Why Does Titan Have an Atmosphere?

Posted on March 28, 2020 by Reece Boggs

It’s pretty perplexing as to why Saturn’s moon, Titan, has such a thick atmosphere but a planet like Mars does not. Since the most widely accepted explanation of why Mars has such a thin atmosphere is it losing its magnetosphere as its core cooled and does not contain nearly as much metallic iron has the Earth’s, it would make sense that Titan would follow the same pattern since it doesn’t have a magnetosphere. The explanation behind this discrepancy is due to the composition of Titan’s atmosphere. Since Titan’s atmosphere is almost entirely nitrogen and nitrogen is able to withstand the lower amounts of solar radiation that Titan receives relative to Mars even without a magnetosphere, Titan is able to maintain an atmosphere of nitrogen. This also explains why Titan wouldn’t have any oxygen, since this is not true for oxygen molecules as they would be broken up by this radiation. This also explains the situation on Mars, since it was believed to once have oxygen, but due to losing its magnetosphere the oxygen was then broken apart and most likely bonded with the iron on the surface, giving it its red tint. The only thing left unexplained is why Mars or the other large Jovian moons lack the nitrogen that Titan and Earth have. Information from this blog and more detailed information on this subject is found in this video.

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Jupiter’s Moons

Posted on March 28, 2020 by emily
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Scientists believe that Jupiter has 79 moons, the most in the solar system. This is most likely because Jupiter is more massive, therefore is can hold on to more massive stuff the orbit around it. Additionally, the fact that Jupiter developed further away from the Sun in the formation process giving it access to more objects to grab into its orbit. Jupiter has four very large moons called the Galilean Moons. These moons include Io, Europa, Ganymede, and Callisto.

Io is the most volcanically active body in the solar system. Io’s surface is covered in sulfur in an array of colors. Jupiter’s immense gravity causes tides on the surface of Io. This tidal heating generates enough heat for volcanic activity and to drive off any water. Io’s interiors consist of a core, and a mantle of partially molten rock, topped by a crust of solid rock covered with sulfur compounds.

Europa’s surface is mostly made of water ice. There is evidence that it may be covering an ocean of water of slushy ice underneath it. There is no cratering on the surface of Europa signifying the surface is relatively young. Europa is heated by tidal heating to the point that the craters are filled with liquid. This moon is very interesting to astrobiologists because the properties and conditions of Europa suggest that it may be a habitable zone where life can prosper. Europa has a core, a rock envelope around the core, a thick, soft ice layer, and a thin crust of impure water ice.

Ganymede is the largest moon in the solar system. It is larger than the planet Mercury. It is the only moon known to have its own internally generated magnetic field. Ganymede has a core, a rock envelope around the core, a thick, soft ice layer, and a thin crust of impure water ice.

Callisto has a heavily cratered surface that is ancient. There is a very small degree of current surface activity. The layering of the interior of Callisto is not very defined and appears to be a mixture of ice and rock.

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The Trouble With Astronomy 🤔

Posted on March 27, 2020 by vsli
“The most distant galaxy ever discovered in the known Universe, GN-z11, has its light come to us from 13.4 billion years ago: when the Universe was only 3% its current age: 407 million years old. But there are even more distant galaxies out there, and we at last have direct evidence for it.”
NASA, ESA, AND G. BACON (STSCI)

“Space,” it says, “is big. Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”

— Douglas Adams, The Hitchhiker’s Guide to the Galaxy

So you want to study space?

Now, how exactly are you going to do that?

Astronomers over the ages have struggled with that exact problem for even longer than astronomy was recognized as a field. We can’t exactly walk over to the Sun and collect a few samples, nor can we travel millions of light years away, or even see what stars at that distance look like with the naked eye. With our most basic abilities, our five senses, we can normally barely use one, our sense of sight, to gather information from space. To imagine that we have grown from believing that the sky was a enclosed, spinning dome surrounding the Earth, to sending humans onto the Moon, to exploring the depths of our solar system and beyond with probes, and now, capturing spectacular imagery of stars and planets that are impossibly far away from us using the strongest telescopes.

One of the most famous early astronomers, Tycho Brahe, was known for his extremely precise naked-eye astronomical observations. He lived in the 16th century, before telescopes were invented and used. Even then, using only his eyesight, he was able to record data accurate to one arcminute, which is 1/60 of a degree! Besides proving that comets and supernovas were much farther away from us than the Moon, the data he collected also proved invaluable to future astronomical models. Even without a telescope, past astronomers were able to prove that the space around us was not merely a projected dome, surrounding us at the same distance away.

In the grand scheme of human history, the “common” knowledge that the planets in our solar system revolve around the Sun hadn’t been widely accepted until after Galileo had solidified arguments against an Earth-cented one, which was in the late 16th to early 17th centuries. That is a mere, give or take, 400 years ago that people used to believe the Earth was the center of the universe! Even public opinion and religious authorities were hurdles to overcome in the history of astronomy.

Fast forward to modern day astronomy, where we have all these amazing tools to help us learn more about how vast space is, what is out there, and how it all connects together. Even now, astronomers struggle with problems such as the Milky Way blocking us from viewing what’s behind its arms, or the length of time it takes for our space probes to reach the farther planets in our solar system, such as Uranus and Neptune, and collect data for us. Though we are able to image planets and galaxies millions of light years away, we still don’t know everything about our own solar system, our home.

These are truly some of humanity’s greatest achievements to be able to learn so much about things that are so far away from us. We’re able to determine the temperature and composition of stars that we’d never be able to get remotely close to, much less touch. We’re able to predict galactic collisions 4.5 billion years from now. (Hello, Andromeda!) We have equations that tell us about how the same physical principles that we use on Earth can explain phenomena in space. We’re even able to establish a timeline of major events from 13.8 BILLION years ago, which was the beginning of our universe, A.K.A. everything, ever!

It’s truly mindblowing, if you think about it.
Let’s pat our astronomers on the back.

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the Gliese 581c

Posted on March 27, 2020 by mcknia1
The Gliese 581 system, featuring the Gliese 581c

Upon learning about exoplanets, I’ve become fascinated with one 20 years light years away from Earth called the Gliese 581c, which resides in the Gliese 581 system. The Gliese 581c was discovered in 2007 using the radial velocity method of detection (tugs on its planet star). At the time of its discovery, it was the smallest exoplanet detected around a main sequence star and the known exoplanet which most resembled our own Earth.

While thought to reside within the habitable zone, it actually lies just beyond it, making it unfit for civilization. The Gliese 581c also suffers from a runaway greenhouse effect due to its proximity to its host star. 

Cool facts about the Gliese 581c:

  • Located third in order from its host star
  • Orbits a red dwarf
  • Classed as a Super Earth (has up to 10x the mass of Earth)
  • Tidally locked (one side faces its host star while the other is in constant darkness)
  • Most similar to Venus
What Gliese 581c would look like.
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The Northern Lights

Posted on March 25, 2020 by fermifurby

The Northern Lights are a natural phenomenon that appear to be fresh out of a fantasy novel. Otherwise known as Aurora Borealis, these lights are the product of the Earth’s magnetic field and high energy particles from the sun. Normally our magnetic field is invisible, but in certain locations, like the Earth’s poles, they become more visible when impacted by high energy light from our solar system’s star. The different colors are the result of the composition of our atmosphere (green for oxygen, and red/blue for nitrogen).

The Northern Lights visible in Iceland

While our magnetic field is a sight to behold when made visible near our poles, its true role in our lives is much more significant. The light that is being absorbed by our magnetic field would prove deadly to life on earth if it were left unimpeded. Furthermore, some species are able to actually navigate by detecting these magnetic fields. Migratory birds and fish are able to navigate long distances thanks to these forces. Scientists are still currently conducting research on other walks of life, and it seems that a larger portion of the animal kingdom can sense these magnetic forces than we first thought. The Earth is unique in how strong its magnetosphere is. This strength is due to having electrically charged liquid, and rotation. We aren’t alone in this regard, Jupiter has a strong magnetic field too!

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The Geology of Mars

Posted on March 24, 2020 by maverickbennett
Ladon-basin-in-full-color
Mars’ rocky surface has craters that differ between the southern and northern hemispheres!

My previous blog discussed the geology of Venus, so this week I thought it would be fun to research the geology and makeup of Mars! Mars and Earth have more similarities than you would think. Having a similar axis tilt, a day just slightly longer than 24 hours, similar land areas because of Earth’s oceans, the presence of polar caps, and season variations during the Martian year, which is about 1.9 Earth years, Mars is not too different than Earth in these aspects.

Like Earth, Mars also experiences many different geological processes. One process is the impact catering on Mars. In the southern hemisphere, Mars has a high elevation and there are many scars from large impact craters that have landed on the planet. In the northern hemisphere, there is a lower elevation and not as many impact craters. Scientists say that these differences between the hemispheres shows us that the southern highlands are an older surface than the northern ones. Moreover, this also suggests that the northern plains had many of their impact craters destroyed by other geological processes. The main geological process that erased these northern land craters was volcanism. On the surface of mars, there are many volcanoes that have rising mantle material which erupt and erase craters. While we have not observed any active volcanic activity on Mars, I think it would be extremely fascinating to observe one. Maybe this could give us even more insight into the differences of elevations and craters on the planet’s surface. What do you think observing an exploding volcano on Mars would tell us? Furthermore, mars also has tectonic plates and erosion. It is crazy that most of the things that happen on Earth also happen on this planet!

Sources: Bennett, The Cosmic Perspective, 8th Edition 2017

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The Geology of Venus: Earth’s “Sister Planet” (Post 3)

Posted on March 24, 2020 by maverickbennett
Image result for venus
Did you know that Venus is the hottest planet in our solar system?

Even though Venus is not the planet closest to the Sun, it is still the hottest planet in our solar system. This is because the planet’s dense atmosphere, which is composed of thick clouds of carbon dioxide and other gases, prevents heat from the Sun from being released into outer space. We are lucky to not be living on Venus because its temperatures reach 880 degrees Fahrenheit! We would melt instantly!

While the surface temperature of Venus differs drastically than Earth’s, the two planets share a few characteristics in common. First, the planets are similar sized and Venus is only about 5% smaller than Earth in radius. Second, these planets’ similar densities and are both very rocky, suggesting that they have similar overall compositions. Because of this, scientists expect that the interiors of Venus and Earth have similar structures and retain about the same level of internal heat. Upon researching the drastically differing surface temperatures of Venus and Earth, these two planets did not seem similar at all. However, the similar characteristics mentioned above make the planet more of a “sister planet” than I previously thought.

Some more fun facts about Venus’ geology include: has a relatively small number of impact craters (indicating that its ancient craters were erased by other geological processes), shows abundant evidence of volcanism and a variety of lava types, surprisingly has a lack of erosion and shows no evidence of Earth-like plate tectonics.

After reading these interesting differences and similarities between Venus and Earth, do you think that the two planets should be called “sister planets?”

Sources: Bennett, The Cosmic Perspective 8th Edition 2017

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Blog #6 (EC): The Fermi Paradox

Posted on March 24, 2020 by John Harrington

An interesting concept that occupies the minds of many philosophers and scientists alike is the idea of life outside of Earth (and outside of our solar system). Italian-American physicist Enrico Fermi posited that there exists a paradox describing the possibility of life outside of our world: there is no physical evidence to prove (or even suggest) that life exists outside Earth, yet all mathematical calculations suggest that this life must exist somewhere. In other words, aliens have to exist, yet we haven’t seen them (or any evidence of them).

In a manner sort of similar to some science fiction novels, Fermi argued that any population in the universe which had access to specific technologies would be able to easily gain control of large portions of the galaxy (and maybe even beyond). For example, if a population had perfected advanced rocket technology, they could easily and rapidly colonize large groups of planets. Does this mean that we humans are the most advanced population in the galaxy/universe? Does this mean that we are the only population in the galaxy/universe? Or does this mean something else? The beauty of this paradox is that it has yet to be solved–and will remain unsolved until we have physical evidence of life outside of our planet.

Image result for fermi paradox
Graphic depiction of the probability of life outside Earth. Forbes.com.
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Blog #5: Pluto’s Demotion

Posted on March 24, 2020 by John Harrington

Several years ago, as I’m sure we all remember, Pluto was demoted from Planet status to Dwarf Planet status. This change was an interesting (and controversial) one because Pluto essentially remains in limbo between the two classifications. Pluto was the smallest planet in the solar system–but it’s now the largest dwarf planet in the solar system. This change in classification has prompted everything from satirical car stickers to scientific proposals that would change the definition of a planet so that Pluto could be a planet again.

Part of what makes Pluto so fascinating is that we know very little about Pluto relative to some of our closer Solar System neighbors. Below, you’ll see a gorgeous image of Pluto, revealing what scientists believe might be evidence of former volcanic activity. The red ice found on the planet might mean that the planet recently ejected pockets of water into space. Many scientists and astronomers alike are excited by this discovery because it tells us that Pluto might contain a sub-surface sea, according to scientists.

Image result for pluto
An image of Pluto, revealing the peaks and cracks along the surface, possibly indicating past volcanic activity. ScienceNews.org.
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The Chelyabinsk Meteor and Other Near-Earth Objects

Posted on March 23, 2020 by gabezharovtothemoon

Both of my parents were born and raised in the Soviet Union, with my dad spending the first twenty years of his life in Chelyabinsk, a city east of the Ural Mountains which serve as a border between Europe and Asia. From my father’s stories, the city did not seem to have much excitement other than the massive tractor plant and the occasional -40 degree weather in the winters. However, in 2013, something very exciting (and terrifying) occurred in Chelyabinsk: a meteor weighing 13,000 tons entered the atmosphere at a speed of over 40,000 miles per hour, and exploded about 18.5 miles above the ground. The flash was brighter than sun, and released more than 30 times the amount of energy as the atomic bomb dropped on Hiroshima.

The Chelyabinsk Meteor’s airburst, as can be found here

Although over 7,000 buildings in the area were damaged and 1,500 people were injured seriously enough to require medical attention, thankfully no one was killed. This was the largest natural object to have entered Earth’s atmosphere since the 1908 Tunguska event (which also happened to hit Russia). However, the Chelyabinsk Meteor is only one of many near-earth objects (NEOs) in our solar system. In order for asteroids, meteors, and comets to be considered NEOs, their closest approach to the Sun must be less than 1.3 astronomical units (AU). Objects are categorized as potentially hazardous objects (PHOs) when their minimum orbital intersection distance with Earth is less than 0.05 astronomical units, or 19.5 lunar distances, and are large enough to cause significant damage if an impact event were to occur. However, this is no reason for panic, as 98% of the known PHOs are not an impact threat over the next 100 years.

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