Seeds from Space

Two years ago, I heard about the Tomatosphere project and applied for my classes to participate. The First the Seed Foundation sent us two packs of seeds, each marked with a different letter. One of the packs of tomato seeds has spent 6 weeks on the International Space Station and the other pack has never left Earth. We don't know which is which until we submit our germination results. 

My classes plant the seeds during the first unit of the year. We're talking about distinguishing living vs. non-living. We start the class with a Do Now from Uncovering Student Ideas in Life Science, Volume 1: 25 New Formative Assessment Probes by Page D. Keeley. The assessment asks students to explain their thinking about whether a packet of tomato seeds is living or not. After some discussion, we work on planting the seeds. I post these directions as they work on planting the seeds. 

This is a great lab to do at the start of the year, as it allows us to talk about control groups (seeds that didn't leave earth) and blind trials to prevent bias or unequal treatment between the two groups. We also work on hypothesis development as I have them decide which seeds they think will germinate best and why. This allows us to emphasize that an experiment is not a failure if the hypothesis is not supported. At the conclusion we begin to introduce the idea of statistical significance as well. 

The first year I did this with my Honors Biology class, they were so invested in these seeds that when I revealed which seeds had been in space, they actually cheered. That first year, I also had my AP Biology class work with the seeds, but the focus was not just on being in space or not, but also on other factors that may affect germination rates. We germinated the seeds on paper towels in petri dishes. Looking back now, I find planting them in cups of dirt more satisfying. 

Last year our germination rates were much lower than the year before. I'm not sure why. It'll be interesting to see the germination rates this fall. I'm hoping that I'll have my students in person long enough to get them planted, then if we have to go virtual, I can just have them bring their cups of planted seeds home and continue the observation from home.