I need 6 FACTS about THE SPIRAL GALAXY

 1)Spiral galaxies are a class of galaxies originally described by astronomer Edwin Hubble in his 1936 work The Realm of the Nebulae.

2) They are part of the Hubble sequence a morphological classification scheme for galaxies.

3) Spiral galaxies usually consist of a rotating disk that contains stars, dust, gas, and a concentration of stars known as the bulge in the center.

4) These bulges are often surrounded by a faint halo of stars, many of which reside in globular clusters – a spherical collection of stars that orbits a galactic core.

5) As such, Spiral galaxies are named after their spiral structures that extend from the center into a galactic disk.

6) They have spiral arms – sites of ongoing star formation that are brighter than the surrounding disk due to the presence of young OB stars that inhabit them.

Explanation:

they have identical fossils of organisms that have evolved over time.

both have animal fossils preserved in them due to weathering and erosion.

they contain different fossils because life on earth has changed through time.

the fossils in them were formed on the surface of earth due to exposure to sunlight.