Answer to Question 1
Most are found by their gravity pulling their stars enough to create observed Doppler shifts as the planets orbit their stars. A few have also been seen to transit the disks of their stars, with drops in the star's light seen in photometers.
Answer to Question 2
Cassini has found a surprisingly active geology on many Saturn moons, e.g. Enceladus. The Huygens probe landed on Titan and photographed hills, valleys, and possibly rivers. It showed pictures of ice rocks on the surface of the planet and its soft landing suggested a slushy ice/rock surface. Radar mapping of Titan showed what appear to be lakes of liquid methane and ethane and Cassini has also photographed Saturn's rings and the gap moons in great detail.
A Star with Three Planets
Primates use their space in a variety of ways: home ranges, core areas, and territories.
While most people resist labels of deviance, some embrace them. In what different ways do these ...
There are many ways for an individual to monitor his or her blood glucose level
Reflectivity of Inner Planets
Two ways of generating genetic variation in meiosis