Dark Night Skies
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	In this episode of Where Two Deserts Meet, we chat with Physical Science Technicians Stacey Manson & Megan Richie. Together, we examine what makes the night sky so special, what we can do to better protect it for future generations, and how to best take it in while visiting Joshua Tree National Park. 
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	Ian:  Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land on which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place. We pay our respects to the people past, present, and emerging who have been here since time in.   

Donovan: Hi, I'm Donovan.
Ian: And I'm Ian.
Donovan: And we're both park rangers here at Joshua Tree National Park, where two deserts meet is a podcast where we investigate topics that often require a bit more detail, and sometimes the help of an expert in the field to gain perspective.
Ian: I got to say Donovan, don't you think it's fascinating that out of all the visitors that visit Joshua Tree National Park, most of them don't even see the other half of the other half.
Donovan: You mean like the south end of the park?
Ian: No, the other half of the park is after dark.
Donovan: Oh, you're right. I guess it is a bit strange, at least for me, since that's actually one of my favorite things here at Joshua Tree.
Ian: Yeah, the dark night sky that can be seen in Joshua Tree is so spectacular. In fact, the park is actually an international dark sky park, which essentially means that Joshua Tree National Park possesses an exceptional or distinguished quality of starry nights and a nocturnal environment that is specifically protected for its scientific, natural, educational, cultural heritage, and for the public enjoyment.
Donovan: Especially the summer Milky Way that's visible during the new moon phase of the lunar cycle really expresses just how dark the night can get out here.
Ian: Oh yeah. I always like to remind people that one important piece of information to keep in mind when trying to plan your trip around the great night skies is check that lunar cycle. Coming to the park on a full moon versus a new moon can make a world of difference with your star visibility.
Donovan: Don't get me wrong though. Visiting the park after dark during a full moon is still great too, because to me that means that the moon will be bright enough that you can see the rocks in the Joshua trees even after the sun goes down. Especially, it's a great time to experience our nocturnal wildlife.
Ian: Ooh, yeah, A bit of a loony experience, you might say.
Donovan: Okay. Yeah, but, well, it's just something about getting to experience the night sky with the Milky Way gasses and those purples and blues covered by trillions and trillions of little glowing orbs with the occasional shooting star crossing your site. That's just really extra spectacular.
Ian: You know, I'm glad we're talking about this, Donovan. It's a good time because with the end of summer approaching a various special event is coming. The Joshua Tree, national Park Night Sky Festival.
Donovan: I love the Night Sky Festival.
Ian: Ah, yeah, same, same. The Night Sky Festival is an amazing event with astronomers, telescopes, stories, and excitement. So as we are getting ready for that event, I figured we could do a little research ahead of time to prepare for what we'll see.
Donovan: Well, you know me, I love to prepare ahead. I'll call Megan Ritchie and Stacy Manson and see if they're available to chat. They are super helpful with all things night sky.
Stacy: Hi, I'm Stacy Manson and I'm a physical science tech here at Joshua Tree. My job duties consist of monitoring three air quality stations, ten portable weather stations, monitoring groundwater, soundscapes night skies, and mitigating abandoned mine land hazards.
Megan: My name is Megan Richie, and I am also a physical science technician here at Joshua Tree National Park. I assist in natural resource monitoring, including our air quality, drilled water wells, weather stations, soundscape, dark night skies, and closing abandoned mineral lands.
Donovan: I think it's safe to say that Megan and Stacy have a long list of duties that they're in charge of here at the park. Something that was clear during the interview was their love for what they do and what inspires them to help conserve our night.
Megan: Viewing the dark sky. I had to have been around eight years old and my parents, you know, I grew up in a mid-sized city, but they woke me up in the middle of the night. We grabbed our sleeping bags and we laid out on the deck. And my memory, if my memory serves me right, I just remember looking up and just seeing meteors or flashes of light. I didn't really understand what I was looking at, but that was my first experience with the night sky. And then coming here to Joshua Tree, seeing the Milky Way for the first time, because growing up in the Southeast you don't see the Milky Way. But coming out here, I couldn't keep my eyes off the sky. I think it's a very personal experience. It's special and everybody experiences it differently. It's something that I feel that can connect you with your present, your past, and your future. I think it's just beautiful.
Stacy: For me, I think the moment that I fell in love with the sky was probably even before elementary school. Very young. My parents had a balcony off their master bedroom and they would set up a bed for us. They would take a mattress out there with sheets and blankets. Myself and my four siblings would all go out there and lay on this bed and just watch the night sky. It was a way for us to bond together to be amazed by the sky above us, to watch meteors, to just watch stars, look for constellations. It was so important as like a family unit to have that bonding experience. That kind of cemented my love of the night Skies.
Ian: So as we mentioned earlier, Joshua Tree National Park is an international dark sky. Which doesn't just mean you can see a lot of stars at night. There is also a sort of community effort going on in order to give you that experience. Stacy and Megan play key roles in working through each requirement for that designation.
Stacy: To become an international dark sky place, you first must have a group of people that are actually interested in protecting a nightscape. People that want to see the stars. Certification involves creating lighting policies, rehabilitating poor quality lighting, educating your neighbors visitors, and about the importance of why do we want to protect our night skies. And then you also must commit to that conservation effort. It's not just one and done, it's a continual commitment to protecting night skies. Park staff have been working on the certification process for years long before I even started back in 2006. The park had to inventory outdoor lighting, retrofit the poor lighting, create a lighting management plan to ensure proper outdoor lighting in the future, and then also document the average sky brightness in the park throughout different areas in the park. We also worked with community members to protect the night sky. There's been a long effort to work with the San Bernardino County to create lighting ordinances that protect the high desert communities. The park continues to educate the public about the importance of a dark night sky and participates in annual night sky festivals hosted at Sky’s the Limit Observatory in Twentynine Palms, CA every year. The park also has to submit an annual report that highlights our commitment to conserving the dark night skies in Joshua Tree. I think one of the reasons that you see that some places are dark night skies and some aren't, is some places have darker skies and you already have people that have been there for a long time going to these places to view the night skies. Places like Los Angeles, where you have a lot of artificial light and there's not a whole lot of stars to be seen, you don't have a whole lot of people living there that are like, “oh man, I wanna protect the skies,” because they just don't know those skies exist.
Megan: Yeah, and I'll piggyback off of what Stacy was talking about community engagement and just getting people outside at night and experiencing the dark sky and getting them excited and passing on their knowledge that they learned to keep our certification up because we want to protect those stars. The East Coast is littered in artificial light, but the West coast is something that we can still protect those dark skies.
Stacy: When Joshua Tree got its certification, The International Dark Sky Association was designating places on a tiered system. You had bronze, you had silver, and you had gold. Gold was like almost perfect, dark night sky, complete absent of artificial light to bronze where you could still see a decent amount of stars but there was also a lot of artificial light in the area. Joshua Tree, on our Western end, we actually meet more of that bronze criteria, but on the eastern end of the park where there's almost no communities out there, it's in the remote desert, we, we almost met the gold standard. We were able to combine those two to designate ourself as a silver tier park.
Donovan: The beauty of the night sky here at Joshua Tree National Park is that people travel from all over the world to see it. But why is that? Why do we not see the same dark night skies in our own hometowns, especially if we live in high populated areas such as big cities?
Stacy: The ability to see stars does vary based off your location. More rural areas, you're going to see more stars. More urban areas, you're going to see less stars. The reason for that is artificial light. Artificial light goes up in the atmosphere and scatters and creates that kind of blanket of light and it dims the stars so you're just not able to see them. Areas like Los Angeles where there's very large amount of people with a lot of lights on, you're just not going to see as many stars as you do here in Joshua Tree where you have much smaller communities.
Megan: I'm from a mid-size city in the Southeast, and one of the first things I noticed when I moved to the Joshua Tree area is just how dark it is out here. I had truly never experienced that kind of darkness. Like having your hand in front of your face and not even be able to see your hand. And I think bouncing off of what Stacy was saying is not only just the lights, but out here in the desert, we have what I call 360 degree view of the sky horizon to sky horizon. A lot of cities have tall buildings and even other rural areas have tall trees. It really obstructs what is straight up above you. What's really unique and special about being out here in a rural desert is that the sky is the limit. You have such a huge canvas of stars up there and it just makes this area very special at night. And it draws quite a good people out here.
Donovan: The general rule of thumb is when looking for a dark night sky, no matter where you're at, the farther away you get from light pollution, the better your visibility of the stars will be. This experience is because of our natural biology. To keep it simple. As our eyes adjust to the dark, they start to create a chemical called rhodopsin which helps our eyes see in low light exposure. Bright lights can bleach the rhodopsin. An example of this would be when you're walking down the street at night and a car drives by with their headlights on, and it might make you feel like you've been blinded momentarily. It often takes several minutes before your eyes are able to readjust again to the dark. Yes, bright lights can affect your rhodopsin, but red light is actually a great tool used by astronomers because it doesn't bleach your rhodopsin. This is mainly because the length of the light waves is much longer. Unfortunately, though light pollution isn't the only thing that can hinder your view of the night sky, other forms of pollution can obstruct our view as well. Light pollution at night is a big contributor to not being able to see stars, but there's also air pollution.
Stacy: Just like during the day, as you mentioned, you'll be in a valley and you're looking across the way. If the air quality's good, you can see the mountains on the other side of the valley very clearly and crisply. But then you'll notice on some days you'll be standing in that valley. When you look across, the mountains are hazy. You may not even be able to see the mountains or behind the mountains. You'll just see the foothills of the mountains. That's because of particle air pollution. We call it particulate matter pollution. What's happening is similar to what you see during the day as the light hits particles and scatters. The more particles you have in the air, the more that light is going to scatter. So just like during the day, at nighttime, starlight and artificial light gets scattered by that air pollution by those particles, and it makes what we call sky glow, a kind of dome over the city where light is trapped. So, air pollution is a big factor in our ability to see stars at night.
Megan: Yeah. our little desert town is growing. We live, walk, and drive on sand, stirring it up. These sources of fugitive dust might seem something small, but when you have these big open areas where they are developing pretty rapidly, it contributes to the bigger haze in the area and therefore obstructs our night sky.
Donovan: Believe it or not, we aren't the only species that needs a dark night sky. Since the beginning of time, plants and animals have adapted to be reliant on the night sky, and a few of those adaptations are still visible in the park today with Joshua Tree National Park, encompassing two desert ecosystems. The plant and animals that live within the park are no strangers to harsh daily temperatures so the night sky is a critical component to their survival.
Stacy: We have the plant Datura wrightii also known as Sacred Datura. And it is a plant that is known to be a vespertine flowering plant. What that means is that it's reliant on the night for blooming. If you've been in the desert and you've seen the beautiful big white trumpet flowers of the datura plant blooming, they'll bloom in the evenings throughout the night and then also in the morning. They're pollinated by moss and other night critters. It's just a really cool plant to see. If you're out on a moonlight hike, you're going to see the datura blooming, and they're just stunning. There's animals out there that a lot of their behaviors kick in when it’s dark. Frogs and toads, they're mating rituals, require darkness. They'll do their croaking and that's important for them to be able to mate. Artificial light can disrupt these behaviors. And then for humans, we have been intrigued by the skies for as long as you can remember. It's inspired art philosophy, mythology, religions, science. It's such an important resource. The stars help us navigate. You have the North Star, which is about one degree off from our North Pole. Because of that star always in the northern sky, we can use that to help us navigate in a north direction. Specific constellations will come up and they mark the passing of the seasons.
Ian: As Stacey mentioned, there are a lot of forms of life that are dependent on clear and starry skies. However, as technology has progressed throughout time, people have started recognizing change. Within the night sky today, more than ever, the amount of light and air pollution is obstructing the views of our nightscapes. It's important to remember that this doesn't just affect plants and animals, but humans too. We not only rely on it for our sleep patterns, but it is also a critical aspect of many culture’s histories. Losing the night sky means losing their histories and stories.
Stacy: As astronomers were some of the first groups of people to become aware that there was an issue with being able to see the night sky, they started to realize that cities were impacting their ability to look through their telescopes and see stars. You have like observatories, like the Palomar and Wilson and Griffith, that are surrounded by large metropolitan areas and a lot of artificial light, and so they kicked off the alarm bells. “Hey, we need to start doing something different. We're not able to see the stars as well as we should!” Because the park service is so big on preserving and conserving and protecting these natural areas, night skies is an important resource for them to protect. The Park Service has developed a whole team of people devoted to learning about and protecting night skies and educating people about night skies. We have the Natural Sounds and Night Skies division in Colorado and they have scientists that will go throughout the different park units with research grade cameras that stitch together mosaics of skies. They're able to determine the sky brightness. This is the heart of what helped us get our Night Sky designation. This scientific number said this just how dark our sky is. The mission of the Park Service is to educate visitors. We want to teach you about why it's so important to protect these areas, and so there's ways that we can teach you on how to conserve the night sky.
Donovan: And ways to conserve the night sky are a lot easier than you may think. Unlike other challenges, the natural spaces facing light pollution may be one of the easiest problems to tackle in our own homes and communities.
Megan: There are many, many easy adjustments that somebody can make in their own homes that will make a huge improvement to the night sky and the communities and the park. Some of those things are as simple as just closing your blinds when it starts to get dark. Making sure that your outdoor lights are shielded and downward facing and that they're actually not encroaching on your neighbor's property. Other things you can do are, instead of having those bright white bulbs, get those amber bulbs. Use warm colored lights, Get involved in your community and get outside at night. All these little things that you can do can really help bring the community together and really increase the visibility in the night sky.
Ian: A lot of these great tips to reduce light pollution come from some amazing data collected by some pretty cool science. When light pollution first started to cause issues, the naked eye was the main tool for observing it. One could easily spot the difference in the night sky between cities and rural areas. However, over time, technology has evolved and enhanced our abilities to not only observe but collect data about nightscapes.
Stacy: So just like the Night Sky division has a team of people with all the fancy equipment, here at Joshua Tree, we're autonomous in our ability to be able to also collect night sky. We have the same equipment that the Night Sky team has. We've worked very closely with the Night Sky team to collect our data. Since before 2006, we've been collecting night sky data and that data we're hoping over time will show us just how our skies are changing as the Coachella Valley gets more developed. As the high desert communities start to grow, we're going to be able to see what those impacts are and we can work with the lighting ordinance that we've been working with the San Bernard Bernardino County on to try and mitigate some of the impacts of that growth in this area. We have a night sky camera. It's a charge-coupled device that can lower core temperature to negative 20 degrees Celsius. And the purpose of that is to try and mitigate as much of the internal noise that that camera is producing itself with light, so that we can get a more accurate reading of what the incoming light is from the sky. The way the camera works is we mount it on a telescope mount. On this device, it helps to move the telescope. You can go up and down. It's 360 degrees around and we have software that was designed to tell that camera to do a 360-degree stitch of the night sky. First, it'll first point upwards, take a photo directly up above the zenith, and then it rotates around. Horizontal with the ground to take 360-degree photos. Then all those photos are stitched together and we have software that will then analyze the light in that. We have some really incredibly smart scientists that were able to determine what are the natural ambient light conditions. They looked at what are the brightness of all the stars seen in the sky, the Milky Way, the zodiac light, and you can subtract that natural light and that will tell us how much light pollution we have in an area.
Donovan: To summarize what Stacy said, the night Sky cameras collect these long, stretched, panoramic photos of the landscapes and analyze the strength of the light pollution affecting your view in a particular area. These fascinating images help play in important role in identifying problem areas for light pollution. They also inspire educational events such as The Night Sky Festival and promote why dark night skies are essential. We were lucky enough to attend one of the pre-Night Sky Festival lectures where Bob Meadows, a physical scientist who specializes in night skies on the national level of the National Park Service, showcased light pollution images that were taken all over the United States at other National Park units as well as Joshua Tree Specifically.
Bob: I'm here today to kind of talk about the origins of our program. It's very unique. It’s specific to the night sky.
Ian: During the lecture, Bob displayed the images that the night sky camera had taken. Imagine a long rectangle image with a stretched out dome that represents the night sky. Key objects on the horizon give indicators of where this photo was. For example, the Joshua Tree photos had Joshua trees and rocks along the bottom. But now, imagine additional orbs of warmer colors from whites to reds than fading into greens and blues across the horizon. These orbs of color represented light pollution and how it was affecting the darkness of the skies in those areas.
Bob: Start to get a little bigger dome of light and a little more impacts there, moving on as you're getting closer to resources. For the most part, the Zenith is unimpacted. You have a national…
Ian: Bob first showed images from around the United States such as Arches National Park and Great Basin National Park, and then moved into Joshua Tree National Park, starting with Cottonwood Campground.
Bob: So this is at the top. This is Cottonwood Campground. That's in the southeast corner of the park. I don't know how many of you have been there. It's a little more remote from a lot of areas. And as you could tell here, not a lot of light pollution. And what you have here, I pointed out, this again, is the Coachella Valley and looking towards the Los Angeles area. This is looking down towards the Mexico border, kind of El Centro, Mexico, that area pretty is further away. But again, if you have clear skies and clear air, light can travel a great distance. This little knob here, that's actually the city of Las Vegas, back in 2000…
Ian: What Bob was showcasing was almost unbelievably. All the way from Cottonwood Campground on the very south side of the park is light pollution from the city of Las Vegas. A place that is over 200 miles away from Cottonwood campground was still affecting the night sky in the Cottonwood area. The light dome in the photos was significantly smaller than the light dome produced by the Coachella Valley, but was still plainly visible. Remember Cottonwood is known to be one of our darker areas in the park. So, what does this mean for other areas of the park?
Donovan: After seeing these images that Bob was sharing, I realized that I really had no idea just how much light pollution was affecting the park. And yes, our night skies are amazing, but it could be better, especially over the years, things have changed. Bob was an amazing speaker to listen to because he showcased that a great challenge takes a great deal of motivation to help tackle, and it was clear that Bob and his work was not only inspiring us, but everybody else in the room.
Ian: After talking with the phenomenal individuals who helped to conserve our night skies, Donovan and I were feeling pretty stoked to get to the Night Sky Festival and see what loving the night sky is all about. Of course, we reminded each other of the tips and tricks to having a successful time when viewing the night.
Donovan: Right, like avoiding blue lights to allow our eyes to adjust to the darkness. Red lights are always a safe bet. They don't affect the rhodopsin in our eyes, so I usually cover an old headlamp with red cellophane. Works pretty well.
Ian: Oh, and remember, we also have to have patience and give the stars the time they need. This means bringing things like a chair, extra layers, food, water, and anything else you may need to help make for a more comfortable viewing experience for yourself.
Donovan: And don't forget to double check the moon phase and rise time, because remember, the light from the moon is really just the sun's reflection. We want to ensure that we're not trying to stargaze while the sunlight is still present.
Ian: And lastly, it's important to scope out a good star viewing place ahead of time. The desert has a lot of sharp plants and nocturnal wildlife. Personally, I don't want to be in their space just as much as they don't want me in theirs. On top of that, some areas in the park might not accommodate parking after dark.
Donovan: And with that in mind, I'd say we're ready to go to the night sky.
Ian: Upon arriving at the Night Sky Festival, Donovan and I were greeted by dozens of astronomers and night sky enthusiasts with telescopes pointed toward the stars and planets above explaining to festival attendees what exactly they were seeing.
Donovan: I'll be careful. Oh yeah, you can see the rings. That's super cool.
Astronomer: Yes. Clearing up well, I got a clear spot about the time. Yeah, time. I say, oh, that's cool. There goes a cloud. Oh. Oh man.
Donovan: That's super cool. Thank you. Thank you. Through some of these telescopes, we got to see blue, yellow, and red stars. The rings of Saturn and several moons of Jupiter. Some telescopes were even set up with TV screens so large that crowds of people were able to gather around and view the stars from trillions of miles away together.
Ian: While it was hard to pull ourselves away from all the amazing sites visible through the party of telescopes, the Night Sky Festival had an impressive schedule of speakers and live music. So of course, we had to go check it out. In fact, Park, superintendent David Smith was emceeing the event and warming up the crowd
David: Galaxy. It's the creation of human life. It's all coming from above us right now. So being able to connect with that is a wonderful gift. And to be able to see it in places like National Parks is a wonderful gift as well.
Ian: So like any unique ecosystem, the original inhabitants provide a crucial lens into understanding the complexity that is the night. Elizabeth Page from the Native American Land Conservancy took the stage and spoke from the perspective of the people who have been here since time immemorial.
Elizabeth: We have all these stories that tell about these stars because we were the first astronomers, we were the first astrophysicists in this desert. I find that so incredibly beautiful to share that story with you as well as origin stories too. It isn't all Scorpio and Sagittarius. It's also the ram and the snakes and all these beautiful desert creatures that we saw in the stars as well.
Donovan: It was one experience, getting to see the stars and constellations through the astronomer’s telescopes, but getting to just sit beneath them, looking up with the naked eye, getting to hear the stories and perspectives of how the constellations formed, felt irreplaceable to understanding their greater context.
Speaker: We got a lot of stars. We got a lot of constellations up there, and I'm hoping that it gets clear enough that we get to see the Milky Way overhead. So, if these clouds get out of the way a little bit more, what we'll see is over by the teapot. If you go back over to the teapot over here, this is the center of our galaxy.
Ian: You probably noticed in our clips from the festival that a few people mentioned sightings of the rare and elusive desert clouds intermittently passing through the sky that night. It's important to remember that while clouds may come and go and are outside of our control, light pollution, where we live is not. As we wrapped up our time at the Night Sky Festival and headed home, we reflected on what we can do to help ensure that amazing events like this can continue.
Donovan: Right? Because as interpretive rangers, we want to ensure that the park is not only protected, but you get to enjoy it to its fullest. Light pollution is an interesting topic. Because it mostly needs your help at home. It needs to be addressed before you even come to the park. To reiterate those tips on lowering your light pollution impact that Megan mentioned before, you can always make sure that your lights are pointed down and use warm tone bulbs, and better yet, just turn off unnecessary lights that you don't need. It's also a great way to save energy. A flip of a switch can make a world of difference when trying to peer beyond our own.
Stacy: Air pollution is going to take a long time. If we stop emitting all the pollution and just stop doing everything, it's going to take decades for that natural system to balance itself out and rebalance itself. All you have to do for light pollution and noise pollution is turn off the light and stop the noise.
Donovan: Where Two Deserts Meet is an official production of Joshua Tree National Park, co-hosted and written by Donovan Smith and Ian Chadwick. Produced and edited by Donovan Smith. We would like to extend. Special thanks to Stacy Manson, Megan Richie and Bob Meadows for taking the time to talk with us. Sharon Lee Hart for letting us use her artwork titled Split as the Cover Art for Where Two Deserts Meet and Bar Stool for their songs Slow Lane Lover, lanky, Lockley Fells and Feather. For more information about the park, please visit our park website at www.nps.gov/jotr. Happy trails.