Stars Wobbling at the Speed of a Desert Tortoise

In recent posts about new observing projects at Kitt Peak National Observatory, I’ve largely focused on the DESI spectrograph which aims to create a three-dimensional map of the northern sky. In fact, I’m in Denver, Colorado this weekend at MileHiCon and I’ll be giving a presentation on this very subject. However, this isn’t the only new instrument I’m helping to deploy and commission.

At the WIYN 3.5-meter we’re installing a spectrograph called NEID. Kitt Peak sits on the land of the Tohono O’Odham people in Southern Arizona. The acronym is derived from the Tohono O’Odham word meaning “to see.” The actual acronym is: NN-EXPLORE Exoplanet Investigations with Doppler Spectroscopy. In other words, it’s an instrument that will be used to look for planets around other stars. Like the DESI spectrograph, fiber optics are mounted to the telescope and feed a spectrograph two floors below the telescope. Just over a week ago, I helped to run the fibers from the point the instrument will be mounted down to the spectrograph room. In the photo, you can see the fiber optic cable laid out like undulating waves at the base of the telescope. The instrument itself will be mounted at the round port that currently has the white, rectangular sign.

The way a spectrograph like NEID finds planets around other stars is by measuring how much they move toward and away from the Earth when they’re pulled by orbiting planets. You likely see spectra all the time. A rainbow is a spectrum of the sun. In a spectrum are characteristic lines caused by elements in the star’s atmosphere. When a planet tugs the star toward Earth, those lines move toward the blue end of the spectrum. When a planet tugs the star away, the lines move toward the red end. Of course, one of the hopes of exoplanet science is to detect Earth-like planets around other stars, or more specifically, Earth-sized planets in the zone around a star where water can be liquid. If you imagine watching our sun from another star, we’d see the Earth pull the sun toward or away from us at about 30 centimeters per second, or about the speed of a desert tortoise!

To see this small motion, you need to be able to see the spectra—the rainbow—at very high resolution. This is more than magnification. You need to see it at great detail. A spectrograph that can do that is often fairly big and it’s very difficult to mount it to the side of a moving telescope. This is why we use a fiber to capture the light and send it to a spectrograph in a different room. This allows the engineers to build the spectrograph as big as they need, but only requires them to mount the fiber to capture the light to the telescope.

Fiber optic cable is meant to be tough, but it can break, so it’s gratifying after we make the run to be able to shine light through the cable and see it at the other end, as we see in this post’s second photo!

Besides looking very specifically for Earth-like planets, the NEID spectrograph will be providing support for NASA’s Transiting Exoplanet Survey Satellite, or TESS, mission, which is searching for exoplanets around the closest stars to Earth. Once TESS discovers a planet, we can observe it with NEID and get more precise mass and density information about the planet. Such measurements help us better understand the composition and formation of the planets around other stars. It’s a very exciting time at Kitt Peak as we deploy these spectrographs which will help us understand both planets in our galactic neighborhood and the overall structure of the universe.

Successful Solar Sailing

The Planetary Society’s LightSail 2 spacecraft launched into orbit on June 25, 2019 and deployed its 32-square meter sails almost a month later on July 23. In the time since sail deployment, it raised its orbit some seven kilometers. Here we see a great shot of the LightSail 2 over Australia.

LightSail 2 image courtesy The Planetary Society

In 1619, astronomer Johannes Kepler noticed that comet tails always point away from the sun and realized that some solar force must produce that effect. Two centuries later, in 1862, James Clerk Maxwell suggested that light has momentum and it was finally demonstrated in 1900. The goal of the LightSail 2 mission was to show that momentum from light could propel a spacecraft. The process of solar sailing is not unlike sailing on the water, only in space, gravity acts like water currents while light acts like wind. As with a sail at sea, the sails must be turned in flight to take the best advantage of the “wind” while the ship moves on the “current.” LightSail 2 accomplishes this via internal reaction wheels. The gif below shows how the sail is turned to take the best advantage of sunlight and raise its orbit.

Josh Spradling / The Planetary Society

The following graph shows the elevation of LightSail2 over the course of the mission. The apogee is the highest point in orbit, the perigee is the lowest point. At LightSail2’s elevation, there are two forces working on the sail besides gravity. The first is light pressure from the sun. The other is atmospheric drag from the Earth. Even though LightSail 2 is in a relatively high orbit, it’s still in the most tenuous parts of the upper atmosphere. The upshot is that the apogee increases because of light pressure, but the perigee decreases because of atmospheric drag. That noted, LightSail 2 has accomplished the mission it set out to do, demonstrate that light can propel a spacecraft.

Image from the LightSail Mission Control Page supported by the Planetary Society

You can keep up to date with the LightSail mission and visit their mission control page by going to http://www.planetary.org/explore/projects/lightsail-solar-sailing/#the-lightsail-2-mission.

It’s worth noting this is a technology in its infancy. That said, with the lessons learned from this mission, there’s promise that solar sails could be used for small unmanned probes in the not-too-distant future, or perhaps they could be used to deflect dangerous asteroids, especially if caught early enough that they only need a small nudge.

In the long run, with much more development and technical innovation, I would like to think solar sails could be used to propel humans across the solar system as I imagine in my novel The Solar Sea. In a little under a week, on Friday October 11, Lynn Moorer will interview me about the novel on her radio show from 12:30-1:00 pm mountain daylight time. If you’re in Las Cruces, you can tune in to 101.5 FM on your radio dial. If you aren’t in Las Cruces, or just don’t listen to shows on the radio, you can stream the show at  https://www.lccommunityradio.org/stream.html. It looks like KTAL Community Radio is building up their archive of past shows, so I’m hoping I can share these interviews with you soon. If you want to read the book before the interview, you can find all the places it’s available by visiting http://www.davidleesummers.com/solar_sea.html.

Cable Wrangling

In previous posts about the DESI spectrograph being installed at Kitt Peak’s Mayall 4-meter telescope, I’ve focused on the 5000 robotic positioners at the telescope’s focal plane, which is up at the top of the telescope, and the ten spectrographs located in a climate controlled room at the telescope’s base. However, I haven’t talked a lot about how the light from the 5000 positioners gets down to those spectrographs. The light travels along optical fibers that run from the telescope’s focal plane down to the room with the spectrographs. The whole distance is roughly 40-meters (or a little less than the length of half a football field).

In the photo to the left, you can see the cables running along the front of the telescope at this angle. They’re draped over the blue horseshoe structure in the foreground. Several of the cables are draped down in the lower left-hand side of the photo. There are ten cables that run from the top of the telescope to the room with the spectrographs. Each cable contains 500 individual optical fibers. Each of these cable bundles feeds one of the spectrographs at the telescope’s base. Since each cable contains 500 optical fibers, they are heavy cables. They’re also very fragile. It would be challenging enough to run these fibers from one point to another if they could be locked down in one position. However, the telescope actually has to move, so we can look at different parts of the sky. This means these heavy, fragile cable bundles have to move too.

Before construction even began on the DESI spectrograph, engineers spent time figuring out the best way to run the cables that minimized how much they had to move. Also, there are devices called e-chains that help assure cables stay nice and neat as the telescope moves. This past week, one of the engineers snapped a photo of me helping to prepare one of the e-chains for installation. He was in a lift up near the telescope’s top and looked down at me and another one of the telescope engineers hard at work. I’m the one in the yellow hard hat.

As I mentioned earlier, these cables are both heavy and fragile. That means there’s been a lot of heavy lifting that requires a great deal of care about where we step and place the cables. We don’t want to bend them too tightly, or they could break. The upshot is that this has been exhausting work. Everyone feels wiped out at the end of the day.

Still, we see the proverbial light at the end of the tunnel, or perhaps that should be the light at the end of the fiber! Once the cables are run, we only need to install the last three spectrographs, then the system will be complete. How soon we’ll start observing with the DESI spectrograph will depend on the results of preliminary testing which has already commenced and will be finished soon after the installation is complete. That said, I am told there’s a very good chance we’ll be pointing DESI at targets on the sky in less than a month. At that point, we may start to understand more about this mysterious thing that astronomers have dubbed dark energy.

A Puzzling Sunday

When I was a kid, I asked my parents for a Star Trek puzzle I saw in the toy store. I think the image was taken from one of the Gold Key comic book covers. I don’t remember how many pieces it was, but it wasn’t an “easy” puzzle because a lot of the pieces were black with stars. Even as a kid, I was obsessive enough that I stuck with it until it was finished.

From that point on, every time a distant relative or family friend asked what kind of gift they should give me, my parents would say jigsaw puzzles. As a parent myself, I can see why. They often have nice pictures and they’re relatively inexpensive, so it doesn’t feel like you’re imposing on those relatives asking for suggestions. The problem is, after doing that first jigsaw puzzle, even though I stuck with it and completed it, I discovered that I didn’t especially like doing it. What’s more, many later puzzles I received had pictures I didn’t even like that much. Oh, they were often pretty enough, but I’d rather see a mountain valley than put together a puzzle with a photo of one.

My wife, though, loves puzzles. She does tell people that she wants puzzles with photos or illustrations she likes, but she is very good with any jigsaw puzzle. Even without looking at the box lid, I’ve seen her pull out random pieces and start putting them together and I’ve seen her put 500-piece puzzles together in under two hours. My daughters have also inherited some of this puzzle skill. So, when our local comic shop started having puzzle tournaments, I suggested to my wife that she should enter. Up until a week ago, she competed in four tournaments with one of my daughters and a friend or two on the team and they’ve won all four. So, it surprised me this past weekend when my wife asked me to join them for the puzzle tournament.

The way these tournaments work is that every team is given the same puzzle. The team gets two hours to work on the puzzle. The first team to complete the puzzle wins. If no one completes it, the team with the largest number of assembled pieces wins. We were given a 1000-piece puzzle featuring an illustration based on John Carpenter’s The Thing. The illustration was largely shades of red and gray. On the team with me were my wife, my youngest daughter and a friend of my daughter’s from school.

Although I’m not altogether a fan of assembling jigsaw puzzles, I’m not bad at them. I’m a sufficiently old-school astronomer that I had to become really good at pattern matching to identify star fields in a telescope eyepiece or on a computer monitor. That old Star Trek puzzle way back probably helped me hone that skill. As an editor, I look for misspelled words and bad grammar. I can see how things fit together from seemingly random patterns. I went along to the tournament for the sake of family together time.

At the end of two hours, we had 261 pieces assembled, a little over a quarter of the puzzle and we were the tournament winners. Our prize—another puzzle. This one was a Scooby-Doo puzzle, that looked a little more to our taste. My wife is now five-for-five at the local comic shop’s puzzle tournaments. She plans to return for at least a couple of more rounds and will compete in the final round at the end of the year. Whether I go back and compete again will depend on how the tournament days line up with my schedule.

This was probably the most fun I had working on a jigsaw puzzle and from what I saw, all the teams had fun. I think for me, the most fun part was spending time and collaborating with my family. I did come away realizing that the obsessive part of me that sees a puzzle through to completion (or until a time limit) is a necessary part to me being a writer. When I start a story, I need to see it through until it’s finished. Stories are not unlike jigsaw puzzles for me in that they often start with flashes of scenes and moments of characters doing something and I really want to see how they all fit together. I think the reason they satisfy me more than puzzles is because I’m the one who created the picture that appears when it’s all finished.

Another fun thing that happened on Sunday is that author Stephanie Kato interviewed me at her blog. Click here to read that interview and learn a little more about me.

DESI Naked!

This weekend finds me at Bubonicon 51 in Albuquerque, New Mexico. I’m moderating panels about space cowboys and large scale scientific surveys. If you’re in town, click the link to get the details and drop by. I’d love to see you there. Of course, part of my interest in large scale scientific surveys has to do with the work I’ve been helping with over the last year and a half, installing the DESI Spectrograph at the Mayall 4-meter telescope at Kitt Peak National Observatory. During my my recent shift at the observatory, I got a rare look at the new instrument not just “under the hood” but before the hood even went on.

In the photo above, you see DESI on the left, just over the orange platform. Standing on the ground floor in the foreground are just a few of the telescope engineers and technicians who have been installing this new, innovative instrument which will be used to make a 3D map of about a third of the known universe. DESI itself is an array of 5000 fibers mounted on robot positioners that can be precisely centered on targets each time the telescope moves. The light from those objects then travels down fibers two stories below. The fiber bundles are ready to be run along the telescope. You see them coiled up on the white carts to the lower right of the photo above. Each black cable contains 500 fibers. One of my jobs this week was labeling those cables so people can keep it straight which cable is which as they run them along the telescope.

Here are all the DESI fiber positioners mounted to the telescope. You can see each of the ten cables coming up into ten sets of fiber positioner “petals.” Each of these petals was installed into the telescope with great care about a month ago. Light was placed on all the fibers and it was confirmed that in all the transportation and installation, none of the fibers were broken. All of them transmit light as expected! This week, the control electronics are being wired up and routed through the telescope. Once this chore is complete, more testing will happen to assure that the fibers still transmit light and each of the robot positioners moves as expected using the electronics routed through the telescope.

All of those fibers will eventually come into a clean room downstairs to a series of ten spectrographs. Do you begin to sense a pattern? Ten petals, ten cables, ten spectrographs. As it turns out, another job of mine this week was helping to install the seventh spectrograph, which you see in the lower right of the photo above. Western fan that I am, I feel like you can now cue Elmer Bernstein’s score for The Magnificent Seven. Of course, that won’t last long. soon we’ll have an eighth, ninth, and tenth spectrograph.

Each of those spectrographs will be used to examine the light from 500 fibers. To make the map, we’ll be using these spectrographs to see how far characteristic chemical lines in spectra have shifted from where they normally sit within the rainbow toward the red end, which is one measure of how far away those objects are. We’ll compare that to statistics of how far apart they are, which turns out to be another measure of how far away they are. That said, just because we’re mostly looking for the redshifts, there will be all kinds of other spectral data available that can tell astronomers all kinds of information about properties of galaxies all over the sky. One of the most exciting things about the DESI program is that this data will be available to all. In this post, I may be laying DESI bare for all to see, but the whole project will be laying much of the universe bare, and in the process expanding the body of astronomical knowledge.

  • For a fictional and frightening look behind the scenes at an astronomical observatory, read The Astronomer’s Crypt.
  • To take a tour through the wonders of the solar system, read The Solar Sea.
  • To travel back in time to the Old West, check out Owl Dance!

Mars Globes

One of the places my family and I visited during our July travels was Lowell Observatory on Mars Hill in Flagstaff, Arizona. This was where Percival Lowell, a former US ambassador to Korea, set up shop in the late nineteenth century to observe the planet Mars and search for the elusive Planet X. One thing that captivated Lowell about Mars were the linear features crisscrossing the planet. The more he observed them, the more he became convinced they were canals built by intelligent beings. Over the years, Lowell would make many maps of Mars and publish essays detailing how the red planet must be an abode of life. Lowell also made globes.

Martian globe on display at Lowell Observatory

As it turns out, Lowell’s canals do not exist. They seem to be the result of some optical phenomena going on within the telescope itself enhanced by wishful thinking. It’s easy to imagine Lowell gazing up at Mars from his chair in Flagstaff, imagining a dying desert world with intelligent Martians hanging on through their ingenuity, digging canals to bring water from the polar caps to arable farm land in the equatorial regions. These ideas would go on to inspire writers like H.G. Wells, Edgar Rice Burroughs, and Ray Bradbury. Even if Lowell’s observations did not prove correct, he succeeded in making Mars a place in people’s imagination that we could visit.

As a young reader, I fell in love with the canal-lined Mars of Ray Bradbury and Edgar Rice Burroughs. When visiting Lowell Observatory, I always thought a Martian canal globe would be a cool souvenir. Unfortunately, they don’t sell them in the gift shop. What’s more, they don’t sell them much of anywhere. Most Mars globes available today show the Mars we’ve mapped via orbiting probes. These are great globes and I’d love one of those, too, but they don’t capture the imagination that stirred me in my earliest days of reading science fiction. I did see that a master globe maker recreated a canal globe a while back and made them available for sale, but I also saw that he charged far more than I could afford. What’s more, when I looked again after visiting Lowell, I couldn’t find them anymore.

Of course, I’m not only a science fiction fan and a professional scientist, I’m a steampunk. If there’s one thing a steampunk knows it’s that when something isn’t available, you just have to go out and make it. My wife and I discussed approaches and I did some searching on the web. I already knew that several images of Lowell’s maps were available online. I found software that would convert rectangular maps to “map gores,” the strips used to make globes. With the power of Adobe Photoshop, I could resize those gores to any ball I wanted. So, I set out to make my own globe. Since this was the first time I’d ever tried something like this, I decided to make a prototype before making a nice one.

Here’s looking at you, kid.

The prototype wasn’t perfect. Despite measuring the ball I used for a form, I sized the gores just a little too small. This could have been a little bit of rounding error from several sources. Also, it took some tries to figure out how to get the gores on smoothly. I mostly figured it out, and I think some better tools would help. Despite that, I think the prototype globe turned out much better than I had any right to expect. In fact, the flaws actually add to the antique look of the globe.

At this point, I’m working on acquiring some better tools and a nice stand for the final globe. Who knows exactly what I’ll do with my new globe-making skills. If a steampunk event shows interest, I’d be happy to share what I’ve learned. Given that the globes aren’t generally available, I might consider making a few for sale, as long as I confirm that I’m not violating any rights by using the old maps and I feel my skills are up to the task.

What I do know is that the globes I make for myself will serve as an inspiration. I look at the globe and dream of Mars as it could have been. When astronauts visit Mars in my novel The Solar Sea, they wax poetic about the old visions of Mars even as they see its real wonders. Of course, Lowell’s crypt next to the dome where he observed Mars was an inspiration for my novel The Astronomer’s Crypt. A part of me would like to think of Lowell’s spirit walking a canal-laced Mars, much as scientists who died did in Camille Flammarion’s novel Urania. As I look around the globe, I see that Lowell named one of the canals, Draco, a name shared with the leader of my Scarlet Order vampires. Maybe there’s a story out there about the Scarlet Order paying a visit to Mars.

Celebrating Kepler’s Success

Over the course of nine years, NASA’s Kepler Space Telescope helped astronomers discover more than 2700 planets. What’s more, the telescope collected so much data that almost a year after the mission’s completion, astronomers are still discovering planets. As each new planet was unveiled, we’d see an artist’s rendering, especially if the planet was deemed of general interest. In 2012, Dr. Steve Howell took the job of Kepler Project Scientist. Soon after, he came to me with an idea for visualizing planets in a much more immersive way than simply painting a picture. He wanted to see science fiction authors tell stories about the planets Kepler was discovering. That led us to create two anthologies about Kepler’s planets.

The annual Smashwords Summer/Winter Sale is underway. It gets its name because where I live in the northern hemisphere, readers are loading up their e-readers for great beach reading and vacations. In the southern hemisphere, it’s the middle of winter and people are spending time in a warm and cozy place reading. This is a great opportunity to celebrate the Kepler Space Telescope’s success by offering our anthologies for half off the cover price! Read on for more details!


A Kepler’s Dozen is an anthology of action-packed, mysterious, and humorous stories all based on real planets discovered by the NASA Kepler mission. Edited by and contributing stories are David Lee Summers, author of The Pirates of Sufiro, and Steve B. Howell, project scientist for the Kepler mission. Whether on a prison colony, in a fast escape from the authorities, or encircling a binary star, thirteen exoplanet stories written by authors such as Mike Brotherton, Laura Givens, and J Alan Erwine will amuse, frighten, and intrigue you while you share fantasy adventures among Kepler’s real-life planets.

“… the stories represent a glimpse of where science fiction might go if real exoplanets are taken as inspiration.” Melinda Baldwin, Physics Today

You can buy A Kepler’s Dozen for half off the cover price at: https://www.smashwords.com/books/view/325583


  • NASA’s Kepler Space Telescope has discovered thousands of new planets.
  • Visiting, much less settling, those worlds will provide innumerable challenges.
  • The men and women who make the journey will be those who don’t fear the odds.
  • They’ll be Kepler’s Cowboys.

Saddle up and take an unforgettable journey to distant star systems. Meet new life forms—some willing to be your friend and others who will see you as the invader. Fight for justice in a lawless frontier. Go on a quest for a few dollars more. David Lee Summers, author of the popular Clockwork Legion novels, and Steve B. Howell, head of the Space Sciences and Astrobiology Division at NASA Ames Research Center, have edited this exciting, fun, and rollicking anthology of fourteen stories and five poems by such authors as Patrick Thomas, Jaleta Clegg, Anthony R. Cardno, L.J. Bonham, and many more!

“If you’re in the mood for science fiction that’s heavy on the science, pore over this enjoyable collection that takes exoplanets and the American West as its inspirations. The stories and poems in Kepler’s Cowboys imagine wild and risky futures for the first generations of exoplanet explorers as they grapple with harsh environments, tight quarters, aliens, and one another.” Melinda Baldwin, Physics Today.

Kepler’s Cowboys is available for half off the cover price at Smashwords: https://www.smashwords.com/books/view/698694