Questions for “Light levitation might help explore Earth’s ‘ignorosphere’”

a photo of the Earth's atmosphere from the International Space Station above a cloudy Philippine Sea

Far above Earth’s clouds, the mesosphere wraps around the planet. There, the air is too thin for airplanes and balloons but too thick for satellites. Now, researchers have discovered a potential way to fly lightweight aircraft in this largely unexplored region – by levitating them with light.


To accompany “Light levitation might help explore Earth’s ‘ignorosphere


Before Reading:

1.  What are at least four things that satellites are used for today?

2.  Why do satellites tend to orbit very high above Earth’s surface? (Hint: Consider the air’s density.) How does the height (altitude) at which a satellite orbits Earth affect what it can see or do?

During Reading:

1.  What is the new way to “fly” being developed at the University of Pennsylvania?

2.  What is the mesosphere? Why would this flight technique be especially useful there? How does it compare to the technique used to fly vehicles in the mesosphere now?

3.  What is the photophoretic effect? What is a light mill and what does the photophoretic effect do to it?

4.  What material did Mohsen Azadi and his team use as sails for their light-levitated “vehicle”? How thick is it? Why did they add carbon nanotubes to the underside of this material?

5.  How did LED light cause their vehicle to lift off?

6.  How do the researchers imagine a light-levitated vehicle would explore the mesosphere?

7.  What is the primary limitation to light levitation?

After Reading:

1.  Read about the poorly understood mesosphere. Now imagine you’re in charge of a research team with access to a light-levitated vehicle. What are three things about the mesosphere that you’d use this vehicle to answer?