From 1609 till his death.
Modern astronomy.
Some of Galileo's most significant work was in the field of kinematics, identifying that the total ...by him (or to be written by him) were forbidden, though this latter part was not enforced. ... Galileo Galilei - major areas of study ...
Galileo !
He discovered the four moons of Jupiter.
Galileo Galilei was an Italian polymath who lived in the 16th and 17th centuries. He made significant contributions to the fields of physics, astronomy, and mathematics. Galileo is often referred to as the "father of observational astronomy" for his pioneering use of telescopes to study the night sky.
I believe that at the time of Galileo and other pioneers in astronomy there was no formal astronomy study; he (and others) must have learned most of what they knew by themselves.
Galileo Galilei
Modern astronomy.
Astronomy
In astronomy, he used a telescope.
Yes
astronomy and philosophy.
yes.
Some of Galileo's most significant work was in the field of kinematics, identifying that the total ...by him (or to be written by him) were forbidden, though this latter part was not enforced. ... Galileo Galilei - major areas of study ...
Astronomy/physics
Galileo !
Galileo