September 2016 • Astronomy.com

Astronomy Insights

Through the Lens: Pop Culture’s

Vision of Space

A Digital Supplement to Astronomy Magazine

© 2016 Kalmbach Publishing Co.

Cover photos taken from Celestron’s L.A. Moonwalk Event

2 ASTRONOMY INSIGHTS • SEPTEMBER 2016

Think today’s society would be the same without the big eye in the sky? Think again.by Liz Kruesi

POP CULTURE TELESCOPE

How Hubble

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The Hubble Space Telescope — arguably one of the greatest tech-nological achievements ever — was in trouble. Astronauts were to conduct a fifth and final ser-

vicing mission of the observatory in 2004, but in January of that year NASA canceled the mission, citing safety concerns. The public, however, wanted to save the great scope. They wrote to astronomers, the space agency, members of Congress, and the media to reinstate the mission. And it worked. In 2006, NASA announced that it would send astronauts to service Hubble one last time.

The telescope clearly has had a pro-found impact during its quarter-century of observations — on science and exploration, of course, but also on a much wider audi-ence. Other scientific facilities have tried to emulate Hubble’s formula, but none has come close to the impact this telescope has had. A combination of attributes makes Hubble an immensely influential project. Its incredible views of the cosmos, which are both gorgeous and real, bring the excitement of discovery to households across the globe. Its images have inspired artists in many mediums to produce musi-cal compositions, paintings, and choreog-raphy. But another aspect — the direct human interaction and involvement in the mission — helps hold Hubble’s science in the public mind.

The early yearsIt was a different story in 1990. When scientists saw Hubble’s first images in May of that year, they were disappointed and frustrated. Technicians had ground and polished the telescope’s 2.4-meter mirror to the wrong shape, so it couldn’t focus the light it collected into crisp points; Hubble had fuzzy vision. Politicians ridiculed the project, comedians made it the brunt of jokes, and the U.S. public thought of it as a costly mistake. People were angry — after all, it was a primarily federally funded mission, so taxpayers had footed much of the bill, some $2.5 billion at that point.

But scientists and engineers had devel-oped Hubble to be serviced. And that aspect of the mission is what saved it.

NASA and the Space Telescope Science Institute (STScI), which operates Hubble, faced the problem and found a solution in

just three years. In December 1993, astro-nauts aboard the space shuttle Endeavour installed two instruments on the telescope: a new camera and the Corrective Optics Space Telescope Axial Replacement (COSTAR) that acted like eyeglasses.

The new lenses worked. Hubble could resolve details never before imaged, like the wisps of gas around baby stars and suns in distant galaxies.

Since the repairs, the telescope has con-tributed to countless scientific discoveries and even a Nobel Prize in physics (see “Hubble’s top seven science discoveries” on p. 28). On a more public level, teachers post Hubble’s spectacular images in classrooms, and outreach materials from the project are part of education curricula throughout the United States, explains STScI’s Kenneth Sembach, who began working with the telescope when it launched.

A familiar toneHubble’s pictures strike a chord with peo-ple. Of course, they are gorgeous, which is no mistake. When the telescope images a celestial object, it does so through filters, each of which allows specific wavelengths to pass through. But Hubble collects more than visible light. Its detectors also can record ultraviolet and infrared radiation. For those images, scientists assign the col-ors red, green, or blue to each filter. The end product is a false-color rendition of the target, but one that effectively conveys its essence while retaining the valuable scientific data.

Many of the images look like works of art, but what’s important, says STScI’s Mario Livio, “is that as beautiful as these things are, they actually exist somewhere in our universe.” The laws of physics and chemistry have created these incredible structures, and Hubble has revealed them.N

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Hubble images collected in the mid-1990s inspired Astronomy Contributing Editor Liz Kruesi to study physics to understand the science respon-sible for the structures in those gorgeous shots.

The “Pillars of Creation,” a star-forming region in the Eagle Nebula (M16), is probably the Hubble Space Telescope’s most iconic image. NASA/ESA/STScI/

JEFF HESTER AND PAUL SCOWEN (ARIZONA STATE UNIVERSITY)

For the observatory’s 20th anniversary, Hubble took this image of the Carina Nebula (NGC 3372).

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Probably the most iconic image from Hubble is its portrait of the “Pillars of Creation” in the Eagle Nebula (M16), which astronomers released in November 1995 (see p. 26). Those three columns of gas and dust, shaped by the radiation and particle winds of newborn stars, fill the field of view. “That image, the way it was framed was brilliant,” says Sembach. “It fit within that chevron shape of the camera that was on board at the time so beauti-fully, and it was orientated in a way that you get the full pillar effect.”

The image shows depth that many pho-tographs of celestial objects can’t capture and gives the pillars three-dimensionality. They look like something you could touch, and that quality helps draw the public in.

But that image struck a chord with peo-ple for another reason, too. The colors sci-entists chose for the composition are familiar. The pillars resemble structures on Earth, which makes this image relatable.

When STScI released the image, the accompanying text drew the following comparison: “The pillars are in some ways akin to buttes in the desert, where basalt and other dense rock have protected a region from erosion, while the surrounding landscape has been worn away over millen-nia.” And although the scales of these objects are vastly different — earthly rock formations can extend from a few to hun-dreds of feet, while the cosmic pillars are a few light-years, or trillions of miles, long — the public embraced the connection.

Art historians also have extended the comparison. Elizabeth Kessler of Stanford University, for example, has studied many Hubble images and written a book about the artistic choices that researchers have used in the photographs. She looked at how scientists frame objects and what colors they assign to different filters. While astronomers designate specific “colors to communicate physical attributes of the nebulae or galaxies, different temperatures, or the locations of different kinds of gases, those same colors often also suggest a kind of earthly landscape,” says Kessler.

Hubble images are ethereal and eerie but at the same time familiar. “I think the images themselves walk this really careful line between looking very alien and strange and exciting,” Kessler says, “and yet they also remind us of places that have been explored and understood here on Earth.”

For researchers, Hubble satisfies a desire to explore, whether by imaging a nearby world or investigating galaxies billions of light-years away. The telescope has imaged dust storms on Mars, discovered disks of material around young stars, and seen qua-sars across the universe. And through all the research, Hubble has brought the public along for the ride. “It has taken the excite-ment that the scientists usually feel with new discoveries and brought it to homes of nonscientists,” says Livio.

On December 18, 2012, scientists at the Space Telescope Science Institute, realizing that the public loves Hubble’s images, released this one they called “A Cosmic Holiday Ornament.” The image shows planetary nebula NGC 5189. NASA/ESA/

THE HUBBLE HERITAGE TEAM (STScI/AURA)

This image, dubbed the Hubble Deep Field, captured the imagination of scientists and the public when the space agency released it in early 1996. R. WILLIAMS (STScI)/THE HUBBLE DEEP FIELD TEAM/NASA

Hubble took this image of star-forming region NGC 3324 to celebrate its 10th anniversary in space. NASA/ESA/THE HUBBLE HERITAGE TEAM (STScI/AURA)/N. SMITH (UNIV. OF CALIFORNIA, BERKELEY)

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1946American physicist Lyman Spitzer

proposes a space telescope.

1969The National Academy of Sciences gives its approval for the Large Space Telescope project.

1977The U.S. Congress approves funding for a space tele-scope. In 1983, NASA names it in honor of Edwin Hubble.

1981The Space Telescope Science Institute begins operations in Baltimore.

APRIL 24, 1990The space shuttle Discovery (STS-31)

launches, carrying the Hubble Space

Telescope and deploying it into

orbit the next day.

JUNE 28, 1991In the movie The Naked Gun 2½: The Smell of Fear, film-makers place a pic-ture of Hubble in the Blue Moon Cafe on a wall displaying fail-ures; it appears between the Titanic and the Hindenburg.

DECEMBER 2, 1993The launch of STS-61, space shuttle Endeavour, marks the first servicing mission. Shuttle astro-nauts install COSTAR.

AUGUST 23, 1996Hubble has traveled 1 billion miles since astronauts placed it in orbit.

FEBRUARY 11, 1997The launch of STS-82, space shuttle Discovery, marks the second servicing mission.

NOVEMBER 7, 1999In the 12th episode of the television series Futurama, the characters destroy the Hubble Space Telescope by mistake.

JULY 13, 1999After 9 years and 80 days, Hubble flies its 50,000th orbit.

MAY 16, 2000Pearl Jam releases Binaural, an album whose cover sports a Hubble image of the Hourglass Nebula.

DECEMBER 24, 2002Hubble has traveled 2 billion miles since astro-nauts placed it in orbit.

AUGUST 11, 2008Hubble flies its 100,000th orbit.

MAY 15, 2009The film Angels & Demons shows a large poster of the Hourglass Nebula in a character’s office at the Large Hadron Collider.

2011Hubble makes its millionth science observation, and the 10,000th sci-ence paper based on its observations is published.

NOVEMBER 15, 2012A Hubble image of the Hourglass Nebula appears on a poster in Raj Koothrappali’s office in The Big Bang Theory.

2015Hubble has observed 40,000 objects and produced 1 million images.

The intersection with artWhile scientifically important, Hubble’s images are works of art and have appeared in exhibits in places like the Walters Art Museum in Baltimore and the Istituto Veneto di Scienze, Lettere ed Arti in the Palazzo Loredan in Venice, Italy. Even artists of different mediums have drawn inspiration from the telescope.

Choreographer Liz Lerman, once the recipient of a MacArthur “genius grant,”

created a contemporary dance titled The Matter of Origins, in which the first half of the piece focused on the physics of the uni-verse. Lerman used images from Hubble, data from particle accelerators, and scien-tific equations throughout.

German artist Tim Otto Roth created two pieces incorporating light and sound that he based on Hubble’s investigation of the universe. His From the Distant Past (see p. 55) showed at the American Museum of

Natural History in New York City and at the Maryland Science Center in Baltimore in 2010; his Heaven’s Carousel showed at Accademia dei Lincei in Rome in 2014.

Composer Paola Prestini recently worked with Livio on a contemporary clas-sical multimedia composition that mixes an orchestral arrangement, vocalists, spo-ken word, and film — all to connect human life to the lives of stars. (The col-laboration also includes a librettist, Royce

Key (and not so key)Hubble moments

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Vavrek, and filmmaker Carmen Kordas.) The Hubble Cantata “fuses the story of the struggle associated with human life with the continuous cosmic battle that stars have to conduct against the universal force of gravity,” says Prestini.

“The structure of the work includes movements and songs by the soloist, with interjecting interludes that include the choir and an electronic tapestry made of [Livio’s] voice, imagined space sounds, plus the improvising of a very special violin soloist,” she adds. “The Hubble images appear during the interludes and take on a life of their own: They contort, grow, and fuse with physical life — reminding us of where life originated and where we might be all headed.”

The Hubble Cantata debuted July 2013 and was performed again in November of that year. The collaboration is expanding the cantata, says Prestini, and the full-length version should be complete for the telescope’s 25th anniversary.

While these examples incorporate the beauty of Hubble photographs, artistic messages, and science, the telescope’s cos-mic imagery also has been used in more commercial instances, like album covers, stamps, and clothing — because, heck, why not wear a dress, swimsuit, or tie adorned with Hubble images?

Hubble house callsBut it’s not just about the images. Another major reason the telescope has had such an impact is the “human involvement in the servicing of Hubble over the years,” says Sembach. “It’s like sending a doc-tor on a house call. The telescope is sick; somebody goes up to fix it.”

This month, Hubble turns 25, and luck isn’t what got the telescope to this point. Scientists and engineers planned the mis-sion well: place the telescope into near-Earth orbit, at a distance where the space shuttle can reach it, and then have astro-nauts service it. During the five servicing missions, astronauts have upgraded the electronics, replaced the telescope’s gyro-scopes (which are crucial for pointing the observatory at celestial targets), and installed new scientific instruments.

Humans have essentially created a new observatory during each servicing mission, says Sembach. And that, he adds, “really helps to keep it at the cutting edge of what scientists are working on. It helps it to actually push that edge.”

It also helps that humans — including the public — got involved to fight a vocal

FROM THE CLASSROOM TO POP CULTUREEditor’s note: The Hubble Space Telescope has catapulted few people into pop culture as fast as Hanny van Arkel. So, Astronomy invited the Dutch schoolteacher to tell her story here.

Back in 2007, I signed up for the online citi-zen science project Galaxy Zoo. Chris Lintott had invited the public to help him classify galaxies acquired with the Sloan Digital Sky Survey using a home computer interface. I had heard about this through Queen guitarist and astrophysicist Brian May, who mentioned it on his website. That my passion for music would one day lead me to become a somewhat well-known amateur astronomer was some-thing I never could have guessed.

In one of the pictures, I spotted a remarkable looking blotch. I sent Lintott an email to ask what it was. Lintott then invited me on the team to investigate using follow-up images taken with Hubble. I certainly learned a lot — not only about the object, but about the process, too. Meanwhile, the press got interested and I became a spokesperson, giving lectures across the world.

There’s also a comic out about my story, and Lintott and May mention Hanny’s Voorwerp (Hanny’s object) in their latest book. I am grateful for these experiences, and I feel fortunate to be able to tell the world that it is a lot of fun to be an amateur astronomer. — Hanny van Arkel

To commemorate Hubble’s 100,000th orbit, astrono-mers released this image of a nebula near star cluster NGC 2074. NASA/ESA/M. LIVIO (STScI)

Hanny van Arkel was a Dutch schoolteacher prior to discov-ering her voor-werp (Dutch for “object”). The media frenzy car-ried her into the heart of pop cul-ture. HANNY VAN ARKEL

In 2007, van Arkel discovered this strange object (now classified as a quasar ionization echo) near the spiral galaxy IC 2497. Since then, astronomers have discovered 19 similar objects. NASA/ESA/W. KEEL (UNIVERSITY OF ALABAMA)/THE GALAXY

ZOO TEAM

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public battle to convince NASA to send up the final servicing mission. (For more on this, see “Saving Hubble” on p. 44.)

The astronomical cultureIn addition to Hubble’s tremendous impact on the public’s interest in science, the project has helped drive research and collaboration in the professional astron-omy community. Just a quick look at sta-tistics compiled by the American Institute of Physics shows a drastic increase in the number of students studying astronomy over the past three decades.

In the mid-1980s, there were some 700 students enrolled in U.S. graduate astron-omy programs; by 2012, the number was up to roughly 1,100. Three decades ago, universities awarded between 70 and 80 doctorates per year; in 2012, the number had doubled to about 150.

On average, some 40 doctoral research projects each year are based on Hubble data, says Sembach. “The pool of postdoc-toral fellows in astronomy is now two or three times bigger than it was just 20 years ago,” says Meg Urry, the current president of the American Astronomical Society. The students who were in their formative edu-cational years — elementary, middle, and high school — when Hubble began sending

back its incredible images and contributing to major discoveries are now early-career professors or postdoctoral researchers.

“Astronomy departments have grown, and, equally important, physics depart-ments have been adding astronomers to their faculty,” Urry says. The statistics are even more telling when looking at under-graduate degrees: In the mid-1980s, about 140 students earned a bachelor’s degree in astronomy, but in 2012, two and a half times as many graduates earned an astronomy bachelor’s.

Hubble also has influenced how and when astronomy proj-ects release their data. When Robert Williams, then director of STScI, and his team collected the individual frames for the Hubble Deep Field (HDF) composite in 1995, they pro-cessed and released the data in two weeks. Scientists who use federally funded astro-nomical instruments have one year to keep the data to themselves for analysis. But the HDF scientists “thought for a facility like Hubble, which was very expensive and paid for by the public, that we owed it to the community, both the professional and the public, to make the important HDF data available immediately,” says Williams.

They helped change the culture of astronomical observing. And now, when

undergoing the peer review process to obtain telescope time, “the panelists who review especially larger proposals tend to favor groups who propose and promise that they will make the data available immedi-ately,” he adds. Future projects, like the Large Synoptic Survey Telescope, set to come online within a decade, will follow

this trend and make all data available immediately.

A long lifeWhile other space

observatories have contributed to major astro-nomical dis-coveries, none has remained operational for as long

as Hubble. In that time, it has

clearly ingrained itself in the minds

of the public, popular culture, and the media.

Williams credits many of Hubble’s later years to the public who fought alongside astronomers to save it a decade ago. “The telescope has been work-ing perfectly since,” he says. Scientists expect to operate Hubble until at least 2020, but “you never know how long it will last,” says Williams. “Space is a hostile environment.”

Whenever that fateful day arrives, says Sembach, “A lot of us are going to feel like we’ve lost a family member.” It’s likely sci-entists involved in the mission won’t be the only ones to feel the loss.

LEARN HOW SCIENTISTS PRODUCE HUBBLE’S ICONIC IMAGERY AT www.Astronomy.com/toc.

Artist Tim Otto Roth’s From the Distant Past translates spectra of distant objects that Hubble captured into green animated laser projections on prominent facades in public spaces, as for instance at the Maryland Science Center in Baltimore in autumn 2011.

For Hubble’s 20th anniversary, the European Space Agency conducted a

Hubble Pop Culture Contest. ESA

A Hubble image of the Hourglass Nebula appears on the cover of the 2000 CD Binaural by the rock band Pearl Jam. California Guitar Trio’s 2010 CD, Andromeda, uses a Hubble image on its cover.

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celestron.com

+ Bill Nye and Robert Picardo hamming it up on the main stage+ VIPs including John Davis, John Stamos, Phil Plait, Colin

Fleming, and Emily Lakdawalla + International Space Station flyover+ 10 telescopes set up for observing planets, the gorgeous

August full Moon, and live imaging of deep space objects with our 11” RASA

+ Focus Astronomy meteorite display

WE’RE STILL REELING FROM THE SUCCESS OF OUR FIRST EVER LA MOONWALK!It was a great night for celebrating art and science and Celestron would like to extend a huge thank you to all of you who attended, to those who donated their time and artistic creativity, and to the staff and volunteers who worked so tirelessly to ensure an amazing event! Through ticket sales, monetary donations, silent auction bids and the sale of featured artwork, LA MoonWalk raised a substantial donation for our beneficiaries, The Planetary Society and Free Arts.org.

CELESTRON IS WALKING ON THE MOOOOON!

SOME OF OUR FAVORITE EVENT HIGHLIGHTS

celestron.com

CHECK OUT OUR ONLINE GALLERY of all the featured art, as well as runner ups and some last minute additions that we couldn’t fit into the show, but were too good to pass up. Thanks again to all the artists, attendees, and volunteers who made it happen - we’ve got a full head of #STEAM and are excited to plan bigger and better for next year’s LA MoonWalk.

GALLERY HIGHLIGHTS:+ 8 custom painted Celestron FirstScopes+ Moon-inspired art gallery

+ Moon time lapse video installation+ Live painting

A BIG THANK YOU TO OUR BENEFICIARIES AND SPONSORS

THE MOON HAS INSPIRED SOME OF HUMANITY’S GREATEST WORKS OF ART We wanted to see some more so we reached out to our collective #STEAM communities and received Moon inspired art from around the world to showcase at our event and online gallery. We exhibited some 40+ works of donated artwork, 8 custom painted telescopes, 2 featured live artists, an autograph session with John Davis of Jimmy Neutron fame, and, with help from Free Arts.org, the kids in attendance were creating art all night long.

LA MoonWalk.com

Want to see the Orion Nebula’s hidden colors? First, take a walk outside to watch flowers in the moonlight. by Stephen James O’Meara

The nature ofobservıng

A TRIP OUTSIDE

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VISUAL OBSERVING CAN BE EITHER A PASTIME OR AN ART. Both are fine, and it’s your choice. But if you desire to see faint stars and nebulae or fine lunar and planetary details, or if you want to penetrate the veil of normal vision, push the lim-its of your telescope, or perhaps one day see what no one has seen before, then observing the world around you — both in the day-time and at night — can help.

The “art” of observationYou don’t need to be behind the eyepiece to improve your observational skills. You can start right now by studying your immediate environment — repeatedly, until you feel you’ve exhausted your visual capabilities. Let’s start with how to use direct vision to improve your observing skills.

Direct vision relies on your eyes’ 6 to 7 million cones that work best in bright light. Cone cells are dense in a little dimple in the center of the retina called the fovea; this small region is responsible for most of the eye’s color perception (more on that later). It is also the location of the eye’s sharpest vision. So if you want to train your eye to see fine lunar and solar fea-tures, you need to master direct vision, not averted vision. You can do this right now, no matter where you are.

For instance, as I write this I’m looking directly at a section of rug beneath my feet. It’s a square, tan-colored rug with an inter-laced V-shaped pattern throughout. The rug has a khaki border with a tiny tear at one corner and faint stitching running along its inner edge. Can I see more?

To find out, I take a second look. This time I see everything I noticed in my first look but in only a fraction of the time. My eyes then start looking for something new, something I might have overlooked. The first thing that stands out is a tiny white stain in the rug near the torn corner; that corner is ever so slightly curled up.

I look away, breathe, and then repeat the exercise. As before, everything I had noticed previously comes quickly into view. My eyes start probing ever deeper for finer

Stephen James O’Meara is a contributing editor of Astronomy who authors the “Secret Sky” column each month.

To see colorful nebulae and the faintest objects, first learn to observe nature. PANARAMKA/ISTOCK/THINKSTOCK

12 ASTRONOMY INSIGHTS • SEPTEMBER 2016

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details. It works. When I look directly at the torn corner, I see a tiny white thread in it. I could go on. The point is, by repeti-tively studying everyday ordinary items in your environment, you can improve your direct observing techniques and apply them when looking through the eyepiece.

Medical students across the nation have embraced the fact that repetitive visual inspection can enhance one’s ability to see exceptionally fine detail. Universities now offer innovative courses to help future phy-sicians “learn how to look” through the study of art. The students repetitively inspect works of art to hone their critical observation skills, which could make all the difference when it comes to interpreting, say, an X-ray or MRI or making an accurate diagnosis. One study in the Journal of the American Medical Association notes that medical students showed about a 10 percent improvement in their ability to detect important details after taking these courses.

Just as paintings become surrogate patients for young doctors, repeated visual observations of anything from art-work to rugs can serve as surrogate tele-scopic objects for you to hone your own observational skills. Next, let’s look out-doors after sunset to help you better understand how your eyes work under different lighting conditions.

Bewitching twilightThe nature of observing starts with observ-ing nature — magic happens every day in the open air. With so many natural phe-nomena occurring, it’s difficult to watch them all. But there’s one that may be of particular interest to observers. Called the

Purkinjě effect, this bewitching color shift occurs during the morning and evening twilight and can help you determine how sensitive your eyes are to color in low light.

Czech physiologist Jan Evangelista Purkinjě (1787—1869) discovered the phe-nomenon in the dawn while walking and meditating. Of it, he wrote: “Objectively, the degree of illumination has a great influence on the intensity of color quality. ... Particularly the brightest colors, red and green, appear darkest. Yellow cannot be distinguished from a rosy red. Blue became noticeable to me first. ... Green appears more bluish to me, and its yellow tint develops

with increasing daylight only.” The sequence happens in reverse after sunset.

In other words, two objects of opposing hues (one red, one blue) under bright light appear equal in intensity. But as the light diminishes, red fades while blue brightens.

To study this color shift, I suggest going out before the Sun sets and recording the color of different flowers, noting say, (on a scale of 1 to 5) how well they stand out against their leafy backgrounds. Particularly observe the contrast between flaming red flower petals and dark green leaves.

Continue to observe the flowers as twi-light deepens, and record what happens.

The blue hour happens just before dawn and right after sunset. Train your eyes to see color in bright nebulae by careful observation of flowers during this magical time of day. BOZHDB/ISTOCK/THINKSTOCK

Light enters the eye through the pupil and hits the retina. In the center of the retina is a dimple called the fovea, which gives the eye most of its color perception. So, in order to see fine lunar and solar features, an observer must master direct vision, not averted vision. ASTRONOMY: ROEN KELLY

See anything odd in this CT scan of a human lung? Most radiologists don’t. Art courses are increasingly offered to help medical students see fine detail through repeated visual inspection. MELISSA VO, TRAFTON DREW, AND JEREMY WOLFE

Your window to the universe

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You’ll be observing in the magical “blue hour” well known to photographers because the sky’s color creates a superluminous light that makes flowers appear to fluoresce.

The blue hour starts about 10 to 15 min-utes after sunset and lasts about 30 minutes, making it more of a blue half-hour. (To find the blue hour at your location, go to www.bluehoursite.com) Generally, there’s only a brief period when the colors achieve maxi-mum intensity, but it is undeniably glorious under perfect atmospheric conditions. Because everyone’s eyes perceive color and light changes differently, it is difficult to say exactly what you’ll experience.

Understanding the Purkinjě effect will help you perceive color in deep-sky objects, such as the reds and greens of the Orion Nebula or the pale blue and aqua hues of bright planetary nebu-lae. So controversial are these colors at times that the only way for you to be certain of your observation is to have absolute confidence in your abil-ity to perceive dim color at night. You can achieve this through visual training — by studying flowers and watching how deep into twilight you can follow their col-ors and at what point they disappear. Repeat observations will build confidence.

Working the night shiftAs night falls, turn your attention to one of the brightest flowers. Look directly at it, and watch how it fades. Next, move your gaze slightly so the flower is just off center, and see how brightly it glows at the periphery of your vision. That’s because the flower’s light is falling on the eye’s night-sensitive rod cells, some 120 million of which line the retina.

Rod cells require 30 minutes to become well adapted to darkness. During that time, the sensitivity of the eye increases by a factor of roughly 10,000. The rods are densest in a ring surrounding the fovea, but that region is not necessarily the most sensitive to faint light.

Repeat this observation several times, being careful to record how you avert your gaze: Where must you look to make faint objects appear brightest in your field of view? I tend to place the object of study toward the upper left from the center of my field of view, which places my direct vision down and to the right — all the while, I keep my attention focused on the object of study, even though I’m not looking directly at it.

Repetitive “averted vision” investigations should reveal your eye’s primary retinal “hot spot” — a region where night-sensitive rods work together most efficiently to make dim objects appear their brightest. Know-ing how to position deep-sky objects (barely visible galaxies, dim nebulae, or clusters of faint stars) on your primary retinal hot spot is arguably the most important factor in making observations at the limit of vision.

The second most critical factor is your confidence level. You acquire this certainty

by passing the dim object of interest over your retinal hot spot repeatedly until you feel 100 percent confident of its reality. In my opinion, there is no middle ground; I either see an object, or I don’t.

Time to zero in If you want to push the limits of your vision to its fullest — to learn not only how to see dim objects at night but also to eke out details in them — you can practice far from city lights under the soft glow of a First Quarter Moon.

When I look at flowers in the moon-light, I notice that they have a variety of

textures. Under this peaceful light, my eyes move rapidly in such a way that a flower starts at the 2 o’clock position in my field of view, moves down and to the lower left toward the outer boundary of the fovea, then down and to the right to my 4 o’clock hot spot, before I rapidly repeat the

inspection over and over. This sweeping process — perfected

by observing Mother Nature — helps me view fine details in, say, a galaxy or nebula through a telescope. After placing the object in my retina’s hot spot, I gently sweep it toward the boundary between the inner edge of the retina’s periphery and the outer fovea. When I do, the dimmest sections of the object disappear, leaving behind the brighter details. I record these features and then sweep the object back to my hot spot, where I can see and note the faintest details.

By continually sweeping the object back and forth across the retina’s rods and cones, I can critically inspect both the brightest and faintest regions and realize the object’s most intricate visual secrets. Stripped of its veil of mystery, the object surrenders itself. As Henry David Thoreau observed, “Nature will bear the closest inspection. She invites us to lay our eye level with her smallest leaf, and take an insect view of its plain.”

As twilight gives way to moonlight, try to record the changing intensity of colorful flowers like those imaged here by the author. You might notice that while reds will fade, blues actually grow brighter in the diminishing light. STEPHEN JAMES O’MEARA

The colors of the cosmos seen through an eye-piece will never come close to those seen in Hubble Space Telescope images, but by training your eyes, you can learn to see shades like those shown in this Orion Nebula sketch. ERIKA RIX

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