he did not use telescope because it was not invented yet
Johannes Kepler
Johannes Kepler determined that all planets have elliptical orbits.
There is no planet that is simply called "Kepler". The Kepler spacecraft discovered various planets, with names such as "Kepler-4b", "Kepler 11-d", etc.
Johannes Kepler proposed that these planets orbit the sun in ellipses, not circles. That is why we have Kepler's Law of Planetary Motion.
Kepler-22b orbits the star Kepler-22.
Elli[tical orbits.
No
Ellipses
Johannes Kepler
Laws of planetary motion.
There are lots of planets in the Kepler series. To answer your question, we need to know to which number Kepler you are asking about.
Johannes Kepler determined that all planets have elliptical orbits.
There is no planet that is simply called "Kepler". The Kepler spacecraft discovered various planets, with names such as "Kepler-4b", "Kepler 11-d", etc.
they use tools
NASA's space telescope "kepler"
Johannes Kepler proposed that these planets orbit the sun in ellipses, not circles. That is why we have Kepler's Law of Planetary Motion.
I'm pretty sure you're thinking of Johannes Kepler.