Today we’re rounding out our planetary tour with ice giants Uranus and Neptune. Both have small rocky cores, thick mantles of ammonia, water, and methane, and atmospheres that make them look greenish and blue. Uranus has a truly weird rotation and relatively dull weather, while Neptune has clouds and storms whipped by tremendous winds. Both have rings and moons, with Neptune’s Triton probably being a captured iceball that has active geology.
We begin our story about 13.7 billion years ago, when all the space, matter, and energy of the known Universe was locked up in a volume less than one trillionth of the size of the point of a pen.
Right now, we know there is water on the Moon. But how much water? Is water largely at the poles? These are Strategic Knowledge Gaps that scientists are working to fill in, and a Resource Prospector robot will be launched to the moon in the 2020's to look for the presence of water
New discoveries have revealed thousands of exoplanets beyond the solar system. Some resemble earth enough that one could be a new home for humanity. Even with cutting-edge technology, finding the perfect one is the scientific challenge of the age.