Astronomy  Studying the Universe
Astronomy is the study of everything beyond Earth's atmosphere  from planets and stars to galaxies and the large-scale structure of the cosmos.
Main Sub-Fields
- Planetary astronomy  the Solar System and exoplanets.
- Stellar astronomy  stellar birth, evolution and death.
- Galactic astronomy  the Milky Way and other galaxies.
- Cosmology  origin, structure and fate of the universe.
Tools of the Trade
Optical, radio, infrared, X-ray and gravitational-wave observatories, paired with huge data pipelines and machine-learning classifiers.