Recon's student space explorers will peer into the Solar System's far frontier

We know much less about the icy rocks  in trans-neptunian space than this artist's illustration implies. Fortunately there's a way to measure the size and shape of objects orbiting 3 billion kilometers from the Sun - let the kids do it. Credit: Nasa

We know much less about the icy rocks  in trans-neptunian space than this artist's illustration implies. Fortunately there's a way to measure the size and shape of objects orbiting 3 billion kilometers from the Sun - let the kids do it. Credit: Nasa

By this time next year a network of 40 high schools across the American West will start exploring the most remote regions of the Solar System. Cal Poly and the Southwest Research Institute announced yesterday the $1 million in National Science Foundation grants that makes this citizen science project possible. 

Dr. Marc Buie, a planetary scientist with the Southwest Research Institute, is one of the few people in the world who have dedicated their careers to studying the Solar System's frontier. Dr. John Keller is a planetary scientist at Cal Poly who works on science education and teacher preparedness. The two co-investigators in Recon, the Research and Education Collaborative Occultation Network, spoke with me about how the project combines citizen science, education outreach, and planetary science.

This Nasa illustration shows just how much of the Solar System remains unexplored. Credit: Nasa

This Nasa illustration shows just how much of the Solar System remains unexplored. Credit: Nasa

Beyond the orbit of Neptune mountains of ice and rock orbit slowly around the Sun. Planetary scientists divide trans-neptunian space into several smaller regions (“smaller” being a relative term): the hypothesized-but-unseen Oort Cloud, the scattered disc where most comets originate, and Pluto’s home in the Kuiper Belt.  Where Pluto was once the only known object so far from the Sun, the Minor Planet Center now lists more than 1,000 of these trans-neptunian objects. 

We know very little about these objects because their size and distance make them little more than faint points of light against the galaxy’s starry background. Pluto itself only covers a few pixels in the Hubble Space Telescope’s cameras. Marc led a project that required 20 computers working for 4 years to turn Hubble's data into these pictures.

This is the best image we can get of Pluto from Earth. It's one of the largest Kuiper Belt Objects so imagine how difficult it is to study objects a fraction of Pluto's size. Credit: Nasa, Esa, and M. Buie (Southwest Research Institute) 

This is the best image we can get of Pluto from Earth. It's one of the largest Kuiper Belt Objects so imagine how difficult it is to study objects a fraction of Pluto's size. Credit: Nasa, Esa, and M. Buie (Southwest Research Institute) 

This is the most detailed view we've ever had of Pluto and its moon Charon orbiting each other. As the New Horizons space probe passes Pluto, it will reveal detailed views of the dwarf planet and its moons. But that may be the last chance to visit a Kuiper Belt Object for decades to come. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

This is the most detailed view we've ever had of Pluto and its moon Charon orbiting each other. As the New Horizons space probe passes Pluto, it will reveal detailed views of the dwarf planet and its moons. But that may be the last chance to visit a Kuiper Belt Object for decades to come. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Studying Kuiper Belt Objects directly is even more challenging thanks to the vast distances involved and the limited space agency budgets. Only 5 Nasa spacecraft - Pioneer 10 and 11, Voyager 1 and 2, and New Horizons - have ventured beyond Neptune’s orbit. New Horizons is the only mission dedicated to Kuiper Belt exploration: it flies by Pluto in 2015 and possibly another object a few years after that. Nasa has no other Kuiper Belt missions on the drawing board so it will be decades before scientists get another close-up look.

Marc’s career in Kuiper Belt research began while studying planetary science at the University of Arizona Tucson’s Lunar and Planetary Laboratory. Digital sensors are ubiquitous today, but the University of Arizona and Nasa’s Jet Propulsion Laboratory first used CCD for astronomy in 1976. Marc’s doctoral research in the early 1980s used early CCD technology to make observations of Pluto. 

Marc: One of the things I liked about studying planetary science was the breadth of study. Instead of the specialization that’s the watchword in today’s degrees, LPL was all about breadth. You’re dealing with geology, chemistry, atmospheres, and dynamics and I really liked that.

What got me interested in Pluto first and then the Kuiper Belt was the concept of the frontier.
— Marc Buie

Marc: What got me interested in Pluto first and then the Kuiper Belt was the concept of the frontier. This was part of the Solar System that we knew very little about. We still need to learn a lot more, but we’re making some progress.

Nasa's Earth Observation team created this illustration of a solar eclipse from above. As the Moon occults the Sun, it casts a shadow that passes over the Earth below. People standing along the shadow's path at the "equator" (the yellow line) see the shadow for a longer period than people standing at the shadow's "poles". Credit: Robert Simmon and Jesse Allen, Suomi-NPP VIIR

Nasa's Earth Observation team created this illustration of a solar eclipse from above. As the Moon occults the Sun, it casts a shadow that passes over the Earth below. People standing along the shadow's path at the "equator" (the yellow line) see the shadow for a longer period than people standing at the shadow's "poles". Credit: Robert Simmon and Jesse Allen, Suomi-NPP VIIR

Fortunately there’s a technique, called occultation research, that lets planetary scientists study these distant objects from Earth using relatively small telescopes. Solar eclipses are occultations. As the Moon passes between the Sun and Earth it blocks the Sun’s light and casts a shadow on Earth’s surface. You can measure the size and shape of the Moon by timing the duration of darkness at several locations perpendicular to the shadow’s path. Darkness lasts longer at the shadow’s equator than at its poles.

Of course there are better ways to measure the size of the Moon, but the same concept gives planetary scientists a useful tool for measuring small objects throughout the Solar System. When a Kuiper Belt Object occults a distant star, it also casts a shadow on Earth’s surface. We can’t see that shadow during the day - the Sun outshines all of the other stars - but at night the star seems to disappear and then reappear as the shadow passes over head. Occultation researchers chase these occultations and use portable telescopes to measure the duration of the shadow’s passing. The data they collect lets them reconstruct the objects' size and shape - and even discover moons and rings circling the objects.

Marc: I think about occultations all the time. It’s a fantastic technique for measuring details about objects that you can’t otherwise get with that fidelity. When we started discovering more and more trans-neptunian objects, the obvious thing was to adapt this thing that I already knew how to do to this new population of bodies.

Marc: Every event is different - that’s why I call it an art. You know the basic principles but sometimes you have to look past that to find out things you’ve maybe not thought about. We spend a lot of money traveling around the world with these 14” portable telescopes. There’s nothing worse than putting 3 months of your life into a project only to get there and know you were in the wrong place and you could have done something about it.

A flying task force of scientists chasing shadows from the other side of the Solar System, as cool as it is, doesn’t come cheap. Marc decided to take a different approach: let the shadows come to him.

Marc: Recon grew out of a brainstorm I had more than 10 years ago: let's put telescopes in schools. We can get them to observe these events and the network as a whole has a great chance of getting the scientific results that we want.

Marc: I needed somebody to help me out to do the educational part of this. I do a lot of the science research, the orbit work, the astrometry. I just don't have enough time in the day to be an expert in the educational side of things.

And that's when John entered the picture. John began his career as a science educator before pursuing a PhD in planetary science from the University of Arizona.

John: I taught middle and high school science for 8 years. I went and got my PhD doing applied research in gamma ray spectroscopy as well as education research into what students thought about the greenhouse effect. I started teaching at Cal Poly in the summer of 2007 where I run the Center for Excellence in Stem Education.

One of the things to come out of that experience is the strong importance of citizen science
— John Keller

John: We run the Stem Teacher and Researcher program where we place pre-service teachers with national research labs. They work with scientists to conduct their own scientific research which they can integrate into the classroom. One of the things to come out of that experience is the strong importance of citizen science... to engage their students.

The NSF had already rejected Marc’s original proposal for an occultation network when 4 years ago a chance meeting at the LPL’s 50th anniversary celebration brought Marc and John together.

Marc: We were at the old hangout where all the grad students used to go. We ended up talking and I got John interested in the project.

John: The Recon project just seemed like a great opportunity to continue planetary science research while working with groups around citizen science and teacher research experiences. I've been grateful to work with Marc because he brings a strong emphasis on education as well as on science which isn't typical among all scientists.

Marc: A month later we submitted our first NSF proposal for funding. That one didn’t go, but we did it a second time and we got funded for the pilot. We applied again and got the full funding which we just got now.

The latest National Science Foundation grant will let Recon expand from its 13-site pilot project (green) to the full 40-site network (blue). Source: Recon

The latest National Science Foundation grant will let Recon expand from its 13-site pilot project (green) to the full 40-site network (blue). Source: Recon

The $1 million in NSF grants supports Recon’s network of 40 rural communities. Schools and community centers along a 1,200 mile line from the Canadian border to the Mexican border agree to host the network’s telescope and conduct occultation observations.

John: The telescope costs about $3,000 and everything else is a little more than $1000. We’re talking about a $4,000-$5,000 investment in hardware which is not within the normal budget of a science teacher who has $20 or $500 to spend.

John: Many of these communities we are working with are very underserved. So you have schools like Tonopah, Nevada, and Chelan and Tonasket in Washington. [Ed: John sent me an update after attending several community meetings last week. Chelan may join a neighboring community rather than become a formal Recon site.] These are very small communities with 500-2,000 people. They’re not used to having people come to their communities and invite them to be part of a research project. Its been really compelling to be involved with students and schools that normally don’t have much STEM education.

Enhancing science education in these communities shares equal footing with the Recon project’s science goals. In exchange for helping Marc and John conduct scientific research, the communities are free to use the telescopes for education and public outreach.

John: The telescopes are available for use [by the communities] for the 340 nights that we’re not doing occultations. It’s been really successful - we’ve got a lot of feedback. Almost every school has done a star party, some as many as 5 per year depending on the school. So they are using it largely for public star parties or star parties to augment class.

John: At least 3 of our high schools [in the 13-site pilot program] now have astronomy classes. Carson City already had an astronomy course but they’ve been implementing a 2-week Recon module in their astronomy program. Feather River College has also implemented a class that’s specifically about the Recon project. They bring community members from Quincy who go through the process of learning about Recon. The other 7 sites are still teaching astronomy as part of their science classes and referring to the Recon project.

Kathy Trujillo, a community member in Hawthorne, Nevada, said in the Recon project’s press release, “The town of Hawthorne, Nevada, and the Mineral County School District now have a telescope to share for educational and community use, the first time ever. The high school was able to offer an astronomy class. Imagine the wonder in a student’s eyes when she sees the rings of Saturn for the first time.”

Marc: My hope was that the process [of occultation research] would be more interesting in an educational framework than the actual scientific data. It you as an individual are going after one of these events your chance of seeing it, in the best case, is one in 20. So you would love to see your answer come out of it, but it doesn’t need to be you. It could be the other team member in Oregon that got it instead of you in Arizona. You still feel part of the whole team and the whole process.

What I’ve come to love most about this project is that our [teacher and student] science teams have come to understand that science is an iterative process
— John Keller

John: I really want them to see what the whole process looks like. What I’m working on is a curriculum cycle in which our students get to do their own main belt asteroid occultation campaigns. They get to do their own occultation predictions and recruit their neighboring school sites. They get to analyze the data back at school during the day and report their results back to Iota [Ed: the International Occultation Timing Association is a pro-am collaboration for studying asteroids using occultations]. Teachers can involve their students in entire science investigations to be part of an entire process from start to finish.

John: What I’ve come to love most about this project is that our [teacher and student] science teams have come to understand that science is an iterative process. They have experienced failures, if you want to use that word, while going out on some campaigns. They’ve done 5 of the 12 steps correctly, they’ve missed step 6 and that event didn’t work out exactly as they hoped. Then the next time they’ve gone out they got to step 9. And the next time they’ve gone out and been successful at recording the event. So I think they come to a better appreciation for the nature of research and that the process of becoming an expert at something is practice.

And that practice will turn Recon into a full-fledged Kuiper Belt observatory. Marc said in the Recon project press release, “Working with our citizen scientists is an effective way to find out the size, shape and several other characteristics of the KBOs we study, which in turn will shed light on the origins of our solar system.”

On the night of a campaign students and teachers from each community will set up their telescopes. As the Kuiper Belt Object’s shadow passes over head and the occulted star winks out, they will record the amount of time the occultation lasts. Marc, John, and their science team will use the data from across the network to study the object. 

Marc: The first and most obvious things that we’re going to get are sizes of these smaller objects. We're going to get enough over the course of the project to know whether there are systematic errors in how we deduce the sizes of these objects via other techniques: the Spitzer Space Telescope detects these things in thermal wavelengths and you use models to come up with a size. But its always good to have some ground truth and that’s what this project is going to provide. 

Marc: The other part of what we’re going to do with them is a little more in the realm of serendipitous science. You’ve heard about the recent occultation by Charklo where they discovered rings around Centaur asteroids? Nobody expected that. Nobody would have predicted it. An now that we know about it we’re still puzzled about it. But is that the only one?

Marc: Every single one of these objects that we observe with Recon we’re going to probe for things like rings. If they’re common we’re going to see them. If they’re not, we won’t, but we will constrain these particular properties.

Marc: The other thing is we know a lot of these objects are binary [Ed: two objects of equal mass orbiting each other]. We know we see binaries in the Hubble Space Telescope right down to the resolution limits of the telescope. Recon is going to be exceptionally good at probing the size and separation that is too close for Hubble to be able to see. We’d like to know where that boundary is where you stop seeing binaries. Does it go right down to contact binaries? Occultations are the only way to provide these constraints. The Recon network is perfect for probing these ultra tight binaries.

Recon’s 40-site network will produce these results, but Marc and John hope to go beyond that by extending occultation research to schools outside the network and to the broader community of amateur astronomers.

John: Realistically, you might expect a dozen or so students who are able to make it out at 12:30 at night to record an occultation event until 2:30 in the morning – and only a handful of our sites will lie within the path of the KBO shadow during any given event.  To scale the impact of this project, we are working on curricula and related classroom activities that will allow teachers to involve all of their students in predictions and data analysis to complement their nighttime efforts.

John: Using our 40 sites as a test community - our pilot for figuring out what works - the curriculum that we’ll be developing will be disseminable to all school sites. You don’t have to be in the Recon network. You just need a telescope with a $1,000 camera which is more accessible to schools that have telescopes already.

Marc: We embrace the amateur with open arms in this project. There’s two things they can do. We’re already bringing them into the project for the first: to be local mentors. We’re engaging them where we can find them and it’s been a great partnership. We’ve met some truly extraordinary people that are very giving of their time and energies and enthusiasm to help teach the teachers. I see this as a huge benefit of the project to bring together the amateur community with the education community where they otherwise wouldn’t know how to meet and talk to each other.

There are some amateurs out there that have the equipment and expertise to make these observations just as well as we can.
— Marc Buie

Marc: There are some amateurs out there that have the equipment and expertise to make these observations just as well as we can. Amateurs have gotten into occultations in a big way doing main belt asteroid occultations. They use catalogs of star positions and JPL’s ephemerides of all the minor planets. When the orbits in these catalogs [became] good enough they started getting good results. We would love for them… to be looking at our candidate events that we’re observing and sort of fill in the gaps. We don’t want them getting on an airplane and flying somewhere to do this. Keep it simple so you don’t mind a 1 in 50 chance of success. If the star is visible in reasonably dark skies - meaning if the Sun is down - go out in your backyard and observe. As many of these people as want to get in on this and do one of these events - the more the merrier.

John: The timing of when that will be most impactful will be after April 2015. Now we only have a quarter of the network trained but after April we’ll have all 40 sites that will be observing Kuiper Belt occultation events. I think once the amateur community sees all 40 sites signed up for events it will be much easier for them to see they can contribute in this way.

Recon is a perfect example of amateur space exploration. Technological change has made research-quality astronomy equipment more affordable. The professional astronomy community’s embrace of amateurs and of education outreach makes collaborative projects more acceptable. And amateurs’ strength in numbers lets their combined efforts produce scientific results that professional astronomers could not afford using traditional techniques. 

Recon’s Kuiper Belt explorers, and the amateur astronomers who join them, will uncover new knowledge about the most remote regions of the Solar System. Just as importantly, a generation of students from the Recon communities will see first-hand that they have what it takes to explore space.

Update 2014/10/25 7:38am: John Keller provided a revised explanation for the curriculum he is developing that more clearly explains the rationale and outcome. 

Update 2014/10/27 10:35am: John sent me an update on Chelan, Washington's status in Recon - as well as correcting some of my typos.