Iphone and Android question

[Ron]

Dear Friends, 

I would REALLY appreciate your feedback on the below:

1. How can I know what frequencies the iphone 10 or in general typical smartphones can detect using the magnetometer?

What frequencies?  What wavelengths in centimeters? 

2. How would/could we use the magnetometer as a "telescope" to observe space and determine structures of planets and their composition?

(I have some ideas - and would love to hear yours!)

Thanks, 

Ron