Final answer:
Neptune is the smallest of the four gas giants and is considered the fourth largest planet in our solar system. It has a deep blue atmosphere and is significantly larger than Earth.
Step-by-step explanation:
The smallest of the four gas giants in our solar system is Neptune. Among Jupiter, Saturn, Uranus, and Neptune, it is Neptune that is the fourth largest in terms of size and mass. The gas giants are made primarily of lighter elements such as hydrogen and helium, and they do not have solid surfaces. Saturn comes after Jupiter in terms of mass but still has only approximately 25% of Jupiter's mass, while Uranus and Neptune both have only about 5%. All four gas giants rotate quickly and have deep atmospheres with massive magnetic fields, particularly Jupiter which has the strongest of any planet. Neptune, despite being the smallest of the giants, is still significantly larger than Earth and is characterized by a deep blue atmosphere due to the presence of methane ice clouds