City Lights from Space

Last night I gave a talk at Wavelength Brewing Company in Vista, California. They live-streamed the event through their Facebook page and you can watch it here:

Telescope Tourist: Kitt Peak & Mont-Mégantic Observatories

Recently I had the chance to visit two observatories in the same week, the first was Kitt Peak National Observatory. As a native and current resident of Tucson, Arizona it's not unusual for me to have the opportunity to visit Kitt Peak. This time was a bit unusual though, as I was there to make an evening presentation on light pollution.

I really love the mosaic at the observatory's visitor center (For some detailed shots of it, have a look here). Nearby there's a second, much smaller mosaic on the building that's also pretty cool. It's located around the corner to the left and it looks like this:

This one depicts the dome of the 4-meter Mayall Telescope sitting on the mountain with a comet above. Speaking of the Mayall, it was a sunset visit to this telescope that made this trip so special.

Here's the view from out in front of the Mayall, looking back at the rest of the mountain. Kitt Peak has one of the largest telescope concentrations on Earth. That's the McMath-Pierce Solar Telescope at left and the Steward Observatory 90" (2.3 meter) Bok Telescope in the foreground at right.

Heading inside the dome, we arrived just in time to see the last orange rays of sunlight kissing the Mayall.

Soon it was dark enough for its astronomical research mission to begin. We snapped a few photos and were soon ushered out. Seeing big scopes (well these days, with BIG super telescopes just around the corner, 4 and 5 meter telescopes are called small) is always a treat and this was no exception.

The next morning I was off to Sherbrooke in Québec, Canada to attend the Third International Conference on Artificial Light at Night. The conference included a field trip to Observatoire Astronomique du Mont-Mégantic.

In 2008 the International Dark-Sky Association designated Mont-Mégantic as the world's first International Dark Sky Reserve. At the heart of the reserve is a research observatory and their visitor center, the ASTROLab.

The ASTROLab has a wonderful array of astronomical exhibits, a gift shop, a theater and more.

Uphill, and behind a gate from there is their is their 1.6 meter telescope, the largest research telescope in eastern North America. That's its dome above, illuminated by moonlight.

For the telescope geeks, here's the telescope's aluminizing chamber located on the ground floor. Periodically telescope's primary mirror needs a new reflective coating of aluminum, which means the mirror needs to be pulled from the telescope, washed and stripped of its old coating. Then the mirror is carefully lowered through a trap door and placed inside this chamber, where a new coating of aluminum is vacuum-deposited on the mirror.

Located in another dome nearby is their so called "Popular Observatory" (I suppose that means the 1.6 meter is unpopular). I didn't photograph it, but inside the dome of the Popular Observatory is a 0.61 meter (24-inch) telescope and nice theater-style seating, making this telescope perfect for public outreach programs. I guess that's what makes it so popular!

In spite of the total mechanical breakdown of the bus on our field trip (don't ask), it was a wonderful trip and I'm glad to have made the visit to Mont-Mégantic. I very much recommend the trip.

Are Your Clouds at Night Bright or Dark?

My day job is working for the International Dark-Sky Association, where it is our mission to fight light pollution. I didn't need it, but I had a pretty vivid reminder of what we are fighting for on my recent vacation in Hawai'i.

My wife and I rented a place in the Puna District of the Big Island, right on the ocean, where there is very little artificial light. The first night there I hadn't yet adjusted to the time change and woke up hours before sunrise. When I realized that I wasn't going to be able to get back to sleep, I grabbed my binoculars and stepped in the dark to the beach-facing balcony. There the glittering majesty of the night sky was an awesome thing to behold. Ocean waves crashed below but my attention was on the sky. The stars of late fall and early winter filled the sky, all the way down to the horizon.

Venus rises, with Orion at right

It has been quite some time since I experienced skies so dark. When Venus finally poked up above the distant clouds its light quite noticeably brightened the deck.

In the evening skies the summer Milky Way (above) was brilliant with its bright 'clouds' of stars and dark lanes of dust instantly visible - no dark adaptation was needed.

Occasionally clouds drifted past and I was reminded of a paper published two years ago, Red is the new black, how the color of urban sky glow varies with cloud cover (pdf). The paper points how how in cities with sky glow clouds actually magnify the problem, but in times before the advent of artificial light skies actually got darker when it was cloudy. There are a lot of implications from this (read the paper), but let me illustrate the phenomenon.

Sagittarius and Scorpius with dark clouds in silhouette

Compare the view (above) that I took last month in Hawai'i with dark clouds silhouetted against the star-filled sky, with this shot (below) that I took last night from my home near Tucson, Arizona.

Sagittarius in cloudy, light polluted skies

The difference is shocking. The two photos were taken on moonless nights, just about 1 month apart with the same camera and settings looking at the same part of the sky.

Even though there are relatively strict outdoor lighting ordinances in Tucson/Pima County, the skies here are awash with light pollution and sky glow. Sadly, many communities have little or no controls of outdoor lighting and there skies there are even worse. The clouds in the photo above are white, almost as if illuminated by moonlight. The likely culprit illuminating the clouds with white light is a sports complex to my south. Clouds in other directions had a more orange hue, as in the photo below:

Cygnus in light polluted, party cloudy skies

The photos show that there is much work to be done in controlling light pollution, even in communities where the effort is underway. Learn more about the problem and what you can do about it at darksky.org.

The Colors of Light

Most of us don't pay too much attention to lighting. Beyond how a light fixture looks, usually in the daytime, there isn't too much thought given to how well it actually does with what it is supposed to do - provide illumination.

There are several important factors that should always be considered for both interior and exterior lighting beyond just aesthetics. Certainly the total amount of light and where that light shines are important considerations, especially outdoors.  Using too much light, especially light that is poorly directed, can lead to excessive light pollution. It turns out that the color (Well, the spectrum really. More on that below.) of light is equally important in preserving the night sky.

It may surprise some to know that the color of light is important for interior lighting too.   

Here's a light fixture with two different CFL bulbs in it. There's a pretty dramatic color difference between the two of them. The one on the left is blue-white in color, while the one on the right has a warmer hue to it.

Most light sources are not pure, single colors, but rather are a mix of different colors. Recall that ordinary sunlight is a mix of colors too. Nature splits them into their components forming a rainbow.
By passing the light of the bulbs above through a spectroscope we can analyze the colors in greater detail:

That's the spectrum of the blueish looking CFL bulb on the left and the warmer one on the right. The graphs show how much of each color there is shining out from each bulb. Blue, green and yellow-orange dominate the mix of the bulb that looks blue-white, while green and yellow-orange dominate from the warmer blub on the right.

Okay, "so what?", you might ask. First off, most people have preference for warmer light sources like the one on the right. Recall (if you're old enough), that when CFL bulbs were first introduced many people complained about how cold and harsh they looked. Those early CFLs were much like the bulb on the left. But it's more than that. In 2010 the International Dark-Sky Association (full disclosure: I work for them) published a paper providing warnings about blue-rich light and how it can cause problems for both interior and exterior use (See also IDA's "Seeing Blue" article here).

The physics of the situation says that any blue light that ends up in the sky, from poorly directed light or even reflection off of the ground, disproportionately brightens the night sky more than any other color. But for interior use, like the CFL bulbs shown here, there are problems too.

It turns out that blue light is an important marker for our internal clocks. Why would that be? Nature has given us an important indicator that tells our bodies when it is daytime - the blue sky.

Here's the spectrum of the daytime sky. No surprise here, it is really blue. Evolution has given us photoreceptors beyond the more familiar cones and rods of the eye that don't contribute to our vision. Instead, they are tuned to blue light, giving our bodies the cues to keep our internal clocks in synch.

That's why it is important to limit the amount of blue light you are exposed to at night. Blue light from CFL bulbs, screens from TVs, smartphones and more can help throw our systems out of whack, leading to sleep disorders and even long term medical problems.

When choosing bulbs be sure to look at the color temperature (CCT) on the packaging. It will use words like "warm white" or "cool white," but you'll also see a number in the Kelvin temperature scale. For the CFL bulbs here, the blue one has a CCT of 5000K and the warm one is 2500K. Generally speaking, lower numbers have less blue light in them.

To help limit my blue light exposure at home I have low CCT bulbs in the house. I also I use the program f.lux for my laptop. It adjusts the color temperature based on the time of day, dropping my display down to 2700K at night.

The Times, They are a Changin'
We're going through a lighting revolution right now as new technologies are appearing. LEDs (Light Emitting Diodes) are becoming affordable and are showing up for inside and outside applications. The spectrum of an LED light source bears little resemblance to that of a CFL, which isn't too surprising as the light is created differently.

Here are the spectra of two different LED lamps. The CCT of the one on the left is 5800K while the one on the right is 2800K. Notice that both of them have a spike of blue light, but it is much smaller in the 2800K light source. For LEDs used inside it is really important to go with the warmer (lower number CCT) sources so as to not disrupt your internal clock.

It is also important to go with warmer choices for outside lighting, but for different reasons.

More and more cities are making the conversion to LED streetlights. It is a concern because, while generally speaking these new LED streetlights are shielded (downward pointing), the cities sometimes end up choosing lights with excessive amounts of blue and, as I said above, blue light disproportionately brightens the night sky more than the other colors do. So if not done properly, a conversion to LED could lead to brighter skies - something those of us interested in astronomy will want to avoid. 

I'll be blogging more about LEDs in a future post.

StarLight Festival in Big Bear!

In just under 10 days the first annual StarLight Festival will take place in Big Bear California. It will be an amazing celebration of astronomy and the night.

I'll be there representing the International Dark-Sky Association and I'll be giving a talk on Saturday at 1 pm. If you are in the area be sure to come on over and check it out. They have an amazing list of events that will be taking place during the Festival that you wont want to miss.

StarLight Festival - IDA from AstronomyOutreach network on Vimeo.

International Dark Sky Week April 20 - 26 2014

Welcome to International Dark Sky Week!

Everyone who cares about astronomy should be concerned about the problem of light pollution, but there are lots of reasons to want to take action on light pollution beyond just the loss of the night sky. Light pollution is caused by excessive use of light at night which in turn is a waste of energy that negatively impacts ecosystems, decreases visibility and even has impacts on our own health.

Insects attracted to light at night

To learn more about the problems of light pollution, how to measure it, and what you can do about it all head on over to the International Dark-Sky Association's web pages for International Dark Sky Week.

You might also want to check out the blog post I wrote about International Dark Sky Week for Astronomers Without Borders.

Telescope Tourist: Mauna Kea Observatory

It has been nearly ten years since I made my first visit to the summit of Mauna Kea on the Big Island of Hawai'i. There is an amazing array of world-class telescopes on the site. At an elevation of 4,205 meters (13,796 feet) above sea level it is one of the world's best observing sites for astronomy.

That's me with (from left to right) the domes of the 3.6-meter Canada-France-Hawaii Telescope, 8.1- meter Gemini North, and the University of Hawaii 2.2-meter telescopes. Back in 2004 I had a behind-the-scenes tour that gave me a close look at five of the telescopes on the mountaintop.

This is the dome of the Gemini North Telescope with the dome of the Canada-France-Hawaii Telescope behind it to the left. This is one of two twin telescopes, with the second being located in Chile. Together, the pair can observe virtually the entire celestial sphere. 

Here's the view from inside the dome. Like all of the big telescopes built since the 1990s it has an altitude-azimuth mount, giving it a very different look from equatorial mounted telescopes like Palomar's Hale Telescope or Mauna Kea's Canada-France-Hawaii Telescope.

There was some dome maintenance taking place during my visit. You can notice that it is partially open. Alas, my visit with Gemini was pretty short but it was a pleasure seeing one of the giant telescopes of the modern age, one of several such telescopes on Mauna Kea.

Subaru, Keck I and Keck II

From there I went on to visit the two telescopes of the W.M. Keck Observatory.

The photo above show the giant, segmented primary mirror of one of the two Keck Telescopes. The primary mirror is composed of 36 hexagonal segments, each 1.8 meters (6 feet) across. Together they work as one mirror 10 meters in diameter. The light reflects off of the primary mirror to a secondary mirror (at top) and then back down to a third mirror (black area near the center) and then off to one of the two white areas on either side at what is called the Nasmyth focus where it is recorded by one of the many scientific instruments.

Here's how the telescope looks standing straight up:

The mirrors are quite thin, just 7.5 cm thick. As the telescope is used for astronomy the position each of each of the mirror segments is monitored and adjusted in real time to ensure proper focus of the telescope. This is called active optics -- not to be confused with adaptive optics, which corrects distortions in light caused by the atmosphere. The Keck Telescopes make use of adaptive optics too (as does Gemini), but not by controlling the shape of the primary mirror. Those corrections happen in one of the Nasmyth instruments.

In the photo above you can see the thin primary mirror segments and the network of active optics controls underneath them.

Me, with Keck II. Maybe next time I'll smile.

Standing in the presence of the Keck telescopes, I was struck by how little they had in common with the elder, formerly world's largest telescope at Palomar. The Kecks each individually are twice as large (with four times the light gathering power of the Hale), yet weigh far less. Their mirrors are faster (more steeply curved) so as to bring light to focus in a shorter distance, meaning the telescopes don't have to be as long and the domes can be smaller. This design keeps costs down, maximizing scientific the return on the dollar. Because of the telescope's framework design and the domes being as small as they can be, there isn't the same sense of space and grandeur that you feel in the presence of a telescope like the Hale. Yet they are still very impressive in their own right. The Keck telescopes have done much to probe the vastness of the universe.

After visiting Keck, I had the chance to see the National Optical Observatory of Japan's 8.2-meter Subaru Telescope. Here I am with the Subaru Telescope:

Standing under the Subaru

It is a versatile telescope that can bring light to focus in one of three different places: Nasmyth, Cassegrain (bottom) or prime (top). Here's a better shot of the telescope:

Notice that there is an instrument package hanging underneath the telescope at the Cassegrain focus and the bright secondary mirror at top (in the center of the blue ring). In this configuration light reflects off of the primary mirror, back up to the secondary mirror and through a hole in the primary mirror down to the instrument package.

Subaru's Faint Object Camera And Spectrograph

While I was at Subaru I had the opportunity to visit the room where the telescope is controlled. Typically, I don't post photos of such places as they tend to look like boring rooms filled with computers. But Subaru's control room had something I had never seen before.

Take a look at what is hanging from the ceiling:

Those are called teru teru bozu dolls. They are handmade dolls that in the Japanese culture reportedly have the power to bring good weather. Yes, even on Mauna Kea there can be bad weather. I don't know much about the Japanese culture but it was fascinating to see these hanging in this high-tech environment.

Gemini, 2.2-meter University of Hawaii Telescope, and the United Kingdom Ifrared Telescope (UKIRT)

My last stop brought me to one of the older and smaller telescopes on the site, the 2.2-meter (88 inch) Telescope. This telescope was established in 1970 and helped to pave the way for the larger instruments that since joined it on the mountain.

Before I left the mountaintop I also had a distant view of the Submillimeter Array:

Finally, while I was in Hawai'i I also had the opportunity to present at AstroDay in Hilo, a major astronomy public outreach event.

I surprised more than a few people there by representing an observatory from the mainland. Curiously, I was set up right next to a booth for the International Dark-Sky Association where I now work.

This year's AstroDay will be held on May 3rd. Here's a Facebook page that describes this year's event. If you are going to be on the Big Island that day, you should make plans to attend.

If you can't make the visit to Mauna Kea, I encourage you to explore the links I placed in this post. You might also be interested in seeing some of the many webcams that are on the mountain. When the daytime weather is nice there are great views of the various domes. At night there can also be some great views of the night sky from the CFHT Cloudcam. 

I hope you've enjoyed this quick look at some of the best astronomical telescopes in the world. I still have a few more observatories to share as a part of my Telescope Tourist posts. Hopefully, I'll have the time to post more of them soon.

My Top Books of 2013

Alas, I didn't get to read as much as I wanted to in 2013. (Although, now that I think about it, it is possible that I might make this statement every year.) Still, there were some books published this year that I enjoyed very much, so much so, that wanted to list my favorite ones here.

In the category of non-fiction I have three titles to recommend that couldn't be more different from each other. First off is, The End of Night: Searching for Darkness in an Age of Artificial Light by Paul Bogard.

The End of Night is an in-depth, thought-provoking, personal look at the problems of light pollution. Author Paul Bogard explores just about every angle of the issue in an engaging, thoughtful way. You can hear Paul read a bit from the book by clicking on this link (it was from his appearance last November at the Annual General Meeting of the International Dark-Sky Association). I highly recommend this book for everyone interested in learning more about light pollution.

Another non-fiction title to make my list is These Are the Voyages TOS Season One by Marc Cushman. It is the authoritative look at the creation of the Star Trek television series.

These Are The Voyages masterfully explores, in vivid detail, the genesis of the series and each episode of the first season of Trek. There have been many behind-the-scenes books written about Trek, but none of them had access to so much original source material. From script drafts to production memos, it's all here. I should note that there have already been two versions of the book. The first edition got out the door with some uncorrected errors (mostly typos) and then some new source material was brought to light, making the Expanded and Revised Edition the one to get. I should note that there remains an error about the music in The City on the Edge of Forever, but it is easily overlooked as the book is a must read for all fans of Star Trek.  

I should also mention An Astronaut's Guide to Life on Earth by Chris Hadfield even though I am not quite done reading it (I just started it yesterday).

While in space, Commander Hadfield owned social media, well, at least the portion of social media that appeals to space geeks. The video of his cover of David Bowie's Space Oddity has had nearly 20 million views on YouTube, while the trailer for his book has had over 1.1 million views, which isn't bad either. The book is an engaging, inside look at the life of an astronaut. It not only chronicles his career (with some amazing, jaw dropping stories) but gives some life lessons for all of us. It is a fun read that I recommend for anyone even casually interested in space travel.

In the world of fiction, I have two books to recommend. The first is The Human Division by John Scalzi.

The Human Division is just plain fun. The book is a series of science fiction short stories (which were originally sold separately) that together form a cohesive tale. It is set in the same universe as his Old Man's War series, but no prior knowledge of that series is really needed. If you enjoy space opera science fiction and don't mind actually having fun while reading, you can't go wrong here.

I don't read much fantasy. I'm pretty much limited to the works of J.R.R. Tolkien and Stephen R. Donaldson (and I guess J.K. Rowling too). As far as I am concerned, Tolkien pretty much invented fantasy and Donaldson perfected it. Donaldson's latest work is The Last Dark. It is the final book in a series of 10 books known as The Chronicles of Thomas Covenant, the Unbeliever.

Donaldson's work is epic. The first book in the series, Lord Foul's Bane was published in 1977 (after the author had 47 rejections!) and followed soon by two more books that completed the tale. Donaldson returned in the 1980 with a second trilogy and 2004 saw the first in a four-book set (over 2,200 pages!) that, with The Last Dark, completes The Last Chronicles of Thomas Covenant. I wont give away any story elements here other than to to say that the works are richly detailed works of fantasy that will enthrall and frustrate the reader. Donaldson's writing is very, very good. If you've not read any of his fantasy and are looking to try something shorter first, consider picking up The Mirror of Her Dreams.

I am sure I missed a lot of good titles this year. I haven't yet had the chance to read Jack McDevitt's latest, Starhawk (it will be next), but feel free to recommend anything in the comments that you enjoyed.

Happy New Year!

A Visit to Westhavelland Nature Park

Last week I was in Berlin Germany attending the first International Artificial Light At Night conference. It was an amazing event that brought together over 100 researchers from five continents. One of the conference excursions was a visit to one of the darkest places in Germany - Westhavelland Nature Park. For some time now there has been a concerted effort to engage the communities that surround the park in an effort for them to improve their outdoor lighting and make and also make an application to the International Dark-Sky Association for official status as one of their Dark Sky Places.

 

It was a long expedition from Berlin (especially since our driver initially headed in the wrong direction) but we had a great visit first to the park's nature center where we were greeted by the mayor of Milow (above, at right with the microphone pointed at him) and the director of the center (to the left of the mayor). 

In addition to exhibits on the natural history of the park, the visitor center has several exhibits devoted to light pollution and the night sky. Above is an iPhone panorama that I shot showing off some of the light pollution displays.

Canon 3Ti, 18mm, f/5.6, ISO 6400, 30 sec

The real treat of the evening came when we ventured into the heart of the park. The shot above is looking west. The white glow just right of center is apparently from a paper mill that clearly needs to improve its outdoor lighting.

Canon 3Ti, 18mm, f/5.6, ISO 6400, 30 sec

This view is looking in the same direction, but with the camera pointed higher. Below is the view to the east. It was taken looking over our bus, which produced the bright glows at the bottom of the frame.

Canon 3Ti, 18mm, f/5.6, ISO 6400, 30 sec

The Milky Way was easily visible even though we were not really given time for our eyes to adapt much at all before we were loaded back into the bus. From there we headed to the village of Gülpe where we were greeted by the chief administrator of the city of Rhinow and treated to some stargazing.

Canon 3Ti, 18mm, f/5.6, ISO 6400, 30 sec

The skies here were not quite as dark and some clouds were drifting through as well, but we had a nice look at the universe.

Canon 3Ti, 18mm, f/5.6, ISO 6400, 30 sec

Be sure to check out this great video of the skies above Westhavelland from Harald Bardenhagen.

Yes, there is light pollution that impacts the park but there has already been significant effort to protect the skies there and the work to bring the surrounding communities in on the dark skies movement are to be commended. 

Westhavelland is just one of several planned dark sky places in Germany and elsewhere in Europe. While attending the conference I had the chance to visit with a few of the  people working on these projects. I certainly wish them much success.