#maurolycus

[quiltofstars]

A heavily cratered region of the Moon // Georges

Read below the cut for an annotated image and some naming history!

Nasireddin crater is named after Nasir al-Din al-Tusi (1201-1274), a Persian polymath who recorded the most accurate observations of the planets of his time.

Baco crater is named after Roger Bacon (c. 1219 - c. 1292), an English philosopher who put heavy emphasis on studying nature through scientific methods.

Walther crater is named after Bernhard Walther (1430-1504), a German astronomer who made precise measurements of the position of Venus.

Stöfler crater is named after Johannes Stöffler (1452-1531), a German astronomer who published a book on how to make and use astrolabes.

Maurolycus crater is named after Francesco Maurolico (1494-1575), a Sicilian astronomer who described a method to measure the size of the Earth.

Fernelius crater is named after Jean Fernal (1497-1558), a French physician who coined the term "physiology" and was the first person to describe the spinal canal.

Nonius crater is named after Pedro Nunes (1502-1578), a Portuguese mathematician who made improvements to the geocentric model of the universe.

Gemma Frisius crater is named after Gemma Frisius (1508-1555), a Dutch mathematician who constructed very accurate globes of the Earth and night sky.

Aliacensis crater is named after Pierre d'Ailly (1351-1420), a French astrologer who wrote about the size of the Earth.

Barocius crater is named after Francesco Barozzi (1537-1604), an Italian mathematician who studied the cosmology of Ptolemy.

Licetus crater is named after Fortunio Liceti (1577-1657), an Italian physician who wrote books defending the Aristotelian universe from the new heliocentric universe.

Clairaut crater is named after Alexis Claude Clairaut (1713-1765), a French mathematician who used Newton's calculus to work on the three-body problem.

Büsching crater is named after Anton Friedrich Büsching (1724-1793), a German geographer who published several books on the geography of Europe.

Breislak crater is named after Scipione Breislak (1748-1826), an Italian geologist who studied the geology of Rome.

Ideler crater is named after Christian Ludwig Ideler (1766-1846), a German astronomer who studied ancient cultures and their time-keeping methods.

Cuvier crater is named after Georges Cuvier (1769-1832), a French zoologist, sometimes called the "father of paleontology."

Faraday crater is named after Michael Faraday (1791-1867), an English physicist who established the concept of electromagnetic fields.

Kaiser crater is named after Frederik Kaiser (1808-1872), a Dutch astronomer who popularized astronomy in the Netherlands and directed the Leiden Observatory.

Miller crater is named after William Allen Miller (1817-1870), a British scientist who studied the composition of the stars and wrote textbooks on chemistry.

Huggins crater is named after William Huggins (1824-1910), British astronomer who studied the spectra of several objects, including the first to take the spectrum of a planetary nebula.

[spacenutspod]

You can tell a lot about a planetary body just by looking at its surface, especially if it has craters. Take Europa, for example. It has a fairly young surface—somewhere between 50 and 100 million years old. That’s practically “new” when you compare it to the age of the Solar System. And, Europa’s icy crust is pretty darned smooth, with only a few craters to change the topography. Planetary scientists already know that Europa’s icy surface is a thin shell over a large interior ocean of salty water. How thin? To find out, a team of researchers led by Brandon Johnson and Shigeru Wakita at Purdue University studied images of large craters on Europa. They used what they saw, coupled with a variety of physical characteristics, to create computer models of that shell. “Previous estimates showed a very thin ice layer over a thick ocean,” said Wakita. “But our research showed that there needs to be a thick layer—so thick that convection in the ice, which has previously been debated, is likely.” The thickness of that shell may well influence whether or not life exists at Europa. Its existence is a topic of intense interest since Europa could provide a reasonably habitable ecosystem for life. It has water, warmth, and organic materials for life to eat. That makes the search for life at Europa quite important. So, what do craters have to do with all this? More About Craters Impact cratering performs a lot of gardening in the Solar System, according to Johnson. He is the first author on a recently published paper discussing these features on Europa. “Craters are found on almost every solid body we’ve ever seen. They are a major driver of change in planetary bodies,” he said. Four featured craters among many on the Moon: the triplet of Theophilus, Cyrillus and Catharina and Maurolycus. Many more craters can be seen across the lunar surface. Credit: Virtual Moon Atlas / Christian LeGrande, Patrick Chevalley Just looking at images of different worlds in the Solar System, we can see some pretty heavily cratered surfaces. The Moon is a good example, as is Mars. And, we see it at many of the smaller bodies, such as the moons of the gas and ice giants. The more craters we see, the older the surface. In some places, multiple overlapping craters indicate a very old surface. In other places, such as at Europa, the craters are fewer and farther between. Something has “paved over” the craters such that any we CAN see were made after the repaving event. In addition, the craters reveal information about the surface as well as the “subsurface” of Europa. “When an impact crater forms, it is essentially probing the subsurface structure of a planetary body,” said Johnson. “By understanding the sizes and shapes of craters on Europa and reproducing their formation with numerical simulations, we’re able to infer information about how thick its ice shell is.” What Europa’s Craters Tell Us This tiny moon is an enigma wrapped in shimmering ice. Its frozen surface hides a rocky inner core covered with a salt-water ocean. Like Earth, it experiences surface plate tectonics, driven by the core region’s heating. Inside, that heating drives currents of warmer water up from the core. That water gets forced to the surface, where it freezes and creates a new layer overlying any other features. This resurfacing happens every 50 to 100 million years. Incoming impactors carve out new craters in that “freshened-up” surface, which gives scientists some pretty easy-to-study craters. They aren’t terribly deep, however, which tells scientists a lot about the structure of the icy shell. Johnson, Wakita, and their team studied images from the Galileo spacecraft to analyze Europa’s craters. In particular, they focused on two multi-ringed basins imaged on this moon. They show two or more concentric rings around the point of the impact that created them. Such basins are fairly rare and usually indicate some kind of large, energetic impact. On Europa, their appearance and formation give clues to the thickness of the icy shell and their thermal structure, which is a way to understand how the shell conducts heat. Multi-ringed Crater Basins Tell a Tale In their study, the Purdue team simulated a multi-ring basin with varying thicknesses of ice. Those thicknesses influence the degree of tidal heating in the shell itself. They also help scientists understand how heat exchange occurs between the bottom of the shell and the underlying ocean. The team found that icy shells thinner than about 15 kilometers don’t show the kinds of multi-ringed basins that exist on Europa. However, a thicker one does. In particular, the best-fit simulation used a 20+ kilometer-thick shell. It consists of two layers: a 6-8 kilometer-thick conductive “lid” that covers up a layer of warm, convecting ice. One of Galileo’s images of the Tyre multi-ringed basin on Europa. There are at least 5-7 rings around the impact crater center. Courtesy: NASA/JPL/ASU. In addition to studying the craters, the team also looked at the types of impactors needed to create those multi-ringed basins on Europa. From the structures seen in the Galileo images, they concluded that the impactors would need to be around 1.5 kilometers in radius to create the multi-ringed basins. Smaller ones wouldn’t create the structures they saw, and bigger impactors would result in very different-looking craters and rings. What About Other Worlds? Europa isn’t the only world at Jupiter with an icy crust. Both Ganymede and Callisto also show cratering, with multi-ring basins. This tells us that these worlds also have to have thick enough icy crusts where such basins can form. Planetary scientists have suggested their crusts are at least 80 to 105 kilometers thick. In their paper, the Purdue teams suggest that since Europa’s crust is likely to be at least 20 kilometers thick (if not more) it’s also likely that Ganymede and Callisto have much thicker crusts than current predictions suggest. Callisto has many more craters than Europa and a thicker icy crust. Image credit: NASA/JPL Finally, although the paper doesn’t specifically address this, the fact that the scientists can deduce impactor size from the characteristics of the resulting craters does provide insight into the sizes of impactors available in Jovian “airspace”. To sustain these kinds of multi-ringed basins, you need a good population of sizable impactors to do the job. Also, for Europa to be so recently “refreshed” really does give a clue to the impact environment in the Jupiter system. While Ganymede and Callisto both have very old surfaces, the existence of “fresh” ice at various cratering sites tells us that they’re still being bombarded in recent times, although they’re not actively resurfacing themselves. These are all additional data points to consider when understanding the habitability of environments, particularly at Europa (and possibly at places such as Enceladus at Saturn). “Understanding the thickness of the ice is vital to theorizing about possible life on Europa,” Johnson said. “How thick the ice shell is controls what kind of processes are happening within it, and that is really important for understanding the exchange of material between the surface and the ocean. That is what will help us understand how all kinds of processes happen on Europa—and help us understand the possibility of life.” For More Information Planetary Scientists Use Physics and Images of Impact Craters to Gauge Thickness of Ice on EuropaMultiring Basin Formation Constrains Europa’s Ice Shell Thickness The post What Can Europa’s Surface Tell Us About the Thickness of Its Ice? appeared first on Universe Today.

[jmonterol]

MIRANDO AL SUR

El hemisferio sur de nuestro satélite está intensamente craterizado. Apenas encontramos mares en dicho hemisferio ya que su corteza es más gruesa que la del norte, por lo que allí no se han producido los flujos de lava que formaron los mares y los impactos meteoríticos no quedaban borrados. Si no disponemos de un mapa detallado, podemos perdernos en el intrincado laberinto de cráteres. 

En la imagen observamos la zona. Son numerosos los cráteres presentes, entre los que podemos destacar Maginus (1), Stofler (2) y Maurolycus (3). 

Maksutov Cassegrain 127. Cámara QHY 5II M.

[vjkstar-blog]

*Lunar* This was captured during the Jupiter-Saturn Conjunction day. MAUROLYCUS Crater is prominent here with Off-centered mountain to the North. Craterlets and lines of crest. *Craters* MAUROLYCUS BAROCIUS CLAIRAUT BUCH and many more *Captured on:* __Dec. 21, 2020 *Equipment*: __Sky-Watcher BK MAK 180mm Pro OTA... __Celestron AVX Mount... __ZWO ASI183MC Camera.... *Processing*: __2006 frames captured in SharpCap __Stacked in Autostakkert3 __Wavelets in Registax __Enhanced in Lightroom & Snapseed *Location:* __Bangalore, Karnataka, India *Sky Conditions:* __Bortle Scale 7.8 __Clear Sky, 8/10 __Few surrounding lights interference #lunar #astronomy #planetary #planetphotography #astrophotography #astrophotographyindia #moonphotography #bangaloreastronomyclub #delhiastronomyclub #sharpcap #skywatcher #celestron #snapseed #zwoasi #karnataka #india © Vijay Kapoor Follow My Instagram for More pics: http://Instagram.com/lunar_mountains_climber (at Bangalore, India) https://www.instagram.com/p/CNMb8CXJifZ/?igshid=uxskbdrvc80m

[scareferencedesk]

I am trying to find historical references to sunglasses or shades. All I can find are references to unreliable sources and dead ends. If you search '12th century chinese sunglasses' lots of articles appear but again, nothing I can use. Do you see anything in the later SCA time period? Thanks!!

*blows dust off Tumblr*

HI THERE.

So the issue I’m running into is a lot of books/websites make reference to smokey quartz being used in 12th century China to shield the eyes/expressions of judges in court - but there’s no citation for this. Which, as a SCAdian Sinologist, makes me raise an eyebrow.

LIke this image being captioned as 12th century smokey quartz glasses. I don’t believe it, because I don’t trust random Tumblr/Pinterest user as a reliable source.

Yeeeaaaah.

I do have images of Tang Dynasty eye-shades, from Secrets of the Silk Road (2010). They were only used as grave goods, though. Apparently the afterlife requires sunglasses. (Really, it was protection against sand and such, not unlike Inuit eyeshades.)

But here’s what I found - but remember your CRAAP test when going through these resources.

https://melnickmedicalmuseum.com/2010/02/17/medieval-sunglasses/

Developments in optometry can be traced back to the 1st century AD

The quest to correct and improve vision is one of man’s oldest medical challenges.By Victoria WardThe Telegraph, November 3, 2010

Medieval optometric traditions. [PDF]L Bieganowski - HINDSIGHT: Journal of Optometry History, 2009 - scholarworks.iu.eduYou can view more past issues of this journal here. [link]

SPECTACLES MENTIONED IN MEDIEVAL LITERATURE (just a citation)A BarnettAmerican Journal of Optometry and Archives of American Academy of Optometry. 19(2):92, FEB 1942

Franciscus Maurolycus and his Photismi de Lumine, a chapter in late medieval optics. (just a citation)(PMID:4922899)Tannebaum SJournal of the American Optometric Association[01 Oct 1970, 41(10):868-869]

http://www.medievalists.net/2016/03/medieval-eyeglasses-wearable-technology-of-the-thirteenth-century/

http://www.antiquespectacles.com/history/ages/through_the_ages.htmThis one makes me go mnnneeeh, but it has some images and some footnotes, though the whole thing isn’t cited super well imho.

The Invention of Spectacles between the East and the WestInteresting perspective - because SO MANY of these articles tend to be Euro-centric. This is refreshing, and has citations! Whee!

http://www.ideafinder.com/history/inventions/sunglasses.htmThis is one Wikipedia cites, and while it has some book references, those books don’t really have citations. So I’m kind of meh.

An uncommon history of common things. Volume 2Author: National Geographic Society (U.S.)Publisher: Washington, D.C. : National Geographic, [2015]

Panati’s extraordinary origins of everyday thingsAuthor: Charles PanatiPublisher: New York, NY : Chartwell Books, 2016.

[jmonterol]

Hacia el sur de la Luna

El hemisferio sur de nuestro satélite está intensamente craterizado, al contrario del hemisferio norte, en el que predominan los mares.

Hacia el cuarto creciente contemplamos ahora un paisaje que se parece a un campo de batalla, en el que destaca el cráter Maurolycus, de 114 km de diámetro y una profundidad de 4,7 km, hacia la mitad de la imagen.

Makstuvov Cassegrain 127. Cámara QHY 5II M

[vjkstar-blog]

*#Lunar Surface*... Captured on Tuesday, 2020.10.07.... *Description*: Wed, 07-Oct-2020 Waning gibbous, 19 days, 78% illuminated, 3,99,659.80 km away from Planet Earth... Features seen in this pic: *Craters*: MAUROLYCUS BAROCIUS GEMMA FRISIUS FARADAY and many more... *Equipment*: __#ExploreScientific ED 127mm Carbon Fiber f/7.5 AirSpaced Triplet APO Refractor... __#TeleVue 2.5x PowerMate... __TS Optics UV/IR Cut 2" Filter __#SoftwareBisque #Paramount MX Mount... __#ZWO ASI185MC #Camera.... *Processing*: __5001 frames captured in #SharpCap __Stacked in #Autostakkert3 __Wavelets in #Registax __Enhanced in #Lightroom & #Snapseed *Sky Conditions*: Minor Hazy Sky... 8/10 *Location*: #Whitefield, #Bangalore, #Karnataka, #India #astronomy #planetary #planetphotography #astrophotography #astrophotographyindia #moonphotography #bangaloreastronomyclub #delhiastronomyclub #karnataka #india (at Bangalore, India) https://www.instagram.com/p/CIUX3q4pM0H/?igshid=11xwi8i2nbglz