Answer to Question 1
Uranus never grew massive enough to capture large amounts of gas from the solar nebula as Jupiter and Saturn did, so it has much less hydrogen and helium. Its internal pressure is enough lower than Jupiter's that it should not contain any liquid metallic hydrogen. Models of Uranus based in part on its density and oblateness suggest that it has a small core of heavy elements and a deep mantle of partly solid water. Although referred to as ice, this material would not be anything like ice on Earth, given the temperatures and pressures inside Uranus. The mantle also contains rocky-composition material and dissolved ammonia and methane. Circulation in this electrically conducting mantle may generate the planet's peculiar magnetic field, which is highly inclined to its axis of rotation. Above this mantle lies a deep hydrogen and helium atmosphere.
Answer to Question 2
Models indicate that the interior of Jupiter is mostly liquid hydrogen. Under very high pressure, liquid hydrogen becomes liquid metallic hydrogen-a material that is a very good conductor of electricity. Most of Jupiter's interior is composed of this material. That large mass of conducting liquid, stirred by convection currents and spun by the planet's rapid rotation, drives the dynamo effect and generates a powerful magnetic field. Jupiter's field is more than 10 times stronger than Earth's. A planet's magnetic field deflects the solar wind and dominates a volume of space around the planet called the magnetosphere.
The same star field photographed with (a) a ground-based telescope, which is subject to poor seeing
A Snapshot of the Sun’s Global Magnetic Field
The Number of Children Americans Think Are Ideal
What are examples of ideal forms?
Under ideal conditions, a single cell of the bacterium E. coli would divide every 20 minutes to ...
Survivorship curves. Blue lines are theoretical curves. Red dots are data from field studies.