections. Miranda was in a 3:1 orbital resonance with Umbriel, another moon of Uranus, and this interaction as well as tidal heating from Uranus generated enough heat to create surface features. Also, meteor strikes could have melted the surface, causing slush to rise up from the mantle and form cliffs and canyons.

Posted in Class, SolarSystem | Tagged astro2110, blog5, miranda, uranus | Comments Off

Callisto, The Ugly Duckling

Posted on April 9, 2023 by andrewccascio

When it comes to Jupiter’s Galilean moons, Callisto is the odd one out. Ganymede is the largest moon in the Solar System, Io is the most volcanically active world in the Solar System, Europa has incredible, potentially life-bearing subsurface liquid oceans, and Callisto… looks as dead as Mercury. It does not take part in the orbital resonance of the other moons and it is the furthest Galilean moon from Jupiter, almost twice as far as the next furthest, Ganymede. Callisto is the ugly duckling.

Callisto lacks volcanic and tectonic features, indicating low internal heat. However, it boasts a magnetic field which requires electrically conducting fluid and convection in its interior. This indicates a possible salty ocean beneath its surface, and, more importantly, potential for life. Oxygen detected in its thin atmosphere supports the cause. That makes possibly three Galilean moons with liquid oceans, all but Io. Who is really the ugly ducking?

If you are curious to see what it would look like to be orbiting Callisto, look no further.

Posted in Class, Moons | Tagged astro2110, blog5, Callisto | Comments Off

The Principal Investigator of the New Horizons Mission

Posted on April 9, 2023 by sydneyastr2110

I like to write my blog posts about a specific topic we discussed in class or used in a homework assignment. The most recent homework assignment concerning the speech given by Alan Stern was especially fascinating to me. Stern did a great job in discussing the New Horizons mission, he covered everything from the team to the budget to the engineering feats to the errors to the outcome. Since we already learned so much about this mission, I figured I would write a post about the principal investigator, Alan Stern. The image below shows him with New Horizons in 2006.

Image credit: NASA

Alan Stern oversaw the New Horizons mission, but he has many other space related accomplishments. He has been the principal investigator for 8 space missions and developed 8 different instruments for use in exploration. If you want to learn more about specific accomplishments, visit this site.

New Horizons was personal for Stern given that he had written his master’s thesis on Pluto. He described, in a NASA interview, the outer solar system as “primitive” which is why he was so eager to explore it, “because we know so little, we have so much to gain,” (Stern). Citing the space exploration of his childhood as his motivation for getting involved in space research, Stern seems to have accomplished both a personal and professional dream with the New Horizons mission.

I will admit that choosing Stern as my topic was somewhat selfish as I was curious about how he got to this position given that I have an interest in space exploration. Stern’s academic credentials include a bachelor’s degree in physics and astronomy, a master’s degree in aerospace engineering, a master’s degree in planetary atmospheres, and a doctorate in astrophysics and planetary science. I will end with his advice for people like me who are interested in a similar career path, “study hard… go to the best school and hook up with the best people you can find. But also take some time out to be a well-rounded person,” (Stern).

Posted in Class, Space Travel | Tagged astro2110, blog6, new horizons, pluto, technology | Comments Off

Birth and Death of Stars

Posted on April 9, 2023 by Rocket Man

The birth and death of stars is a complex and intriguing process that occurs over millions or even billions of years. Understanding this process is important for gaining a deeper understanding of our universe and the conditions necessary for life to exist.

The birth of a star begins with a cloud of gas and dust called a nebula. The nebula is a region where gravity is strong enough to overcome the outward pressure of the gas and dust. As the nebula contracts, it begins to spin, and a protostar is formed at the center. The protostar is not yet a star, but it is the precursor to one.

Figure: The stars that we are seeing in the night sky are just like us. They were also born once, and they are going to die one day. Source: Britannica

As the protostar continues to contract, it becomes hotter and denser, and nuclear reactions begin to occur at its core. These reactions produce the energy that powers the star and allows it to shine. The star has now entered the main sequence phase, where it will spend most of its life.

The life of a star on the main sequence depends on its mass. Smaller stars, known as red dwarfs, can burn their fuel for trillions of years. Larger stars, on the other hand, have shorter lifetimes and burn their fuel more quickly. Stars that are more massive than about eight times the mass of the sun will eventually explode in a supernova, while smaller stars will simply fade away.

As a star ages, it will eventually run out of fuel. When this happens, the core will contract, and the outer layers will expand, forming a red giant. During this phase, the star’s outer layers will become cool enough to allow heavier elements to form, through a process known as nucleosynthesis.

The red giant phase is a particularly interesting period in a star’s life cycle. Some stars will undergo a series of pulsations that cause them to periodically shrink and swell, making them variable stars. Others will lose their outer layers entirely, forming a planetary nebula.

Once a star has entered the red giant phase, its ultimate fate depends on its mass. Smaller stars will eventually lose their outer layers and become white dwarfs, while larger stars will explode in a supernova, leaving behind either a neutron star or a black hole.

A white dwarf is a dense, incredibly hot object that is supported by electron degeneracy pressure. These objects are about the size of Earth but have masses similar to that of the sun. They emit a tremendous amount of energy, but eventually, they will cool and become dimmer over billions of years.

A supernova, on the other hand, is a catastrophic explosion that occurs when a massive star runs out of fuel. The explosion can briefly outshine entire galaxies and produce a wide variety of elements that are essential for life. If the star’s core is massive enough, it will collapse into a black hole, a region of space where the gravitational pull is so strong that not even light can escape.

The study of the birth and death of stars is essential for understanding the origins of the elements that make up our universe. The heavier elements, such as iron and gold, can only be produced through the fusion reactions that occur in stars or the violent explosions that accompany the deaths of massive stars.

Moreover, studying the life cycle of stars can provide insight into the long-term fate of our own solar system. The sun, for example, is currently in the main sequence phase, but it will eventually become a red giant and engulf the inner planets, including Earth. By studying the evolution of stars, we can gain a better understanding of the conditions necessary for life to exist and the potential for habitable worlds elsewhere in the universe.

Posted in Class, Science, Stars | Tagged astro2110, blog6 | Comments Off

Dwarf Planet Eris

Posted on April 9, 2023 by Rocket Man

Eris, the largest known dwarf planet in the Solar System, was discovered in 2005 by a team of astronomers led by Mike Brown. With a diameter of approximately 2,326 kilometers, Eris is located in the outer Solar System and has an elliptical orbit that takes it from as close as 38.2 astronomical units (AU) to as far as 97.6 AU from the Sun. This translates to a revolution period of approximately 557 Earth years.

Eris’s unique orbit and composition have fascinated astronomers since its discovery. Its surface is believed to be predominantly rock and ice, with some traces of methane and nitrogen. Spectroscopic analysis has revealed that its surface is covered in a layer of frozen nitrogen and methane, which gives it a distinct red color. The presence of these volatile compounds suggests that Eris may have originated in the Kuiper Belt, a region of the Solar System beyond Neptune that is home to a vast array of icy objects.

Eris’s discovery played a significant role in the reclassification of Pluto as a dwarf planet by the International Astronomical Union (IAU) in 2006. Prior to Eris’s discovery, Pluto had been considered the ninth planet in the Solar System. However, Eris’s size and distance from the Sun were found to be similar to those of Pluto, leading the IAU to create a new classification for celestial objects known as dwarf planets. These objects are defined as celestial bodies that are large enough to be rounded by their own gravity but have not cleared their orbits of other debris.

The study of Eris has provided valuable insights into the formation and evolution of the Solar System. Eris is believed to be a remnant from the early Solar System, and its composition and orbit may contain clues about the conditions and processes that shaped our cosmic neighborhood. Additionally, Eris’s highly elliptical orbit suggests that it may have interacted with other objects in the outer Solar System, potentially playing a role in the formation of other celestial bodies.

Figure: Eris and its moon Dysnomia through the eye of an artist. Source: ESO

Eris’s moon is also an interesting object in the solar system. Eris’s moon Dysnomia was discovered in 2005, shortly after Eris’s discovery, by the same team of astronomers led by Mike Brown. Dysnomia is relatively small, with a diameter of approximately 700 kilometers, and orbits Eris at a distance of approximately 37,000 kilometers. Dysnomia’s origin is not well understood, but it is believed to have been created during a collision between Eris and another object in the early Solar System.

The discovery of Eris and its classification as a dwarf planet have also led to new questions and debates among astronomers. One such debate concerns the definition of a planet. While dwarf planets like Eris and Pluto are considered distinct from regular planets, there is ongoing discussion about what exactly constitutes a planet. Some scientists have argued that the criteria for classifying celestial bodies as planets should be revised, while others maintain that the current criteria are sufficient.

Despite the ongoing debates and questions surrounding Eris and its classification, it remains a valuable object of study for astronomers and space enthusiasts alike. Eris’s unique orbit and composition provide important insights into the formation and evolution of the Solar System, and continued study and exploration of Eris and other dwarf planets will undoubtedly yield new discoveries and insights in the years to come.

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Neptune

Posted on April 9, 2023 by shuhuaiwang

In the outermost layer of the solar system, there is a sapphire-like planet walking quietly. It is Neptune, the fourth largest and third most massive planet in the solar system. It is blue because its atmosphere is made up of hydrogen and helium, as well as methane. Well, it didn’t actually walk quietly. Neptune’s wind is the largest in the solar system (wind speed can reach 2100km/h). These factors contribute to Neptune’s atmosphere being one of the coldest places in the solar system.

With the basic information out of the way, let’s talk about what’s going to happen in the future. What concerns me the most is Neptune retrograde. At the end of June this year, Neptune will be retrograde (we’ve seen this before). Neptune’s retrograde motion will last for half a year. Another thing is that from mid-September onwards, the Moon will block Neptune. But that doesn’t mean we can’t see Neptune retrograde, or that we can see the Moon occult Neptune. In fact, we can see Neptune retrograde almost anywhere on Earth, but we can only see lunar occultations of Neptune from Antarctica.

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Jupiter’s Great Red Spot

Posted on April 9, 2023 by brandodan

The Great Red Spot on Jupiter is a deep, powerful vortex that is broader than Earth and has been churning for hundreds of years. Its driving mechanism differs from that of other vortices, suggesting that it derives its energy from denser and deeper layers of the atmosphere. The energy mechanisms causing the Great Red Spot might be better understood by comparing studies of Jupiter’s atmospheric dynamics with those of gas giants orbiting other stars.

Mission Juno

NASA’s Juno spacecraft, orbiting Jupiter. Source: NASA

The Juno probe from NASA is now circling Jupiter and investigating its internal mechanisms to learn more about the planet’s formation and development. The most recent research from the expedition, which was published in Science, sheds light on the dimensions of the Great Red Spot and other intense storms on Jupiter. Scientists were able to characterize the dynamics of Jupiter’s weather and how it has changed over time thanks to data that Juno collected through microwave observations and gravity measurements. Although confirmation would need measurements that are now too small for Juno to discern, the Great Red Spot’s roots reach at least 240 km beneath Jupiter’s cloud tops, and the vortex likely eventually dissipates.

The Great Red Spot apparently doesn’t have an abrupt cut-off point, but instead fades away gradually, according to Juno’s gravity measurements. The deep roots of the Spot may account for its endurance. The energy that powers the Great Red Spot is distinct from the energy that powers the weather on Earth. The precise energy mechanisms involved are yet unclear. Juno’s microwave radiometer enables researchers to generate heat maps of Jupiter’s atmospheric layers and investigate the planet’s temperature at various levels since Jupiter emits a large portion of its internal heat in the form of microwaves.

Conclusion

In conclusion, the Big Red Spot on Jupiter continues to be a fascinating topic for researchers, and the Juno mission has shed light on its dynamics and genesis. The processes that drive this enormous vortex and its function in Jupiter’s atmospheric dynamics may ultimately be better understood with continued research and technological breakthroughs. Insights into the behavior of gas giants within and beyond our solar system can be gained from research on Jupiter and its Great Red Spot!

Posted in General, Science | Tagged astro2110, blog6, jupiter | Comments Off

Strange Dwarf Planets!

Posted on April 9, 2023 by brandodan

Dwarf planet Pluto. Source: NASA’s New Horizons Mission

We all recognize Pluto as one of the most famous dwarf planets in our solar system. Since its reclassification in 2006, moreover, it has continued to intrigue both astronomers and the general public. From its icy surface to its various moons, Pluto is an incredibly unique world.

However, there are many more interesting dwarf planets besides Pluto out there. There are several other ‘strange’ worlds far into our solar system. Let’s explore some of them!

Eris

Eris is a dwarf planet that we’ve briefly mentioned in class. It is the topic that sparked discussion regarding Pluto’s ‘planet’ classification. Eris has a greater mass than Pluto, but Pluto is still the largest known dwarf planet. Eris’s higher density suggests that it might have stayed warm for a long period of time due to radioactive heat. All of this points towards Eris having possibly held an ice-covered liquid ocean in the past.

2007 OR10

2007 OR10 is a candidate dwarf planet that has an eccentric orbit of 550 Earth years! Throughout its orbit, it reaches about as close as Neptune (to the Sun) and reaches as far away as twice Pluto’s distance. Astronomers also estimate that this dwarf planet’s diameter is about 2/3 the size of Pluto’s. It is also known that it has an icy and deep red surface. Researchers believe there may exist cryovolcanoes considering the surface is covered in water ice.

Sedna

Another potential dwarf planet, Sedna has an unusual orbit that lasts roughly 11,400 years! Astronomers believe it originated from the Oort Cloud and was hit by a passing star, knocking it to where it is now (all due to its strange orbit). Sedna is also one of the reddest objects in our solar system. We can potentially learn about our solar system’s early history from studying its surface despite not knowing much about it.

Quaoar

The last dwarf planet I will discuss is Quaoar. It was discovered two decades ago and has a diameter roughly half of Pluto’s. Researchers believe Quaoar has water ice and possible cryovolcanoes on its surface. This dwarf planet’s size is similar to Charon, Pluto’s large moon. Quaoar also has a relatively bright surface, which suggests that there might have been geological activity in the recent past.

In all, these strange yet fascinating dwarf planets challenge our current understanding of the solar system’s formation and evolution. By studying them, we can learn more about what created our cosmic neighborhood and possibly gain insights into the early universe!

Posted in Dwarf Planets, General, Science | Tagged astro2110, blog5 | Comments Off

Pluto

Posted on April 9, 2023 by shuhuaiwang

Pluto is a particularly interesting dwarf planet, which is located in the Kuiper Belt. When humans first discovered Pluto, it was identified as the ninth planet in the solar system. Until 2006, Pluto was considered a dwarf planet because of its small size and the abundance of other debris in its orbit. Pluto has a highly elliptical orbit, and it takes 248 years to complete one orbit.

There are many interesting things about Pluto. About the naming of Pluto. It comes from the name of the Roman god of the underworld, which also honors Percival Lowell. When it comes to Percival Lowell, we have to talk about Planet X. This is a hypothesis that existed from the 19th century to the beginning of the 20th century. It is believed that there is a planet outside Neptune that affects the orbits of Neptune and Uranus, which was proposed by Percival Lowell. Pluto was thought to be Planet X at the time, but later measurements revealed that Pluto’s mass was far from enough to affect the orbits of Neptune and Uranus. In the end, Ernest Brown concluded that the discovery of Pluto might just be an accident.

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Mine

Posted on April 9, 2023 by oilrigatoni

Gotteem. This ain’t about Valentine’s Day. Nor is it about Minecraft. Nor the seagulls from Finding Nemo. This is about asteroid mining. You’ve been jabaited. But stick around for the ride of your life, or well, a mildly exciting exploration of the next generation of mining.

The Earth is limited in its resources, as we know. We’ve all heard of the aluminum shortages, the helium shortages, the lithium shortages, etc. Well, it’s only going to get worse as we build more infrastructure and technology. Luckily, we’ve got a large, basically unlimited supply of metal and other resources floating in space: asteroids. These are both useful for Earthly endeavors as well as our extra-planetary exploration. There are a bunch of different types of these rocky wanderers. C-type Asteroids don’t have a lot of practical value on Earth, as they are mostly water and organic material-rich. However, in colonized space areas, these resources could help for astro-botany, another subject my blog has discussed. Also, the phosphorus C-type asteroids contain is useful in both space and on Earth, since phosphorus is becoming more constricted on our planet. S-type asteroids hold much more value, containing large quantities of iron, cobalt, and nickel. They also contain rarer metals, like gold, rhodium, and platinum.

There are a number of problems with getting resources from asteroids. First, we’d need to find the metals we need before landing on them, or otherwise it is extremely unfeasible. This could be done by using sensors to check the reflected light from an asteroid, and from that data determine the asteroid’s composition. Some plans consider just collecting small samples, then analyze them with physical machinery. At the moment, the proto-mission from NASA is returning to Earth. OSIRIS-REx is the first space mission sent specifically to sample an asteroid (Bennu). Launched in 2016, it is scheduled to return in fall of 2023. It had UV, infrared, and visible light sensors to collect tons of information, including composition analysis of the asteroid. It is also bringing home a small portion of the surface as well. This is the first step from turning the (almost hopelessly) theoretical concept of asteroid mining to an actuality. But OSIRIS_REx’s small sample is not nearly the amount needed to make something like asteroid mining profitable. Next comes the difficulty of of physically mining the asteroids in economically sustainable quantities.

Some plans have described toting the asteroids into orbit around Earth to then be processed. Others propose using spider-like robots to swarm the asteroids and collect samples that way. At the end of the day, most of the designs are still far theoretical, and need much advancement before they even near viability. The plans also use the Moon as an industrial processing center to then ship the resources to Earth or other civilizations.

The main problem with asteroid mining is there is no infrastructure in place. It requires control centers, docking stations, processing hubs, and other places to maintain a mining operation in space. It isn’t efficient to process the raw resources on Earth, especially if some are getting sent to other colonies in the solar system. The escape velocity is difficult to overcome and requires amounts of fuel and energy to achieve. But to build that much infrastructure in space would require a ton of materials, which would be both expensive and time-consuming to send from Earth. Some proposals use raw material from asteroids in space from initial missions to build the rest of the infrastructure for a larger scale operation. But this is the primary limiting factor in asteroid mining.

Another problem is that the metals aren’t in veins as they are on Earth; rather, due to lack of geological activity, they are more homogeneously distributed throughout the asteroid. This makes them more difficult to collect.

There are legal barriers in place as well. Who would own the asteroids? The most recent international space treaty addressing this concern is the UN’s Outer Space Treaty from 1966. Yes, from 1966. So it’s not exactly in touch with modernity. Some seem to think that it will be whoever lands on it first, but the legality is still off for grabs. At least within the United States, the Space Act of 2015 gives companies the right to whatever resources they mine, so that is a bonus for these domestic companies.

Asteroid mining could be the next big industry, or it could be a bust. In my opinion, it will be a big thing in the next century, but looking forward fifteen to twenty years, it won’t come to fruition. We just don’t have the infrastructure for it yet. It is still extremely expensive to send rockets to space, much less the many to build a processing center in orbit or on the moon. We are also still dealing with big problems on Earth… um, climate change still exists. Maybe we should wait to send hundreds of rockets into orbit while we are struggling to reduce the carbon footprint in every other way. But that is just my opinion.

Posted in Class, General, Public Policy | Tagged asteroids, astro2110, blog5, mining | Comments Off