Neptune is the eighth planet from the Sun and the fourth largest
(by diameter). Neptune is smaller in diameter but larger in mass than Uranus. Its color is blue
and it has Neptune has 13 known moons; 7 small named ones and Triton plus four discovered in 2002
and one
discovered in 2003
orbit: 4,504,000,000 km (30.06 AU)
from Sun
diameter:
49,532 km (equatorial)
mass: 1.0247e26 kg
Neptune's Satellites
Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
--------- -------- ------ ------- ---------- -----
Naiad 48 29 ? Voyager 2 1989
Thalassa 50 40 ? Voyager 2 1989
Despina 53 74 ? Voyager 2 1989
Galatea 62 79 ? Voyager 2 1989
Larissa 74 96 ? Voyager 2 1989
Proteus 118 209 ? Voyager 2 1989
Triton 355 1350 2.14e22 Lassell 1846
Nereid 5509 170 ? Kuiper 1949
Halimede 15728 61 ? 2002
Sao 22422 40 ? 2002
Laomedeia 23571 40 ? 2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Read more about Neptune l Neptune facts, pictures and information. by nineplanets.org Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
--------- -------- ------ ------- ---------- -----
Naiad 48 29 ? Voyager 2 1989
Thalassa 50 40 ? Voyager 2 1989
Despina 53 74 ? Voyager 2 1989
Galatea 62 79 ? Voyager 2 1989
Larissa 74 96 ? Voyager 2 1989
Proteus 118 209 ? Voyager 2 1989
Triton 355 1350 2.14e22 Lassell 1846
Nereid 5509 170 ? Kuiper 1949
Halimede 15728 61 ? 2002
Sao 22422 40 ? 2002
Laomedeia 23571 40 ? 2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
--------- -------- ------ ------- ---------- -----
Naiad 48 29 ? Voyager 2 1989
Thalassa 50 40 ? Voyager 2 1989
Despina 53 74 ? Voyager 2 1989
Galatea 62 79 ? Voyager 2 1989
Larissa 74 96 ? Voyager 2 1989
Proteus 118 209 ? Voyager 2 1989
Triton 355 1350 2.14e22 Lassell 1846
Nereid 5509 170 ? Kuiper 1949
Halimede 15728 61 ? 2002
Sao 22422 40 ? 2002
Laomedeia 23571 40 ? 2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Read more about Neptune l Neptune facts, pictures and information. by nineplanets.org Distance Radius Mass Satellite (000 km) (km) (kg) Discoverer Date --------- -------- ------ ------- ---------- ----- Naiad 48 29 ? Voyager 2 1989 Thalassa 50 40 ? Voyager 2 1989 Despina 53 74 ? Voyager 2 1989 Galatea 62 79 ? Voyager 2 1989 Larissa 74 96 ? Voyager 2 1989 Proteus 118 209 ? Voyager 2 1989 Triton 355 1350 2.14e22 Lassell 1846 Nereid 5509 170 ? Kuiper 1949 Halimede 15728 61 ? 2002 Sao 22422 40 ? 2002 Laomedeia 23571 40 ? 2002 Psamathe 46695 38 ? 2003 Neso 48387 60 ? 2002
Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
--------- -------- ------ ------- ---------- -----
Naiad 48 29 ? Voyager 2 1989
Thalassa 50 40 ? Voyager 2 1989
Despina 53 74 ? Voyager 2 1989
Galatea 62 79 ? Voyager 2 1989
Larissa 74 96 ? Voyager 2 1989
Proteus 118 209 ? Voyager 2 1989
Triton 355 1350 2.14e22 Lassell 1846
Nereid 5509 170 ? Kuiper 1949
Halimede 15728 61 ? 2002
Sao 22422 40 ? 2002
Laomedeia 23571 40 ? 2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
--------- -------- ------ ------- ---------- -----
Naiad 48 29 ? Voyager 2 1989
Thalassa 50 40 ? Voyager 2 1989
Despina 53 74 ? Voyager 2 1989
Galatea 62 79 ? Voyager 2 1989
Larissa 74 96 ? Voyager 2 1989
Proteus 118 209 ? Voyager 2 1989
Triton 355 1350 2.14e22 Lassell 1846
Nereid 5509 170 ? Kuiper 1949
Halimede 15728 61 ? 2002
Sao 22422 40 ? 2002
Laomedeia 23571 40 ? 2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Distance Radius Mass
Satellite (000 km) (km) (kg) Discoverer Date
Halimede 15728 61 ?
2002
Sao 22422
40 ? 2002
Laomedeia 23571 40 ?
2002
Psamathe 46695 38 ? 2003
Neso 48387 60 ? 2002
Distance Width
Ring (km)
(km) aka
Diffuse 41900
15 1989N3R, Galle
Inner 53200 15
1989N2R, LeVerrier
Plateau 53200
5800 1989N4R, Lassell,
Arago
Main 62930
< 50 1989N1R, Adams
(distance
is from Neptune's center to the ring's inner edge)
Neptune is one of the most unique planets in the solar system that is why it is one of my favorite planets.
A
new article in the journal Nature Physics says that there could be oceans of
liquid diamonds with floating diamond icebergs on Neptune and Uranus.
The
research, based on the first detailed measurements of the melting point of
diamond, found diamond behaves like water during freezing and melting, with
solid forms floating atop liquid forms. The surprising revelation gives
scientists a new understanding about diamonds and some of the most distant
planets in our solar system.
“Diamond
is a relatively common material on Earth, but its melting point has never been
measured,” said Eggert. “You can’t just raise the temperature and have it melt,
you have to also go to high pressures, which makes it very difficult to measure
the temperature.”
Other
groups, notably scientists from Sandia National Laboratories, successfully
melted diamond years ago, but they were unable to measure the pressure and
temperature at which the diamond melted.
Diamond
is an incredibly hard material. That alone makes it difficult to melt. But
diamond has another quality that makes it even harder to measure its melting
point. Diamond doesn’t like to stay diamond when it gets hot. When diamond is
heated to extreme temperatures it physically changes, from diamond to graphite.
The
graphite, and not the diamond, then melts into a liquid. The trick for the
scientists was to heat the diamond up while simultaneously stopping it from
transforming into graphite.
Eggert
and his colleagues took a small, natural, clear diamond, about a tenth of a
carat by weight and half a millimeter thick, and blasted it with lasers at
ultrahigh pressures like those found on gas giants like Neptune and Uranus.
The
scientists liquefied the diamond at pressures 40 million times greater than
what a person feels when standing at sea level on Earth. From there they slowly
reduced the temperature and pressure.
When
the pressure dropped to about 11 million times the atmospheric pressure at sea
level on Earth and the temperature dropped to about 50,000 degrees, solid
chunks of diamond began to appear. The pressure kept dropping, but the
temperature of the diamond remained the same, with more and more chunks of
diamond forming.
Then
the diamond did something unexpected. The chunks of diamond didn’t sink. They
floated. Microscopic diamond ice burgs floated in a tiny sea of liquid diamond.
The diamond was behaving like water.
After
the discovery of Uranus, it was noticed that its orbit was not as it should be
in accordance with Newton's
laws. It was
therefore predicted that another more distant planet must be perturbing Uranus' orbit.
Neptune was first observed by Galle
and d'Arrest on 1846 Sept 23
very near to the locations independently predicted by Adams and Le Verrier from
calculations based on the observed positions of Jupiter, Saturn and Uranus. An international
dispute arose between the English and French (though not, apparently between
Adams and Le Verrier personally) over priority and the right to name the new
planet; they are now jointly credited with Neptune's discovery. Subsequent
observations have shown that the orbits calculated by Adams and Le Verrier
diverge from Neptune's actual orbit fairly quickly. Had the search for the
planet taken place a few years earlier or later it would not have been found
anywhere near the predicted location.
More
than two centuries earlier, in 1613, Galileo observed Neptune
when it happened to be very near Jupiter, but he thought it was just a star. On
two successive nights he actually noticed that it moved slightly with respect
to another nearby star. But on the subsequent nights it was out of his field of
view. Had he seen it on the previous few nights Neptune's motion would have
been obvious to him. But, alas, cloudy skies prevented obsevations on those few
critical days.
Neptune
has been visited by only one spacecraft, Voyager 2 on Aug 25 1989.
Much of we know about Neptune comes from this single encounter. But
fortunately, recent ground-based and HST observations have
added a great deal, too.
Because
Pluto's orbit is so
eccentric, it sometimes crosses the orbit
of Neptune making Neptune the most distant planet from the Sun for a few years.
Neptune's
composition is probably similar to Uranus': various "ices" and rock with
about 15% hydrogen and a little helium. Like Uranus, but unlike Jupiter and
Saturn, it may not have a distinct internal layering but rather to be more or
less uniform in composition. But there is most likely a small core (about the
mass of the Earth) of rocky material. Its atmosphere is mostly hydrogen and
helium with a small amount of methane.
Neptune's
blue color is largely the result of absorption of red light by methane in the
atmosphere but there is some additional as-yet-unidentified chromophore which
gives the clouds their rich blue tint.
Like a typical gas planet, Neptune has
rapid winds confined to bands of latitude and large storms or vortices.
Neptune's winds are the fastest in the solar system, reaching 2000 km/hour.
Like Jupiter and
Saturn, Neptune has an internal heat source -- it radiates more than twice as
much energy as it receives from the Sun.
At
the time of the Voyager encounter, Neptune's most prominent feature
was the Great Dark Spot (left) in the southern hemisphere.
It was about half the size as Jupiter's Great Red Spot (about the
same diameter as Earth).
Neptune's winds blew the Great Dark Spot westward at 300 meters/second (700
mph). Voyager 2
also saw a smaller dark spot in the southern hemisphere and a small irregular
white cloud that zips around Neptune every 16 hours or so now known as
"The Scooter" (right). It may be a plume rising from lower in the
atmosphere but its true nature remains a mystery.
However,
HST
observations of Neptune
(left) in 1994 show that the Great Dark Spot has disappeared! It has either
simply dissipated or is currently being masked by other aspects of the
atmosphere. A few months later HST discovered a new dark spot in Neptune's
northern hemisphere. This indicates that Neptune's atmosphere changes rapidly,
perhaps due to slight changes in the temperature differences between the tops
and bottoms of the clouds.
Neptune
also has rings. Earth-based observations showed only faint arcs instead
of complete rings, but Voyager 2's
images showed them to be complete rings with bright clumps. One of the rings
appears to have a curious twisted structure (right).
Like Uranus and Jupiter, Neptune's rings are very dark but their composition is unknown.
Neptune's
rings have been given names: the outermost is Adams (which contains three
prominent arcs now named Liberty, Equality and Fraternity), next is an unnamed
ring co-orbital with Galatea,
then Leverrier (whose outer extensions are called Lassell and Arago), and
finally the faint but broad Galle.
Neptune's
magnetic field is, like Uranus', oddly oriented and probably generated by
motions of conductive material (probably water) in its middle layers.
Neptune can be seen with
binoculars (if you know exactly where to look) but a large telescope is needed
to see anything other than a tiny disk. There are several Web sites
that show the current position of Neptune (and the other planets) in the sky,
but much more detailed charts will be required to actually find it. Such charts
can be created with a planetarium
program.
NEPTUNE ROCKS MY BLUE WORLD..!!! <3