Galileo first observed Neptune but mistook it for a star. In 1846, Galle and d'Arrest localized Neptune and it was initially called the planet exterior to Uranus. Friedrich von Struve later suggested the name Neptune. Neptune has a solid core and layers of ice, ammonia and water surrounding it. Its atmosphere contains hydrogen, helium and methane with wind speeds up to 2000 km/h. Voyager 2 was the only spacecraft to visit Neptune in 1989 and made discoveries about its magnetic field, weather and 13 moons including Triton.
3. Discovery
Neptune was discovered by Galileo Galilei, but he
thought that Neptune was a star.
Neptune was localized by Galle and d’Arrest in 1846.
Then, many people given the discovery to Galle.
4. Naming
First, a few years after Galileo founded Neptune, this
one was called “the planet exterior to Uranus”.
After that, Galle and Challis suggested the names of
Janus and Oceanus, respectively.
Then Friedrich von Struve suggested the actual name
in honour of the roman god of the sea, in 1846.
6. Internal structure
The internal structure of Neptune not differ greatly
from that of Uranus. Neptune have a solid core mass
similar to that of the earth, comprising a mixture of ice
and various silicates, surrounded by a layer rich in
methane and ammonia water to which overlaps an
atmosphere comprising hydrogen, helium and
methane.
7. Atmosphere
The atmosphere of Neptune is buffeted by strong
winds that are known and could reach 2000 km / h.
Like the other gas giants, the winds are usually
confined to well-defined bands between latitudes.
They also are huge storms (vortices) located, similar to
Jupiter's Great Red Spot.
8. Space Missions
Neptune was visited only once and it was by
NASA’s spacecraft Voyager 2, on August 25, 1989.
The spacecraft verified the existence of a magnetic
field surrounding the planet and discovered that
the field was offset from the centre and tilted in a
manner similar to the field around Uranus. The
question of the planet's rotation period was settled
using measurements of radio emissions. Voyager 2
also showed that Neptune had a surprisingly active
weather system. Six new moons were discovered,
and the planet was shown to have more than one
ring.
10. Moons of Neptune
Neptune has 13 moons around him. The names of the
firsts 7 names of the Neptune’s naturals satellites are:
Naiad;
Thalassa;
Despina;
Galatea;
Larissa;
Proteus;
Triton, the biggest one.