Answers

ConceptChecks

ConceptCheck 6-1: No. Venus is perpetually shrouded in a thick layer of clouds and because visible light does not penetrate the clouds, no light escapes for us to observe from Earth.

ConceptCheck 6-2: All large impactors, regardless of shape or angle of impact, will carve out a nearly circular crater with a tall central peak in the middle due to the shock wave created. Earth’s thin atmosphere will not protect the surface from large impacts.

ConceptCheck 6-3: The line on the graph would not be horizontal, but instead be sloped upward, showing that more and more impacts have occurred over the duration of the Moon’s existence.

ConceptCheck 6-4: Because surfaces that are covered with impact craters have not been smoothed over by lava flows, we would infer that a hypothetical Caloris Basin covered in craters would be very old.

ConceptCheck 6-5: Without wind from a moving atmosphere and without resurfacing from tectonics, those tire tracks will remain until they are obliterated into a crater by an impact.

ConceptCheck 6-6: Mountain chains form where rigid plates collide, and the absence of these features suggests that Venus is a single-plate planet.

ConceptCheck 6-7: When overly thick plates collide, it is nearly impossible for one plate to be subducted beneath another plate, making it impossible for subduction zones and their accompanying mountain chains to form.

ConceptCheck 6-8: The oldest lava flows have craters from ancient impacts that have distorted their appearance, whereas the youngest lava flows are mostly crater free.

ConceptCheck 6-9: Lava flowing from extremely active volcanoes smooths over and covers any craters almost immediately.

ConceptCheck 6-10: The “runaway” term refers to the fact that an increase in temperature causes changes in the atmosphere, which causes the temperature to rise even higher and higher.

ConceptCheck 6-11: The temperature on Mars might be increased through the greenhouse effect if CO2 could be successfully added to the atmosphere.

ConceptCheck 6-12: Instead of freezing, the water would quickly evaporate into the atmosphere, due to the low atmospheric pressure on Mars.

ConceptCheck 6-13: Rapidly moving water will pick up and move rocks to a flood plain far from where they originated, resulting in a location with highly varying rock types.

ConceptCheck 6-14: Some deposits of frozen water could be shielded from sunlight along darkly shadowed crater walls that never glimpse sunlight.

ConceptCheck 6-15: The seemingly solid, but slushy, ice covering Europa flows like “ice rafts,” disrupting the continuous lines formed by the ridges.

ConceptCheck 6-16: The squeezing and flexing of Europa as it moves around Jupiter causes friction-releasing energy in the form of heat, keeping water there from permanently freezing.