Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus?
A) that it once had a much stronger magnetic field than it does today
B) that the greenhouse effect on Venus must have been much weaker in the distant past
C) that it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space
D) that volcanoes on Venus did not outgas as much water as volcanoes on Earth
Question 2
What would happen to Earth if we somehow moved our planet to the orbit of Venus?
A) Temperatures would rise only slightly, but enough to melt the polar caps.
B) The fact that we have oceans would moderate the temperature change due to moving our planet, so temperature would hardly change at all.
C) Being so much closer to the Sun would almost immediately cause the surface of Earth to melt, and all our cities would then be destroyed by the hot lava.
D) Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.
The Sun as it appears from the surface of Earth before sunset.
Atmosphere of Venus in UV, by Pioneer Venus Orbiter in 1979
The Sun as it appears from the surface of the Earth at Sunset.
Earth, water, air
Earth’s orientation
Earth’s Oldest Preserved Rocks – 3.8 Billion Years Old, Greenland