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On Thursday, humankind is deliberately crashing a spaceship into another planet! We could easily be the evil aliens in someone else’s space drama. Well, at least we could be, if there were any remote chance that Mercury, the intended target of our bombardment, were a possible haven for life. And bombardment is not really the right word: what is actually scheduled is the seemly & rational conclusion to NASA’s MESSENGER mission, a highly successful exploration of the solar system’s mysterious innermost world. The mission has been ongoing for more than a decade (a decade of our Earth time—or nearly 40 Mercury years).
The 485-kilogram (1,069 pound) MESSENGER spacecraft was launched from Cape Canaveral in August 2004. The space probe has an awkward and contrived government acronym, which is why I keep talking about it in all caps—I’m not shouting (although planetary exploration does make me very excited). The craft took some amazing pictures of Venus (a planet which always calls to me) on its way to Mercury. Then MESSENGER flew by the small planet multiple times before entering orbit on March 18, 2011 (the first human spacecraft to do so). Since then MESSENGER has extensively scanned and mapped the surface of Mercury—a planet which is surprisingly elusive to astronomers because of its proximity to the sun. The mission revealed some surprising results which are leading to big new questions.
Mercury has a small diameter—it is actually smaller in area than some of the moons of Saturn and Jupiter—but it has substantial mass because much of it is made of heavy metals. The face of the small world is thought to be ancient: scientists speculated that its bland pitted face might date back to the formation of the solar system, but it seems that Mercury does harbor secrets.
The mission featured a big surprise. Messenger found surface water in the form of ice frozen inside the polar craters of Mercury. This was not really a shock—astronomers have suspected that ice was present due to radio-telescope readings. What was surprising was that the ice was coated with tarlike black goo. My poor roommate (who is always wandering the house pointing at films, stains, and accretions in horror) would not be surprised by a black coating on anything, however scientists were taken aback because Mercury was not thought to have any “volatile” compounds. According to the current models of planetary formation, elements like chlorine, sulfur, potassium and sodium should have boiled away during the cataclysmic high-temperature formation of Mercury…yet there they are, like the scum in my kitchen. The scientific data from MESSENGER is likely to force a rethink of planetary formation (although frankly, considering all of the weird exoplanets that are being discovered, scientists probably need to refine their theories about planetary accretion anyway). The mission also measured subtle planetary flux which should give us a better sense of Mercury’s composition and internal workings.

The yellow patches show areas where water ice is believed to exist. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)
All good things must end, however, and MESSENGER has run out of fuel for maneuvering. Mission controllers have opted for an operatic exit and they are smashing the craft into the planet’s surface at 8,750 miles per hour (nearly four kilometers per second). This should create an 18 meter (50 foot) wide crater. Future scientists will have a known fresh disturbance to use as a benchmark for assessing the ancient craters of Mercury. Perhaps the plume will reveal some interesting secrets as well.
Unfortunately, it will be a while before we see the results of our destructive acts. The site of impact is hidden from Earth, and we have no other spacecraft in any proximity to Mercury. A European and Japanese collaboration called BepiColombo is scheduled to launch from Earth in 2017 and arrive at Mercury in 2024. Perhaps we will have new questions for whatever answers MESSENGER is about to divulge in its unseen but spectacular final act!
Update: Through some grotesque oversight, NASA failed to portray MESSENGER’s final moments through the magic of art. I took the liberty of providing my own interpretation above. NASA did not return my questions about whether the spacecraft will wail in a plaintive manner as it impacts the surface–so I am forced to assume that it will. Did I mention that Mercury has no atmosphere? You should probably ignore that…
One of life’s disappointments is the dearth of fine art concerning outer space. Outer space is vast beyond imagining: it contains everything known. Indeed, we live in space (albeit on a little blue planet hurtling around an obscure yellow star)–but cosmic wonders do not seem to have called out to the greatest artists of the past as much as religious or earthly subjects. There are of course many commercial illustrations featuring the elements of science fiction: starships, ringed planets, exploding suns, and tentacled aliens (all of which I like) and there are also didactic scientific illustrations, which attempt to show binary stars, ring galaxies, quasars and other celestial subjects. Yet only rarely does a fine artist turn his eyes towards the heavens, and it is even less frequent that such a work captures the magnificence and enormity of astronomy.
Fortunately the Dutch artist MC Escher was such an artist. His space-themed engravings utilize religious, architectural, and biological elements in order to give a sense of scale and mystery. The familiar architecture and subjects are transcended and eclipsed by the enormity of the cosmic subjects. Here are two of his woodcuts which directly concern outer space.
The first print is a wood engraving entitled The Dream (Mantis Religiosa) shows a fallen bishop stretched on a catafalque as a huge otherworldly praying mantis stands on his chest (the whole work is a sort of pun on the mantis’ taxonomical name Mantis religiosa “the religious mantis”. The buildings arround the bishop and the bug are dissipating to reveal the wonders of the night sky. The bishop’s world of religious mysteries and social control are vanishing in the face of his death. Greater mysteries are coming to life and beckoning the anxious viewer.
The colored woodcut “Other World” shows a simurgh standing above, below and in front of the viewer in a spatially impossible gazebo on an alien world. The simurgh is a mythical animal from ancient Persian literature and art which combines human and avian elements. Sufi mystics sometimes utilize the simurgh as a metaphor for the unknowable nature of divinity. Yet here the simurgh is dwarfed by the craters beneath him and by the planetary rings filling up the sky above. A strange horn hangs above, below, and to the side of the viewer. Perhaps it is a shofar from ancient Judea or a cornucopia from the great goat Amalthea. Whatever the case, the viewer has become unfixed in mathematical space and is simultaneously looking at the world from many different vantage points. A galaxy hangs in the sky above as a reminder of the viewer’s insignificance.
Above all it is Escher’s manipulation of spatial constructs within his art that makes the viewer realize the mathematical mysteries which we are daily enmeshed in. The multidimensional geometric oddities rendered by Escher’s steady hand in two dimensions characterize a universe which contains both order and mystery. Giant bugs and bird/human hybrids are only symbols of our quest to learn the underpinnings of the firmament. Escher’s art is one of the few places where science and art go together hand in hand as partners. This synthesis gives a lasting greatness to his artwork, which are undiminished by popularity and mass reproduction.
On July 1st 1916 at 7:28 AM, the British Army detonated the Lochnagar mine–two underground charges of a high explosive compound called ammonal (respectively 24,000lb and 30,000lb) thereby entirely vaporizing a large section of trenches filled with German infantryman. This was only one of 17 giant mines which the British exploded in Northern France that morning. In fact there were an original total of 21 buried explosive charges—but, because of various exigencies, two of these were not exploded until much later on July 1st (one of the remaining charges was detonated by lightning many years after the war, and another was never found).
The explosions followed 16 days of heavy artillery fire and immediately preceded a general infantry charge which began the Battle of the Somme. It was an appropriately apocalyptic beginning of the worst day ever for the British armed forces—by midnight there were 57,470 British casualties (19,240 of whom died of their injuries). The battle of the Somme itself ground on until 18 November, 1916 by which point it had claimed over 1,200,000 casualties from both sides. More than three hundred thousand people were killed during the course of the battle.
Today the huge scars from that morning have been filled in by farmland—with the notable exception of Lochnagar crater, which was privately purchased and left as a monument to the futility and destruction of World War I. Erosion is taking its toll on the crater, yet, even after nearly a century, the great hole still has a diameter of approximately 91 meters (300 feet) and a depth of 21 meters (70 feet). Lochnagar crater is said to be the largest extant crater created by human artifice during war (obviously pit mines and nuclear test sites are much larger). It still possesses a unique horror—a round void in the placid farmlands of Picardy. To this day the grain fields around it yield rusted rifles, dented helmets, and skeletons in addition to wheat.
I am writing about this disquieting pockmark as preparation for writing about Armistice Day later this week, when we can reflect on World War I — surely one of the most comprehensive disasters to befall humankind. I am also writing about the largest wartime crater on earth, as an opportunity to note how feebly small it is in comparison to even modest meteor impact craters such as Lake Lonar or Kaali Craters, both of which happened in the remote past–to say nothing of giants like the Manicouagan Crater in Quebec which has a diameter of 70 kilometers (even after 225 million years of erosion).
Of course all of this should really be cause to reflect on how lucky we are—not only have we missed the Great War (except for you, Florence Green, if you’re reading this), but we have also missed all sorts of other unfortunate events. Today at 6:28 PM EST, an asteroid passed by the Earth. At its closest point it was nearer to us than the moon. The space rock (unsentimentally named “2005 YU55”) was about the size of an aircraft carrier and was traveling faster than 13 km (8 miles) a second. An amateur astrophysicist on the web estimates that it would have created a crater more than 5 kilometers in diameter if it had struck a limestone region of Earth.
Born in 1857, Konstantin Tsiolkovsky grew up in a remote province of Tsarist Russia with his 17 brothers and sisters. His father, Edward Ciołkowskia, was a Polish orthodox priest who had been deported deep into the heart of Russia as a result of his political activities. Edward Russianized his name and married an educated Tartar woman: the two then proceeded to have many children (of whom Konstantin was fifth). When he was 9 years old Konstantin caught scarlet fever and barely survived. Once he finally recovered, he was deaf or very nearly so. Because of his hearing problem he was denied admittance to elementary school and he quickly fell behind his peers. His mother died when he was 13 and his family’s poverty prevented him from moving forward in the world.

Konstantin Tsiolkovsky on a Soviet Stamp ( I'm sorry that I'm still thinking about stamps even in the midst of this remarkable tale)
This is a very grim and Russian story so far but here is where it becomes extraordinary. Isolated and alone, Konstantin made his way to Moscow. He was teaching himself at the Chertkovskaya Library where a very strange and brilliant man named Nikolai Fyodorovich Fyodorov was an employee. Fyodorov was a transhumanist philosopher and a futurist who believed that humankind’s path forward leads ultimately to technological transcendence and divinity. He felt that scientific progress would eventually lead to physical immortality and then ultimately to the resurrection of all people who have ever died (Fyodorov liked to think “outside of the box”). With the tutelage and mentorship of Fyodorov, Tsiolkovsky taught himself math. He took an active interest in Fyodorov’s scientific philosophy and even began to wonder what could be done with all of the immense number of dead humans if and when they returned. The thought led Konstantin Tsiolkovsky to think about outer space and the subject came to dominate the rest of his life.
Inspired by Fyodorov’s wild ideas and by the science fiction of Jules Verne, Tsiolkovsky began to invent the science necessary to carry humans up gravity’s well and beyond this world. The Encyclopedia of Science summarizes his work as follows:
Tsiolkovsky produced some of the earliest scientific literature on spaceflight, including the classic work Exploration of Space by Means of Reactive Apparatus (1896). In 1898 he derived the basic formula that determines how rockets perform – the rocket equation. This formula was first published in 1903, a few months before the Wright brothers’ historic manned flight. It appeared, together with many other of Tsilokovsky’s seminal ideas on spaceflight, in an article called “Investigating Space with Rocket Devices,” in the Russian journal Nauchnoye Obozreniye (Science Review). Unfortunately, the same issue also ran a political revolutionary piece that led to its confiscation by the Tsarist authorities. Since none of Tsiolkovsky’s subsequent writings were widely circulated at the time (he paid for their publication himself out of his meager teacher’s wage), it was many years before news of his work spread to the West.
No one understood Tsiolkovsky’s work at the time he wrote them. Today the basic concepts behind space travel—such as multistage rockets, orbital velocity, and compressed liquid fuels–are widely understood [Ed. not according to the comments of any given article about space exploration on CNN] but at the dawn of the twentieth century they were wildly fantastic and incomprehensible to international scientists much less to Tsarist Russians. Tsiolkovsky did not stop at elementary proposals of space travel and the fundamental underpinnings of rocketry. He also came up with sophisticated ideas such as using graphite rudders for rocket telemetry, cooling combustion nozzles with cryogenic propellants, and pumping fuel from storage tanks into the rocket’s combustion chamber.
His neighbors regarded him as an eccentric outsider—a deaf schoolteacher mumbling gibberish—but Tsiolkovsky kept on coming up with brilliant ideas, some of which are still ahead of their time. In 1895 he was inspired by the Eiffel Tower to propose the creation of a 35,790 kilometer tall tower surmounted by “a celestial castle” from which objects could be launched directly into space: it was the first conception of a space elevator. By the twenties, as the scientific minds of the new Soviet Union began to realize how innovative Tsiolkovsky’s ideas were, he was contemplating sustainable space habitats and galactic colonization.
Today Konstantin Tsiolkovsky is considered the father of theoretical astronautics—or more simply the father of spaceflight. Sputnik was launched on his one hundredth birthday. Soviet propagandists built many statues and monuments to Tsiolkovsky but the greatest tribute to his legacy (apart of course from humankind’s space programs–which grew from his ideas) has been seen by only a few humans. Tsiolkovsky crater, the most prominent feature on the dark side of the moon is named in his honor.
Between 7500 and 2500 years ago, a space object composed of coarse octahedrite fell into Earth’s gravity well and broke into huge flaming pieces. Although much of the object’s mass and velocity were lost passing through the atmosphere, a number of large pieces (with a total mass estimated to be about eighty tons) struck the Saareemaa island in what is now northern Estonia. Since these fragments were traveling between 10 and 20 kilometers per second, a substantial amount of kinetic energy was released: the impact probably had approximately the same energy yield as the Hiroshima atomic bomb. The area was inhabited by Bronze Age humans and those who were not incinerated must have been appalled when a ball of incandescent hellfire swallowed a whole forest with deafening thunder.
The impact formed the Kaali crater field. Since the impact occurred so recently, the craters are still quite pronounced. The largest crater has a diameter of 110 meters (330 feet) and contains a freshwater lake at its bottom. The smallest crater (which I unfortunately could not find a picture of) is only about 10 meters across and a meter deep.
As at Lake Lonar and the Great Serpeant Mound Crater, there is sacred architecture affiliated with the Kaali Crater field. During the Iron Age, unknown masons constructed a 470 meter long stone wall around the lake. Since the body of water is nearly a perfect circle it looks deceptively small but, aas you can see in the picture at the top, the lake is actually large and deep. Kaali Lake has been a sacred lake for a long time and local reverence suggests that it still is. Additionally, numerous domestic animal remains from the area around the lake indicate that the area has been a sacrificial ground for thousands of years. In fact some animal sacrifices date as recently as the 17th century—it seems that Estonia’s conversion to Christianity did not preclude some surviving pagan traditions. Certain stories from Finnish mythology seem to relate to the lake: one tale relates how a trickster god stole the sun. The virgin goddess of the air, trying to make manufacture a second sun let a flaming spark fall down—it drifted into the forested islands south of Finland and caused a great fire which humankind saved and used for heating, cooking, and forging.
In the impact crater of a giant meteor, an unknown ancient race built the largest snake effigy on the planet… Is this the beginning of a lurid sci-fi fantasy novel? No, it’s the description of an actual place. This haunting structure which was built for unknown reasons by a mystery race can be found in deepest…um…Ohio!
The Great Serpent Mound is an ancient earthwork located in Adams County, Ohio. Shaped like a snake devouring an egg, the mound is 410 meters (1,330 feet long) and a meter tall (3 feet). The undulating form of the snake has been tied to astronomical phenomena but it is unclear why it was built or what purposes (if any) it served. It reminds me somewhat of the Rainbow Serpent, Wadjet, Nüwa, and other snake deities, but since there is no historical or ethnological record of its purpose, such connections are only airy speculation.
An even greater mystery of the structure is who built it. Over the years scholars and archaeologists have variously posited that it was created by the Adena culture (1000 to 200 BC), or by tribes from the Hopewell tradition (200 BC to 500 AD), or by the Fort Ancient culture (1000 AD-1750 AD). Of course the mound was known long before its “discovery” by European settlers. Unfortunately, the Native Americans of the region seemed just as confused about its provenance as anyone. For what it is worth, Native Americans of the Lenni Lenape (later Delaware) nation told missionaries that the mound was built by the Allegheny or Allegewi People, (who were also sometimes called the Tallegewi), a possibly mythical progenitor race who lived in the Ohio Valley in ancient times before 1200 BC.
It is obvious that a date is thoroughly confused when it varies by as much as 3,000 years! Fortunately there are a few pieces of actual evidence associated with the mound. Adena graves were found and excavated near the Serpent Mound (Adena people were culturally and physically distinct from other peoples of the Ohio valley). Other Adena sites have revealed that these peoples built elaborate circular and winding earthworks and had a fascination with astronomical phenomena. The few pieces of Aedena art even seem to bear an aesthetic connection.
Frustratingly, carbon dating of charcoal taken from within the mound seems to indicate that it was built (or at least refurbished) long after the Adena culture declined and vanished. Conducted in the nineteen nineties, these tests indicated that parts (or all) of the Serpent Mound was built around 1070 AD. The mound would thus have been made by people of the Fort Ancient Culture–but the Fort Ancient people do not seem to have evinced the same artistic and cosmological sensibilities as are reflected in the mound. Additionally the mound was uncharacteristic of Fort Ancient culture in its lack of buried valuables.
Charcoal fragments are easily displaced by bioturbation and burrowing animals, so the carbon dating stands in question. The Fort Ancient people are known to have had contact with the intense pyramid building, city-dwelling (serpent worshipping) Mississippian cultures which were flourishing from Illinois down to the Gulf of Mexico. Perhaps outside cultural influences lead to the mound’s construction. Furthermore the Fort Ancient people got their name from the fact that they lived on huge earthworks built by the vanished Hopewell people (who are also potential builders of the Great Serpent Mound). Perhaps the Fort Ancient tribes also renovated and re-purposed the Great Serpent Mound from older Adena or Hopewell builders. We simply are not certain about who crafted the Great Serpent Mound–but it is to be hoped that further evidence will clarify the issue.
By now space enthusiast readers are probably chaffing at all of this human history: in the first paragraph I mentioned that the Great Serpent Mound is located in a meteor impact crater. Waymarking.com relates how the crater was discovered by scholars studying the Great Serpent Mound:
After the mound was discovered it was noticed that the geology of the surrounding area differed greatly from that found elsewhere in Ohio. John Locke, who explored the area in the 1830’s noted that “a region of no small extent had sunk down several hundred feet, producing faults, dislocations and upturnings of the layers of the rocks.” At the time he thought the he had discovered a “sunken mountain.” Some of the areas look like they have slid straight down while others have risen almost 1,000 feet straight up. Over time more evidence has been found. Eventually in the 1970’s, core samples were taken from the crater area. Scientists have found iridium at levels up to 10 times that normally found in the Earth’s crust, soot from what may be scorched limestone, deformed grains of sand, and quartz with microscopic fractures. In addition “shatter cones” have been found from the surface down similar to those found in Nevada at nuclear weapon test sites.
Such features are the smoking gun evidence of meteor strikes and scientists have since concluded that the crater is about 250 million years old (which was approximately the same era the Paleozoic came to an end). Over a quarter of a billion years the crater has deformed greatly, to such an extent that it is not immediately recognizable (unlike more contemporary strike sites such as Lake Lonar).

Lake Lonar
Approximately 650,000 years ago, an outer space object–either a comet or a meteor– struck the Deccan plateau (an immense basaltic flow on the Indian subcontinent dating back to the twilight of the dinosaurs). The resultant crater in Maharashtra is now the sight of a very interesting saltwater lake, Lake Lonar. The geology of this region has been intensely studied because the great basaltic mass of the Deccan traps is thought to mirror the igneous geology of Mars and the moon.
Lake Lonar proper is nearly circular with a diameter of 1.2 kilometers. The greater meteor crater rim is about 1.8 kilometers and the crater measures 500 feet deep in the deepest part of the lake. In addition to the obvious features of an extraterrestrial impact (um, a large round hole), the region features many other unique geological signs of such an event. Maskelynite, a material only naturally known from meteorites and meteorite impact areas, is found around Lake Lonar, as are silicate minerals with planar deformation features (distinctive high-stress crystalline irregularities which have only been found in silicates from meteorites, craters, and nuclear test areas). The deeper geology of the lake region displays shatter cones in the bedrock, and extreme deformation of the basalt layers. Finally the surrounding region has been spattered with a non-volcanic ejecta blanket.

Lake Lonar: pink-beige indicates bare ground, blue and off-white indicate human-made structures, dark blue indicates water, green indicates vegetation, and dull purple indicates fallow fields (NASA: Terra Satellite)
By measuring the accumulated radiation in certain crystals (aka thermoluminescence) scientists had assigned an approximate age of 50,000 years to the crater. However a 2010 study of isotopic Argon in Lonar impact melt rock estimated the true time of impact to be 650,000 years ago (give or take 80,000 years). The compelling 2010 study drily notes “The discrepancy between the thermoluminescence age and the new isotopic 40/Ar/39Ar age is flagrant.”
Several abandoned temples and archaeological sights are also located around the lake. For example, the beautiful Daitya Sudan Temple to Vishnu was built by the Chalukya Dynasty which ruled of Maharashtra from the 6th and 12th centuries. The local town, Lonar, still has an active temple to Vishnu, the great protector of the universe who features prominently in local legend. According to the Skanda Purana (a canon of Hindu scripture universally cited when a story is doubtful or can not be found elsewhere) a great underworld demon, Lonasur, lived where Lake Lonar is today. From time to time the demon would venture from his subterranean abode to torment the countryside and challenge the gods. Assuming the form of an extremely beautiful young man, Vishnu…somehow convinced the demon’s sisters to divulge where the monster could be found. The god then lifted up the countryside like a great lid and found the demon hiding in his huge circular lair. After Vishnu slew the demon, the demon’s dwelling place filled up with water made salty by the fiend’s blood.
Although threatened by India’s ever growing sprawl, Lonar Lake is a rich wetland with abundant wildlife—particularly birds. The jungles, fields, and lake are a birder’s paradise featuring flamingos, grebes, black-winged stilts, dabchicks, ducks, shell-ducks, shovellers, teals, herons, rollers, parakeets, hoopoes, weavers, larks, tailorbirds, magpies, robins, swallows, peacocks, coots, white-necked storks, lapwings, grey wagtails, black droungos, green bee-eaters, and tailorbirds (to name just some).
Mimas is a moon of Saturn. Discovered late in the 18th century by the astonishing Sir William Herschel, Mimas is the smallest (known) astronomical body which is spherical from self-gravitation (here is an explanation of what that means). The moon’s most noteworthy feature is an enormous impact crater named Herschel which is 130 kilometres (81 mi) across–about the same as the distance between New York and Philadelphia. Wikipedia gives some additional dimensions of the crater:
Herschel’s diameter is almost a third of [Mimas’] diameter; its walls are approximately 5 kilometres (3.1 mi) high, parts of its floor measure 10 kilometres (6.2 mi) deep, and its central peak rises 6 kilometres (3.7 mi) above the crater floor.
If you were standing in the crater (which you should not do!) it would be a great broken plain surrounded by cliffs thirteen times taller than the Empire State Building. In the middle you could see a huge mountain slightly shorter than the tallest mountain in North America. Jagged craters and valleys as deep as Lake Baikal would lie around you.

Mimas orbits above Saturn. The dark lines are shadows cast by the rings (Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA)
A great series of impact cracks on the opposite side of the moon would seem to indicate that the collision which created Herschel nearly shattered Mimas (which is composed principally of ice).
The moon’s name might be of passing interest to followers of my Deities of the Underworld category. In Greek mythology, Mimas was one of the monstrous sons of Gaia. He was born with snakes for legs and he was clad in full armor. In the Aeneid, Virgil tells the story of how Hephaestus imprisoned Mimas under Vesuvius during Gaia’s great rebellion against the Olympian gods. As the imprisoned giant shakes so to does the area around the Bay of Naples.
As I was researching this article, I was struck by how many moons Saturn has! As a special bonus feature, here is an alphabetic list of Saturn’s named moons (several more remain anonymous): Aegaeon, Aegir, Albiorix, Anthe, Atlas, Bebhionn, Bergelmir, Bestla, Calypso, Daphnis, Dione, Enceladus, Epimetheus, Erriapus, Farbauti, Fenrir, Fornjot, Greip, Hati, Helene, Hyperion, Hyrrokkin, Iapetus, Ijiraq, Janus, Jarnsaxa, Kari, Kiviuq, Loge, Methone, Mimas, Mundilfari, Narvi, Paaliaq, Pallene, Pan, Pandora, Phoebe, Polydeuces, Prometheus, Rhea, Siarnaq, Skadi, Skoll, Surtur, Suttung, Tarqeq, Tarvos, Telesto, Tethys, Thrym, Titan and Ymir.