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I was going to write about problems with the Kepler space telescope, a NASA space observatory 75 million kilometers from Earth which monitors the stars to discover Earthlike exoplanets.  This weekend something went wonky and the craft slipped into emergency mode.  It was feared to be damaged to the point of inoperability….but then the NASA engineers dedicated a whole array of radio signals on the so Deep Space Network (spacecraft telecommunications system) to awaking the spacecraft and getting it back in operating condition.  So I don’t have a blog post…which turns out to be good news.  Hooray for Kepler—let’s find some exoplanets!

The Atacama Desert (towards the Andes)

The Atacama Desert (towards the Andes)

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.

giant_magellan_telescope_rendering

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.

giant_magellan_telescope_mirrors

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.

alien-world-red

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).

giant-magellan-telescope-artists-view-4

 

George Ellery Hale

George Ellery Hale

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).

Yerkes 40 inch Refracting Scope at Williams Bay, Wisconsin

Yerkes 40 inch Refracting Scope at Williams Bay, Wisconsin

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.

 The 100 inch (2.5 m) Hooker telescope at Mount Wilson Observatory near Los Angeles, California

The 100 inch (2.5 m) Hooker telescope at Mount Wilson Observatory near Los Angeles, California

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.

The Mt. Wilson 60-inch design is a bent-Cassegrain reflector with a 60-inch diameter primary mirror

The Mt. Wilson 60-inch design is a bent-Cassegrain reflector with a 60-inch diameter primary mirror

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).

The 200-inch (5.1 m) Hale Telescope (f/3.3)

The 200-inch (5.1 m) Hale Telescope (f/3.3)

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.

mxy-superfriends

A Composite Image of M104--The Sombrero Galaxy--taken from the Hubble Space Teelscope in Summer of 2003

A Composite Image of M104–The Sombrero Galaxy–taken from the Hubble Space Teelscope in Summer of 2003 (click on the image for a full-sized version)

Today I am posting some pictures of what I think is the most beautiful deep space object.  The Sombrero Galaxy (M104) is a nearby galaxy which is visible edge-on in the constellation of Virgo.  Actually, calling it an object might be a bit misleading since M104 consists of more than 400 billion stars–not to mention numerous associated globular clusters, innumerable planets, immense clouds of gas & gas, and a supermassive black hole which lies in the center.  The black hole in the center of M104 isn’t a mild mannered & quiescent black hole like the one in the center of the Milky Way either.  Based on the speed of revolution of the stars near the middle of M104, astronomers calculate that the central black hole has a billion times the mass of the sun.

An Infrared false-color image of the Sombrero Galaxy

An Infrared false-color image of the Sombrero Galaxy

In cosmic terms, the Sombrero galaxy is nearby—which is to say it is merely 28-odd million light years away.  The galaxy was discovered in the late eighteenth century by Pierre Méchain . Other prominent 18th century astronomers subsequently observed and studied M104, including Charles Messier (which is the reason the galaxy is included in the “Messier” catalog and has a M-designation) and the redoubtable William Herschel who noted a “dark-stratum” bounding the luminous central bulge.  We now know that this ring around M104 is a toroid dust lane of vast proportions which halos the galaxy.   Astronomers initially thought that the Sombrero Galaxy was an unbarred spiral galaxy, but thanks to observations from NASA’s Spitzer space telescope (an infrared scope orbiting Earth), the scientific community has revised their estimation of its size upward.  It lies somewhere between a spiral galaxy and an elliptical galaxy.   In other words, when you look at the Sombrero Galaxy, you are looking at something vast beyond human comprehension—a galaxy bigger than our own filled with who knows what things we will never know.  And yet if you expand the Hubble photo at the top of this post, you will see that all of the little stars shining around M104 are other galaxies farther away.

Olé!

Olé!

 

During the 1950’s, astronomers using the first radio telescopes started discovering a mysterious class of heavenly objects.  Certain discreet points in the sky blazed brightly with low-frequency electromagnetic radiation–yet when the scientists looked at the spots through conventional optic telescopes, it was impossible to discover a source for this energy.  Some of these radio flares came from incredibly faint smudges and some issued from what seemed like empty space. Astronomers called the mystery flares “quasi-stellar radio sources” (QUASAR) because they believed such discreetly focused energy must come from stellar-like objects.  Further study revealed that the photons issuing from quasars were red-shifted, which meant that the quasars were rushing away from the solar system at high velocities.

An Artist's interpretation of a Quasar

Only in the 60’s did optical telescopes become powerful enough to associate certain quasars with the cores of extremely distant galaxies.  The reason no luminous objects were initially associated with quasars was because quasars turned out to be profoundly distant—the closest were billions of light years away.  They were visible to early radio telescopes only because of their immense energy output and their beam-like focus.

An X-ray image shows the quasar PKS 1127-145 (credit: NASA)

Scientific consensus concerning these massive energy flares did not fully coalesce until the 1980s.  Today astronomers believe that quasars are powered by accretion of material into super-massive black holes which lie at the center of dynamic young galaxies.  Such phenomena are called “active galactic nuclei” (AGN). As radio telescopes and time-space modeling grew more sophisticated it became obvious that quasars (which produce low-frequency radiation) were not the only energy flares associated with AGN.  Giant beams of different spectrums of electromagnetic radiation are possible depending on the galaxy.  Quasars and their ilk produce incomprehensible amounts of energy—the most luminous active galactic nuclei radiate exotic energy at a rate that can exceed the output of an average galaxy by a thousand times (equivalent to the energy from two trillion suns).  To produce such energy the brightest known quasars consume roughly 1000 solar masses of matter within an earth year (which is equivalent to swallowing/burning 600 Earths per minute).

Yikes

Galaxies change as they age. Today the Milky Way Galaxy is a mostly responsible middle aged galaxy (which only occasionally cuts lose with something crazy like the luminous blue hypergiant Eta Carinae) however there are reasons to think that in the past the Milky Way was a deeply troubled teen-aged galaxy ablaze with self-destructive fury just like the AGN galaxies we see at the far edges of space.  Assuming they exist, alien astronomers in galaxies billions of light years away probably see our galaxy as a blazing quasar–because they are looking at its distant violent past.

Active Galaxies Collide (painting by Don Dixon for "Scientific American")

Of course galaxies are not always quiescent.  Some astrophysicists theorize that in 3 to 5 billion years, when the Andromeda Galaxy collides with the Milky Way, the black holes in the center of one or both galaxies could begin swallowing up matter (or could merge) reigniting a super bright fountain of high energy particles again visible throughout the universe.

The great astronomer, Sir Frederick William Herschel fundamentally remade humanity’s perception of the universe with his scientific discoveries.  In addition to intelligence, diligence, and acuity, he possessed substantial personal creativity and boundless energy–as exemplified by his remarkable musical career.  His wildly outre convictions about extraterrestrial life, however, would embarrass even a hardened UFO nut.  As a scientist, Herschel could not prove his speculations about life beyond earth–and therefore he did not publish such ideas in scientific journals.  His philosophical essays and his personal correspondences (the latter of which only fully came to light in 1912), however show how keenly he believed in extraterrestrial life and civilization and how tirelessly he looked for aliens.

William Herschel and his sister (and collaborator) Caroline Herschel

Since the moon is the closest celestial body to earth and the most easily observed with a telescope, it was a natural place for Herschel to begin his search for extraterrestrials.  In a letter to a friend, Herschel described how he believed the craters of the moon were Lunarian cities and dwellings (laid out like the Roman “circus” meaning a large ring):

As upon the Earth several Alterations have been, and are daily, made of a size sufficient to be seen by the inhabitants of the Moon, such as building Towns, cutting canals for Navigation, making turnpike roads &c: may we not expect something of a similar Nature on the Moon? – There is a reason to be assigned for circular-Buildings on the Moon, which is that, as the Atmosphere there is much rarer than ours and of consequence not so capable of refracting and (by means of clouds shining therein) reflecting the light of the sun, it is natural enough to suppose that a Circus will remedy this deficiency, For in that shape of Building one half will have the directed light and the other half the reflected light of the Sun.  Perhaps, then on the Moon every town is one very large Circus?…Should this be true ought we not to watch the erection of any new small Circus as the Lunarians may the Building of a new Town on the Earth….By reflecting a little on the subject I am almost convinced that those numberless small Circuses we see on the Moon are the works of the Lunarians and may be called their Towns….Now if we could discover any new erection it is evident an exact list of those Towns that are already built will be necessary.  But this is no easy undertaking to make out, and will require the observation of many a careful Astronomer and the most capital Instruments that can be had.  However this is what I will begin.

Of course this spectacular misapprehension becomes more comprehensible considering how long it took humanity to understand the nature of craters (it wasn’t until the 1960’s that work by astrogeologist Gene Shoemaker, brought about widespread scientific consensus that craters were caused by impacts).  Yet Herschel was so devoted to his Lunarians that he came perilously close to inventing findings. As he carefully scrutinized the moon for other living things night after night, imperfect optics and his yearning for alien life sometimes got the best of him.  Here is a drawing of a shadow which he perceived might be a forest.

Herschel did not believe that the moon was the only other sphere to support life–he believed that life could be found on all heavenly bodies which are spherical from self-gravitation.  And Herschel really meant all such bodies: in the Royal Society’s Philosophical Transactions in 1795 he speculated about beings living on the sun,

The sun…appears to be nothing else than a very eminent, large, and lucid planet, evidently the first, or in strictness of speaking, the only primary one of our system….Its similarity to the other globes of the solar system …leads us to suppose that it is most probably inhabited …by beings whose organs are adapted to the peculiar circumstances of that vast globe.

Hershel thought that all of the stars in the universe were like the sun—densely habited and supporting an orbiting network of habited worlds. He wrote “since stars appear to be suns, and suns, according to the common opinion, are bodies that serve to enlighten, warm, and sustain a system of planets, we may have an idea of numberless globes that serve for the habitation of living creatures.” Additionally, Herschel believed that the nebula he observed were other “universes” like our own, each containing innumerable stars—all of which were habited.  He was wrong in his interpretation of the particular gaseous nebulae he was looking at, but he was quite right about the existence and nature of other galaxies (although this idea was not proved or accepted until the work of Edwin Hubble).

The Rosette nebula, a stellar nursery about 5,000 light-years from Earth in the Unicorn constellation (photographed by the Herschel Space Observatory, ESA)

Poor Herschel’s hunches about extraterrestrial life seem quaint to us now. Couched in boyish exuberance and 18th century idioms, they almost seem risible. Yet Herschel was right about exoplanets and about galaxies beyond our own.  He seems to have been the only person of his time to begin to apprehend how vast the universe really is.  Thanks to the work of many scientists and explorers we can write off life on the moon and (almost certainly) the sun.  However, even with our robot probes and our telescopes, the solar system is shockingly unknown.  And beyond the solar system, the large exoplanets we currently know about are strange hot giants we did not expect. The preliminary results of the Kepler mission are beginning to trickle in, and they hint at a profusion of planets (and other things) much more heterogeneous and odd than cosmic uniformitarians might expect.   If blogging has taught me one thing, it is not to underestimate Sir Frederick William Herschel (a conclusion I hardly anticipated).  So while I chuckle about the perfectly circular cities of the lunarians, I am also keeping an open mind about the immense number of unknown worlds.

NGC 7331, a spiral galaxy discovered by Herschel which he mistakenly believed was a nebula(which he mistakenly thought were like galaxies)

Also (as I suspect Sir William felt), I am sad about how many things are simply unknowable.

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