Twenty Questions on Neptune Trivia Quiz

Answer: True

While all the gas giants have fast moving winds, Neptune's winds are the fastest at around 1,000 miles per hour.

Answer: 49,500 kilometers

Neptune is the smallest of the gas giants and the farthest gas giant from the Sun.

Answer: 17 times the Earth's mass

Although Uranus is larger, Neptune's mass is greater than Uranus.

Answer: Yes

Because Pluto's orbit is so eccentric, Pluto crosses over Neptune's orbit to make Neptune the farthest known planet in the Solar System. This happened between the years 1979 - 1999.

Answer: 16.1 hours

Jupiter rotates in 9.8 hours, Saturn at 10.2 hours and Uranus in 17.9 hours.

Answer: 1846

Neptune was discovered on September 23, 1846.

Answer: False

Neptune's orbit takes 165 years, so its first completed orbit since its discovery was in 2010. It won't complete another until 2175.

Answer: Triton

Triton is an interesting satellite. It's orbit is retrograde around Neptune and it has a tenuous atmosphere. Triton must have formed elsewhere in the Solar System and then been "captured" by Neptune. Eventually, Triton will either break up or crash into Neptune since its orbit is being lowered by tidal interactions with Neptune.

Answer: True

Neptune's heat source radiates about twice as much energy as it receives from the Sun.

Answer: Poseidon

Poseidon, the god of the sea. An interesting fact about Neptune, when Voyager 2 visited the gas giant in 1989 there was a Great Dark Spot, one Earth diameter wide. Observations by the Hubble Space Telescope taken in 1994 show that the Great Dark Spot has disappeared! It has either dissipated or is being covered by some other process taking place in Neptune's atmosphere.

Answer: Nereid

Nereid was discovered in 1949 by Gerard Kuiper (who also discovered the atmosphere of Saturn) and Nereid is about 340 kilometers in diameter. Proteus, Larissa and Naiad were all discovered by Voyager 2 and are all less than 400 kilometers in diameter. Proteus is actually larger than Nereid but it orbits a lot closer to Neptune, only 188 kilometers from Neptune. Nereid orbits about 5,500 kilometers from Neptune.

Answer: 2,700 kilometers in diameter

Triton was discovered by Lassell in 1846 only a few weeks after Neptune was discovered.

Answer: Blue

Like Uranus, the blue color comes from the absorption of red light by methane in the atmosphere of Neptune.

Answer: 1989

Twelve years and almost three billion miles after it was launched. Voyager 2 encountered Neptune on August 25, 1989.

Answer: Triton

Triton is the only large satellite in the Solar System with a retrograde orbit around its planet. This suggests that Triton formed elsewhere in the Solar System and was later captured by Neptune.

Answer: Six

They are Naiad, Thalassa, Despoina, Galatea, Larissa and Proteus and all of them orbit Neptune inside of Triton.

Answer: False

Triton does have a very tenuous atmosphere of nitrogen-methane with a surface pressure of fourteen microbars, about 1/70,000 that of Earth.

Answer: John Couch Adams and Urbain J. J. Leverrier

Both had independently calculated where Neptune should be. Leverrier sent his results to Johann Galle, a German observer, who discovered Neptune the next day. Adams had actually sent his results several years earlier to Sir George Airy who did not bother to search since he didn't have any confidence in Adams' work. History has decided that both men get credit.

Answer: True

Although Neptune is just slightly smaller than Uranus, it is much farther away. Neptune is 8th magnitude in brightness and far below naked eye visibility.

Answer: .3 times the Earth's Moon

Triton's density is slightly greater than some of Saturn's icy moons.