Space Photo

Space Photo

Your glass of gelatin filter should be mounted in front of the camera lens. Tape and Plasti-tak will work, but it’s a good idea to get a gelation filter mount for your camera. It is important that the filter not rattle about, for it the filter moves during an exposure, double images may result.

A third type of filter – the interference filter – exist; however, those with a range of 5 or 10nm around two inches square may cost $100 or more. Also, several technical difficulties are associated with interference filters. Only light passing perpendicularly through an interference filter is properly filtered; light at all other angles is filtered at a shorter wavelength. This will result in a loss of sensitivity for nebulae at the edge of your camera’s field of view. This effect shows on some of the pictures in this text. Some H-alpha interference filters also leak light at shorter wavelengths – enough that they may even look blue! In this case, an extra red filter (which may be difficult to mount properly) is necessary. If you have a Schmidt camera, an interference filter will not work very well because of the camera’s fast optics. Considering the cost and other problems involved, don’t star with and interference filter. After you’ve gained experience with glass and gelatin filters, you may feel the added expense is justified.

Rosette Nebula. The nebulosities NGc-2237 (The Rosette) and NGC-2264. Image by Oliver Stein

Gaseous nebulae are very faint, so long exposures are needed. The best exposure depends on the brightness of the nebula and the sky, the f-ratio of the camera, the type of filter and the sensitivity of the film. All these can vary; in particular, film sensitivity varies substantially from one production run to another, so it isn’t possible to recommend exact exposure. You’ll have to start with a trial exposure and then adjust the time as necessary. Too short a time will not reveal the full extent of the nebulosity, while too long a time will result in sky fogging the exposure completely.

On a dark night away from city lights, with an f/2 or f/2.8 camera lens and any of the recommended filters, your trial exposure should be about an hour. Develop the film after each night’s work so you know what alterations to make in the next night’s shooting. To help judge what these corrections should be, it is essential to keep a record of the length of each exposure, the filter used, and how bright the sky appeared. In city suburbs, your exposures may fog in only 5 or 10 minutes – but you’ll still find you’ll record objects you couldn’t without the filter.

Of course, there is a tradeoff to be made between exposure times and f-ratios. Low f-rations allow shorter exposures but suffer more from lens aberrations that deform the star images. For most nebulae, even the shortest exposures necessary are long enough that some method of guiding is needed. You’ll need a well-aligned equatorial mount with an accurate drive for guiding hour long exposures. (The problem of accurate guiding was discussed in Photography in Astronomy in January 1975 and June 1976.)

For locating nebulae suitable for H-alpha photography, one of the best resources available is the Skalnate Pleso Atlas of the Heavens and its companion catalog. These are publications of the Czechoslovakian Academy of Sciences, but are available in the United States from the Sky Publishing Corporation. In the Atlas, emission regions are indicated in green (though unfortunately so are reflection nebulae which emit blue light rather than red). Some of the large, very faint nebulae, such as those associated with the stars Zeta Ophiuchi and Lambda Orionis, are not properly shown in the Atlas. However, it does show most of the objects appearing in the list accompanying this text. Norton’s Atlas is less useful for finding nebulae; the maps use Herschel designations which need to be converted to NGC numbers to be of use, and Norton’s is not as complete as the Skalnate Pleso Atlas.

Although there is a wealth of nebulae to be photographed, astrophotographers seem to concentrate on the same old ones such as the North America nebula and the Orion. But many other areas deserve as much attention. The nebulosities in Monoceros are good subjects for 35mm work. Although you’ve seen many pictures showing the nebulosity in Sagittarius, you probably haven’t seen any showing the nebulae in Scorpius and around Zeta Ophiuchi. Pictures of Cassiopeia would be rewarding if they showed the nebulosities to the north and east of the constellation.

Although we’ve been concerned here with wide-angle 35mm work, those with telephoto lenses or Schmidt cameras will find there are many smaller objects that deserve attention. If you like the Cygnus loop, there is a similar object in Gemini: IC-443. Instead of the North America nebula, why not try the nearby IC-1396? The Lambda Orionis nebula would just about fill the field of view of a small Schmidt camera: IC-405 and IC-410 in Auriga would also look good. An interesting subject for Schmidt work is the Dividing Cell nebula (NGC-6888) in Cygnus.

H-alpha photography is comparatively simple and a very successful technique for amateur astrophotographers. The results here, though not perfect, should be encouraging to others.

Extended list of Deep Sky Nebulae. H-Alpha Objects For Your Camera

Barnard’s loop, Lambda Orionis, NGC-2264, NGC-2237 (Rosette nebula), M-42 (Orion nebula), IC-434 (Horsehead nebula), IC-2177, NGC-1499 (California nebula), IC-405, IC-410, IC-443, HGC-7822, IC-1805, IC-1848, IC-1570, Gamma Cygni, NGC-7000 (North America nebula), Cignus loop (Veil nebula), IC-1396, , NGC-6820, NGC-6888 (Dividing cell nebula), M-8 (Lagoon nebula), M-16 (Eagle nebula), M-17 (Omega nebula), IC-4628, M-20 (Trifid nebula), Zeta Ophiuchi, Tau Scorpii, Pi Scorpii, Sigma Scorpii, IC-4608.

(By John Davis, William Tobin and Joel Eaton, Astronomy Magazine, August 1976)

Red Light Sky Photography

Red Light Sky Photography

When a massive star forms, not only does it shine with the light of 10,000 suns, but it also lights up the surrounding gas. These glowing clouds of gas are called gaseous nebulae. Stars shine at all wavelengths. But these nebulae are more particular as they radiate most of their energy at only a few special places in the spectrum. With cheap and simple equipment, the astrophotographer can capture these faint glowing clouds of gas by viewing them in their special wavelengths. Many of these nebulae cover several degrees of sky – thus they’ll look impressive in the field-of-view of an ordinary 35-mm camera. Besides a camera, all that is needed to photograph these objects is a clock driven mount, the proper filter and some special film.

The best wavelength for photographing these nebulae is that of the Hydrogen-alpha (H-alpha) emission line at 656 nanometers wavelength. Light at 656 nm is deep red – deeper than ordinary film will record. (Ordinary film stops working before the eye stops seeing to prevent the lips and noses from coming out too light on snapshots.) Special film is required for deep sky nebular photography, and the most useful is Kodak 103aE. It is good for two reasons: 1) The basic emulsion – type 103 – has been treated to make it sensitive to some red wavelengths – which is what the E stands for, and 2) 103aE film has been treated to supress reciprocity failure – which is what the a means. Also suitable is 103aF film, though it is not as good because it is sensitive too far into the red.

Hubble. Hubble Space Telescope-Image of Supernova 1994D (SN1994D) in galaxy NGC 4526 (SN 1994D is the bright spot on the lower left). Source of the photograph : NASA/ESA

How can a film be too sensitive? In nebular photography, you want to capture objects which emit a very peculiar spectrum with light mainly in one narrow line. But must of the sources of contaminating background light emit over a wide part of the spectrum. If we can select a narrow “window” in the spectrum, using a filter and film properly chosen to make that window as narrow as possible, we can record more of the Nebula without recording background light which will fog and destroy the image of the nebula. So we must choose a filter (called a short cut filter) which cuts off all wavelengths shorter than the line we are to record, and we must choose a film that isn’t sensitive to wavelengths longer then we want. 103ae was designed to cut off at wavelengths just a bit longer than H-alpha. On the other hand, 103aF was designed to record very deep red light, and in so doing, it records unwanted background light when you photograph the nebulae.

The unwanted background light comes from many sources. Even on the very darkest night the sky has some brightness, called nightglow. The light from billions of stars in our galaxy can also wash out the nebulae, most of which lie against the background of the Milky Way. And unfortunately, city light pollution often provides the greatest source of unwanted illumination. A carefully-chosen film-filter combination can help – but not eliminate – the effects of city lights. The moon can be a nuisance too, and deep sky astrophotography should be done when the moon is down or close to new.

In choosing your filter, you’ll especially want to avoid transmitting the bright oxygen airglow emission lines at 630 and 636nm (part of the nightglow). A filter that is as opaque as possible at 636nm – but as transparent as possible at 656nm – is best. Two kinds of filters are available: glass and gelatin. The best inexpensive filters are made of colored glass; the Corning #2403 and Schott #RG-645. They begin to transmit light at wavelengths around 640nm, and continue being transparent well into the infrared. In combination with an E film, which cuts off soon after the H-alpha line at 656nm, it is possible to get a peak of sensivity of the film and filter together that is only 20 to 30nm wide and centered on H-alpha. An F film, with its sensitivity extending farther into the red, gives sensitivity to a wider range of wavelengths.

Starting your experiments in H-alpha photography, a gelatin filter has two advantages: cheapness and availability. A two-inch square Kodak Wratten filter will be available in your photostore, whereas glass filters must be ordered from industrial suppliers. You best bet in a gelatin filter is the Kodak Wratten #92. Other deep red filters such as a Wratten #29 will work, but not as well because they pass more of the sky background. Gelatin filters are soft; they scratch easily and can be damaged by moisture. With reasonable care, however, they’ll give adequate service.

The proper film and filter can record the H-alpha line without recording much unwanted glow from the night sky.

Wratten filters may be ordered through your local photo dealer. Kodak publication B-3 (“Kodak filters for Scientifc and Technical purposes”) may be ordered from Dept. 454, Eastman Kodak Company, Rochester, N.Y., 14650, or obtained through your local photo dealer.

Corning filter information is available from Robert C. Saxton, Optical Products Dept. , Corning Glass Works, Corning, N.Y. 14830. The #2403 filter must be ordered through Corning dealers (names are supplied by Corning), as Cs 2-58. A two inch square filter (polished) costs about $10. Corning’s catalog can be purchased for $1.

Schott filters can be ordered from Schott Optical Glass, Inc., Duryea, Pa 18642. The RG-645 (polished) filter, two inches square and 3mm thick, costs $12.15. (Schott’s minimum order is $30). No catalog is available, but inquiries may be directed to Jim Speicher, Product Manager.

Baird-Atomic, Inc. 125 Middlesex Turnpike, Bedford, Massachusetts 01730, is one of many suppliers of interference filters. Their standard filter 11-3-4 (6563-A) costs $77 in the two-square-inch size. Better filters are available at higher prices, and their catalog is available upon request.

(This text was published in Astronomy Magazine, July 1976, and has an historic value).

Crew: Scientist, veteran, rookie

Crew: Scientist, veteran, rookie

(Time, December 11, 1972)

It has always been a source of great annoyance to scientists: Though the Apollo Program is one of the milestones in the history of scientific exploration, they have been precluded from participating directly in it. Now, confident of the Apollo landing techniques perfected by the military pilots on previous missions, NASA has chosen a handsome 37 year-old geologist named Harrison (Jack) Schmitt to be co-pilot of Apollo 17. If all goes well, Schmitt next week will take an historic step: he will become the first scientist from Earth to walk on another world.

Schmitt’s preparation began long before Apollo was conceived. The son of a mining geologist, he grew up in Silver City, New Mexico, and decided early in life to become a geologist himself. As a youngster he visited mining camps, explored Indian reservations and made rock-hunting forays into the lunar-like deserts of the Southwest. At Caltech he studied under Ian Campbell and other noted earth scientists, including some of the men who will be watching his every move over TV from Mission Control’s science support room.

Harrison Schmitt on the Moon. Photo: NASA, photo in public domain

In 1964, armed with a new doctorate in geology from Harvard, Schmitt joined the US Geological Survey at Flagstaff, Arizona. There he was assigned the job of assembling photographs taken by unmanned Ranger spacecraft into detailed lunar maps for future moon walkers. Schmitt was fascinated by the task. Recalls former NASA Geologist Gene Shoemaker: “Jack caught the space bug”. Indeed as soon as NASA began recruiting scientist-astronauts in 1965, Schmitt applied. He was accepted despite a minor physical problem: an unusual and painful elongation of the large intestine.

The decision by NASA doctors proved sound. Throughout his rigorous preparation, the geologist astronaut has maintained superb health and excelled as a trainee. He ranked second in his class of 50 at Air Force flight school, and has spent countless hours on field trips everywhere from Iceland to Hawaii teaching fellow astronauts how to spot and select geologically significant rocks. He worked closely with NASA scientists in devising scoops, shovels and other tools on the Moon. Says NASA Flight Director Gene Kranz: “If anyone deserves a flight, is Jack Schmitt”.

As a professional geologist, Schmitt will be under intense pressure to provide his colleagues with the best possible lunar specimens and descriptions of the landscape. To make sure that his performance meets his own high standards, Schmitt has been working at a furious pace. Scientists in Houston still talk about the time they took Schmitt to lunch at a local top-less restaurant, where they all engaged in the usual space-flight shoptalk. Later, when one of the group asked what he thought of the amply proportioned girl who had served him, Bachelor Schmitt was astonished. “When was she topless?”, he asked. “I didn’t even notice”.

Schmitt’s companion on the surface of the Moon will be the mission commander, Navy Captain Eugene Cernan, 38. A veteran astronaut, Cernan took a space flight of Gemini 9 and flew the Apollo 10 lunar module to within nine miles of the Moon’s surface in 1969, during the final test of the Apollo system before an actual landing. Born in Chicago’s North Side to first-generation Czechoslovak-American parents he excelled in athletics in high school but turned down college football scholarships in order to study engineering at Purdue and join the naval ROTC. Married and the father of a nine-year-old girl, he is deeply religious (Roman Catholic), a friend of Vice President Spiro Agnew (who has dined at the Cernan home) and unashamedly patriotic. “For me,” he says of the first lunar landing, “it wasn’t than man first stepped out on the Moon; it was that an American was planting the American flag for all the world to see.”

Commander Ronald Evans, 39, Apollo 17’s third crew member, is also a Navy Flyer. In fact, he and Cernan were studying together at the Navy’s postgraduate School in Monterey, California, in 1963 when Cernan learned that he had been accepted by NASA and Evans was told that he had been turned down (he made it three years later). “That night,” Evans recalls, “Gene and I went out and got totally sloshed.” Born in the Kansas wheat-belt town of St. Francis, where his father worked for a wheat-silage company, Evans was an Eagle Scout, a math whiz and an all-around athlete. After graduating from the University of Kansas, where he held an NROTC scholarship, he won his wings at Pensacola, Florida. Subsequently he flew 100 carrier missions off Indochina and became the first Viet Nam veteran in the astronaut ranks. A modhish dresser (typical garb: white slacks, maroon sports jacket, pink tie and shirt), he is married and the father of two children: a daughter, 13, and a son, 11. As pilot of the command ship America, he will remain in orbit around the Moon while Schmitt and Cernan explore the lunar surface. Unlike earlier command pilots, he will not be totally alone. In lunar orbit with him will be the participants in a medical experiment to determine the effects of cosmic rays on space travelers: five pocket mice.

The Greening of the Astronauts

The Greening of the Astronauts

What are astronauts?

What am I?

Hero, pilot, explorer in love

With myself and with my work.

Unheeding the many dangers that lurk

In outer space or here on earth,

I accept all as due my birth.

– Al Worden.

Before Apollo 15 carried him to the Moon in July 1971, Astronaut Worden been particularly introspective. Poetry had had no place in his life; he rarely read any, and he had never written a line. But something happened to Worden as he orbited the Moon alone in the command ship Endeavor while his crewmates explored the lunar surface. Since his return, he has been moved to put his feelings about space flight into verse, some of it deeply personal and soul searching. Worden’s new interest is only one example of an extraordinary post-flight phenomenon. In spite of their undeserved reputation as unemotional automatons, many of space travelers have been profoundly moved by their experiences away from Earth. In some cases, they have returned to begin entirely different lives. Says Apollo 9 Astronaut Rusty Schweickart: “I am not the same man. None of us are.”

A fictional world with wildly colored marble. Illustration by Elena

Deeply moved

Schweickart himself is a striking example of what might be called the Lunar Effect. Before the flight he was totally committed to his life as an astronaut. But as floated outside Apollo 9 on his space walk 160 miles above the planet Earth, he was overwhelmed by emotion. “I completely lost my identity sweeping past me below.” Now he spends long hours at a Houston clinic for drug addicts, takes part in a volunteer telephone-counseling service for troubles youngsters, and is involved in a local chapter of practitioners of transcendental meditation.

“Something happens to you out there”, explains Apollo 14 Astronaut Ed Mitchell. As a result of what happened to him, he quit the space program, divorced his wife and begun to devote himself full-time to an unlikely pursuit for an M.I.T. graduate: research into extrasensory perception (ESP), which he felt might help people round the world to achieve greater “intuitive: communication.

Walking on the Moon was a religious experience for Apollo 15 Astronaut Jim Irwin, who was “deeply moved by the beauty of the lunar mountains and felt the presence of God”. A month after his return, he said: “I knew that God had called me to his service”. He quit the astronaut program, dubbed himself the “Moon missionary”, and became a lay preacher on the Southern Baptist evangelic circuit.

While he was peering out of the hatch of Apollo 16 onto the lunar landscape, Charles Duke recalled, “I was overwhelmed by the certainty that what I was witnessing was part of the universality of God”. When he looked at his fresh footprints in the almost ageless lunar dust, “I was choked up. Tears came. It was the most deeply moving experience of my life.” Even the sometimes brittle Alan Shepard, America’s first man in space, admitted that he had changed: “I was a rotten s.o.b. before I left. Now I’m just a s.o.b.”

The deepest emotions in space seem to have involved man’s home planet. Says Neil Armstrong, the first man on the Moon who later became a professor of engineering at the University of Cincinnati:” I remember on the trip home on Apollo 11 it suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.

The Apollo 8’s Bill Anders, seeing the Earth from out there evoked “feelings about humanity and human needs that I never had before.” Tom Stafford, a veteran of the Gemini 6 and 9 and Apollo 10 flights, puts it more strongly: “You don’t look down at the world as an American but as a human being”. Other astronauts found the isolation of space exhilarating even when they were behind the Moon, out of touch with the Earth. Michael Collins was actually delighted to be left behind in the Apollo 11 command ship after Armstrong and Aldrin departed for their moon walk: “I knew I was alone in a way that no earthling had ever been before.”

Seen from space the distant Earth turned the thoughts of many astronauts to environmental problems. “I wondered how everyone is going to live on that small, crowded globe,” recalled John Young of Apollo 10 and 16. Even during the tense hours after the explosion of an oxygen tank, Apollo’s 13 Jack Swigert found himself concerned with the terrestrial environment – and suddenly certain about how to preserve it: “I became convinced that space technology – earth-resources, satellites, solar-energy generators, global communication networks and the like – is the answer to the environmental disasters that threaten this fragile Earth”.

Compulsion

Some astronauts were less affected by their trips in space than by acclaim afterword. When he returned from the first lunar landing, Buzz Aldrin, Armstrong’s moon walking companion, found himself totally unequipped to play the hero’s role during the countless public appearances required of him. Soon he was on his way to what he later called “a good old-fashioned American nervous break-down”. In contrast, other astronauts seem to have taken full advantage of the acclaim: John Glenn made a run for the US Senate in Ohio, Wally Schirra appeared as a commentator and in commercials on television, Frank Borman took over a vice-presidency at Eastern Airlines, Al Shepard has made lucrative connections with Houston’s business community, and the list goes on and on… In fact, once the glow of fame wears off, some astronauts have found it painful to slip back into anonymity. “You know, the honeys stop doing handstands when you walk into a rooms, that sort of thing”, said once Mike Collins, who was personally pleased to be free of that artificial life-style. Pete Conrad, Apollo 12’s ebullient commander added: “Who is a bigger bore than a former college football player who bends your ears about all those touch-downs he scored?”

Though the impact of their experience varies widely, most astronauts agree that there is an inevitable, universal consequence of space flight, perhaps best expressed by Ed Mitchell: “You develop an instant global conciseness, a people orientation, an intense dissatisfaction with the state of the world and a compulsion to do something about it.” If that is a significant effect of space flight, and if it can be conveyed successfully to the people of the world, the pay-off from Apollo may be inestimably richer than anyone anticipated.

America's First Manned Flight

America’s First Manned Flight

The United States took its first small step toward the Moon on May 5, 1961. On that occasion, Alan Shepard became the first American to fly in space as he rode his cramped Mercury capsule to an altitude of 116 before splashing down in the Atlantic Ocean 302 miles from the Cape Canaveral launch pad.

Although Shepard’s flight was brief – about fifteen minutes – it represented a major technical and political breakthrough for the American space program. America needed a breakthrough to keep pace with the Soviet space program. Cosmonaut Yuri Gagarin became the first man to fly in space on April 12, 1961, completing one full Earth orbit.

Alan Shepard. Photo in public domain

In the meantime, the American program was floundering. Just ten days before Shepard’s flight an unmanned Mercury-Atlas vehicle was destroyed by ground controllers when it veered off course. With Gagarin’s triumphant orbital mission, the United States was forced to play catch-up once again.

NASA chose Shepard, a thirty-seven-year-old Navy Lieutenant Commander to make the first suborbital flight. His Freedom 7 spacecraft was lofted into space by a Redstone rocket booster. The Redstone ignited at 9.34 a.m. on May 5, 1961, and by 9.50, Shepard was bobbing atop the Atlantic waiting for the recovery ship USS Lake Champlain.

Shepard suffered no ill effects from his brief exposure to the space environment, setting the stage for longer orbital flights for years to come. More important, his mission gave President Kennedy John F. Kennedy the confidence to set a tough goal for the US space program. On May 25, the same year, Kennedy committed the United States to landing a man on the Moon by the end of the decade.

Science Fiction is not just about the future of space ships travelling to other planets, it is fiction based on science and I am using science as my basis for my fiction, but it's the science of prehistory - palaeontology and archaeology - rather than astronomy or physics (Jean M. Auel). Illustration: © Megan Jorgensen.