Wallpaper Wednesday: NGC 6902

5 06 2019
The spiral galaxy NGC 6902 was discovered in 1836 by John Herschel.
ESO / SPECULOOS Team / E. Jehin

The SPECULOOS Southern Observatory saw first light in December 2017. Located at ESO’s Paranal Observatory in Chile, SPECULOOS is designed to hunt for exoplanets around small, cool stars.

This image of NGC 6902, a galaxy about 120 million light-years from Earth in the direction of Sagittarius, was taken to test one of the four 1-meter telescopes that comprise SPECULOOS.

Visit the ESO site to download high-res versions of this image.

Wallpaper Wednesday: SDO and Sunspots

16 07 2014

"Sweeping Arches and Loops", solar magnetic activity viewed in the ultraviolet, June 30, 2014.

“Sweeping Arches and Loops”, solar magnetic activity viewed in the ultraviolet, June 30, 2014.

Looking at some of the photos returned by NASA’s Solar Dynamics Observatory (SDO), you’d think contemporary solar observing had little in common with what was being done at Kodaikanal c. 1900-1910. But in addition to the dramatic images of solar loops like the one shown above, SDO also sends back sunspot records that closely resemble the photos and charts produced by C. Michie Smith, John Evershed, and company.

"Spots Galore," July 8, 2014. Image credit: Solar Dynamics Observatory/NASA

“Spots Galore,” July 8, 2014. Image credit: Solar Dynamics Observatory/NASA

According to SDO/NASA:

“The Sun sported a whole slew of substantial sunspots over the past 11 days (July 1-10, 2014). This movie and still show the Sun in filtered white light speckled with more and larger sunspots than we have seen in quite some time. Sunspots are darker, cooler regions on the Sun created by intense magnetic fields poking through the surface. The Sun may have passed its peak level of activity, but it will still be producing many more sunspots and solar storms during the rest of this solar cycle. The still image was taken on July 8 at 22:24 UT.”

Looks familiar!

Visit the NASA/SDO gallery to see more images of solar activity. Like the two above images, most are stills excerpted from videos. Click through each image to reach the links to .mov and .mp4 files.

Upcoming LADEE Launch

2 09 2013

NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft sits in the nose-cone at the top of the full Minotaur V launch vehicle stack.

LADEE in the Fully-Stacked Minotaur V Fairing. Image credit: NASA Ames/ Zion Young

If you’ve been missing your lunar reconnaissance instruments since the GRAIL impact, you might find some relief through the upcoming launch of  the Lunar Atmosphere and Dust Environment Explorer (LADEE). Don’t get too attached to LADEE’s instruments, though—this mission will only last about 160 days. The mission team has allowed thirty days travel time (from Earth to lunar orbit), thirty days for positioning and shake-down, and 100 days for science.

My first reaction to the LADEE project was, “Whoa. You mean we don’t know that already?” Many people feel that the Moon is old hat, a been-there-done-that kind of place. But it turns out we don’t really know much about out closest neighbor, despite the success of the Apollo missions. Did you know that the Moon has an atmosphere? Three of LADEE’s science projects (the Ultraviolet and Visible Light Spectrometer; the Neutral Mass Spectrometer; and the Lunar Dust Experiment) will be studying it through spectral and particle analysis. The fourth component of the payload, the Lunar Laser Communications Demonstration, revolves around a search for a faster means of communicating in space.

If conditions are right, I should be able to see the LADEE launch Friday, September 6, 2013. More correctly, I should be able to watch the launch vehicle (a Minotaur V) streak across the tree tops at T+90 seconds, give or take a few seconds. The launch window opens at 11:27 p.m. EDT and LADEE will be leaving Earth from the Wallops Flight Facility in eastern Virginia. If you’re on the east coast between North Carolina and the Maritimes, with an open view to the east-north, you might be able to see the rocket. If you fancy a trip out to Wallops, you can find a list of public viewing sites here.

Maximum Elevation Map.  Image courtesty: Orbital

Maximum Elevation Map. Image courtesy: Orbital

From the Orbital Minotaur V website: “This map shows the maximum elevation (degrees above the horizon) that the Minotaur V rocket will reach depending on your location along the east coast. The further away you are from the launch site, the closer to the horizon the rocket will be. As a reference, when you look at your fist with your arm fully outstretched, it spans approximately 10 degrees. Thus if you are in Washington, DC the highest point the Minotaur V will reach is approximately 13 degrees above the horizon, or just slightly more than a fist’s width. The contours shown stop below 5 degrees. It is unlikely that you’ll be able to view the rocket when it is below 5 degrees due to buildings, vegetation, and other terrain features.”

First Site Map. Image courtesy Orbital.

First Site Map. Image courtesy: Orbital

From the Orbital Minotaur V website: “This map shows the rough time at which you can first expect to see the Minotaur V rocket after it is launched. It represents the time at which the rocket will reach 5 degrees above the horizon and varies depending on your location along the east coast. We have selected 5 degrees as it is unlikely that you’ll be able to view the rocket when it is below 5 degrees due to buildings, vegetation, and other terrain features. As a reference, when you look at your fist with your arm fully outstretched, it spans approximately 10 degrees. As an example, using this map when observing from Washington, DC shows that the Minotaur V rocket will reach 5 degrees above the horizon approximately 54 seconds after launch (L + 54 sec).”

Happy LADEE Launch!

ETA: I forgot to tell you that you can follow LADEE on twitter at https://twitter.com/NASALADEE!

S. A. Mitchell and the Leander McCormick Observatory

17 04 2013

S. A. Mitchell with 26-inch refractor. Image courtesy McCormick Museum, University of Virginia

S. A. Mitchell with 26-inch refractor. Image courtesy McCormick Museum, University of Virginia

I’ve written before about the dispersal of the book collection that once belonged to Frank K. Edmondson. My wife picked up a couple more of his books for me recently, one of which seems particularly appropriate to discuss at this point in my career.

Book cover, from the collection of Frank K. Edmondson.

Book cover, from the collection of Frank K. Edmondson.

This is a fascinating handbook written in 1947 by Samuel A. Mitchell, director emeritus of the McCormick Observatory at University of Virginia. It’s a modest little book but it makes clear the entangled nature of American astronomy at the beginning of the twentieth century.

Mitchell’s career as an astronomer opened at the Yerkes Observatory, where he “imbibed a small modicum of the research spirit that [he] found there…” [p. 8] He was inspired especially by E. E. Barnard, who had been on staff at Lick Observatory, and Frank Schleslinger, later of the Allegheny Observatory at Pittsburgh. He was impressed by Barnard’s dedication (“If  Barnard’s enthusiasm for research could keep him at the telescope with such bitter temperatures [-26 F], why should not I, at the age of 24, not take pattern from the older man?”), but his research trajectory followed that of Schlesinger. [p. 10] As he describes it:

The coming of the photographic plate to the aid of the astronomer and of the largest refractor in the world (dedicated in 1897) brought a great opportunity to ascertain what new information could be found regarding the difficult research of measuring stellar distances. The astronomical  world is under a great debt to Professor Frank Schlesinger when he demonstrated in masterful fashion that the parallaxes possibly by photography with the 40-inch Yerkes refractor gave stellar distances with a very great increase in accuracy over the earlier results from visual observations with much smaller telescopes.[p. 13]

Schlesinger’s departure for the Allegheny in 1905 left a gap in the Yerkes program. Mitchell took the opportunity to fill it, beginning his life’s pursuit of the measure of parallax through the use of photography.

The determination of stellar distances through observation and comparative photography formed the core of Mitchell’s research when he became the director of the McCormick Observatory in 1913. Similar efforts were underway at the Allegheny Observatory, where Schlesinger oversaw a 30-inch photographic refractor; at Mount Wilson, where Adriaan van Maanen worked with the 60-inch reflector; at Sproul Observatory (Swarthmore), under John A. Miller with a 24-inch visual refractor; and at Greenwich Royal Observatory with its 26-inch photographic refractor. Charles P. Olivier, native of Charlottesville and later founder of the American Meteor Society, and Harold Alden, arriving from the Yale Observatory in South Africa, joined Mitchell’s efforts at Virginia. [p. 15]

Mitchell arrived at McCormick while on soft money. That is, he “accepted the directorship with no promises from University of Virginia.” [p. 17] Luckily, he was the recipient of the Ernest Kempton Adams Research Fellowship from Columbia University. His fellowship period ended before Virginia decided to pony up some research money, but Edward Dean Adams (father of E. K. Adams, for whom the fellowship was named) decided—after consultation with George E. Hale, once of Yerkes, at the time of Mount Wilson—to give Mitchell a special financial award given the potential significance of his work.

I’m tempted here to start “following the money.” Edward Dean Adams was the president of the Cataract Construction Company, “a new organization of capitalists which ha[d] been formed to furnish electricity and electric power upon a scale of tremendous magnitude by employing the Falls of Niagara to generate the electric fluid.” [see original NYT article here, examine the Edward D. Adams Station Power plant here] Any of you who have driven an International Harvester have used a piece of the Leander McCormick legacy—IH came out of the McCormick Harvesting Machine Company, founded by Leander and his brother, William. McCormick’s planned donation was interrupted by a downturn in his finances after the Great Chicago Fire. So tempting, but I’ll leave the analysis of capital to another time.

For now, let me just jump forward in time to highlight a few more connections between American astronomers. Mitchell died on February 22, 1960, in Bloomington, Indiana. He was the father of Allan C. G. Mitchell, the chair of IU’s Physics Department, director of the university’s cyclotron program between 1942-44, and colleague of Frank Edmondson. Sadly, Allan Mitchell died young, outliving his father by fewer than the three years (read his obituary here). My question is: did Edmondson acquire this book directly from Samuel Mitchell, perhaps when he moved to Bloomington after his retirement? Or did Allan give it to him? Did he pick it up because he knew and worked with Allan? How did he end up with No. 114 out of a run of 200?

S. A. Mitchell's signature, back page of handbook.

S. A. Mitchell’s signature, back page of handbook

Oh, and why is this appropriate to discuss at this point in my career? I recently accepted a two-year appointment at University of Virginia, which means this little book is making the return trip from Bloomington to Charlottesville via Edison, NJ. I hope someone is keeping track of the movement.

Wallpaper Wednesday (Aristarchos, Helmos Observatory)

27 02 2013

Snow on Mount Helmos. Photo credit: Helmos Observatory/National Observatory Athens

Snow on Mount Helmos. Photo credit: Helmos Observatory/National Observatory of Athens

This astonishing image of Helmos Observatory (look closely) introduces the news item posted by the Royal Astronomical Society. Panos Boumis of the National Observatory Athens and John Meaburn of the University of Manchester have published the results of their research based on observations made with Aristarchos, the 2.3 m telescope at Helmos Observatory. Aristarchos only saw first light in 2005, so that Boumis and Meaburn are revealing their conclusions so soon is pretty exciting. In order to measure the distance and age of three lobes of the nebula KjPn8 (in other words, three parts of the gaseous shell that was ejected by a star as it collapsed into a white dwarf), they attached a narrowband camera to the telescope. By comparing the imaging results over the course of several months (years?), they were able to track the velocity and expansion of the lobes; from there, they calculated the distance and age of the nebula.

It’s interesting enough to learn that KjPn8 is some 8000 light years away from Earth. Even more interesting, however, is the conclusion that the lobes were created at different times: 3200, 7200 and *50,000* years ago. That’s…what…the Paleolithic? Homo neandrathalensis has another 10-20,000 years to go extinct and Homo sapiens has just arrived in Europe. That’s seriously cool stuff.

Click on the image to go to the original, posted by the Helmos Observatory.

Wallpaper Wednesday (Pierre Auger Observatory)

13 02 2013

Surface Detector, Pierre Auger Observatory. Photo credit: Pierre Auger Observatory

Surface Detector, Pierre Auger Observatory. Photo credit: Pierre Auger Observatory

It was surprisingly difficult to locate an image to illustrate today’s post. I was inspired by the March 2013 cover story in Astronomy magazine. Written by Yvette Cendes (follow her on twitter at @whereisyvette), the article outlines the structure and research goals of the Pierre Auger Observatory in Argentina. As you can probably see from the image above, Pierre Auger is a different sort of facility, more akin to the neutrino detectors I discussed last year than South America’s more famous observatory, ESO at Paranal.

I read Cendes’ article a few hours after one of our weekly “Networks of Exchange” colloquia, the focus of which tends to be the  materiality of science. This week, we were back on the subject of astronomy and how the tools—and the movement of tools—shape practice. I’m not sure anyone is ready to attribute agency to the instruments, but I feel like we’re moving closer to the default position of architects/designers, which is that objects shape experience and subjectivity in unexpected ways that have little to do with human or social intent.

At any rate, I was inspired by Cendes’ article to think more intently about the construction of scientific spaces. One one hand, it seems as if cosmic-ray detectors are minimally invasive, small-scale structures with low profiles slotted into what Cendes describes as a “truly remote and empty corner of the world.” On the other hand, the observatory is backed by a multi-national contingent of 500 scientists from 55 institutions, which means that regardless of the physical location of the detectors, the exchange of data also requires a robust communications infrastructure with a global reach.

I was completely intrigued by one of the graphics that accompanied the article. It shows the distribution of particle detectors on the pampas northeast of Malargüe. Here is a very similar graphic, published a few years ago in the CERN Courier:

Distribution of water tanks, Pierre Auger Observatory. Image credit: CERN

Distribution of water tanks, Pierre Auger Observatory. Image credit: CERN

As Cendes explains, we can expect a ultra-high energy cosmic ray (UHECR)  strike only once per square-mile of Earth’s surface every 39 years. The distribution of 1,600 water tanks over an area of 3,000 sq. km with a 1-km module maximizes the chances of detecting a UHECR strike. This graphic raises more questions for me than it answers, though. That is, it illustrates quite well the system for detecting UHECRs, but as a historian, I wonder about labor processes behind the land survey, the construction and placement of the tanks, the cadastral maps that must have determined the boundaries of the observatory, the rationalization and flattening of the landscape into an instrument of measure, and the occupation of “nothingness”.

Some of my questions were answered by the “Voices of the Universe” video issued by the observatory. I was intrigued by Paul Mantsch’s assertion that the project transcended nationalist aspirations. As I’ve noted elsewehere, there is a significant number of NASA supporters in the United States who want us to return to the “glory days” of a U.S.-dominant space program. While I wish we as a people would do a better job supporting NASA, projects like the Pierre Auger Observatory demonstrate that “national” science, if it ever existed, is almost extinct.

Okay, this was a rather loosely constructed post (and I didn’t even get to the part about Auger North or ESO’s Deep Space Antenna 3, 30km south of Malargüe), the point of which was just to say: cosmic ray research is very interesting, Cendes’ article lead me to new questions, and you should probably pick up a copy of the March issue of Astronomy.

Wallpaper Wednesday (Snow at ESO’s Paranal)

26 12 2012

Dark Sky and White Desert. Photo credit: ESO/Yuri Beletsky

Dark Sky and White Desert. Photo credit: ESO/Yuri Beletsky

It’s difficult to find a snowy shot of the observatory at Cerro Paranal. The air is so dry in the Atacama Desert that precipitation is a rarity, even at the elevation of 2,600 meters (8,500 feet). In addition to the domes of the VLT, this wintry scene includes a satellite trail and a meteor trail. Such good fortune for a photographer!

Right click on the image to download an image for your computer desktop (right sidebar of the ESO page).

GRAIL Impact: Why now?

13 12 2012

GRAIL’s Final Resting Spot. Image courtesy: NASA/GSFC

A little over a year ago, I posted an image of Delta II rocket on its pad to mark the launch of NASA’s GRAIL mission. Today, I’m posting a map of the Moon that shows where the GRAIL spacecrafts will hit on Monday (17 Dec 2012). The twin probes were always meant to be disposable; once they’d completed their mission (mapping the Moon’s gravitational field), they were to be crashed deliberately into the lunar surface.

NASA could just let “Ebb and Flow” die a natural death, so to speak. The twins aren’t quite empty of fuel yet, but eventually, they would find their own way to the lunar surface. If you chased down the article I mentioned yesterday and read its final section, however, you already know why NASA is reluctant to let that happen.[1] Two words: lunar heritage.

Lunar Heritage Sites and GRAIL’s Final Mile. Image courtesy: NASA/JPL-Caltech

The map above shows all the sites NASA considers “heritage” (click to enlarge). The Apollo landing sites are marked in green. The Surveyor sites are yellow. Russia’s Lunakhod landing sites are red triangles; their Luna landing sites are red squares (unintentionally funny?). As recently as 2009, when Launius published his article on space heritage, very little discussion had taken place on the safeguarding or preservation of any lunar landing sites, American or Russian. It’s difficult to say what prompted the sudden surge of concern, but my educated guesses are:

  • Successes of private entities like SpaceX make NASA nervous. It was probably difficult to imagine a real threat to something located on the moon. It’s not so difficult to imagine it today, though.
  • Less pressing, I think, is the possibility that another nation will land on the Moon and lay claim to what the United States and the Soviet Union (Russia) left behind. It may happen, but not before SpaceX gets there.
  • State entities pushing on federal policies. For instance, in 2010, the California State Historical Resources Commission voted to include the Apollo 11 landing site and relics on the California Register of Historical Resources. New Mexico has also laid claim to it as state heritage. This  leads to more pressure for Tranquility Base to be named as a National Historic Landmark.
  • Expansion of the nominating criteria/categories for inclusion on UNESCO’s World Heritage List. Tranquility Base has already been nominated for inclusion once on the list. At one time, the list included only architectural monuments. From there it has expanded to include gardens, cultural landscapes, intangible heritage, underwater sites, and natural sites. It’s only a matter of time before World also means Universe.
  • The Lunar Reconnaissance Orbiter Camera has made it clear that there are artifacts involved, not just activity. In theory, the 2008 Convention for the Safeguarding of Intangible Cultural Heritage could be stretched to cover “space exploration” as a significant cultural practice, but significant space detritus is more likely to be included on the World Heritage List.

We’ve only begun to talk about the issues at stake—the difference between “space history” and “space heritage,” who owns the Moon, who owns the Universe, why do we keep throwing things away in space. Hopefully, policy will evolve along with our thought processes. In the meantime, I encourage you to track down Launius’ article, which represents some of the current thinking on the subject.


[1] Roger D. Launius, “Abandoned in Place: Interpreting the U.S. Material Culture of the Moon Race,” The Public Historian, Vol. 31, No. 3 (Summer 2009), 9-38. (e-mail me if you can’t find a copy of this article!)

Wallpaper Wednesday (Submillimetre Astronomy)

14 11 2012

Atacama Pathfinder Experiment (APEX), Chajnantor Observatory, Chile. Photo credit: ESO/H.H.Heyer

Operating on the theory that I am eventually going to finish writing my first book, I’ve begun doing research for my next large project, on early twentieth-century solar and radio observatories. Flipping through the articles on my desk, I ran across one from the 1960s about instruments for observing in the submillimetre wavelength range.[1] Reading it prompted me to wonder if there was any recent news about the Atacama Pathfinder Experiment (APEX) telescope. The search for news from APEX led me to today’s wallpaper.

Every time I visit the ESO website, I’m newly impressed with the online archive. I’ve commented on the image collection before, but the instrument documentation is superb as well. So, too, is the video archive. If you want to learn more about millimetre and submillimetre observations, check out the APEX trailer. Or, you can watch it just because it’s beautiful.


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Click on the image at the head of this post to download the wallpaper.
[1] A. E. Salomonovich, “Some Problems and Instrumental Features of Submillimetre Astronomy,” Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 264, No. 1150, A Discussion on Infrared Astronomy (Apr. 24, 1969), pp.

Wallpaper Wednesday

17 10 2012

Milky Way, Southern Cross, alpha Centauri, Carina Nebula. Photo credit: A. Fujii

Threaded through the partisan bickering during the debates on twitter last night was a string of tweets discussing ESO’s discovery of a planet in the Alpha Centauri system.[1] According to ESO’s press release, the planet was detected through the observation of “wobbles” in Alpha Centauri B’s path of motion. Astronomers speculated that the gravitational pull of an orbiting body was generating the irregularities. Putting the HARPS instrument on the 3.6-metre telescope at the La Silla Observatory to work on the problem, they discovered a planet with an orbital period of 3.2 days. The twitter is excited because Alpha Centauri B is a lot like our Sun and the newly discovered planet has the same mass as Earth—the theory being that our planetary twin has been discovered orbiting the star closest to our solar system. I’m not too worked up about the twinning possibilities, but I do think it’s cool that HARPS is doing exactly what it was supposed to do: find new planets.

In related news, I was intrigued by NASA’s response to ESO’s announcement. It’s as if they’re taking the discovery of the new planet a bit personally. Their press release, ostensibly a statement of congratulations to ESO on its accomplishment, reads more like an attempt to stake a claim on exoplanets of the universe. “We, too, have exoplanet finding capabilities! We have Hubble! We have Kepler! We have the James Webb Space Telescope!”

Click on the image to download wallpaper.


[1] Two stars comprise the Alpha Centauri system, Alpha Centauri A & B. They are indistinguishable to the naked eye, so we usually refer to them in the singular, as in “Alpha Centauri, the brightest star in the constellation Centaurus.”

Observatories and Instruments