Monthly Archives: February 2018
A brief history of Martian exploration – as the InSight Lander prepares to launch
Helen Maynard-Casely, Australian Nuclear Science and Technology Organisation
Roughly every two years Mars and Earth wander a bit closer to each other, making the leap between these two planets a little easier. In July this year, Mars will only be about 58 million kilometres away – and NASA is set to take advantage by launching their next mission to the red planet in May 2018. The InSight Lander, will be the first Mars mission to investigate the planet’s “inner space”, and will listen for marsquakes to investigate the crust, mantle, and core.
InSight will join two rovers currently exploring the surface of Mars, and 14 spacecraft that are in orbit about it – albeit only six of which are currently sending us data.
Ice mined on Mars could provide water for humans exploring space
Why does Mars, the red planet, have such a hold over us?
There are, after all, seven (or eight) other planets to explore – and yet we seem to have such a hang up on this one.
I guess it’s the tantalising nature of Mars. Here is a planet that we could conceivably walk on (unlike the gas giants), without being crushed by atmospheric pressure (like on Venus), having to deal with the radiation of being closer to the sun (Mercury) or just being far too far away (like Pluto). It calls to us through science fiction and fact, a planet that is so like our own Earth, but so unlike it at the same time.
The six current operational missions show that the fascination with Mars isn’t limited to one country, as European, Russian, American and Indian space agencies all have stakes in these crafts.
For comparison: our other nearest neighbour, Venus, only has one spacecraft currently in orbit about it, Akatsuki the spacecraft that wouldn’t quit. In fact, after the dramatic ending of the Cassini spacecraft, the only other planet currently being orbited by an Earth-built satellite is Jupiter, with the Juno mission.
Juno mission unveils Jupiter’s complex interior, weather and magnetism
Water on Mars
But, while our progress to walking on Mars has been very slow, our progress in understanding our neighbour has been really quite impressive. When I started my planetary science degree in 2001, the course did not include sedimentology, the branch of geology that investigates how water has shaped rocks. It was deemed there was no point as no water has been seen on any other planet.
By the time I was in third year, the first years students behind me were getting well versed in how water could push around sand, silt and clay on other planets.
Finding water on Mars had been an obsession to many, and thanks to data from Mars rovers Spirit, Opportunity and latterly Curiosity we know that it’s there – just trapped in the rocks. A couple of years ago it was thought that we had even found water flowing on the surface of Mars, but that evidence is (ahem) drying up now.
Dear diary: another day in the life on Mars
However, whether the water flows or is trapped in the rocks, the next question is where is the rest of it? If many of the rocks we see on Mars had been laid down by water – where is that water now?
The answer would be tangled up with the fate of Mars’s atmosphere. Though pitifully thin now, it must have been thick enough in the past to support flowing water on the surface. The mission of the spacecraft Maven (along with others) has been investigating this question – and all evidence is pointing to the Sun as the culprit for Mars’ missing atmosphere, with the solar wind gradually stripping it away.
It’s often touted that we know more about the surface of Mars than we do the bottom of our own oceans – and in terms of mapping resolution that’s true. Through the efforts of four orbiting missions we know how old most of the surface is, as well as how active it has been.
You can spend a joyful afternoon of procrastination flitting through HiRISE images that show sweeping dunes and pock-marked plains on Mars. With these images we can really apply our understanding of processes on Earth to what makes up the surface of Mars – from the formations of geological features, the movement of dust and sand and how the ice caps change through the seasons.
What’s inside Mars?
So we know there is water on Mars, we know where its atmosphere went and also the shifts of its sands – but there’s a missing piece of the puzzle. What’s on the inside?
To be fair, in this respect the interior of our own Earth is just as much of a mystery – but we have had centuries of seismic studies. From monitoring the passage of earthquakes through our planet we have built a picture of the layers that make up its interior. From that we’ve been able to undertake experiments that recreate the conditions and add more to that picture. At the moment we can only guess at the conditions within the interior of Mars – something that the InSight mission will answer.
Before we colonise Mars, let’s look to our problems on Earth
After this, the next hurdle will be getting something back from Mars. We have a handful of meteorites that we know came from Mars, but having a sample that’s been collected and returned from a known location will priceless. NASA’s next rover, Mars 2020, will plan to do just this – but the return to Earth bit is still to be worked out.
From sample return to human exploration is still a massive step, and will require a number of innovations to get there. But with the knowledge we’ve built from the missions over the last decade, it’s becoming more of a reality.
Helen Maynard-Casely, Instrument Scientist, Australian Nuclear Science and Technology Organisation
This article was originally published on The Conversation. Read the original article.
Mythbusting Ancient Rome: did Christians ban the ancient Olympics?
Caillan Davenport, Macquarie University and Shushma Malik, University of Roehampton
Every two years, when the Winter or Summer Olympics comes around, we hear about how the games staged at Olympia in Greece since 776 B.C. came to a sudden end in the late fourth century A.D. The finger is pointed at the Christian Roman emperor Theodosius I (A.D. 379-395), who is said to have banned the Olympics in the 390s as part of a wider political program directed against pagan religion, its rituals, and its festivals.
The idea that the athletic contests – held in honour of the Greek god Zeus for over a thousand years – were shut down by a puritanical Christian emperor makes for a good story. But is it actually true?
Theodosius I did issue a series of edicts against pagan sacrifice in the years A.D. 391-392. These have been preserved in a collection of laws known as the Theodosian Code, which was compiled in the fifth century A.D. by the emperor’s grandson. An excerpt from one of these edicts states:
No person at all … shall sacrifice an innocent victim to senseless images in any place at all or in any city. He shall not, by more secret wickedness, venerate his lar with fire, his genius with wine, his penates with fragrant odours; he shall not burn lights to them, place incense before them, or suspend wreaths for them.
Neither this passage, nor any of the other edicts in the Theodosian Code, actually mentions the abolition of the Olympic Games, as the historian Ingomar Weiler has pointed out. Sacrifices and libations to the gods had long been a part of the ancient Olympics, as with other Greek festivals. But the evidence suggests that sacrifices had largely ceased to take place at these events by the mid-fourth century as a result of changes in religious practices.
The games at Olympia remained popular throughout the Roman period, with athletes competing both for their personal fame and for glory for their home city. A recently discovered inscription listing victorious athletes demonstrates that the games were still going strong through to Theodosius I’s reign. The court poet Claudian then refers to the Olympics in A.D. 399, after the emperor’s death.
The most conclusive evidence of the games’ survival after Theodosius I issued his ban on sacrifice can be found in the work of an anonymous literary commentator. He states that the Olympics ceased to be held in the fifth century A.D., during the reign of Theodosius I’s grandson, Theodosius II (A.D. 408-450):
Since the Temple of Olympian Zeus had caught fire, both the Elean festival and the Olympic Games came to an end.
Olympic festivals (named after the original games at Olympia) continued to take place elsewhere in the Roman empire as well. The Olympics at Ephesus are attested until A.D. 420, and they continued at Antioch in Syria until the early sixth century A.D. Even though public entertainments were often criticised by Christian clerics, a prominent Christian senator, Leontios, intended to stage his own Olympics in Chalcedon in the mid-fifth century A.D. He would not have dared to do this if the imperial administration had banned such festivals.
What did cause the games at Olympia to end in the fifth century A.D.? Archaeological evidence shows that the site and the infrastructure for the contests (such as the buildings used to house athletes) fell into disuse. The statue of Zeus, one of the seven wonders of the world, was removed from the temple and taken to Constantinople. The workshop of Phidias, who built the statue, was converted into a church. This evidence suggests a gradual decline and re-appropriation of the space at Olympia.
The historian Sofie Remijsen has argued that the end of the games was not the result of an imperial edict against paganism, but a change in economic circumstances. Long-term developments in the administration of the empire during the fourth century A.D. meant that rich elites increasingly had to sponsor contests out of their own pockets, and the civic funds set up to support the games were used for other purposes. The contests at Olympia ended because no one could afford it. Such a fate may eventually befall the modern games, as spiralling costs make hosting the Olympics an unattractive proposition.
Let the games continue
The notion that Theodosius I banned the Olympics has quite a history. Back in the 11th century, the Byzantine author Georgius Cedrenus cited the now familiar story of the ban, but it came back into the popular imagination with the advent of the modern Olympic Games under the auspices of Pierre de Coubertin in the late 19th century.
De Coubertin, a French aristocrat, had an inherent belief in the “character-building” capacity of sport. Alongside English educator William Penny Brookes, he formed a committee with a mission to restore the Olympic Games to their former glory, minus tripods, incense, and sacrifices. Athens was the place and 1896 was the year. Following the games, de Coubertin reflected upon his achievement in Century Illustrated Magazine:
It was a thrilling moment. Fifteen hundred and two years before, the Emperor Theodosius had suppressed the Olympic games, thinking, no doubt, that in abolishing this hated survival of paganism he was furthering the cause of progress; and here [opening the games] was a Christian monarch, amid the applause of an assemblage composed almost exclusively of Christians, announcing the formal annulment of the imperial decree; while a few feet away stood the archbishop of Athens, and Père Didon, the celebrated Dominican preacher, who, in his Easter sermon in the Catholic cathedral the day before, had paid an eloquent tribute to pagan Greece.
De Coubertin highlights a problem: for centuries newspapers, periodicals, and literature had propagated the belief that pagan practices, including the Olympics, had rightly been stamped out by the rise and spread of Christianity. Yet the modern Olympic founder was taking pleasure not only in the fact that the games had been revived but also that a Dominican preacher (who was, incidentally, also the inventor of the Olympic motto) had paid tribute to pagan Greece.
The answer to this apparent contradiction lies in de Coubertin’s wider modern Olympic message, which itself was based on an idealised version of Classical Greece. However critically Greek and Roman paganism were viewed, the status of Classical Greece as the home of Socrates, Plato, and Aristotle had always confirmed its place at the centre of European education. For physical educationalists such as de Coubertin, nothing topped the pinnacle of the Olympic Games, Greece’s oldest and most popular sporting event.
The key was to adapt the games to “the needs and taste of the age”. This meant no more trappings of religious cult. Thus, when Père Didon praised “pagan Greece”, it was as the home of “beauty, grace, and strength all in one” (de Coubertin’s words); the perfect, philosophical place to educate the energetic youth of any era.
Ending with a whimper not a bang
Ultimately, the blame for ending the Olympic Games was laid at the feet of Theodosius I because it was difficult for people to believe that the festival – a defining cultural symbol of antiquity – simply fizzled out after more than a thousand years. The conflict between paganism and Christianity in the later Roman empire became an easy way of explaining the end of this great athletic contest.
By the time de Coubertin came to revive the Olympics in the 19th century, this story was set in stone. In restaging the games in a modern world, he drew inspiration from the athleticism of the Classical Greeks, but left the pagan rituals of the ancient world far behind.
Caillan Davenport, Senior Lecturer in Roman History, Macquarie University and Shushma Malik, Lecturer in Classics, University of Roehampton
This article was originally published on The Conversation. Read the original article.
Friday essay: the erotic art of Ancient Greece and Rome
Craig Barker, University of Sydney
In our sexual histories series, authors explore changing sexual mores from antiquity to today.
Rarely does L.P. Hartley’s dictum that “the past is a foreign country” hold more firmly than in the area of sexuality in classical art. Erotic images and depictions of genitalia, the phallus in particular, were incredibly popular motifs across a wide range of media in ancient Greece and Rome.
Simply put, sex is everywhere in Greek and Roman art. Explicit sexual representations were common on Athenian black-figure and red-figure vases of the sixth and fifth centuries BC. They are often eye-openingly confronting in nature.
The Romans too were surrounded by sex. The phallus, sculpted in bronze as tintinnabula (wind chimes), were commonly found in the gardens of the houses of Pompeii, and sculpted in relief on wall panels, such as the famous one from a Roman bakery telling us hic habitat felicitas (“here dwells happiness”).
However these classical images of erotic acts and genitalia reflect more than a sex obsessed culture. The depictions of sexuality and sexual activities in classical art seem to have had a wide variety of uses. And our interpretations of these images – often censorious in modern times – reveal much about our own attitudes to sex.
When the collection of antiquities first began in earnest in the 17th and 18th centuries, the openness of ancient eroticism puzzled and troubled Enlightenment audiences. This bewilderment only intensified after excavations began at the rediscovered Roman towns of Pompeii and Herculaneum.
The Gabinetto Segreto (the so-called “Secret Cabinet”) of the Museo Archeologico Nazionale di Napoli best typifies the modern response to classical sexuality in art – repression and suppression.
The secret cabinet was founded in 1819, when Francis I, King of Naples, visited the museum with his wife and young daughter. Shocked by the explicit imagery, he ordered all items of a sexual nature be removed from view and locked in the cabinet. Access would be restricted to scholars, of “mature age and respected morals”. That was, male scholars only.
In Pompeii itself, where explicit material such as the wallpaintings of the brothel was retained in situ, metal shutters were installed. These shutters restricted access to only male tourists willing to pay additional fees, until as recently as the 1960s.
Of course, the secrecy of the collection in the cabinet only increased its fame, even if access was at times difficult. John Murray’s Handbook to South Italy and Naples (1853) sanctimoniously states that permission was exceedingly difficult to obtain:
Very few therefore have seen the collection; and those who have, are said to have no desire to repeat their visit.
The cabinet was not opened to the general public until 2000 (despite protests by the Catholic Church). Since 2005, the collection has been displayed in a separate room; the objects have still not been reunited with contemporary non-sexual artefacts as they were in antiquity.
Literature also felt the wrath of the censors, with works such as Aristophanes’ plays mistranslated to obscure their “offensive” sexual and scatalogical references. Lest we try to claim any moral and liberal superiority in the 21st century, the infamous marble sculptural depiction of Pan copulating with a goat from the collection still shocks modern audiences.
The censorship of ancient sexuality is perhaps best typified by the long tradition of removing genitals from classical sculpture.
The Vatican Museum in particular (but not exclusively) was famed for altering classical art for the sake of contemporary morals and sensibilities. The application of carved and cast fig leaves to cover the genitalia was common, if incongruous.
It also indicated a modern willingness to associate nudity with sexuality, which would have puzzled an ancient audience, for whom the body’s physical form was in itself regarded as perfection. So have we been misreading ancient sexuality all this time? Well, yes.
It is difficult to tell to what extent ancient audiences used explicit erotic imagery for arousal. Certainly, the erotic scenes that were popular on vessels would have given the Athenian parties a titillating atmosphere as wine was consumed.
These types of scenes are especially popular on the kylix, or wine-cup, particularly within the tondo (central panel of the cup). Hetairai (courtesans) and pornai (prostitutes) may well have attended the same symposia, so the scenes may have been used as a stimuli.
Painted erotica was replaced by moulded depictions in the later Greek and Roman eras, but the use must have been similar, and the association of sex with drinking is strong in this series.
The application of sexual scenes to oil lamps by the Romans is perhaps the most likely scenario where the object was actually used within the setting of love-making. Erotica is common on mould-made lamps.
The phallus and fertility
Although female nudity was not uncommon (particularly in association with the goddess Aphrodite), phallic symbolism was at the centre of much classical art.
The phallus would often be depicted on Hermes, Pan, Priapus or similar deities across various art forms. Rather than being seen as erotic, its symbolism here was often associated with protection, fertility and even healing. We have already seen the phallus used in a range of domestic and commercial contexts in Pompeii, a clear reflection of its protective properties.
A herm was a stone sculpture with a head (usually of Hermes) above a rectangular pillar, upon which male genitals were carved. These blocks were positioned at borders and boundaries for protection, and were so highly valued that in 415 BC when the hermai of Athens were vandalised prior to the departure of the Athenian fleet many believed this would threaten the success of the naval mission.
A famous fresco from the House of the Vetti in Pompeii shows Priapus, a minor deity and guardian of livestock, plants and gardens. He has a massive penis, holds a bag of coins, and has a bowl of fruit at his feet. As researcher Claudia Moser writes, the image represents three kinds of prosperity: growth (the large member), fertility (the fruit), and affluence (the bag of money).
It is worth noting that even a casual glance at classical sculptures in a museum will reveal that the penis on marble depictions of nude gods and heroes is often quite small. Classical cultural ideals valued a smaller penis over a larger, often to the surprise of modern audiences.
All representations of large penises in classical art are associated with lustfulness and foolishness. Priapus was so despised by the other gods he was thrown off Mt Olympus. Bigger was not better for the Greeks and Romans.
Myths and sex
Classical mythology is based upon sex: myths abound with stories of incest, intermarriage, polygamy and adultery, so artistic depictions of mythology were bound to depict these sometimes explicit tales. Zeus’s cavalier attitude towards female consent within these myths (among many examples, he raped Leda in the guise of a swan and Danae while disguised as the rain) reinforced misogynistic ideas of male domination and female subservience.
The phallus was also highlighted in depictions of Dionysiac revelry. Dionysos, the Greek god of wine, theatre and transformation was highly sexualised, as were his followers – the male satyrs and female maenads, and their depiction on wine vessels is not surprising.
Satyrs were half-men, half-goats. Somewhat comic, yet also tragic to a degree, they were inveterate masturbators and party animals with an appetite for dancing, wine and women. Indeed the word satyriasis has survived today, classified in the World Health Organisation’s International Classification of Diseases (ICD) as a form of male hypersexuality, alongside the female form, nymphomania.
The intention of the ithyphallic (erect) satyrs is clear in their appearance on vases (even if they rarely caught the maenads they were chasing); at the same time their massive erect penises are indicative of the “beastliness” and grotesque ugliness of a large penis as opposed to the classical ideal of male beauty represented by a smaller one.
Actors who performed in satyr plays during dramatic festivals took to the stage and orchestra with fake phallus costumes to indicate that they were not humans, but these mythical beasts of Dionysus.
Early collectors of classical art were shocked to discover that the Greeks and Romans they so admired were earthy humans too with a range of sexual needs and desires. But in emphasising the sexual aspects of this art they underplayed the non-sexual role of phallic symbols.
Craig Barker, Education Manager, Sydney University Museums, University of Sydney
This article was originally published on The Conversation. Read the original article.
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