1. Celestial object identification and planetary features: sketches used to identify comets, galaxies, nebulae, aurorae, solar corona, and planetary characteristics like Saturn’s rings through telescopic observation

2. Stellar evolution and classification: youngest stars as main sequence, smallest as neutron stars, H–R diagram positioning by spectral class and magnitude, implications of redshift from Hubble’s law indicating universal expansion

3. Historical astronomy and Galileo’s evidence: Jupiter’s moons and Venus’ phases proving heliocentric model, Moon surface irregularities supporting non-divine celestial objects, modern telescope enhancements in aperture and focal length improving resolution

4. Exoplanet detection and transit method: light curve dips indicating planetary transits, estimation of planet diameter using orbital velocity and transit time, identification of habitable conditions based on temperature and position in star system

5. Lunar exploration and missions: Luna 3 imaging of Moon’s far side, Apollo 11 mission energy comparison for Earth vs. Moon launch, landing trajectory explanation, Moon research on geology and surface conditions

6. Jupiter’s properties and its moons: low density despite large volume, Great Red Spot characteristics and delayed observation due to technological limits, Europa’s eclipse shadow, evidence of Jupiter’s orbital migration