Thanks to a University of Arizona student and her childhood dream, visitors to the UArizona campus now can take a walk through the solar system at the same time.

Zarah Brown, a doctoral student at the UArizona Lunar and Planetary Laboratory, led the installation of 11 plaques depicting various objects of the solar system true to scale. Designed to show the relative sizes and distances of solar system objects at a 1:5 billion scale, the outreach project aims to make space science accessible to people of all ages and backgrounds and to highlight UArizona's accomplishments exploring the solar system.

Dedicated with a ribbon-cutting ceremony on Sept. 8, the stations comprising the Arizona Scale Model Solar System are spaced out across two-thirds of a mile of campus between the Kuiper Space Sciences Building and the intersection of East University Boulevard and North Euclid Avenue.

A project website, accessible by QR codes at each stop, will provide information via screen readers for the visually impaired, as well as additional details as new scientific discoveries are made.

The project is the result of collaborative efforts made possible by the support of the NASA Space Grant program and an anonymous benefactor. 

Brown talked to University of Arizona News about her childhood dream, what drove her to make it a reality and what sets the Arizona Scale Model Solar System apart from similar installations.

Q: How did you get the idea for this project?

A: I wanted to do this for a really long time. In second grade, I had a poster of the solar system that I loved, and it had all of the numbers on there, all of the planets, their sizes and their distances. And that was great, except they all were represented at the same size and distance from each other, and I thought, "I want this to be right. I want it to look right." So I decided to draw my own solar system model on a sheet of paper. I had my little calculator out, and I was figuring it out. And soon I was like, "Oh, my goodness, I'm going to need another sheet of paper” the farther out I got into the solar system. At some point I said, "Dad! I need more paper." I needed a ream of paper to get to the end of the solar system, and that was just mind-blowing at that young age. Since then, I've always found that experience to be just so compelling and fascinating and wonderful. It had me totally rethink who I am, how big our planet is, and how vast space is.

A young visitor spots Bennu, the target asteroid of the UArizona-led OSIRIS-REx mission, on the plaque featuring the asteroid belt, which is located at the entrance of the Flandrau Science Center and Planetarium.Daniel Stolte/University Communications

Q: What can you tell us about the design of the plaques?

A: They are 30 inches wide and 20 inches tall, and each of them has a depiction of the solar system object silhouetted against the sun, at the same scale, so you can see how big the planet is compared to the sun. The plaques provide details on the mass, diameter, surface gravity and temperature of various solar system objects, as well as stories about related University of Arizona scientific contributions. The interpretive information on each plaque is complemented by NASA images and illustrations by James Keane, an alumnus of the University of Arizona Lunar and Planetary Laboratory. 

Q: Can you give us a sneak preview of the objects featured in your installation?

A: The sun is located outside of the Kuiper Space Sciences building. At the scale of 1:5 billion, it measures 10.9 inches across. Next, a few steps away is Mercury, the innermost planet of the solar system. It's just a tiny dot against the sun, and because it is so close to it, it's a hot, dry planet with no atmosphere. Any atmosphere it might have had when it formed would have long been stripped away by the sun.

Across from Mercury, on the other side of the walkway leading up to the front of the building is Venus. Next, a few steps to the west, is a plaque for the Earth and the moon. From here, you can see the "moon tree" in the background, which is kind of neat, because that's the tree that went to the moon as a seed during the Apollo missions and then came back and was planted here. If you continue walking westward, you'll encounter Mars at the walkway up to Flandrau Science Center, followed by a big gap before we reach Jupiter in front of the Sonett Space Science Building. In that gap, a plaque for the asteroid belt was placed at the corner of University Boulevard and Cherry Avenue. The asteroid belt isn't typically featured in solar system scale models, but given all of our wonderful work around asteroids, most notably the OSIRIS-REx sample return mission, we thought it would be very important to include the asteroid belt.

Passing Jupiter, we continue to walk westward until we reach the Modern Languages Building, where we encounter Saturn, which happens to be my favorite planet. As we keep walking past the Student Union, we arrive at the plaque for Uranus, just north of Old Main. By the time we reach Neptune, the outermost of the planets, we are at the edge of campus on the opposite end of where we started. That planet's plaque is located just east of the stone wall at Main Gate.

Q: What about Pluto, the dwarf planet that is no longer recognized as a "proper" planet?

A: We have slated a home for Pluto along the pedestrian walkway amid the shops near University Boulevard and Euclid Avenue. This property is owned by the Marshall Foundation, which aims to support education for children and young adults in the Tucson community.

Q: Who provided the content? Did you write all of the narratives?

A: I know that I'm not an expert in every single object in our solar system, so I had a team of about 10 graduate students in LPL (the Lunar and Planetary Laboratory) who helped me write an initial draft focusing on which aspects of each object are the most interesting and outlining some of the facts.

Q: What do you hope to accomplish with this project?

A: My main goal is to have the wonder of the universe that we live in be more accessible to anyone who comes to campus. I'm really passionate about science being accessible to the public. I think that sometimes scientists get very focused on their aspect of research, and we don't always do the best at translating what we're learning to everyone. I also hope that seeing how small the Earth is compared to the vastness of space might give people the type of perspective that would have them see how precious our planet is and how precious one another are.

UA News - Take a Stroll Through the Solar System – on the UArizona Campus