Suppose we discover a super-Earth at a distance of 10AU from its star. Should we consider it to be potentially habitable?
A) Yes, its atmosphere may contain substantial amounts of greenhouse-type gases that can keep the planet warm beyond the usual boundaries assumed for habitable zones.
B) Yes, because its host star must be much bigger in order to have a super-Earth, so it will be much hotter there.
C) No, only planets at approximately 1AU will ever be potentially habitable.
D) No, greenhouse gases freeze-out at those distances.
Question 2
Collisions between galaxies is thought to
A) have stopped about 5 billion years ago.
B) be commonplace.
C) have never occurred.
D) be extremely rare.
E) have only occurred between 10 and 15 billion years ago.
The Sun as it appears from the surface of Earth before sunset.
Earth as viewed from Lunar orbit during the Apollo 8 mission, Christmas Eve, 1968. Africa is at the
A Rotating, Magnetized Neutron Star
Earth-Sun Relationships
Astronaut Rachel leaves Earth in a spaceship at a speed of 0.960c relative to an observer on ...
Gravitational Potential Energy for the Earth problem