Planet Series III: Saturn

Written by Matt Lastovka

Here, in the third installation of our Planet Series, I will discuss Saturn. Known for its stunning beauty and dazzling rings, Saturn is perhaps the most recognizable object in our Solar System.  I hope I can convince you that Saturn is the most interesting planet in our solar system.

It is the farthest planet from Earth that can be seen with the naked eye, and thus the earliest recorded observation of Saturn date to about 700 BCE from ancient Assyria. The Greeks named it after Kronos, the god of agriculture and father of Zeus around 400 BCE. The Romans later changed the name to Saturn when they rebranded the ancient Greek gods. Most ancient astronomers, however, could not see Saturn’s rings, with the possible exception of New Zealand’s Maori, whose name for Saturn translates roughly to “surrounded by a headband.” Even when Galileo first trained his telescope on Saturn, he did not recognize the rings. He thought Saturn was some kind of triple-planet system. It wasn’t until 1655 that Christiaan Huygens first described and sketched Saturn’s rings.

Saturn’s internal structure is similar to Jupiter’s. It contains a dense, rocky core surrounded by a large atmosphere of hydrogen and helium. Interestingly, Saturn is the only planet in our Solar System whose average density is less than water, meaning Saturn would float in a sufficiently large bathtub. Saturn’s atmosphere is characterized by intense winds, which can reach up to 500 meters per second (about 4.5 times faster than the strongest hurricanes on Earth). Saturn also has a massive, hexagon-shaped storm at its North Pole measuring 20,000 miles across.

Saturn’s rings are made of small ice and dust particles, most ranging in size from tiny grains to chunks as big as a house. They are incredibly thin, only measuring about 300 feet in height. That might seem like a lot, but if you blew up a sheet of paper to the size of Saturn’s rings, it would be a thousand times thicker than Saturn’s rings. They may have been formed by when the planet’s strong gravity shredded one or more of its moons about 100 million years ago, making Saturn’s rings a very new phenomenon in our Solar System. Some astronomers also suggest that they will disappear in about 50 million years when they are swallowed into Saturn itself.

Arguably the most interesting parts of Saturn are its moons. Saturn has at least 83 different moons, ranging in size from a few hundred miles in size to larger than Mercury. Mimas is known for having a large crater making it look suspiciously like the Death Star. Phoebe is located within the rings and carved out an empty band within the ring structure. The largest moon, Titan, has a thick atmosphere, and liquid lakes and rivers on its surface. However, Titan is too cold for water to be a liquid; instead, it has liquid methane on its surface, and it even rains methane. Enceladus is believed to have subsurface water oceans and features jets similar to geysers that were found to have organic molecules in them. These jets may be powered by hydrothermal vents in the oceans, which are significant because those are the places life is believed to have started on Earth. The presenc of the building blocks of life in such a place makes Enceladus a potential home for microbial life.

Sources:

https://www.theatlantic.com/science/archive/2016/01/a-major-correction/422514/

https://solarsystem.nasa.gov/planets/saturn/overview/

https://solarsystem.nasa.gov/moons/saturn-moons/overview/

https://slate.com/technology/2014/05/saturn-s-rings-to-scale-thinner-than-paper.html

Planet Series II: Venus

Written by Anya Phillips

Welcome to installment II of Planet Series; today I will discuss Venus. Thesis statement: Venus is a boiling brownish rock that we can basically never ever visit, but Venus is nuanced, and it deserves our love. Please love Venus. Let’s get into it.

We’re all astronomers here, so let’s start off with speed running some planetary science facts before I pretend to be a WGSST major at the end. In general, the planets in our solar system have average surface temperatures that drop off with increasing distance from the Sun. It follows that Mercury is the warmest planet, right? WRONG! We’ve failed to consider the effects of a planet’s atmosphere on its temperature! Earth has a nice substantial atmosphere, which keeps us toasty with trapped radiation from the Sun, even from 150 million kilometers away. But Earth’s atmosphere is put to SHAME by that of Venus. Atmospheres like ours (in which carbon-based molecules trap heat from the sun) are kept in check by something called the Carbon Cycle. It’s sort of like the water cycle. Basically, carbon gets outgassed from the beneath Earth’s surface (think volcanoes and geysers), is absorbed by water in the atmosphere which rains down, ultimately causing the carbon to be deposited from the oceans back into the Earth’s crust, and the cycle repeats. It’s actually way more complicated than that and also involves organic matter processing carbon but for our purposes know that large bodies of water are important for carrying carbon back to the ocean floors where it reenters Earth’s crust.

The idea is that Venus started out like Earth—with liquid oceans and a respectable but not inescapable atmosphere. But, being so close much closer to the Sun, Venus’ oceans evaporated. Without the ocean to dissolve carbon-based molecules and let them reabsorb into the crust, Venus’s carbon cycle spun out of control. All of Venus’ carbon was outgassed into its atmosphere, and that along with all of the water vapor is what makes the atmosphere the greenhouse we know today, trapping heat from the Sun, and giving Venus an average surface temperature of 900 degrees F (~475 C), hot enough to melt lead. Missions that have landed on Venus’ surface (google the Russian Venera program!) have lasted less than 2 hours before dying completely.

Okay enough science. Let’s briefly get into some cultural references to the planet Venus. For a lot of us, the saying “men are from mars and women are from Venus” comes to mind, demonstrating traditional stereotypes of masculinity and femininity as Mars is the Roman god of war and Venus that of beauty and love. Perhaps a bit more scientifically, we can look to the fictional astronomer Ellie Arroway from Carl Sagan’s Contact, who is written to view Venus as “a planet that had let itself go,” disappointed at its seeming inhabitability. Or there’s my favorite reference, in the artist Mitski’s song “Nobody,” in which she sings “Venus, planet of love, was destroyed by global warming, did its people want too much too?” Mitski both references Venus’ ties with femininity and desire, and its place in our minds as a cautionary tale if we let Earth’s atmosphere get too thick by extracting, or wanting, too much from our planet.

So, there are some things to unpack here. First, Venus as a failed Earth, a disappointment. I don’t think Venus’s hostile surface should disqualify it from being your favorite planet! Is it not so incredibly interesting that our neighbor is so similar and yet so different from our home planet? Even if we can’t live there, is it not interesting to imagine the types of creatures who might, either floating in the balmy upper atmosphere or toughing it out through the metallic-frost-covered mountains?

Second, Venus as a cautionary tale—what could happen to Earth humans continue to burn fossil fuels, effectively outgassing carbon faster than it can be reabsorbed, thickening the atmosphere, heating the Earth, causing the oceans to evaporate, and halting the carbon cycle… perhaps a bit depressing, I’ll give you that. But consider this view of Venus an opportunity to examine the entanglement between the scientific and the social spheres. It forces us to understand that the action of a society wielding power over which it has little control and with capitalistic intentions has the ability to geologically alter an entire planet! Venus’s spiraling into a sulfuric hell world was the fault of the sun, but Earth’s doing so could be the fault only of a people who wanted too much.

Lastly, Venus and the feminine. What a contradiction, but also my favorite thing about Venus! The juxtaposition of a planet culturally associated with softness, tenderness, sensuality, and womanhood which beneath its clouds is in fact so hostile that the arrival of humans to it would mean instant death for those humans…I just find it so compelling. Perhaps Venus’s existence speaks to the experience of being perceived one way and feeling completely out of step with that perception. I’m thinking of hashtag femme in stem moments like quietly taking notes about magnetostatics while a male classmate antagonistically interrupts the only woman physics professor you’ve ever had to tell her that she’s using the right-hand rule incorrectly. Or gender-neutrally laughing along as a male classmate announces that “today we’re joined by a female.” Or nodding while a professor brings up the cool paper by “what’s his name?” that you read last weekend before extensively stalking the woman who wrote it to see if she’d be a good Ph.D. advisor. Or calmly listening to professors at Astro coffee discuss the latest space controversies the week Roe v. Wade is overturned by the supreme court, completely torn apart inside but unable to externalize it in this context…

Actually, maybe that’s a little too much for Planet Series, but here’s to the boiling rage that comes with trying to assimilate! I guess Venus exemplifies

  1. being yourself even if yourself isn’t what others want you to be
  2. The hostility that can be contained in a single harmless-looking body

That’s why I love it and why you should also love it.

Sources:

image credit: https://solarsystem.nasa.gov/planets/venus/in-depth/ 

https://www.google.com/search?q=roman+venus&oq=roman+venus&a

qs=chrome..69i57j0i512l2j0i22i30j0i10i22i30j0i22i30l5.2082j0j9&sourceid=chrome&ie=UTF-8

https://www.smithsonianmag.com/smart-news/on-venus-it-snows-metal-99154/#:~:text=On%20the%20lower%20Venusian%20plains,basalt%20in%2

0the%20Venusian%20lowlands.

And google searching “carbon cycle diagram”

 

Planet Series I: Pluto

Written by Kaia Atzberger

Once upon a December, the story of Anastasia was made popular when a woman claimed she was the believably dead princess. Years of controversy brought attention to her story from the public. As it turned out, the woman was an imposter. However, historians have argued that the intriguing commotion she created caused people to care about the Romanov’s story which they wouldn’t have without the claim. One could argue this is what happened to Pluto. If Pluto hadn’t been a planet first would we care? I’m here to argue why Pluto’s story does make it so fascinating but why it is incredibly interesting on its own merit as well.

How many planets are in the solar system? Eight, nine, hundreds? It depends on who and when you ask. The ancient Babylonians could detect Mercury, Venus, Mars, Jupiter, and Saturn with just the naked eye. The development of better telescopes and overall technology led to further discoveries of Uranus and Neptune. Building off of Percival Lowell’s search for a Planet X, Clyde Tombaugh examined pairs of photographic plates using a blink-microscope comparator. Then, on the momentous day of February 18, 1930, the planets and the fates and all the stars aligned when Tombaugh discovered a moving object now known as Pluto in the Kuiper Belt. He had done it!

Not only was this the first planet to be discovered in almost 100 years, but it was also the only one to be discovered in the United States and the only planet to be named by a child. Venetia Burney was well versed in Greek mythology and upon Pluto’s discovery, suggested the name to her grandfather. He was friends with a member of the Royal Astronomical Society who passed it forward to the astronomers at Lowell Observatory. They unanimously voted in favor of her choice.

Pluto lived in glory for less than one full Plutonian year. In 2005, a man named Mike Brown discovered Eris which appeared larger than Pluto. This led astronomers to officially consider the definition of a planet, which until then had not been formalized. In 2006, the IAU was asked to determine whether Pluto, Eris, and potentially hundreds more celestial bodies would be classified as planets. They decided a planet must orbit a star, have enough gravitational force to attain a
spherical shape, and clear its orbit of similar size objects. Pluto failed the third criterion and was redefined as a dwarf planet. Eris did as well and Mike Brown recalls in his memoir that he was sad his discovery would never achieve planethood. However, can we discuss this IAU definition? It is incredibly vague and scientists continue to argue over it. As astronomy is a constantly evolving study, I’m of the opinion that we shouldn’t blindly accept that the IAU’s decision will never change. In fact, Pluto is still legally a planet whenever it passes over the skies of New Mexico where it was discovered.

Pushing past history, Pluto has many wondrous features. First of all, Pluto has an adorable ice valley in the shape of a heart. It’s a world with blue skies, mountains the size of the Rockies, and red snow. Pluto’s moons Hydra, Kerberos, Styx, and Nix are quite small but its fifth moon, Charon, is quite impressive. It is of similar size to Pluto and its gravitational influence tidally locks the two creating a nearly binary system. In 2015, the New Horizons mission took beautiful pictures during the first-ever spacecraft visit to Pluto. Among New Horizons’ exciting discoveries, it found that Pluto is surprisingly geologically active. Interestingly, the principal investigator of this mission, Alan Stern, is one of the more notable advocates against the IAU’s reclassification.
Ultimately, there are so many reasons why Pluto is the best planet. It has a compelling story, unique characteristics, and scientific appeal. Learning about Pluto is what made me want to study astronomy. It may not be an official planet (for now), but it will always hold a special place in my heart.

Sources:
“I Was Anastasia” by Ariel Lawhon
https://en.wikipedia.org/wiki/Timeline_of_discovery_of_Solar_System_planets_and_their_moon
s
https://en.wikipedia.org/wiki/Pluto#Discovery
“Plates, Pluto, and Planets X” by Clyde Tombaugh in Sky & Telescope April 1991
“The Girl Who Named Pluto” by Alice B. McGinty and Elizabeth Haidle
“How I Killed Pluto and Why It Had It Coming” by Mike Brown
https://solarsystem.nasa.gov/planets/in-depth/