There are many moons of Saturn, but the two largest are Titan and Enceladus. Titan is an enormous moon, the second largest in the Solar System after Jupiter’s Ganymede. It is notable for its thick atmosphere, which is made up of mostly Nitrogen compounds. Its surface is characterized as geologically young, with evidence of lakes and other surface liquid features that are likely made up of hydrocarbons.
Enceladus is a much smaller moon, about 1/10 the size of Titan. It has a snowy and icy surface that contains both very old and very young terrains. Heated by tidal heating, there is evidence of recent ice volcanoes, and the fresh material makes Enceladus the most reflective object known in the Solar System. Enceladus is also thought to have a liquid interior, further evidence for a source of heating and active geological processes on the moon such as tectonic activity that produces the large rifts and scars that can be seen along the surface.
Comets are relatively small bodies in our solar system comprised of dust, rock, gases, and ice. They are remnants from the formation of the solar system, and their solid bodies, or nuclei, can range from a few miles to dozens of miles wide. When its orbit gets close to the sun, this nucleus heats up and forms an atmosphere, called a coma, and a tail made of gas and dust particles facing away from the sun that can be millions of miles long. There are currently 3,743 known comets in our solar system, but it is estimated that billions exist in the Kuiper Belt and Oort Cloud. We can usually only detect comets whose orbits come near the sun since this is when the coma and tail form. The comets in the outer solar system are too cold to release this large stream of gas and dust, so they are harder to detect. Despite this, comets have been discovered near other stars in the Milky Way, and probably exist throughout the universe.
If you’re like me, you’ve heard plenty about black holes, but your only real understanding comes from a couple Interstellar screenings. The movie does a pretty great job being accurate, but even the excessively brilliant characters don’t know whats going on behind the scenes. This blog is an exploration of the phenomena, equal parts for curiosity and so I can stand my ground when I mention I have a minor in astronomy.
To me, the name “black hole” is somewhat misleading. There’s no expanse or hole to fill, but rather an excess of mass that is super tightly packed. The hole in question is actually what all of that mass does to spacetime, our way of conceptualizing the intersection of time and space. The intensely concentrated gravity drags down that fabric of reality, creating a deep pit that even light can’t climb out of, earning the “black” of black hole.
Visualization of effect on spacetime
Due to the trap that black holes set for light, they’re difficult to detect. It turns out one of the easiest ways to pick up on them is to recognize what they’re known for: gravity. Observing inconsistencies in orbits and trajectories can sound the alarm for a black hole pulling the strings behind the scenes.
One of the many wonders of our cosmos that peaked my curiosity to the world of astrophysics was the concept of the wormhole. After seeing a wormhole being used in one of my favorite movies, Interstellar , I became even more fascinated with this topic as it I was given a cinematic and visual example of how one could theoretically be utilized by humans. In the film, humans from the future discovered a way to create and place wormholes and in turn placed one in the present world’s solar system so that they could escape their dying planet. This has always been an interesting debate amongst humans. In the event the Earth was no longer a viable option for humans, we then could turn to the stars to find a more suitable home. As shown in the movie, a wormhole could be a way for us to reach worlds far beyond our own solar system. To explain the concept behind wormholes in a very basic way, imagine two points on separate ends of a piece of paper represent two points in space. The distance all the way across is far too long in relation to space. But what if there was a way to reduce this distance. Now imagine folding the piece of paper and the two points on the pieces of paper are on top of each other. Then you can reach far distances in a shorter period of time. Despite being a very obvious over simplification, this is the main concept behind their benefits for us. Unfortunately for us though, wormholes are not possible for at the moment and only an interesting topic in science fiction. However, some scientists believe that we may soon be able to prove that wormholes are a real part of the universe. The scientific way of describing such phenomenon is known as the Einstein-Rosen bridge. An Einstein-Rosen bridge is rooted in Albert Einstein’s general theory of relativity, a work that caused us to change the way we viewed gravity. Fortunately for humans, there is no need to leave our planet at the moment, but it still is intriguing to know our possible options in the future. Ultimately, movies such as Interstellar teach us that instead of looking for new planets, we should be focused on protecting and preserving our own.
Jupiter has many moons, but the largest of them are the Galilean moon, Ganymede, Callisto, Europa, and Io. This post will explore the defining features of these Jovian moons.
The largest of Jupiter’s moons is Ganymede, the largest moon in the Solar System. In fact, Ganymede is larger than Mercury. This moon has a liquid core that produces the only known magnetic field in the moons of the Solar System. It is thought that there is a liquid water ocean beneath the surface of Ganymede, something that is thought to occur on other moons as well. The surface of Ganymede is heavily cratered and therefore very old. The moons Ganymede, Europa, and Io are in 1:2:4 resonance, which influences the level of tidal heating on each world.
Slightly larger than Earth’s moon, Io is the innermost of Jupiter’s moons and is extremely geologically active. There are over 400 active volcanoes on Io, a feat that is caused by friction due to tidal heating between Jupiter and the other large moons. The surface of Io is largely coated in Sulfur, which gives it a distinct yellowish color. Volcanism is a key feature of Io that also impact Jupiter as well. Emissions from Io’s atmosphere have inflated Jupiter’s magnetic field, making it much stronger than it would be without Io.
Europa is slightly smaller than Earth’s moon and has a smooth surface largely made out of water ice. The lack of cratering suggests geological activity on Europa such as plate tectonic-like activity that recycles water ice from the subsurface to the surface and back again. Another interesting feature of Europa is its internal ocean, which is likely heated by vents and sustained by tidal heating. The discovery of such conditions has opened the door to questions about the possibility of finding life on Europa.
Finally, there is Callisto, the second largest of Jupiter’s moons. The surface of Callisto is nearly all covered in craters and is therefore extremely old, aided by the fact that it does not experience much tidal heating. This moon is also thought to have an ocean deep below the surface.
As compared to other moons, Neptune’s Triton was captured into Neptune’s orbit. This was found out due to its backward rotation and how it rotates at a high inclination to Neptune’s equator. Rather than being formed in the disk of gas around Neptune, Triton was most likely captured into Neptune’s orbit.
There is one way as to how this happened: Triton could have been a member of a binary Kuiper belt object that passed close to Neptune and lost energy and was soon captured. Triton shares many similarities with Pluto, the most well known world of the Kuipter belt. They are both very cold worlds with similar sizes and proportions of ice and rock.
Growing up, I grew to recognize Jupiter’s distinctive birthmark, but I never attempted to understand it. I figured their were clever astronomers out there who knew what was going on and I’d end up absorbing what they know from a TED talk at 1.5x speed. After looking into it though, it turns out the Great Red Spot is largely a mystery.
It’s well established that the Great Red Spot is a weather system in Jupiter’s atmosphere. It is massive – spanning roughly three Earths across in the late 1970’s. It is fast – reaching up to 425 mph on the edges, nearly 200 mph faster than the fastest hurricane wind ever recorded on Earth. Past that, not much more is known. Experts guess at things like its composition and what makes it red, but there isn’t anything conclusive yet.
The Great Red Spot + Europa
There’s still much to be learned about what goes on in the vast storm that sits in Jupiter’s atmosphere. More missions to the outer solar system, better equipped to explore the red expanse, are essential to figuring out its mysteries.
Eris is a trans-Neptunian object and is the second-largest dwarf planet in the solar system. It was discovered in 2005. It is .28 % the mass of Earth. Eris has one large moon, Dsymonia.It is about 96 AU away from the sun. Its orbital period is 559 Years. Its surface has methane ice. This shows that Eris has always been at the solar system’s edge.
Dr. Alan Stern is most known for his role as the principal investigator of the New Horizons mission to explore Pluto and the Kuiper Belt. Recently, Dr. Stern spoke at Purdue University on October 10, 2019, discussing and examining the topic of “What If We Return to Pluto?” During this discussion, he detailed many interesting facts about Pluto. For example, he mentions how before we had obtained clearer images of the outer planets, they had not realized how many of the rocks similar to the size of Pluto orbited the sun. We also discovered that Pluto is just one of many dwarf planets that are all very small in comparison to the rest of the planets. For reference, he compares Pluto to being only as large as North America. To some, this may seem notable, however he refutes this by showing how this may seem large but in the context and scale of planets, being as large as a continent is very small. He also explained the reasons why it was important to visit something so far away in our solar system. He discusses how before New Horizons, the best picture of Pluto ever taken was a blurry blob in space. Due to its distance, this is the best that could have been taken of Pluto and was even regarded as being revolutionary at the time. In contrast, pictures of Earth were incredibly clear and we were capable of depicting what was occurring on planets because of such pictures. Since Pluto was so far away, it was needed to explore further out to get a more accurate depiction of it. Scientific pioneers and explorers such as Dr. Stern are why our exploration of the solar system has reached these levels. Because of people like him, I am now eagerly waiting to see or even one day be a part of our world’s future chapter in space exploration.
Posted inClass, Universe|Taggedastro2110, blog5, pluto|Comments Off on Interesting facts about Pluto and our path to exploring it
Extrasolar planets can be difficult to detect because they are tiny, far away, and dim, but the Doppler Method provides an indirect way to find them. This method involves looking for alternating blueshifts and redshifts in the star’s spectrum, which reveal a star’s motion around its center of mass. This motion could reveal the presence of planets orbiting the star.
We can then look at how the star’s orbital velocity changes over its orbit. The slight changes in the star’s orbital velocity can tell us if it is orbitted by a planet. The planet’s gravitational tug on the star would cause these velocity changes.
The Doppler Method is effective because of its sensitivity. It can measure very slight doppler shifts, which can tell us about the presence of very small planets orbiting stars. However, because more massive planets have larger gravitational tugs on their stars, they are easier to detect. These stars have greater velocities as a result, which makes the shifts due to their planet’s tug easier to see. Also, planets closer to their star are easier to detect. These planets have shorter orbital periods, so we can analyze their orbits in less time.
Do you think the Doppler Method or the Astrometric Method is more effective? For which types of planets?
