Dancing Water Drops In Earth Orbit

An astronaut once told me that fellow space flier Don Pettit could fix anything with a paper clip. Indeed, Pettit has nicknames like Mr. Wizard and Mr. Fixit, and he is well-known for his Saturday Morning Science videos during his first stay on the International Space Station and his “Zero G Coffee Cup” from a space shuttle mission he was on in 2008. Now in his second long-duration stint on the ISS, Pettit has a new video series called “Science off the Sphere” and the first video is above. Pettit uses “knittin” needles (watch the video to hear Pettit’s pronunciation) and water droplets to demonstrate physics in space, and shows what fun astronauts can have with water in zero-G with his ‘dancing’ water droplets.

This new video series is partnership between NASA and the American Physical Society. But there’s more than just videos, as at the end of each video Pettit poses a challenge question. Submit your answers at the Science Off the Sphere website for a chance to have your name read from space and receive a snazzy t-shirt from Earth.

Here’s this week’s Challenge Question:

In the end of the video, Dr. Pettit put a nylon knitting needle near the syringe used to squirt water droplets onto the Teflon knitting needle. Why did Dr. Pettit need a nylon needle near the injected drops and why must the other needle be Teflon?

A winner will be randomly chosen from all correct answers submitted. You have one week from the date the challenge is posted. The winner will receive a “Science off the Sphere” t-shirt and have their name and answer read by Dr. Pettit from the ISS. Winners and answers are posted one week after the challenge question is posed.