The solar radius is the distance between the core and the outer edge of a star. Betelgeuse, Rigel, and Polaris all have large solar radii. Sirius B, Epsilon
Eridani and Barnard's Star all have small solar radii? What is the relationship
between the solar radius and the brightness of stars?

How much energy moves onto the next level, in an energy pyramid

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?