Dark matter is ___.
a. a cloud of black holes and brown dwarfs in the galactic halo
b. extremely cold, supermassive molecular clouds in the disk
c. an unknown type of mass that does not emit or absorb photons
d. the substance of which black holes are made
e. a theory to explain galactic formation that has been proven wrong
Question 2
The circular velocity of a satellite orbiting Earth is given by . In this equation, M represents the ____.
a. mass of the satellite, and r its radius
b. mass of the satellite, and r the distance from Earth to the satellite
c. mass of the satellite, and r the distance from Earth's surface to the satellite
d. mass of Earth, and r the radius of Earth
e. mass of Earth, and r is the distance from Earth to the satellite
Brown hyena cub
Mapping Dark Matter
The basal ganglia are clusters of gray matter that control learned movement and are involved with ...