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Matthew Siegler, Earth Sciences, What If The Moon Were Bigger?

GeorgiaWorld

Originally Posted: May 25, 2016

The questions kids ask about science aren’t always easy to answer. Sometimes, their little brains can lead to big places adults forget to explore. With that in mind, we’ve started a new series called Science Question From a Toddler, which will use kids’ curiosity as a jumping-off point to investigate the scientific wonders that adults don’t even think to ask about. I want the toddlers in your life to be a part of it! Send me their science questions and they may serve as the inspiration for a column. And now, our toddler …


Q: How big is the moon? What if it were bigger? — Hagen G., age 5

The first part of your question is easy-peasy. The moon has a circumference of 6,783.5 miles, about 27 percent that of Earth. Imagine setting out from Boston and walking to Peshawar, Pakistan. (Don’t do this. Among other hazards, there is an ocean in the way.) That same walk would take you all the way around the moon at its equator. Here’s another way to think of it: If Earth is a softball, then the moon is a shooter marble. (The circumference of the sun, in this analogy, is represented by the General Sherman sequoia, one of the largest trees in the world.)

But what about a bigger moon? This part of your question took me from a simple Google search to sitting on the telephone with a planetary scientist while we both made thinking sounds and waved our hands around in an attempt to gesture our way through logical speculation about gravitational physics. So, thanks for that, Hagen.

The scientist, Matthew Siegler, is a research assistant professor at Southern Methodist University and an associate research scientist at the Planetary Science Institute.1 He told me that the question of what would happen if the moon were bigger matters because the moon and Earth are a system. Our gravitational pull affects the moon. The moon’s gravitational pull affects us. We’re linked to each other by the push and pull of invisible hands. And that has some big impacts on our planet. READ MORE