Describe one factor that can make relative dating difficult

This word for a bug or malfunction was popularized in the 1962 book into orbit by the mercury astronauts

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted

Explain how earths tilt and revolution around the sun affects weather and climate