Touching the void

Astrophysicists lead Perkins students in hands-on exploration of our solar system and the vastness of space

Students touch a ball of play-doh.

Students compares the size of two "planets" made out of Play-Doh. Photo Credit: Kelsey Grousbeck.

June 2, 2015

Visualizing the solar system is no easy feat, regardless of whether you’re sighted or blind. It is difficult, after all, to imagine a planet that is over a thousand times larger than your own, unless you’re an astrophysicist.

Jabran Zahid and Wanda Diaz Merced have spent their careers studying the universe, most recently through a grant from Harvard University. They shared some of that knowledge during a recent visit to the Perkins campus, where they led a hands-on astronomy lesson for 18 students in the Secondary Program.

“I want you to get a sense of our neighborhood – the solar system,” said Merced. “When I leave here today you will all want to be astronomers and astrophysicists.”

Merced, who is blind, led students in two activities designed to give them a sense of the size and scale of the planets, as well as their distance from the sun and each other.

In the first, students folded strips of paper, creating a sequence of creases that helped illustrate the distance between the cluster of inner planets, including Mercury, Venus and Earth, and remote outer planets like Uranus and Neptune that circle billions of miles from the sun.

Merced then passed out cans of Play-Doh to students, and asked them to mash the contents together into a giant, multicolored ball.

“That big ball should be our solar system,” she said.

Working in teams, students divided the ball into 10 equal parts. Six of those parts were combined to form Jupiter, the largest planet in the solar system. The remaining dough was divided further, and used to build other planets that were deposited into boxes with corresponding braille labels.

When only a small scrap of dough remained, Merced gave students a now-familiar direction: divide the dough into 10 even smaller pieces.  

“How do you break a crumb into 10 crumbs?” asked Jonah, 17, incredulous.  

Those crumbs were combined to form the smallest planets in the solar system. When all eight planets were completed, students were able to feel the difference between mammoth planets like Jupiter and Saturn and smaller ones like Mercury and Mars. Earth, the fourth smallest planet, was smaller than a green pea.

“We’re puny,” remarked Shea, 17, as he held the planet in his hand.  

For students with visual impairments, this kind of tactile exercise is often the most effective way to learn about difficult concepts like the comparative size of planets and the vastness of space, said Perkins science teacher Kate Fraser.

“Creating hands-on activities where the relative distances and size can be presented is extremely helpful,” she said. “Students could ‘see’ it all right in front of them with their hands.”

The lesson also gave students the chance to interact with an astrophysicist who happens to be blind.   

“Meeting a person who is visually impaired with Wanda’s knowledge and reputation is enormously valuable for our students,” said Pat Ryan, supervisor of Outreach Short Courses, who organized the visit. “Teachers give them the message that they can be successful in any field they want. Wanda gives our students living proof that they can achieve at the highest level.”

Learn more about making science lessons accessible to students who are blind or visually impaired »