Hobbies And Interests
Planetary Phases
When Galileo first observed the phases of Venus, he used his discovery to confirm the rotation of the planets around the sun. Like Venus, Mercury also goes through phases, waxing and waning as it moves through its orbit. Mars is the only outer planet that shows slight phase variations. The other outer planets, including Neptune, never show significant phases when viewed from Earth.
Neptune's Discovery
In 1846 French astronomers confirmed Neptune's existence, which had been suspected for decades. Neptune was first located with the guidance of mathematical predictions and was the first planet to be discovered in this way. After Uranus was discovered in 1781, astronomers observed irregularities in its orbit and hypothesized that the gravitational pull of an unknown planet could be responsible. However, these suspicions were unconfirmed until a French mathematician named Urbain Jean Joseph Le Verrier caught the attention of astronomers with his calculations, leading to the planet's discovery.
Neptune and Voyager 2
Voyager 2 was the first -- and so far the only -- spacecraft to reach Neptune, and during its 12-year journey across the solar system, it gathered much of the information astronomers currently have about the planet. Because Voyager 2 was able to view the planet at different angles than can be observed from Earth, its cameras were able to capture Neptune in different phases, from crescent to full.
Observing Neptune
Like Uranus, Neptune appears blue in color because of the methane in its atmosphere. Neptune's environment is tumultuous, with higher wind speeds than any other planet, clocking in at 1,500 miles per hour. A large circular storm known as the Great Dark Spot, similar to Jupiter's Great Red Spot, moves westward at roughly 745 miles per hour across Neptune. Several dark rings surround Neptune, and eight moons orbit the planet.