A scale model at the U of A turns a walk around campus into an epic space journey

A sprawling new facility at the University of Arizona is designed to provide a true-to-life picture of our solar system in all its humble vastness.

The Arizona Scale Model Solar System is a collection of 10 informational signs that extend from the Kuiper Space Sciences Building in the UA Mall to the Main Gate at the west end of campus.

Each sign represents a planet or other celestial object, carefully positioned to reflect its relative position in orbit around the sun. Even at 1:5 billion scale, the screen covers more than half a mile. It takes about 10 minutes to walk from the Sun to Neptune, a real-world (real-space?) distance of nearly 2.8 billion miles.

“Astronomical scales can be difficult to understand,” said project leader Zarah Brown, a doctoral student at the UA Lunar and Planetary Laboratory.

The posters provide details on the mass, diameter, surface gravity and temperature of each object in the solar system. They are illustrated with images from NASA and artwork by James Keane, a student at the Lunar and Planetarium Laboratory.

The permanent exhibit also serves as a tribute to the university’s enormous contributions to planetary science. At each stop on the solar system tour, visitors can read about UA research related to that object.

Brown said they had no problem finding all the Tucson connections they needed. “It was harder to choose which ones to include,” she said.

The signs went up at the end of August. The university hosted a ribbon-cutting ceremony for the facility Friday in front of the Kuiper Building.

That’s where the Sun can be found, shrunken to the size of a basketball, along with the rest of the inner solar system: Mercury, Venus, Earth and Mars, all clustered within about 150 feet of each other.

Distances increase as you move west along the UA Mall, beyond the asteroid belt. The signs of Uranus and Neptune are two-tenths of a mile apart.

“This gives an idea of ​​how lonely and vast the outer solar system is and why some of these objects are poorly studied. It’s harder to reach them,” said Brown, who is finishing his Ph.D. dissertation on the upper atmosphere of Saturn.

The solar system walking tour was developed with the help of a multidisciplinary team that included about 10 graduate researchers who helped write and edit the information on the posters. The exhibit was funded through a NASA Space Grant scholarship that was awarded to Brown in 2020 and later extended.

She said she has been fascinated by the enormity of the solar system since she first learned about it in elementary school.

Once, as a child, she attempted to draw the planets at the proper scale and distance using a calculator and some art supplies, but had to abandon the effort when she realized she was going to have to ask her father for several hundred dollars. . more sheets of paper.

“It was amazing. There’s all this empty space around us. Everything that seems so big and important is actually very small,” Brown said. “This has been something I’ve felt compelled to do for a long time.”

The solar system exhibit is designed to serve as an educational tool for both UA students and campus visitors. As part of the project, Brown is writing lab exercises to help undergraduates conceptualize large numbers and large distances by walking through the facility and doing calculations along the way.

Brown said there’s a bit of “environmentalism” included in the sign of Venus, where a “runaway greenhouse effect” has made the planet hot enough to melt human-built space probes in a matter of minutes.

“The interaction between the surface and the atmosphere are the same processes that are happening on Earth,” he said.

A QR code on each sign links to a website that can be used with a screen reader for the visually impaired. Brown hopes that one day the website will be expanded to include additional information about the solar system and the UA’s role in its exploration, along with updates as new discoveries are made.

The installation was organized based on the average orbital distance of each object, although some minor adjustments were made to ensure that the signals ended in a safe and convenient location.

“We were wrong about Neptune,” Brown said. “It would be more correct to put it in the middle of Park Avenue.”

Instead, it can be found just inside the volcanic rock wall of the Main Gate at Park and University Boulevard.

Eventually, the facility will extend off campus about 700 feet to include Pluto. Brown said they plan to place that sign near the corner of University and Euclid Avenue as soon as they finalize a legal agreement with the Marshall Foundation, which owns much of the Main Gate Square commercial development there.

“We decided to include it because I think the argument about whether Pluto is a planet is amazing,” Brown said. “It gets people emotionally excited, which is sometimes hard to do with some of these space topics that people don’t necessarily feel personally invested in. People have definite opinions about Pluto.”

He added that the demoted dwarf planet has such a strange, elongated orbit that its sign could actually be located as far away as Time Market, another third of a mile farther west on University Boulevard.

And if that’s not mind-blowing enough, consider this: If you wanted to include Proxima Centauri, the closest star to our sun, Brown said the scale model would have to be expanded by about 5,000 miles, roughly the distance between Tucson and Glasgow. Scotland.

“One of the conclusions someone could draw from this model is that we are very valuable and small,” Brown said. “Why don’t we take care of our only home? And why don’t we treat each other a little better? The only thing we really have is each other in this enormous amount of vast space.”