Exam Flashcards
What did Hermann Von helholtz and lord kelvin propose was the source of the Suns energy in the mid-19th century?
Gravitational contraction
What is the lowest level of the earths atmosphere called?
Troposphere
What theory prompted scientists to consider that mass can be converted to energy and vice versa, and that this process could be the source of the Suns energy?
Theory of relativity
What did Hans bethe’s theory propose is the primary source of the suns energy?
Nuclear fusion
Where in the sun are the temperature and density of hydrogen great enough to support fusion?
Center
What is ursa major an example of?
Constellation
Approximately how many days does the sun take to revolve around the celestial sphere?
365.25
What happens when the moon is between the earth and the sun?
The moon appears as the palest silver of moonlight.
What force on the sun balances the force of gravity?
Forces tending to expand the gas.
️What has strengthened nations that encouraged exploration.
Development if new technologies
How did individuals who did not actually explore benefit from the exploration by others?
Larger understanding of their world.
What problem eventually led to the invention of the portable watch and the marine clock?
Sailor’s problem of latitude.
What type of spacecraft is the new Orion?
Crew exploration vehicle.
What can you reasonably guess if you know the density of a celestial object?
Composition of the object.
What do scientists think the core of the earth is made up of, primarily?
Iron and nickel.
