General Science: Earth and Space Flashcards

What is the primary cause of ocean tides on Earth?

Answer: The gravitational pull of the Moon and, to a lesser extent, the Sun

Ocean tides are caused primarily by the Moon's gravitational pull on Earth's water. The Sun also contributes, though with about half the Moon's tidal force due to its much greater distance despite its larger mass.

What process in the water cycle involves water vapor changing directly into ice without becoming liquid first?

Answer: Deposition

Deposition is the phase change from gas (water vapor) directly to solid (ice) without passing through the liquid phase. Frost forming on surfaces on cold mornings is a common example of deposition.

Which planet in our solar system has the Great Red Spot, a massive storm system?

Answer: Jupiter

Jupiter's Great Red Spot is an enormous anticyclonic storm that has been observed for over 350 years. It is large enough to contain two or three Earths and features wind speeds up to 400 mph.

What is the Mohorovicic discontinuity (Moho)?

Answer: The boundary between the crust and the mantle

The Moho is the boundary between Earth's crust and mantle, identified by a sharp change in seismic wave velocities. It was discovered by Croatian seismologist Andrija Mohorovicic in 1909.

What type of galaxy is the Milky Way?

Answer: Barred spiral galaxy

The Milky Way is classified as a barred spiral galaxy (type SBbc). It has a central bar-shaped structure of stars from which spiral arms extend outward in a pinwheel pattern.

What causes an earthquake?

Answer: Sudden release of energy from the movement of tectonic plates along faults

Earthquakes occur when stress accumulated along geological faults is suddenly released as tectonic plates move past, over, or away from each other. The released energy travels as seismic waves through Earth.