Sydney shows Jet and Sean a cool experiment - dropping different items from the same height to see which reaches the ground first. That reminds Sean of a video he watched of an astronaut on the Moon dropping a hammer and a feather from the same height. They reach the ground at the same time. And the reason is atmosphere - or lack of it - on the Moon. Jet laughs - really? Wait, what's atmosphere? Well, the kids know the best way to find out - into the wagon/saucer! Our kids and Celery fly to the edge of the Earth's atmosphere to learn what it does... and then go to the Moon. Is the atmosphere around the Moon the same as the Earth's? And what happens when our kids do the hammer-feather drop on the lunar surface? / Sydney brings Jet and Sean to the DSA to visit her mom, DR. AMY SKELLEY, and check out her work. Dr. Skelley is a robotics engineer who makes outer space robotic and gadget dreams a reality.