You are currently browsing the category archive for the ‘Space’ category.
During the last several years one of the most exciting aspects of astronomy has been data from two orbiting space observatories concerning planets which lie outside our solar system. The NASA space telescope Kepler discovers such planets by simultaneously measuring the light from thousands of stars for the faint dimming that occurs when a planet passes between the star and Kepler. The French satellite COROT (“COnvection ROtation and planetary Transits”) finds exoplanets by tracking the slight oscillations in distant stars caused by the gravitational tug of orbiting planets. The subtlety and elegant precision of both methods is astounding.
Sadly such astonishing engineering seems to have been near the edge of our technological abilities. Yesterday Kepler went into safe mode (a sort of automatic shut-down triggered by a crisis). Apparently a reaction wheel (a flywheel used to orient the spacecraft in relation to the stars) failed and Kepler can no longer be aimed properly. The orbital observatory initially had four reaction wheels—one of which was a spare– however the spare wheel failed in July of 2012 and at least three wheels are required to operate the satellite. If NASA cannot somehow reactivate the flywheel, then the mission is over.
Likewise on November 2, COROT suffered from a computer failure which made it impossible to collect data from the satellite and its status remains uncertain. Most likely it is offline forever. So our ability to find huge numbers of exoplanets via space observatory has temporarily been halted.
Kepler was launched in 2009 for a four year mission, however the mission was recently extended until 2016 (since it took longer to collect and make sense of the data then initially planned). At last count Kepler had discovered 132 planets and was monitoring more than 2,700 further candidate planet. As of November 2011, COROT had found 24 new worlds and was screening around 600 additional candidates for confirmation. Additionally two years of Kepler data has been downloaded but not yet interpreted so post-mortem discoveries may lie ahead.
It is frustrating that the age of almost daily discovery of new worlds has come to a temporary end due to equipment failure, however a new generation of planet finding missions is already on the drawing board. To quote The Guardian:
The European Space Agency announced last year that it would launch the Characterising Exoplanets Satellite (Cheops) in 2017 to study bright stars with known planets orbiting them. Nasa’s successor to Kepler will be the Transiting Exoplanet Survey Satellite (Tess), which will conduct a survey of planets around more than two million stars over the course of two years.
RIP Kepler and COROT, you discovered so many planets and you will be missed, but your successors will be even greater.
Gamma rays have the most energy of any wave in the electromagnetic spectrum (which includes more familiar radiation such as x-rays, radio, and visible light). The wavelength of gamma rays (10 picometers and smaller–which is a subatomic scale) is less than that of any other sort of EM radiation. Such radiation is created in the event horizons of massive black holes and during the destruction of gigantically massive stars. Comic book enthusiasts know gamma rays as the mysterious super force which created and empowers the incredible hulk, although actual cell biologists recognize gamma rays as ionizing radiation–supremely hazardous to living entities.
On Saturday, April 27, the Fermi Gamma-Ray Telescope (a NASA satellite which orbits around Earth) detected a sudden brilliant surge of gamma radiation from the collapse of a super massive star in a galaxy 3.6 billion light-years away. Gamma ray burst travel in vastly powerful beams which are very narrow–an effect which is a result of the shape of supernovae, as illustrated in the picture above. Our old friend Eta Carinae has probably exploded and produced such a burst by now. A gamma ray bust from a nearby Wolf–Rayet would probably fry away life on our planet if it were aimed directly at Earth, but such explosions are increasingly rare as the universe ages. Scientists can monitor gamma bursts from the edge of the universe (i.e. the distant past) but such a powerful event has never been monitored by our modern satellites and observatories from a middle range until now.
As the gamma ray burst fades (and the astronomy community begins to assess the initial data) other observatories will be on the lookout for the next wave of phenomena associated with the supernova. Most of the energy of a supernova explosion is believed to be dissipated as neutrinos (esoteric subatomic particles which react very little with physical matter in this universe). Fortunately humankind now possesses a sophisticated neutrino observatory on the South Pole where thousands of sensors are imbedded within a vast amount of Antarctic ice. In the rare cases where neutrinos interact with matter, they produce a cascade of charged particles which can emit Cherenkov radiation (familiar as the spooky blue glow in a nuclear reactor). Understanding the neutrino signature of such an event would potentially further our understanding of the physical parameters of existence.
Also, a luminous flash of less energetic radiation (x-rays, radio waves, light, and so forth) should be following the gamma ray burst. We understand these parts of supernovae better (since they are visible from many angles unlike the linear gamma ray bursts), but it should still be pretty–and round out our understanding of the full astronomical event.
The Atacama Desert of Chile is the driest place on Earth. The desert is bounded in the west by the Chilean Coastal Range, which blocks moisture from the Pacific. On the east of the Atacama run the mighty Andes Mountains which catch almost all the rainfall from the Amazon Basin. Thus trapped between ranges, the desert receives 4 inches of rain every thousand years. Because of the dryness, people are very sparse in the Atacama: they are found only at rare oases or as desiccated (but well preserved) mummies lying in pits.
The high altitude, dryness, and lack of nearby cities (with their lights and radio waves) make the Atacama a paradise for astronomers. On a mountaintop 8000 feet up on the Atacama side of the Andes, engineers and scientists are working to put together one of the wonders of this age.
The Giant Magellan Telescope (hereafter the “GMT”) will be a miracle of engineering. When it is completed in 2019 it will be larger than any telescope on Earth. The scope is so giant that it will be mounted in a huge open, moving building (rather than the gun-turret-like buildings observatories are traditionally housed in). No organization on Earth is capable of making a mirror large enough for the necessary purposes, so seven immense 8.4 meter mirrors are being used together to create a single optical surface with a collecting area of 24.5 meters (80 feet in diameter). The mirrors are the pinnacle of optics: if they were scaled up to the size of the continental United States, the difference between the highest and the lowest point would only be an inch.
The scope will be much more powerful than the Hubble telescope and take much clearer pictures despite being within the atmosphere of Earth. In the past decade, telescope makers have used cutting edge engineering to compensate for atmospheric distortions. To do so they fire multiple lasers grouped around the primary mirrors high into the atmosphere. These beams of light excite sodium atoms in the sky which fluoresce—creating tiny “stars” of known wavelength, which serve as points of reference for the adaptive optics. The official website of the GMT further explains the mechanism used to counteract atmospheric turbulence once these benchmarks are obtained:
The telescope’s secondary mirrors are actually flexible. Under each secondary mirror surface, there are hundreds of actuators that will constantly adjust the mirrors to counteract atmospheric turbulence. These actuators, controlled by advanced computers, will transform twinkling stars into clear steady points of light. It is in this way that the GMT will offer images that are 10 times sharper than the Hubble Space Telescope.
The telescope is designed to solve some of the fundamental mysteries about the universe. Scientists hope it will help them find out about the nature of dark matter and dark energy (which are thought to make up most of the mass of the universe). Astronomers also hope to find out how the first galaxies formed and (perhaps) to ascertain the ultimate fate of the universe. Most excitingly of all, the telescope should be large enough to peek at some of the exoplanets we are discovering by the thousands. If life exists anywhere near us, the GMT should provide us with compelling evidence in the next twenty years.
The National Science Foundation was initially going to contribute heavily to the telescope but, since the United States Government has become indifferent to science and knowledge, other institutions have been forced to pick up the slack. The scope is being built by a cooperative effort between The University of Chicago, The University of Texas at Austin, The Australian National University, The Carnegie Institution for Science, Harvard University, The Korea Astronomy and Space Science Institute, the Smithsonian Institution, Texas A&M University, & The University of Arizona (so you can probably help out by donating to any of these institutions, particularly the lovable University of Chicago).
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!
George Ellory Hale was the sickly (and only) child of a wealthy Chicago elevator magnate. At an early age Hale showed an affinity for science and quickly began thinking of astronomy in much deeper terms than the mere cataloging and plotting of stars (which was the direction of the discipline when he began his career). In 1889, as he was traveling on a Chicago streetcar, Hale had an epiphany about how to build a machine to photograph and analyze the sun. He thereafter invented the spectroheliograph, which revolutionized stellar physics, and he operated the first spectroheliograph from his private observatory in his parents’ backyard. Hale was a master of studying light in order to understand the physical characteristics and chemical composition of stars, which made him one of the first (if not the first) people to be officially called an astrophysicist.
Because of his obsession with starlight, Hale was also obsessed with building telescopes. His dual ties to the world of academic astronomy (he studied at MIT) and the world of business wealth gave him a unique ability to put together observatories and institutions. Throughout the course of his life, Hale was instrumental in building four of the world’s largest telescopes (each telescope substantially outsizing the previous one).
Working as a professor and department head for the University of Chicago, he first spearheaded the creation of the Charles T. Yerkes Observatory at Lake Geneva, Wisconsin which featured a 40 inch refracting telescope (the largest refractor ever used for scientific discovery). When his plans outgrew the University of Chicago’s budgetary constraints, Hale joined forces with the Carnegie Institute to build a sixty inch reflecting telescope at Mt. Wilson Solar Observatory near Pasadena. In 1908, this telescope, the largest in the world, was operational, but Hale was already building a 100 inch reflecting scope. This larger scope became world famous when Edwin Hubble used it to demonstrate that the universe is expanding. Hale was still not done: he laid plans and institutional groundwork for the 200 inch reflector at Mount Palomar. Although Hale died before the Palomar scope was complete, the final observatory more than fulfilled his vision. The Palomar telescope was the world’s most important observatory between 1948 and 1992.
Because this is a short article I have glossed over the technical, scientific, and administrative hurdles faced by Hale in creating these telescopes, but, suffice to say the challenges were daunting. Each scope was accompanied by breakthroughs in engineering, architecture, and material science.
Hale was not content to merely create 4 of the world’s largest telescopes. He was also one of the founding trustees at California Institute of Technology. Hale’s contacts and savvy were one of the fundamental reasons that Caltech so quickly moved to International prominence (and maintained its status as one of the world’s foremost scientific institutions).
Hale was an indefatigable scientist, administrator, and thinker who accomplished a huge amount in his life. His far-sighted observatories and his pioneering work in astrophysics laid the groundwork for humankind’s most profound discoveries about the actual nature of the universe. However Hale suffered terribly from neurological and psychological problems. He was sometimes incapacitated by headaches, insomnia, and a horrible ringing noise. Throughout his adult life he consulted with an elf or demon which appeared to him when the ringing in his head reached an unbearable pitch. Psychologists and biographers have argued that this visitation was not actually a hallucination but rather a sort of allegorical figure used by Hale to personify his manic-depression. Hale’s writings (and the accounts of those around him) cast doubt upon this interpretation. He spent increasing amounts of time in sanitariums and he was fully institutionalized for the last years of his life. Many biographers add this detail as a sort of embarrassing footnote to an otherwise glorious life of innovation and discovery. Perhaps it should not be a dismissive footnote—Hale’s madness and his greatness went together. Lesser men—or saner ones—could probably not have built huge eyes with which humankind stared into the darkness of deep space.
Brian May is an astrophysicist who pursued a career in music. He is the guitarist for the rock band Queen and he is more famous for writing “Fat Bottomed Girls”, “We Will Rock You”, & “Who Wants to Live Forever” than for anything he wrote while obtaining his Astrophysics degrees. Brian was popularizing Galaxy Zoo on his blog (Galaxy Zoo is an online project which seeks public help in classifying vast numbers of galaxies. A Dutch fan, Hanny van Arkel (a schoolteacher by trade), became interested in the project and started working on the site when she spotted a huge weird glowing green thing below spiral galaxy IC 2497. She presented her findings to professional astronomers, who were also perplexed by the ghostly shape. They duly named the object in her honor “Hanny’s Voorwerp” (which is Dutch for “Hanny’s thing”).
So what is Hanny’s Voorwerp? The leading theory is that the supermassive black hole in the center of IC 2497 created huge jets of energy and gas as it (messily) devoured great masses of matter at the center of that galaxy. These esoteric plumes interacted with an unrelated stream of gaseous matter hundreds of thousands of light years long (which is longer than our galaxy). The thin clouds of glass then fluoresced like a krypton sign or a Scooby-Doo ghost.
Thanks Brian May and Hanny! This is one fancy voorwerp.
Maria Tomasula is a contemporary artist who paints strange collections of beautiful items coalescing into miniature glowing geometric systems (usually against an empty black outer space backdrop). Dew, flowers, and fruit are the most frequent items in these compositions, but sculptures, amphibians, skulls, mollusks, weapons, and disembodied organs (among other things) also find their way into these little microcosms.
Tomasula paints the shining or dewy objects which make up her still life works with finicky photorealism, yet the abstract structure of the works takes these images towards mathematical abstraction. Her delightful little paintings give us the aesthetics of the natural world as viewed through a dark melting kaleidoscope.
Tomasula has a particular flair for teasing humankind’s magpie-like fascination with shininess and bright colors. From across the gallery, her works beguile the viewer closer and closer. Only when one is next to them does one notice the carnivorous pitcher plants and bird skulls among the velvet, petals, and jewels. However the dark imagery does not outshine the sensuous appeal of these fastidious spirals, loops, and curtains. Tomasula invites us to reach into the dark fractal pattern of beauty to grab the waxy flowers, the moist fruits, the polished gems…if we dare.
After several blog posts describing spaceplanes (like the sleek experimental British Skylon plane), it is time to write about one of the alternative proposals for reusable space-capable craft which are capable of both take-off and landing. In the old spaceman fantasies from the golden age of science fiction, human explorers flew their rockets to another world, dropped through the atmosphere and landed vertically. Their rocket set around while the astronauts had fantastical adventures. Then they rushed back aboard and blasted off!
Last week (March 7th, 2013) an experimental rocket named Grasshopper flew a record 80 meters (263 feet) before landing perfectly on the launch pad where it started. Grasshopper was built by Space Exploration Technologies or SpaceX, the private space transport company founded by PayPal billionaire, Elon Musk (who–based on his name and his legacy–may be a James Bond villain or an alien philanthropist). SpaceX is the first privately funded company to successfully launch a spacecraft into orbit and recover it and the budding company has also been first past numerous other milestones in the commercialization of space. Instead of giving everything Roman names like NASA, SpaceX gives its crafts and components Arthurian names such as Merlin, Kestrel, and Draco (I’m going to pretend there was a grasshopper at least somewhere in T. H. White).
The reusable first stage tests of Grasshopper are breaking new ground in the fields of guidance and stability (which are required to land a Grasshopper). If all continues to go well the company plans on supersonic tests later this year. As these become more glorious and more dangerous it is unclear if they will seek to have their current Texas facility made into an official spaceport or if they will move out to the blazing glory of White Sands with the Airforce, NASA, and Virgin Galactic. Whatever the case I salute them for flying a smokestack around the countryside and then landing it on a basketball court. Perhaps I was too hasty to dismiss the possibilities of commercial spaceflight!
Back in 2011, as the space shuttle program wound down, Ferrebeekeeper published what seemed like an elegy to spaceplanes—mixed-use vehicles capable of operating both as spacecraft and aircraft (most notably the space shuttles). The dwindling national interest in science and exploration once seemed to indicate that the shuttle program would be the last spaceplane program for a long time. However, as the United States abandons its interest in cutting-edge Aerospace projects, other nations and private interests are picking up the slack.
Skylon is a British spaceplane concept from a private company, Reaction Engines Limited. During the eighties, Rolls Royce and British Aerospace, poured money and knowledge into the creation of a vehicle named HOTOL (an awkward acronym which stands for HOrizontal TakeOff and Landing). Although huge amounts of human energy went into HOTOL, it was canceled because of lack of funding. Reaction Engines Limited is trying to build on the extensive HOTOL designs.
Skylon certainly has a futuristic look. It has a long slender needle-like fuselage with stubby delta wings sticking out midway. Each of these wings is mounted at the end with a SABRE (Synthetic Air Breathing Engine). These next-generation engines are the real key to achieving single-stage-to-orbit spaceflight (a milestone which has long proven elusive for space engineers). Ideally the plane could take off from a runway and speed up to Mach 5.4 as it left the atmosphere and entered orbit. After deploying its payload it could then glide back down to Earth like a normal plane.
Skylon would be constructed of a carbon fiber frame with heat resistant ceramic tiling and it would employ liquid hydrogen as a fuel to loft its 82 meter long (269 ft) body into near-space (before switching to internal liquid oxygen as it left the atmosphere). Like HOTOL before it, Skylon was stuck in funding purgatory for a long time, but recently a huge chunk of funding became available to test the viability of the various systems. These tests were successfully completed in November of 2012 and Reaction is now moving forward with the building of Skylon.
Skylon is designed to be vastly cheaper than the shuttle or any current rocket programs (and it would cut down on space debris). Engineers estimate that one of the crafts could be ready to launch again in only two days after a successful landing (as opposed to the shuttle which required months of refitting). Let’s hope the technology works out. Although unmanned interplanetary craft are accomplishing great things, it has been too long since there was a flashy achievement