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Exciting news from the heavens! Today NASA has reported that the Kepler mission has discovered 3 new planets in the habitable zones of two distant stars. Of the thousands of worlds so far discovered, these three are most likely to be habitable. Best of all the planets are crazy!
Kepler is a NASA space telescope which was launched on March, 2009. It makes use of an incredibly sensitive photometer to simultaneously & incessantly monitor the brightness of over 150,000 nearby stars. The brightness of a star dims slightly whenever an exoplanet transits between it and Kepler. Thanks to Kepler’s inhuman vigilance and robotic ability to perceive nearly imperceptible light changes, we are now discovering thousands of new planets, although most of them are Jovian sized gas worlds.
The three worlds reported today lie in the habitable zone—the region around a star where water exists in a liquid form (as it does here on beautiful Earth). Two of the newly discovered habitable zone planets are in a five planet system orbiting a dwarf star just two-thirds the size of the sun which lies 1,200 light years from Earth. Here is a diagram of the Kepler 62 system.
Of these five worlds, two lie in the habitable zone, Kepler 62f and Kepler 62e. Kepler 62 F is most likely a rocky planet and is only 40 percent larger than Earth. It has an orbit which last 267 (Earth) days. So far it is the smallest exoplanet found in the habitable zone. The star it orbits is 7 billion years old (as opposed to the sun which is four and a half billion years old) so life would have had plenty of time to develop. The other habitable zone planet in the Kepler 62 system, Kepler 62e is probably about 60% larger than our planet. It is somewhat closer to the star and astrophysicists speculate it may be a water world of deep oceans.
The other new exoplanet Kepler-69c appears to orbit a star very similar to Earth’s sun. It orbits at the inward edge of the habitable zone (nearing where Venus is in our solar system) so it may be hot. The planet is estimated to be about 70% larger than Earth, and is also thought to be a water world with oceans thousands of kilometers deep. I am finding it impossible not to imagine those vast oceans filled with asbestos shelled sea-turtles the size of dump trucks, huge shoals of thermophile micro-squid, and burning-hot chartreuse uber-penguins, but if any life is actually on Kepler-69c, it is probably extremely different from Earth life.
Of course Kepler can only find these planets; it is unable to observe very much about them. In order to do that, humankind will need some sort of huge amazing super telescope. Speaking of which, tune in next week when I write about humankind’s plans for building a huge amazing super telescope in the Chilean Andes!
Tonight is Yuri’s Night, when space enthusiasts around the world celebrate the first human trip to outer space made by Yuri Gagarin fifty two years ago. You can read about Yuri here. It is an excellent occasion to assess what is most exciting in space exploration. Unfortunately nobody has jumped forward to build a floating colony on Venus. Indeed NASA seems rather flat footed lately—building a series of colorless rockets and sending successive similar rovers to Mars. Fortunately there is one exciting mission which still has not definitively been cancelled because of budget stalemate.
The Europa Clipper mission is a $2bn dollar project to launch a probe to Jupiter’s moon Europa, a large icy satellite covered in cracked ice. Europa is slightly smaller than Earth’s moon and has a thin oxygen atmosphere. It is one of the smoothest items in the solar system. Astronomers believe that an ocean of liquid water lies beneath Europa which is warmed by tidal flexing (a process which causes orbital and rotational energy to be converted into heat). The surface of Europa is bathed in exotic radiation which rips apart water molecules and leaves oxidants like hydrogen peroxide. All of this means that Europa is the most likely planet in the solar system to harbor unknown life. It has even been theorized that beneath the ice the ocean could have black smoker type environments–and just possibly thermal vent or “cold seep” ecosystems.
Because of this, scientists have been anxious to get a closer look at the intriguing moon. Various proposals have been put forward for missions directly to the moon. The Pioneer and Voyager spacecraft took pictures of it as they flew through the solar system and subsequent missions also took readings and photos—but there has been no Europa-centric mission to really find out about the oceans below the cracked ice. One (amazing!) proposal was to send a nuclear powered melt probe to melt through the ice and sink to the bottom of the ocean, whereupon a mini-sub probe would emerge and explore the extraterrestrial ocean! That plan was shelved because it was too expensive (and nobody could figure out how to sterilize the probe). The proposed Europa Clipper mission is more modest but still quite amazing. Here’s how the Jet Propulsion Laboratory describes it:
The Europa Clipper mission would send a highly capable, radiation-tolerant spacecraft into a long, looping orbit around Jupiter to perform repeated close flybys of Europa.
The possible payload of science instruments under consideration includes radar to penetrate the frozen crust and determine the thickness of the ice shell, an infrared spectrometer to investigate the composition of Europa’s surface materials, a topographic camera for high-resolution imaging of surface features, and an ion and neutral mass spectrometer to analyze the moon’s trace atmosphere during flybys…The nominal Europa Clipper mission would perform 32 flybys of Europa at altitudes varying from 2700 km to 25 km.
That sounds amazing! Join me in lifting a glass to Yuri Gagarin and also join me in hoping that our moribund government funds this far-sighted mission to what might be life’s other home in the solar system!
Here’s another strange painting from contemporary master of surrealism, Mark Ryden. The subject is the “tree of life” a subject which comes up in religion, philosophy, science, and art. A tree of life from Greek myth even found its way onto this blog several Octobers ago. In Ryden’s interpretation, a princess with a bouquet and a baby sits suspended in a sentient tree. Hidden among the boughs are the seven platonic solids. Beneath her a bear and a monarch symbolize some unknown dualism.Somehow this painting combines Crivelli’s creepy diagram-like realism with half of the topics from Ferrebeekeeper. Seriously there are hymenopterans, crowns, trees, mammals, a snake, and garden flowers (not to mention all of the colorsfrom a master’s palate). The only things missing are a Chinese spaceship and an underworld god (and even the latter is hinted at by the death’s head and the tree’s occult eye).
As always I am moved by Ryden’s realism and by his eerie milieu, but I am at a loss as to the cohesive meaning. Perhaps there isn’t one and the piece is meant to convey atmospheric mystery and sacredness of a renowned tree which does not actually exist anymore than does platonic perfection.
This week’s posts [concerning translucent sea slugs, wasps named for a crazy pop star, an elusive Indochinese cousin of the cow, and whole sunless ecoystems] have all been about finding new life-forms. There is, of course, only one place such a topic can ultimately wind up—far beyond the living jungles, azure seas, and swirling clouds of our beautiful home planet, out in the immensity of space where the greatest question of all waits like a magic golden apple spinning in darkness.
Is there life elsewhere?
Unfortunately the current answer is incomplete: all known life–in all of its ineffable variety–is Earth-based…yet the universe is vast beyond comprehension. So I’m going to mark this down as “probably.”
Many ancient societies reckoned that other worlds existed. The Norse had their nine worlds joined together by the great ash tree Yggrdasil. The Chinese had myths about Chang’e and the Jade rabbit on the moon. Even the stolid Christians believe in heaven & hell, which are places filled with intelligent beings that are not on earth (ergo, alien realms somewhere out there in the multiverse). William Herschel, great astronomer of the Enlightenment, believed that life was everwhere—particularly everywhere in the solar system.
When humankind entered space age, we used our burgeoning technology to examine the solar system for signs of Sir William’s spacefolk. Although we did not find the Venusian space hotties we were looking for (dammit), we did discover that among our neighboring planets, there are several other possible homes for earthlike living things. The cloud tops of Venus are inviting and could host bacteria-like life (although I hope not, since I want us to build a second home there). For centuries, scientists and fabulists speculated about life of Mars. We now know that the Martian magnetosphere died and the planet’s atmosphere was swept away, but perhaps there are some hardy extremophile bacteria living in the Martian rocks somewhere. It’s a sad scenario to imagine them on their dying world—like little kids left in a bathtub going cold. Certain moons of Jupiter & Saturn seem to be the real best bet for life in the solar system. The Jovian moons Europa, Ganymede, and Callisto are all believed to have extensive liquid oceans beneath their crust. Likewise the Saturn moons Titan and Enceladus are believed to have subsurface water. The discovery of life on Earth which did not directly require photosynthesis (like the cold seeps from yesterday’s post) has given scientists hope that bacterial mats—or maybe something even more advanced–exists on one of these moons.
So maybe there are some bacteria analogs or conodont-like creatures squiggling around in some cranny of the solar system. Perhaps life takes on an unknown form and we already flew over a clever, good-hearted ammonia-based life form on Enceladus (which NASA analysts then promptly dismissed as a snowbank), but I doubt it. The true answers to the questions about life lie out there among the stars. Exoplanets are being discovered at a tremendous rate and everyone hopes that some of the more earthlike examples harbor life. Unfortunately our technology is nowhere close to being able to spot the planets themselves and gauge whether life is there by means of spectrograph. We are stuck waiting for peers who are either broadcasting radio signals or screwing around with the fundamental nature of existence in such a way that would bring them to our attention. Indeed as humankind’s technological savvy grows, scientists are looking for more sophisticated signs of advanced life such as black holes of less than 3.5 solar masses or sophisticated particle radiation which could only be created (or detected) by civilizations of huge sophistication. All we can say right now is that, after a hundred years of looking, we have not found a lot of radio chatter in our neck of the galaxy—which is an answer of sorts itself.
Perhaps we are among the first sentient beings in this area of space (or anywhere, for that matter). The first generation of stars had to live and die before there were any raw materials for chemically based life. It took billions of years to get where we are, and, despite a few perilous missteps and accidents, life on Earth has been lucky. In my opinion some of those planets we are discovering are almost certainly covered with microbial life, but not many have little green scientists in many-armed lab coats firing up their radio telescopes (or forging little suits of chain mail a few hundred years behind us).
In writing about the Curiosity rover, I humorously mentioned how much it looked like the aliens from golden age science fiction. It seems we are also broadcasting retro style messages to the stars. Above is the print-out version of the Arecibo message—one of the loudest broadcasts we have sent. It’s like a macramé knitted by Dr. Zoidberg’s great aunt or a valentine from Atari’s space invaders! Imagine if you pointed your radio telescope at the heavens and received a message like that! Maybe the aliens are scared of us or maybe they don’t want to talk to a species with such homespun tastes!
So, after the whole post we are no closer to knowing if there is life in the cosmos, but what did you expect? Did you think I would tell you some secret here before you saw it blaring out of every news station on the planet? [If you did think that, then thank you so much!] I believe that extraterrestrial life is out there. I even believe that intelligent extraterrestrials are out there, but the universe really is ridiculously, ridiculously vast. It’s going to take a while to find our fellow living beings. In the mean time have faith (which is not advice I thought I would be giving) and keep looking up at the cold distant heavens.
Imagine standing high above planet Earth and looking down at the blue and white band of seas surrounding Antarctica. You are looking at one of the most important features of the Earth’s surface. The turning of the planet and strong westerly winds drive the cold deep waters of the Southern Ocean into the planet’s largest and most powerful current system, the Antarctic Circumpolar Current (ACC). The clockwise current isolates the frozen continent into its own self-replicating climate. Since there are no great land masses lying in the ring of open water at these latitudes, the ACC also forces waters from the ocean depths up to the surface. This upwelling brings rich nutrients from the depths and causes immense blooms of phytoplankton (which in turn nurture life throughout all the world-ocean). Additionally the current stirs the circulation of the Atlantic, Pacific, and Indian Oceans.
The ACC has been known to sailors for centuries. A sailing ship can travel west along the current with great speed (if the sailors have the bravery and stamina to confront the fierce winds of “the roaring forties”). The “clipper route” was the fastest sailing route around the world, but it was dangerous. The three great capes (Cape Horn, the Cape of Good Hope, and Cape Leeuwin) all claimed innumerable lives as did wind, ice, and storm. Today the clipper route has been abandoned as self-powered ships bring their cargoes of plastic junk straight across the ocean from China (and then cut across the Panama Canal) but sailing enthusiasts still recognize the fastest way to ride the wind around the planet. The major circumnavigation sailboat races all travel the clipper route.
The true history and significance of the ACC vastly exceeds the paltry recent concerns of navigation and world trade. Geologists estimate that the ACC current began spinning around 34 million years ago at the end of the Eocene epoch as Antarctica split from Australia and drifted further south. When still connected, Antarctica and Australia had been a place where cold southern water and chill weather mixed together with tropical warmth—thus causing the whole planet to warm up. However when Antarctica drifted south, it started a series of climate feedback loops. The oceans around the continent began to freeze and ice started to build up on the mountains. An entire continental ecosystem began to change in the cold. The tropical forests (which had been filled with strange marsupials) began to die and become tundra. As the Oligocene progressed and Drake’s Passage widened, the rivers–once filled with catfish–turned to ice. The landmasses of Antarctica became crushed down under immense glaciers. Antarctica died in the cold. By 15 million years ago it was as it is now, home to only tardigrades, lichen, and a handful of visiting birds and seals.
Even now the Antarctic Circumpolar Current still isolates the continent from the warmth of the rest of the world. Yet through upwelling of iron and other nutrients, the current bolsters an immense fecundity of phytoplankton–the great primary producer of the ocean. Masses of copepods and krill feed on the algae and the diatoms and they in turn are eaten by fish, mollusks, mammals, birds, filter feeders…everything. The great southern oceans are among the most diverse and strange habitats for living things. It is there that the largest mollusk on the planet is found—which is the subject of an upcoming post.
It is spring again and the huge ornamental cherry tree which lives in my back yard is blooming (weeks earlier than it bloomed last year). Frequent readers know my fondness for both trees and flower gardens; and the Japanese cherry tree magnificently combines both things. It is a stately and elegant mid-sized tree of great vigor, which for one week (or less) is covered in clouds of gorgeous pale pink flowers. When it is fully in bloom, the tree is unrivaled in its beauty. Even the most lovely orchids and roses do not put on a display so simultaneously delicate and ostentatious.
Last year I wrote about the Hanami festival, which has steadily grown more important in Japanese society since its beginnings a thousand years ago during the Nara period. The flower appreciation festival now grips Japan as a national fervor which dominates the spring season and monopolizes the news. Hanami however is merely an outward expression of a much larger cultural concept, “Mono no aware” (物の哀れ) which translates approximately as “”the pathos of things” or “sensitivity to ephemera.”
Mono no aware involves a gentle wistful sadness for the impermanence of all things. The cherry blossoms come back year after year, yet childhood fades away before one even knows. Lovers with whom we dallied under the pink branches move out and drift away. The mayflies die. Our pets die. We die. Life runs by so quickly that we might as well be cherry blossoms ourselves, here for a beautiful fleeting moment before being shaken away into oblivion by some gust of wind or random happenstance. The idea of life’s beautiful brevity grows out of the flinty Buddhism for which Japan is famous and it gives rise to many famous tropes of Japanese culture (like the stoic samurai prepared to throw away his life in a lightning quick duel, or the suicidal lover, or the moth in the flame). There is an undercurrent of cupio dissolvi running through humankind and it seems particularly pronounced in the Japanese psyche.
However I like to imagine Mono no aware (and the cherry tree, and all trees, and all living things) less in terms of Japan’s Buddhism and more in terms of the animistic nature-based religions of East Asia like Shinto or Daoism. Look at the cherry blossoms more closely over many generations and you will see that they themselves change. Today’s blossoms are big showy gaudy things engineered by untold generations of nurserymen to appeal most directly to human taste. If you look long enough you will see that blossoms themselves are an innovation—a design leap by which plants appeal to animals to help out with the critical work of reproduction (and it works tremendously well! There is a cherry tree from Japan in my back yard in Brooklyn). The seasons themselves change, as demonstrated by this year’s unseasonable warmth (to say nothing of the warmth of the Eocene). The oceans rise and fall. Animals burgeon and fall into extinction. The world is made of clouds and storms and water rather than unchanging stone. In fact that metaphor doesn’t even hold up– geologists look at mountain faces and see the eons of erosion and shift with uncanny clarity. The stones themselves dance and shift and change as much as the fickle water (albeit so slowly that we can not clearly see them do so).
Year after year the blossoms come and go. It is beautiful and sad. But it would be sadder if they never opened up, or even sadder yet if, having bloomed, the pink petals never fell but hung forever as though in some fairy land. Change is a critical part of living things. Children grow up for a reason. Lovers quarrel and part because they did not belong together. The samurais and warriors and noblemen of yesteryear have been replaced by kinder smarter better people, and it is to be hoped that we will likewise be replaced. As you sit drinking beneath the flowers and the stars, don’t be overwhelmed by the fact that spring flashes by so fast. Be appreciative of the beauty and meaning you have today and start dreaming of how to make the next spring even better.
Today’s post topic is located in the depths of space far far away from the bats, pumpkins, and haunted deserts I have been writing about for October. The dwarf planet Ceres is located in the midst of the asteroid belt between Jupiter and Mars. The only dwarf planet in the inner solar system, Ceres is only 950 km (590 miles) in diameter, but it is sufficiently large to have become spherical from its own gravity (and it is by far the largest asteroid). Named after Ceres (Demeter), the mythological goddess of growing things whose daughter was abducted by Hades and who gave the secrets of agriculture to humankind through the farmer Triptolemus, the dwarf planet was discovered in 1801 by Italian astronomer Giuseppe Piazzi, a Roman Catholic priest of the Theatine order. Ceres was the first asteroid to be discovered and it comprises a third of the asteroid belt’s total mass.
The nebular hypothesis proposes that the solar system formed as a great cloud of space dust and gas coalesced into a disk which then further coagulated into small clumps, then into planetesimals, then into moon-sized planetary embryos, and finally into planets. Ceres is one of the few (or maybe the only) planetary embryos which formed four and a half billion years ago but somehow did not get smushed together with other like bodies to form a planet or hurled off into deep space. The dwarf planet probably consists of a rocky core surrounded with an icy mantle of frozen water. Ceres is believed to contains 200 million cubic kilometers of water–more fresh water than in all the lakes, rivers, clouds, swamps, ponds (and everything else) on Earth. The Hubble telescope has photographed several mysterious surface features on Ceres including a dark spot believed to be a crater (now informally named after Piazzi) and several bright spots, the nature of which is unknown.
Astronomers are profoundly curious about Ceres and hope to better understand the history of the solar system by examining this surviving planetary embryo. Additionally, the chemical makeup of Ceres is similar to that of Earth. Scientists seeking extraterrestrial life have concentrated on Europa and Mars, but Ceres is next on their short list.
Astronomers will soon have some of their answers about Ceres. The asteroid probe Dawn is currently orbiting the asteroid Vesta–but its mission there is scheduled to end in July of 2012. At that point Dawn will power up its ion thrusters and fly to Ceres. In February of 2015 Dawn will enter permanent orbit around the little planet and we will finally have some of our answers.
According to the New York Daily News, nobody has seen a wild rabbit in Central Park since 2006 (way to horde a story for Easter, Daily News). The indigenous eastern cottontail, Sylvilagus floridanus, which once flourished in Central Park, seems to have been completely eradicated from Manhattan. One ecologist fairly convincingly blamed the ubiquitous raccoon for spreading parasites (I am inclined to agree after seeing the havoc those masked bandits can wreak upon a garden or anything else) but nobody truly knows the cause for the bunnies’ vanishing act: other potential culprits include feral cats, eagles (!), coyotes, and disease.
The big story of our time—and, indeed the big story since the Hadean era, when life apparently emerged from the slime—is the peculiar and complicated relationships within ecosystems. I would like to make this a major theme of subsequent posts (after all it is the underlying tale of all living things), but right now I’m just sad about the rabbits. Hopefully Prospect Park and Greenwood cemetery still have bunnies. I’m pretty sure I’ve seen them there more recently then 2006, but I’m going to have to keep my eyes peeled and ask my Brooklyn neighbors to do the same.