Answer to Question 1
You could visit two kinds of terrain on the Moon. The dark gray areas visible from Earth are the smooth lunar lowlands which astronomers named maria, drawing on the Latin word for seas. You could also visit the lighter-colored mountainous lunar highlands. The Moon looks quite bright in the night sky seen from Earth. In fact, the albedo of the near side of the Moon is only 0.12, meaning it reflects only 12 percent of the light that hits it. The Moon looks bright only in contrast to the night sky. In reality, it is a dark gray world.
Answer to Question 2
Many features on Venus testify to its volcanic history. Long, narrow lava channels meander for thousands of kilometers. Radar maps reveal many volcanoes, faults, and sunken regions produced when magma below the surface drained away. Other volcanic features include the coronae, circular bulges up to 2600 km (1600 mi) in diameter bordered by fractures, volcanoes, and lava flows. These appear to be produced by rising convection currents of molten magma that push up under the crust. When the magma withdraws, the crust sinks back, and the circular fractures mark the edge of the original upwelling.
The Interiors of Earth and Mercury
Orbital Motion of Earth and Other Planets
Earth’s Climate System
The Last Man on Earth
Example of an antibody-mediated immune response.
Hypersensitive Response