Maria (pronounced Ma-RYE-ah) Mitchell (1818-1889), America’s first female professor of astronomy, was born August 1, 1818 on Nantucket Island (Massachusetts). Her interest in astronomy was encouraged by her father, and she assisted him with his research at a time when few women were allowed an opportunity to do scientific research. She discovered a comet in 1847 at the age of 29, and this brought her fame as one of America’s few women scientists. She was employed for many years as a computer (a person who performs lengthy mathematical calculations), and then taught astronomy at Vassar College for many years (1865-1888), a women’s college in Poughkeepsie, New York. At Vassar, she was also the director of the Vassar College Observatory. A devoted teacher, she believed that students learn best by doing real research projects. In 1869, she traveled to Burlington, Iowa with six of her students to observe a total solar eclipse.
The Maria Mitchell Observatory was established on Nantucket Island in 1908, and today continues its long legacy of public outreach and undergraduate research.
“When we are chafed and fretted by small cares, a look at the stars will show us the littleness of our own interests.”
“We travel to learn; and I have never been in any country where they did not do something better than we do it, think some thoughts better than we think, catch some inspiration from heights above our own.”
“Question everything.”
“The best that can be said of my life so far is that it has been industrious, and the best that can be said of me is that I have not pretended to what I was not.”
When I was boy, age 8-11, I remember being enthralled by a television show called Voyage to the Bottom of the Sea. I even remember playing with a classic Bic pen, pretending it was the submarine Seaview.
Now, 60 years later, I decided to watch the whole series again. Despite all its flaws (some of which I list below), some of the episodes are pretty good.
What are the flaws? First and foremost, it is clear that Irwin Allen—the show’s creator—and many of his writers did not have a good understanding of basic science. Once you get past that, and the Seaview “popping wheelies“, the Seaview “rock-and-roll” incidents (camera is rocked as the cast rushes from side to side on the set, simulating the submarine being tossed around), the frequent on-board pyrotechnic fires, a circuitry room that begs for a more secure door and an armed guard, and the all-too-frequent “monster of the week” and “mind control” episodes, you’ll always find an excellent cast of regulars (led by Richard Basehart and David Hedison), talented guest stars, and some imaginative stories.
So here goes…
Before you watch the television series episodes, I recommend you watch two submarine-themed movies.
The Enemy Below (1957) This is a great movie, and includes David Hedison (credited as Al Hedison as Lt. Ware of the USS Haynes) who would go on to play Captain Lee Crane in the Voyage to the Bottom of the Sea television series.
Voyage to the Bottom of the Sea (1961) This is the Irwin Allen film that later launched the television series. Once you get past the scientific inaccuracies (the Van Allen Belts on fire??), there is an excellent cast featuring such luminaries as Walter Pidgeon, Joan Fontaine, the ever beautiful and alluring Barbara Eden (before I Dream of Jeannie), Peter Lorre, Robert Sterling, Michael Ansara (before his role as the Klingon Kang in Star Trek and who was married to Barbara Eden at the time!), Frankie Avalon, and Del Monroe as Seaman Kowski who would go on the play Seaman Kowalski in the television series.
Voyage to the Bottom of the Sea (1964-1968) The television series ran for four seasons. Here are my picks for the best episodes.
Season 1 (1964-1965)
Season 1, Episode 2: “The City Beneath the Sea”
Season 1, Episode 3: “The Fear-Makers”
Season 1, Episode 6: “The Sky Is Falling”
Season 1, Episode 7: “Turn Back the Clock”
Season 1, Episode 9: “Hot Line” Directed by John Brahm of Twilight Zone fame, and guests include James Doohan and Michael Ansara before Star Trek.
Season 1, Episode 10: “Submarine Sunk Here”
Season 1, Episode 11: “The Magnus Beam” Guests include Malachi Throne before his appearance on Star Trek.
Season 1, Episode 15: “Long Live the King”
Season 1, Episode 16: “Hail to the Chief”
Season 1, Episode 17: “The Last Battle”
Season 1, Episode 18: “Mutiny”
Season 1, Episode 19: “Doomsday”
Season 1, Episode 20: “The Invaders”
Season 1, Episode 23: “The Human Computer”
Season 1, Episode 28: “The Creature”
Season 2 (1965-1966)
Season 2, Episode 3: “…And Five of Us Are Left”
Season 2, Episode 10: “The Silent Saboteurs” Guests includes George Takei before Star Trek.
Season 2, Episode 15: “Killers of the Deep” Guests includes Michael Ansara before Star Trek.
Season 2, Episode 17: “The Phantom Strikes”
Season 2, Episode 22: “The Death Ship”
Season 2, Episode 26: “The Return of the Phantom”
Season 3 (1966-1967)
Season 3, Episode 5: “The Terrible Toys”
Season 3, Episode 13: “The Lost Bomb”
Season 3, Episode 19: “The Mermaid”
Season 3, Episode 23: “Doomsday Island”
Season 4 (1967-1968)
Season 4, Episode 3: “Cave of the Dead” Guest star Warren Stevens was also a guest on Star Trek later that year.
Season 4, Episode 5: “Sealed Orders”
Season 4, Episode 6: “Man of Many Faces”
Season 4, Episode 7: “Fatal Cargo”
Season 4, Episode 8: “Time Lock”
Season 4, Episode 9: “Rescue”
Season 4, Episode 24: “The Edge of Doom”
Season 4, Episode 26: “No Way Back”
Of the 110 episodes of Voyage to the Bottom of the Sea produced, I think that 33 of them (30%) are well worth watching. Season 1 was the only season filmed in black-and-white, and the only season that had 32 episodes instead of 26. It was also the best season, with 15 great episodes. The next best season was the fourth and final season with 8 great episodes, followed by Season 2 with 6 great episodes. Season 3 was the worst season with only 4 great episodes.
A dear friend of mine passed away suddenly last week while mowing the lawn at his cottage in St. Charles, Illinois. Most of us are lucky to have maybe a dozen friends. Dean must have had hundreds. He was as generous and kind-hearted as anyone I have ever known. And incredibly knowledgeable about observational astronomy and optics.
I first met Dean while I was an undergraduate student at Iowa State University in the late 1970s. He was hired by Dr. Willet Beavers to make stellar radial velocity observations using the 24-inch telescope at ISU’s Erwin W. Fick Observatory. I was the primary data analyst reducing the data from the telescope, and all of us were amazed at how many stars Dean could observe in a night! I believe Dean was the most productive observer Fick Observatory ever had.
Dean and I were part of the ISU team that traveled to a farm near Riverton, Manitoba, Canada to observe the total solar eclipse on February 26, 1979.
Iowa State University Solar Eclipse Expedition – February 26, 1979 Front Row (left to right): Dan Peterson, Maria Meyers, Chuck Hoelzen, Ed Sexauer Back Row (left to right): David Oesper, Jim Pierce, David Cook, Mike Andrews, Prof. Stan Williams, Prof. Willet Beavers, Dean Ketelsen, Joe Eitter
After graduation and working for Fick Observatory before the radial velocity grant money ran out (temporarily), I moved to Dell Rapids, South Dakota to work for the EROS Data Center near Sioux Falls. But, before I left, Dean gave me a Unitron refractor. One of many examples of his generosity.
Soon after I moved to South Dakota, Dean moved to Tucson, Arizona to become a telescope operator on the Mayall 4-meter telescope at Kitt Peak National Observatory. Then, as now, the 4-meter scope was heavily scheduled, but on Christmas and New Year’s he sometimes had the scope to himself for photography and visual observing. I asked him once, “What is the most impressive object you ever saw with the Kitt Peak 4-meter?” His reply: “The crescent moon!” I received some beautiful black & white large prints of galaxies and nebulae from Dean taken with one of the large Kitt Peak instruments. I framed and cherished these astrophotos.
Dean left the telescope operator position at Kitt Peak a few years later and began working at the University of Arizona Mirror Lab where he remained for the rest of his life. He was directly involved in fabricating several of the 8.4-meter mirrors—the largest monolithic telescope mirrors in the world—as well as smaller optics as well. Early in his career at the Mirror Lab, Dean was also working part-time on a Master’s degree in Optical Science at the University of Arizona, but he was never able to complete it before classes he took more than five years earlier no longer counted towards his degree. And I can see why. Dean led a rich and busy life, and his many friends and acquaintances were always his first priority.
Dean’s hospitality was legendary. My family regularly visited Tucson over the years, and Dean was always a most gracious host, transporting us to see all the good sights whenever we visited. A tour of the Mirror Lab was often included, so—thanks to Dean—I have been there many a time.
Dean’s generosity was also legendary. Besides the Unitron refractor and astrophotos, many years ago Dean “loaned” me a pair of Fujinon 16×70 binoculars, and after I moved to Tucson in 2022, he gave me a pair of Celestron 25 x 100 binoculars as a house-warming gift, no longer following any pretense that this would be a loan.
Over a several year period, Dean made a 24-inch mirror for the Ames Area Amateur Astronomers in Iowa, which they are still using today in a Dobsonian telescope built by club members. And, speaking of Dobsonians, Dean was a close acquaintance of John Dobson, and they often got together at star parties.
Dean Ketelsen with John Dobson at a star party
Here are some recent examples of Dean’s generosity. When Suzy and I came to Tucson to visit December 26-30, 2021, Dean and his dear friend Susan Yager picked us up at the Amtrak station and they both spent a lot of time with us as we were thinking about moving to Tucson. Ditto for our March 6-10, 2022 house-hunting trip. I was planning to take Amtrak back to Wisconsin with a stop in Alpine, TX to visit my daughter and her family while Suzy flew to Chicago to get back to work sooner, but Dean was driving from Tucson to St. Charles, Illinois so I rode with him. Though he didn’t have to, Dean went out of his way to drop me off in Dodgeville, Wisconsin and then went on to St. Charles.
Before that house-hunting trip, Dean had reached out to the relatives in charge of Derald Nye’s estate, knowing that I would be losing my backyard research observatory in Wisconsin and that it might be possible for me to purchase his home in Corona de Tucson, which would include an observatory. Unfortunately, that opportunity did not happen, but Dean subsequently put in a good word for me so that I could serve on the 16-inch Meade telescope committee which will add that telescope to the TAAA’s TIMPA observing site.
Before we moved to Tucson, Dean offered to transport my astronomical optics in his large van so that I didn’t need to entrust that delicate equipment to the movers. A week before moving, we drove from Dodgeville and he drove from St. Charles where we met up in Rockford at Lino’s for pizza (great restaurant!) and the transfer of optical equipment to his van afterwards. Needless to say, that equipment arrived safe and sound and in perfect condition at our new house just a few days after the movers when Dean made the trip back to Tucson.
After we moved to Tucson on May 1, 2022, besides restaurant get-togethers at Daily Mae’s and Bianchi’s, Dean & Susan joined John & Lana Gilkison at our house to observe the May 15, 2022 total lunar eclipse. Dean (and Susan) picked me up twice for dark-sky observing: once to watch the Tau Herculid meteor shower Memorial Day 2022 at his favorite observing spot along the road to the top of Kitt Peak, and once to observe from Empire Ranch SSE of Tucson. I was looking forward to many more observing sessions with Dean, but sadly that will not happen. I have lost my best observing buddy here.
No one person can relate all the accolades and experiences that Dean had, but I know of a few. Dean received the 2002 Las Cumbres Amateur Outreach Award from the Astronomical Society of the Pacific, and the asteroid 124075 Ketelsen (2001 GT1) was named after him.
Dean Ketelsen receiving the 2002 Las Cumbres Amateur Outreach Award from the Astronomical Society of the Pacific
Dean was primarily responsible for reincarnating the Grand Canyon Star Party in 1991. He was a primary organizer for many years, and I believe he had attended every year since, including this year. I had the good fortune to attend in 2006, and gave one of the “Twilight Talks”. The most wonderful aspect of this star party that makes it very special and decidedly different from other star parties I have attended is that thousands of enthusiastic visitors to Grand Canyon National Park from all around the world are regaled by a twilight talk each night followed by observing through nearly 50 telescopes, binoculars, and green-laser-pointed constellations and satellites. The enthusiasm of the amateur astronomers sharing their love of astronomy with folks who are in an unusually good mood because they’re on vacation in a beautiful place is a winning combination. Dean had a lot to do with that vibe!
Dean was also an excellent public speaker, and frequently gave public astronomy talks and talks about the exciting things happening at the Mirror Lab.
Joan Oesper, Dean Ketelsen, Melinda Ketelsen, and David Oesper at Yerkes Observatory in 2008
Dean was an incredible photographer, whether the subject was astronomical, terrestrial, or people. He and his wife Melinda, who passed away after a long battle with cancer in 2016, have a blog called The Ketelsens! that includes many of his photos and descriptions of many of their experiences through the last posting on May 31, 2020—during the COVID-19 pandemic. I sincerely hope this blog will be moved to a permanent location on the internet before his blogspot account runs out. It would be a terrible shame to lose this treasure!
The Ketelsens!
We’re glad to see you here! Come and share our daily lives with us, we welcome your company and your comments. We hope there is something here for everyone!
And, speaking of photography, Dean first suggested many years ago the idea of stereo photography of the aurora. To the best of my knowledge, this has seldom been done, though with cellular phones and digital cameras now it would be relatively easy to coordinate such a venture. Two observers separated by a hundred miles or more with identical cameras, lenses, and exposure times would need to take pictures of the aurora at exactly the same time and in exactly the same direction (centered on the same star or constellation). The results, I’m sure, would be spectacular!
I have found it difficult to capture all I want to say about Dean in this article, but I’d like to finish by sharing with you the recent email communications I had from Dean, right up to the day before he died. All but one of my emails to Dean are unimportant in the context of this article, so they are not included here.
June 4, 2023 email from Dean Ketelsen Just got word from Elinor’s niece Cathy (Prescott) that Elinor died a couple weeks ago. Evidently fell and broke her arm in several places, contracted pneumonia and died a week later. So sad – about the last of that generation of friends. She and David Levine, Derald Nye, Mike Terenzoni and I were the only folks (and Vicki!) at Grand Canyon #1. No memorial is planned, but I’ve already asked thru Cathy for a vial of her ashes – maybe we can have our own at the Canyon next year!
July 26, 2023 email from Dean Ketelsen Hi David- How are you surviving the heat? I’ve been up in St Charles coming up on 4 weeks and it has been delightful! This week is the worst, supposed to be up over 90, I think for the first time, tomorrow and Friday before dropping to low 80s for the weekend. I love those sunny days in the 70s, though we have been getting some smoke from the Canadian fires, some days worse than others.
The closer it comes, the less I’m excited about the annular eclipse. Plus I’ve got a “Ketelsen reunion” on 8 October, and after driving to the Midwest, not sure I’m up for returning after less than a week! So may watch the partial phase from here. Still thinking about next April. My first wife Vicki’s sister and her family live in Dallas and am welcome there. I’ve sent them a map of the path and they are looking for a location closer to the center line for a small group. Will see what they come up with. Not sure I’m interested in trying to chase clear spots – again, will see what sort of a zoo it is!
Probably back in Tucson about the weekend of the 12th. Hopefully temp will have dropped a little towards normal!
Hang in there!
-Dean
August 5, 2023 email from Dean Ketelsen Hi David- This article caught my eye in NYT online site. The hospital mixup was only a few miles from Riverton where we observed the ’79 solar eclipse…
Dean texted me about a Space X rocket launch from Vandenberg on August 7. I called him and we talked briefly on the phone. Little did I know it would be the last time I would hear his voice. Then, he sent me this email:
Good Luck!
From:launch-alert-bounces@mailman.qth.net <launch-alert-bounces@mailman.qth.net> on behalf of Launch Alert <launch-alert@mailman.qth.net> Sent: Monday, August 7, 2023 1:02 PM To:launch-alert@mailman.qth.net <launch-alert@mailman.qth.net> Subject: [EXT][Launch Alert] Launch on Schedule
External Email
Tonight’s launch of a Falcon 9 rocket from Vandenberg SFB appears to be on schedule. The following is an update from SpaceX:
“SpaceX is targeting Monday, August 7 at 8:57 p.m. PT (03:57 UTC on August 8) for a Falcon 9 launch of 15 Starlink satellites to low-Earth orbit from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California.”
For launch and countdown status, go to…
August 7, 2023 email from David Oesper to Dean Ketelsen Hi Dean, Thanks for letting me know about this. We had partly cloudy skies tonight, which didn’t help, and I had to observe from my patio so if, as I suspect, the launch would only have been visible close to the WNW horizon, I wouldn’t have been able to see it. I thought I might be able to see one of the stage separations as it was heading to our southern sky here, but no luck with that either. Oh well, it was worth a try, anyway.
Thanks,
Dave
August 8, 2023 email from Dean Ketelsen Hey David- Watching the launch online, I could see the sunset from the onboard camera, but I don’t think it ever rose into bright sunset. Still, Ben Bailly of TAAA captured the enclosed last night. Still, not as spectacular as what it could be – the second taken be non-astronomer friend from Sabino Canyon area 10 months ago she noticed w/o advance warning…. Better luck next time!
-Dean
Dean died the following day. Here is his obituary:
Dean’s obituary states that there will be a future gathering in Tucson to celebrate Dean’s life. As soon as that event is announced, I’ll post the information here in a comment.
Dean Ketelsen – Public Star Party at Sabino Canyon – April 29, 1989
I encourage you to share your personal remembrances of Dean by posting a comment here.
It’s too bad the remarkable Russian-born American astronomer Otto Struve (1897-1963) never lived to see the discovery of the first exoplanets, especially considering how he was probably the first to suggest the two main techniques by which they are now discovered.
The first discovery of something that could be called an exoplanet was announced in 1992 by the Polish astronomer Aleksander Wolszczan (1946-) and Canadian astronomer Dale Frail (1961-). They found two planets orbiting a neutron star 2,300 light years away in the constellation Virgo. This neutron star is the pulsar PSR 1257+12, which had only recently been discovered by Wolszczan (1990). The pulsar planets were detected using a variant of the Doppler (radial velocity) method, and a third planet was discovered by the same team in 1994. These planets likely formed from the debris disk formed when two white dwarf stars merged, so they could be considered “exotic” planets, quite unlike anything found in our solar system.
In 1995, the first exoplanet orbiting a “normal” star was announced by Swiss astronomers Michel Mayor (1942-) and Didier Queloz (1966-). Using the Doppler (radial velocity) method, they found a “hot Jupiter” orbiting the star 51 Pegasi at a distance of 51 light years (nice coincidence!).
In 1999, independent teams led by Canadian-American astronomer David Charbonneau (1974-) and American astronomer Gregory W. Henry (1972-) were the first to use the transit method to detect an exoplanet. They confirmed a hot Jupiter orbiting the star HD 209458 (also in Pegasus, another nice coincidence) 157 light years distant that had been discovered using the Doppler (radial velocity) technique only weeks earlier.
As you can see, the 1990s was the decade when exoplanetary science got its start!
Getting back to the prescience of Otto Struve—40 years prior to the discovery of the first exoplanets—Joshua Winn (1972-) in his newly-published The Little Book of Exoplanets writes:
Although the discovery of hot Jupiters came as a surprise, it’s not quite true that nobody foresaw them. In 1952, Otto Struve, an astronomer at the University of California at Berkeley, published a short paper pointing out that the precision of Doppler measurements had become good enough to detect planets—but only if there existed planets at least as massive as Jupiter with orbital periods as short as a few days. Setting aside the question of how such a planet might have formed, he realized there is no law of physics that forbids such planets from existing. In an alternate history, Struve’s paper inspired astronomers to launch a thousand ships and explore nearby stars for hot Jupiters. In fact, his paper languished in obscurity. None of the pioneers—neither Walker, Latham, Mayor, nor Queloz—were influenced by Struve’s paper. The planet around 51 Pegasi probably could have been discovered in the early 1960s, or surely by Walker in the 1980s, had the Telescope Time Allocation Committee allowed him to observe a larger number of stars.
Here is Otto Struve’s 1952 paper in its entirety (references omitted), published in the October 1952 issue of The Observatory.
PROPOSAL FOR A PROJECT OF HIGH-PRECISION STELLAR RADIAL VELOCITY WORK
By Otto Struve
With the completion of the great radial-velocity programmes of the major observatories, the impression seems to have gained ground that the measurement of Doppler displacements in stellar spectra is less important at the present time than it was prior to the completion of R. E. Wilson’s new radial-velocity catalogue.
I believe that this impression is incorrect, and I should like to support my contention by presenting a proposal for the solution of a characteristic astrophysical problem.
One of the burning questions of astronomy deals with the frequency of planet-like bodies in the galaxy which belong to stars other than the Sun. K. A. Strand’s discovery of a planet-like companion in the system of 61 Cygni, which was recently confirmed by A. N. Deitch at Poulkovo, and similar results announced for other stars by P. Van de Kamp and D. Reuyl and E. Holmberg have stimulated interest in this problem. I have suggested elsewhere that the absence of rapid axial rotation in all normal solar-type stars (the only rapidly-rotating G and K stars are either W Ursae Majoris binaries or T Tauri nebular variables, or they possess peculiar spectra) suggests that these stars have somehow converted their angular momentum of axial rotation into angular momentum of orbital motion of planets. Hence, there may be many objects of planet-like character in the galaxy.
But how should we proceed to detect them? The method of direct photography used by Strand is, of course, excellent for nearby binary systems, but it is quite limited in scope. There seems to be at present no way to discover objects of the mass and size of Jupiter; nor is there much hope that we could discover objects ten times as large in mass as Jupiter, if they are at distances of one or more astronomical units from their parent stars.
But there seems to be no compelling reason why the hypothetical stellar planets should not, in some instances, be much closer to their parent stars than is the case in the solar system. It would be of interest to test whether there are any such objects.
We know that stellar companions can exist at very small distances. It is not unreasonable that a planet might exist at a distance of 1/50 astronomical unit, or about 3,000,000 km. Its period around a star of solar mass would then be about 1 day.
We can write Kepler’s third law in the form . Since the orbital velocity of the Earth is 30 km/sec, our hypothetical planet would have a velocity of roughly 200 km/sec. If the mass of this planet were equal to that of Jupiter, it would cause the observed radial velocity of the parent star to oscillate with a range of ± 0.2 km/sec—a quantity that might be just detectable with the most powerful Coudé spectrographs in existence. A planet ten times the mass of Jupiter would be very easy to detect, since it would cause the observed radial velocity of the star to oscillate with ± 2 km/sec. This is correct only for those orbits whose inclinations are 90°. But even for more moderate inclinations it should be possible, without much difficulty, to discover planets of 10 times the mass of Jupiter by the Doppler effect.
There would, of course, also be eclipses. Assuming that the mean density of the planet is five times that of the star (which may be optimistic for such a large planet) the projected eclipsed area is about 1/50th of that of the star, and the loss of light in stellar magnitudes is about 0.02. This, too, should be ascertainable by modern photoelectric methods, though the spectrographic test would probably be more accurate. The advantage of the photometric procedure would be its fainter limiting magnitude compared to that of the high-dispersion spectrographic technique.
Perhaps one way to attack the problem would be to start the spectrographic search among members of relatively wide visual binary systems, where the radial velocity of the companion can be used as a convenient and reliable standard of velocity, and should help in establishing at once whether one (or both) members are spectroscopic binaries of the type here considered.
Berkeley Astronomical Department, University of California. 1952 July 24.
I recently received a membership renewal notice from the International Dark-Sky Association (IDA) quoting Christopher Kyba that if light pollution continues to grow at the rate it currently is, “Orion’s belt will disappear at some point.”
This made me remember that I had written an IDA Information Sheet back in March 1997 that also had addressed how light pollution could erase much of the Orion constellation. I wrote,
Orion, arguably the most prominent of the constellations, begins to look more like “Orion, the Hunted” under a magnitude +4.0 sky. Under a magnitude +3.0 sky, Orion is on his deathbed. When light pollution is so bad that we have a magnitude +2.0 sky, only blazing Betelgeuse, regal Rigel, and Bellatrix and Alnilam remain to regale us.
Speaking of the IDA Information Sheets, I was the IDA Information Sheet Editor from 1996-1999, during which time I revised and edited most of the existing information sheets, edited and added many new ones from a number of contributors, as well as contributed many new ones that I authored, though I never credited myself as the author. One of the ones that I wrote was IDA Information Sheet 120, referenced above (and shown below). I have a complete hard copy set of IDA Information Sheets 1 through 175, the last of which was published in June 2000. I also have WordPerfect Macintosh source files for IDA Information Sheets 1 through 158, the last of which was completed on October 27, 1999.
It is a shame that these IDA Information Sheets are no longer available anywhere on the Internet. At the very least, they are of historical interest, and I would say that much of the content is still relevant. Presumably, the IDA still has all of these information sheets, but after the Dave Crawford era, they have decided to remove access to them.
Finally, I want to express my disappointment that the International Dark-Sky Association has recently decided to change their name to DarkSky International. They are still in the process of changing everything over, but once that transition is complete, the IDA will be no more. The break with the Dave Crawford era will be complete. I, for one, will never forget how much Dave Crawford was able to accomplish during those early years, and how proud I was to have been a part of it.
The IDA/DSI is still a great organization, and I strongly encourage you to generously support it, as I do. It remains the most effective organization in the world addressing light pollution and the loss of our night sky and the natural nighttime environment.
The celestial sphere is a jigsaw puzzle with 88 pieces. The oldest piece is arguably the constellation Ursa Major, The Great Bear. Based on historical writings, prehistoric art, and the knowledge that this group of stars represented a bear in many cultures scattered throughout the world leads scholars to believe that this constellation was first described around 11,000 B.C., perhaps earlier.
The newest constellations are the 17 listed in the table below. Thirteen of these were invented by French astronomer Nicolas-Louis de Lacaille (1713-1762) during his stay at the Cape of Good Hope in 1751 and 1752, and the other four (Puppis, Pyxis, Vela, and Carina) are portions of the ancient enormous constellation Argo Navis, described by Ptolemy (c. 100 – c. 170). Though all of these constellations reside completely in the southern hemisphere of the sky (and thus can be best observed in the southern hemisphere), all but two of them (Mensa and Octans) have a portion that rises above the southern horizon as seen from Tucson, however scant and brief.
Newest Constellations
Constellation
Description
Declination
Puppis
The Stern (of Argo Navis)
-51˚ to -11˚
Pyxis
The Compass (of Argo Navis)
-37˚ to -17˚
Fornax
The Laboratory Furnace
-40˚ to -24˚
Antlia
The Air Pump
-40˚ to -25˚
Sculptor
The Sculptor's Workshop
-39˚ to -25˚
Caelum
The Sculptor's Chisel
-49˚ to -27˚
Microscopium
The Microscope
-45˚ to -27˚
Vela
The Sail (of Argo Navis)
-57˚ to -37˚
Horologium
The Pendulum Clock
-67˚ to -40˚
Norma
The Carpenter's Square
-60˚ to -42˚
Pictor
The Painter's Easel
-64˚ to -43˚
Telescopium
The Telescope
-57˚ to -45˚
Carina
The Keel (of Argo Navis)
-76˚ to -51˚
Reticulum
The Net
-67˚ to -53˚
Circinus
The Compasses
-71˚ to -55˚
Mensa
The Table Mountain
-85˚ to -70˚
Octans
The Octant
-90˚ to -74˚
Which (mostly) northern constellations were added last? Around 70 years prior to Lacaille, Johannes Hevelius (1611-1687) described the seven constellations in the table below. These constellations were first published posthumously in 1690.
Newest More Northerly Constellations
Constellation
Description
Declination
Lynx
The Lynx
+33˚ to +62˚
Lacerta
The Lizard
+35˚ to +57˚
Canes Venatici
The Hunting Dogs
+28˚ to +52˚
Leo Minor
The Lion Cub
+23˚ to +41˚
Vulpecula
The Fox
+19˚ to +29˚
Sextans
The Sextant
-12˚ to +6˚
Scutum
The Shield
-16˚ to -4˚
Let us now return to the oldest constellation, Ursa Major. The earliest extant literary work describing the constellations, including Ursa Major, is Phainómena by the Greek didactic poet Aratus (c. 315 BC – 240 BC). Phainómena is based on an earlier work by the Greek astronomer and mathematician Eudoxus of Cnidus (c. 408 BC – c. 355 BC), now lost. Earlier, the Greek poets Homer and Hesiod (~700 BC) mentioned the constellations, and we know that the Babylonians had a well-developed system of constellations (~2000 BC), as did the Sumerians even earlier (~4000 BC), later assimilated by the Greeks.
Here is what Aratus says in Phainómena about Ursa Major, in context.
The numerous stars, scattered in different directions, sweep all alike across the sky every day continuously for ever. The axis, however, does not move even slightly from its place, but just stays for ever fixed, holds the earth in the centre evenly balanced, and rotates the sky itself. Two poles terminate it at the two ends; but one is not visible, while the opposite one in the north is high above the horizon. On either side of it two Bears wheel in unison, and so they are called the Wagons. They keep their heads for ever pointing to each other's loins, and for ever they move with shoulders leading, aligned towards the shoulders, but in opposite directions. If the tale is true, these Bears ascended to the sky from Crete by the will of great Zeus, because when he was a child then in fragrant Lyctus near Mount Ida, they deposited him in a cave and tended him for the year, while the Curetes of Dicte kept Cronus deceived. Now one of the Bears men call Cynosura by name, the other Helice. Helice is the one by which Greek men at sea judge the course to steer their ships, while Phoenicians cross the sea relying on the other. Now the one is clear and easy to identify, Helice, being visible in all its grandeur as soon as night begins; the other is slight, yet a better guide to sailors, for it revolves entirely in a smaller circle: so by it the Sidonians sail the straightest course.
Between the two Bears, in the likeness of a river, winds a great wonder, the Dragon, writhing around and about at enormous length; on either side of its coil the Bears move, keeping clear of the dark-blue ocean. It reaches over one of them with the tip of its tail, and intercepts the other with its coil. The tip of its tail ends level with the head of the Bear Helice, and Cynosura keeps her head within its coil. The coil winds past her very head, goes as far as her foot, then turns back again and runs upward. In the Dragon's head there is not just a single star shining by itself, but two on the temples and two on the eyes, while one below them occupies the jaw-point of the awesome monster. Its head is slanted and looks altogether as if it is inclined towards the tip of Helice's tail: the mouth and the right temple are in a very straight line with the tip of the tail. The head of the Dragon passes through the point where the end of settings and the start of risings blend with each other.
DNA sequencing is revolutionizing the study of human origins and prehistory, but also genealogy.
The number of ancestors you have at each preceding generation is given by 2n, where n = 1, 2, 3, and so on (parents, grandparents, great-grandparents, etc.). The total number of ancestors you have back to any preceding generation is given by 2n+1 – 2. The number of ancestors for the first seven generations is shown in the following table.
Generation
n
Generation Ancestors
Cumulative Ancestors
Parents
1
2
2
Grandparents
2
4
6
Great-Grandparents
3
8
14
2G-Grandparents
4
16
30
3G-Grandparents
5
32
62
4G-Grandparents
6
64
126
5G-Grandparents
7
128
254
It is natural to wonder, is there a point at which you don’t receive any distinguishable1 DNA from an ancestor? As an example, looking at your 128 great-great-great-great-great-grandparents, what are the chances that any one of them contributed no DNA to you? The answer is about 0.5%. You would expect, on average, that 128×0.005 = 0.64 ancestors at this generation has contributed nothing to your DNA. In other words, either 127 or 128 of your 5G-grandparents contributed to your DNA. As we go even further back in time, the number of ancestors at each preceding generation that did not contribute to your DNA rapidly increases, as shown in the following table.
Generation
n
Generation Ancestors
Likelihood of inherited DNA
Parents
1
2
100%
Grandparents
2
4
100%
G-Grandparents
3
8
100%
2G-Grandparents
4
16
100%
3G-Grandparents
5
32
100%
4G-Grandparents
6
64
99.99%
5G-Grandparents
7
128
99.5%
6G-Grandparents
8
256
96%
7G-Grandparents
9
512
84%
8G-Grandparents
10
1024
64%
So you can see that of your 1,024 G-G-G-G-G-G-G-G-grandparents, you will not have received any DNA from about 1024×0.36 = 369 of them.
Another question you might have relates to cousins. What is the probability that you and a cousin share DNA? That is shown in the following table.
Relationship
Likelihood of a DNA Match
Sibling
100%
1st Cousin
100%
2nd Cousin
100%
3rd Cousin
98%
4th Cousin
71%
5th Cousin
32%
6th Cousin
11%
7th Cousin
3.2%
As you can see, beyond your 3rd cousins, there’s a reasonably good chance you have no distinguishable DNA in common.
DNA Tests
The usual DNA test that most folks get is an autosomal DNA test. It is that test that we are referring to in the sections above.
There are two other DNA tests you might want to consider. The Y-DNA test and the mtDNA test, which allow you to trace your patrilineal (father) and matrilineal (mother) lines, respectively.
Y-DNA Tests
A Y-DNA test looks at the Y-chromosome, which only men have. The Y-chromosome is passed down from father to son generation after generation virtually unchanged. So if you are male and took the Y-DNA test, and another male also took the Y-DNA test, if they matched you would know that you are both descended from the same common ancestor along male lines, whether it could be proved by records or not. I’ll use myself as an example.
I have been able to trace my male line ancestors back to my 7G-grandfather.
Ancestor
Relationship
Andreas Oesper (?-1721)
7G-Grandfather
Andreas Oesper (1709-1776)
6G-Grandfather
Zacharias Oesper (1744-1792)
5G-Grandfather
Johann Georg Oesper (1780-?)
4G-Grandfather
Johann Peter Oesper (1817-1890)
3G-Grandfather
Ernst William Oesper I (1846-1918)
2G-Grandfather
Ernst William Oesper II (1874-1951)
Great-Grandfather
Ernst William Oesper III (1904-1976)
Grandfather
Ernst William Oesper IV (1928-1997)
Father
David Oesper (1956-)
Self
Any male that descended along the male line from any of these ancestors (or unknown earlier generations) would have a Y-DNA match with me. They probably also have the surname Oesper, but not necessarily for a variety of reasons.
Though we haven’t both taken a Y-DNA test, my 2nd cousin once removed Pete Oesper and I would have matching Y-chromosomes. Pete is descended along the male line from my great-great-grandfather Ernst William Oesper I.
mtDNA Tests
A mitochondrial DNA (mtDNA) test looks at the mitochondria, which both males and females have. Mitochondrial DNA is passed down from a mother to her children generation after generation virtually unchanged. So if you and another person took a mtDNA test, if they matched you would know that you are both descended from the same female ancestor along mother-lines, whether it could be proved by records or not. I’ll again use myself as an example.
I have been able to trace my female line ancestors only back to my great-grandmother, or perhaps my great-great-grandmother, but all we have for her is a first name and perhaps not even that.
Ancestor
Relationship
Mary? (?-?)
2G-Grandmother
Katherine Curtin (1855-1931)
Great-Grandmother
Sarah Geneva Smith (1896-1992)
Grandmother
Carla Mary Pieroni (1929-1985)
Mother
David Oesper (1956-)
Self
My great-grandmother Katherine Curtin and her brother and sister were orphaned at a young age in New York City. We know that her parents immigrated from Ireland, but nothing more for certain. If I were to take a mtDNA test and could find someone in Ireland who is a mtDNA match, they would likely have descended along the female line from the same female ancestor as me, presumably my great-great-great grandmother, or her mother, grandmother, etc. See how it works?
1 All humans have about 99.5% identical DNA. The half percent that differs between us is what we might call traceable or distinguishable DNA. When you see the term DNA in this article, we are always referring to the portion of the human genome that is distinguishable between individuals, present and past.
I’d like to thank Paul Martsching for emails he sent to me that I utilized in the writing of this article. I alone am responsible for any errors or inaccuracies herein, so please let me know if you find anything in need of correction.
Using the newly-invented telescope, French astronomer Nicolas-Claude Fabri de Peiresc (1580-1637) discovered the now-famous Orion Nebula (M42) when he was 29 years old, 410 years ago on this day.
November 26, 1610.
But wait a minute. You and I can see a nebulous “star” below the belt of Orion with our unaided eyes under a reasonably dark sky. Why wasn’t this object discovered long before the invention of the telescope?
Apparently, there is no known report of a “nebulous star” in the sword of Orion prior to Peiresc’s discovery. Is the Orion nebula brighter now than it was a few centuries ago? Is it possible an earlier observational report somehow got missed or was not properly interpreted?
There is speculation that the Maya civilization of Mesoamerica recognized the Orion Nebula long before Peiresc’s discovery, describing it as smoke from the smoldering embers of creation.
One can only stand in wonderment at the knowledge and experiences of hundreds of generations of men, women, and children who are utterly unknown to us today. Passed from person to person and generation to generation through oral tradition, never written down and eventually lost. Or written down on documents that later disintegrated or were purposefully destroyed.
Who hasn’t wished that they could could time travel back to the past? Have you ever wondered what your current location looked like a hundred years ago? A thousand years ago? Ten thousand or more years ago? Though sending humans into the past will probably never be possible, who’s to say that we won’t eventually figure out a way to view and perhaps even hear the past, without actually being there or having the ability to change it?
Pittsburgh telescope maker, optician, and educator John Alfred Brashear (1840-1920) was born 180 years ago this day. His world-renowned optical company made much of the astronomical equipment in use in the United States during the late 19th and early 20th centuries. His works included a 30-inch refractor for Allegheny Observatory in Pittsburgh, a 15-inch refractor for the Dominion Observatory in Canada, and the 8-inch refractor at the Drake University Municipal Observatory in Des Moines, Iowa.
My good friend, telescope maker Drew Sorenson in Jefferson, Iowa, has been a fan of John Brashear for many years. Not only does Drew make fine refractors as did Brashear, but there is more than a little resemblance between the two men. Drew introduced me to a delightful book entitled John A. Brashear: The Autobiography of A Man who Loved the Stars, which was first published posthumously in 1924. For anyone interested in the history of astronomy and the life of a scientist and humanitarian who struggled from near-obscurity to great success with only an elementary school education, this book is a must-read.
Here are three of my favorite passages from the book.
Somewhere beneath the stars is work which you alone were meant to do. Never rest until you have found it.
There is another yarn I cannot resist telling. The young farmer who had been bringing Mrs. Brashear her supply of vegetables asked her one day if I would let him look in the big telescope if he came up some clear evening. She encouraged him to do so, and I found him waiting one night to see the sights. I did not know whether or not he had any knowledge of astronomy, but I asked him what he would like to look at. He replied, “Juniper.” I told him that unfortunately that planet was not visible in the sky at the time. Then he expressed a desire to see “Satan.” But his Satanic Majesty was not around either. The climax came when he asked if I could show him the “Star of Jerusalem!” I ended it by showing him the moon and some clusters, and he went home very happy.
I remember, too, an old gentleman over eighty years of age who climbed the hill one moonlight night for a look in the telescope. The good man was utterly exhausted when he reached the house, and Ma and I had him lie down on the lounge to rest before climbing the stairs to the telescope. The views that night were fine, and I can hear the soliloquy yet of the dear fellow as he said, “For many years I have desired to see the beauties of the heavens in a telescope. I have read about them and heard lectures about them, but I never dreamed they were so beautiful.” We invited him to stay all night; but as it was moonlight, and much easier for him to go down the hill than to come up, he insisted on going home. I went part of the way with him to see that he got along all right; and all the way he expressed his delight at having the wish of a lifetime gratified that night.
Three weeks later the funeral cortège of that old man passed along the road on the opposite hillside that led to the cemetery, and it has always been a pleasure to remember that I was able to be of some service in gratifying one of his desires of a lifetime.
I think that all my life I have been partial to old people and children, and it has always been a source of genuine pleasure to contribute to their happiness.
John A. Brashear: The Autobiography of A Man who Loved the Stars (1924)
On this date 140 years ago, American physician and prominent amateur astronomer Henry Draper (1837-1882) made the first successful photograph of the Great Nebula in Orion, now usually referred to as the Orion Nebula. He used an 11-inch telescope (an Alvan Clark refractor!) and an exposure time of 50 minutes for the black and white photograph.
First photograph of the Orion Nebula, September 30, 1880. (Henry Draper)
Draper continued to improve his technique, and a year and a half later he obtained a 137-minute exposure showing much more detail.
Photograph of the Orion Nebula, March 14, 1882. (Henry Draper)
It really is amazing how image recording technology has improved over the past century and a half! At its best, film-based photography had a quantum efficiency of only about 2%, which means that only 2 out of every 100 photons of light impinging on the photographic medium is actually recorded. The rest is reflected or absorbed. The human eye—when well dark adapted—has a quantum efficiency of 15% or better, easily besting photography. Why, then, do photographs of deep sky objects show so much more detail than what can be seen through the eyepiece? The explanation is that the human eye can integrate photons and hold an image for only about 0.1 second. Film, on the other hand, can hold an image much longer. Even with reciprocity failure, photographic media like film can collect photons for minutes or even hours, giving them a big advantage over the human eye. But charge-coupled devices (CCDs) are a considerable improvement over older technologies since they typically have a quantum efficiency of 70% up to 90% or more. The CCD has truly revolutionized both professional and amateur astronomy in recent decades.
. Since the orbital velocity of the Earth is 30 km/sec, our hypothetical planet would have a velocity of roughly 200 km/sec. If the mass of this planet were equal to that of Jupiter, it would cause the observed radial velocity of the parent star to oscillate with a range of ± 0.2 km/sec—a quantity that might be just detectable with the most powerful Coudé spectrographs in existence. A planet ten times the mass of Jupiter would be very easy to detect, since it would cause the observed radial velocity of the star to oscillate with ± 2 km/sec. This is correct only for those orbits whose inclinations are 90°. But even for more moderate inclinations it should be possible, without much difficulty, to discover planets of 10 times the mass of Jupiter by the Doppler effect.
