Questions tagged [neptune]

Questions regarding Neptune, the 8th and furthest major planet orbiting Earth's sun.

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When was the last time a total solar eclipse on Neptune courtesy of Triton occured, and when will be the next?

If Triton had an equatorial orbit, then solar eclipses would occur around the Neptunian equinox - same as with Saturn and Uranus. But Triton's orbit is infamously inclined to Neptune's equator, so ...
user267545's user avatar
2 votes
0 answers
53 views

what is the pressure in Neptune where the density reach 1g/cm^3?

from this graph, it looks like it should be around 20000km from the center. So it is about 0.8 radius. However, I cannot imagine this is correct. The pressure is probably only a few bar at that height....
Wang's user avatar
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3 votes
1 answer
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How accurate is the Sudarsky Scale today?

How accurate is the Sudarsky scale of gas-giant classification today? Do the different classes still exist, and look roughly the same?
Kazon's user avatar
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0 votes
1 answer
111 views

How close to Neptune would I have to be to see it with the naked eye?

I am in space. What is the maximum distance that I could be from Neptune and see it with the naked eye. You can choose the optimal position. Also, assume that I have 20/20 vision.
Starship - On Strike's user avatar
4 votes
1 answer
213 views

How do I know that I’ve found Neptune?

So, recently I went out for a look at Neptune with my telescope and I found the general area of where Neptune was. However, when I took a see for myself, there were a ton of blue stars everywhere and ...
Prince Pugs's user avatar
8 votes
1 answer
226 views

What are those blobs in each of the two bright rings of Neptune shown in the new JWST image?

What is this bright blue object taken by the Webb telescope? includes the new JWST infrared image of Neptune and Triton. The disk of Neptune shows interesting features but I'm drawn to Neptunes's ...
uhoh's user avatar
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8 votes
1 answer
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What is this bright blue object taken by the Webb telescope?

From NASA - New Webb Image captures clearest view of Neptune's rings in decades: Does anyone know what the bright blue on the left top corner of the picture is? It is a reflection of sorts or is it a ...
DialFrost's user avatar
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2 votes
1 answer
247 views

Dates of Passage of Neptune at Aphelion and Perihelion

I'm working with a group of colleagues on a Solar System simulator. We need two items of data that are missing to us: the nearest dates of passage of Neptune at Aphelion and Perihelion.
LittleCoder's user avatar
8 votes
1 answer
998 views

How am I supposed to locate the planets Uranus and Neptune with a 70 mm f/5.7 refractor?

I can locate all of the planets other than Uranus and Neptune. This is mainly because they are very dim and I live where there is just enough light pollution so that I can't spot them. I have a Gysker ...
Oscar's user avatar
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23 votes
4 answers
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Why is Neptune a darker blue than Uranus?

If Neptune and Uranus have similar composition then why is Neptune a darker blue than Uranus?
sno's user avatar
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3 votes
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What was "wrong" about the motion of Neptune in 1984?

The cover story of the March 1984 issue of RUN, a popular computing magazine, was written by noted astronomer Charles T. Kowal. In the article, he describes how he uses his home computer, a Commodore ...
Psychonaut's user avatar
0 votes
1 answer
162 views

Will the planets be pushed outwards when the sun goes red giant?

When the sun goes red giant will the planets be pushed outwards towards the periphery of the solar system? If so, will this happen simultaneously to all planets or could, for example, a planet like ...
Constantthin's user avatar
13 votes
4 answers
4k views

Could Neptune be viewed with the naked eye from Uranus?

Which star or planet in our night sky can match what Neptune would look like when viewed from Uranus, or one of its moons? The answer would be for the most favourable condition, which is when Neptune ...
Constantthin's user avatar
2 votes
3 answers
170 views

Neptune's eccentricity stability

Will Neptune's orbital eccentricity remain lower than earth's forever? It currently is at around 0.008, compared to Earth's 0.0167.
איתי מרלוב's user avatar
3 votes
2 answers
245 views

Why doesn't Triton orbit over Neptune's equator?

In this answer, I wrote (on another account) why most moons orbit over their planet's equator. Any rotating planet has an equatorial bulge that shifts its moons' orbits around its equator over long ...
user177107's user avatar
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-1 votes
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What are the most efficient ways to terraform Neptune's moon Triton? [closed]

I have seen on various sites and on youtube videos pertaining to the terraform of various planets and moons that are not habitable for now but they can be habitable in near future. What are the ways ...
saurabh shukla's user avatar
1 vote
1 answer
102 views

App Stellarium and hourly wobbling motion of Neptune

In Stellarium when I zoom in on Neptune to be able to see your daily rotation. I select Neptune, center it (space bar) and then make increments of one solar hour (command +). I notice that the axis ...
Dante_Astroboy's user avatar
6 votes
1 answer
954 views

Why is the magnetic axis of Uranus and Neptune off center?

It(Uranus) rotates on its side, tilted almost 98 degrees from the plane of its orbit around the sun. The axis of its magnetic field is tilted too, at a 59-degree angle from the rotational axis. The ...
Nilay Ghosh's user avatar
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7 votes
1 answer
590 views

Why was Neptune rather than Uranus chosen as an archetype?

The largest exoplanets are typically called Jupiter-like planets, or hot/cold Jupiters. Since Jupiter is the largest most massive planet in our Solar system, it makes sense that it would be chosen as ...
usernumber's user avatar
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Neptune time of perihelion/ephemeris dates

Is there a data online for the time of perihelion of Neptune between 2000AD and 3000AD? I need values in Julian Date (JD). I tried using HORIZONS Web interface, but it won't generate ephemeris for ...
posfan12's user avatar
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35 votes
3 answers
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Can Pluto be seen with the naked eye from Neptune when Pluto and Neptune are closest?

When Neptune and Pluto are closest, about 100 million mi (160 million km) from each other, would an observer on Neptune (or rather on one of its moons, since Neptune is gaseous) be able to see Pluto, ...
Plutos Loyer's user avatar
2 votes
1 answer
235 views

Why are the moons of Neptune sorted by diameter?

The five moons closest to Neptune are sorted by increasing size. Naiad < Thalassa < Despina < Galatea < Larissa. The trend continues with Proteus and Triton, only interrupted by Hippocamp, ...
usernumber's user avatar
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2 votes
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Qualities of gas giant atmospheres at a density of 1 gram per cubic centimeter

At what depth in the atmospheres of the gas giants does the density of their atmospheres equal 1 gram per cubic centimeter? What is the pressure and temperature at these depths? Are the radiations ...
user141802's user avatar
3 votes
0 answers
98 views

Discovery papers for Uranus and Neptune

I would like to have the discovery papers, notices or announcements done by Herschel with Uranus and Le Verrier with Neptune. I know that Herschel adressed the Royal Society and Le Verrier sent some ...
Swike's user avatar
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10 votes
2 answers
474 views

How fast is Neptune getting brighter? When was was this first noticed and reported?

This answer to Compute Planet's Apparent Visual Magnitude reports the new work on planetary magnitudes, and contains an intriguing blurb about Neptune: Neptune keeps getting brighter. No one knows ...
uhoh's user avatar
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1 vote
1 answer
142 views

Will Triton have a thicker atmosphere as the Solar System ages?

With an average temperature of around 34 kelvin, Triton is extremely cold. Currently, it has a thin mostly nitrogen atmosphere with a pressure of around 1 Pa. However, its surface has large deposits ...
Daniel's user avatar
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1 vote
2 answers
483 views

Transit of Uranus from Neptune

I would like to help find sources or calculations for the following dates found in Wikipedia (in French). The next Uranus transit from Neptune will happen : ...
A BOUZINAC's user avatar
4 votes
1 answer
190 views

Composition of ice giants

After reading the paper "The Measured Compositions of Uranus and Neptune from their Formation on the CO Ice Line", I was left with doubts which I would like to clarify. Firstly, the paper proposes ...
URIZEN's user avatar
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0 answers
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What exactly is the relationship between the orbits of Neptune's moons Naiad and Thalassa?

Scitechdaily's Wild Orbits of Neptune Moons a ‘Dance of Avoidance’ [Video] links to the YouTube video Neptune Moon Dance (Naiad and Thalassa) and says: In this perpetual choreography, Naiad swirls ...
uhoh's user avatar
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0 votes
1 answer
2k views

Neptune's Internal Heat Source

Unlike its sister planet Uranus,Neptune has a substantial internal heat source which gives rise to a dynamic atmosphere & weather. Wikipedia says: As with Uranus, the source of this heating ...
Michael Walsby's user avatar
4 votes
1 answer
184 views

What constraints are there on solid material in the ice giants?

Recently there has been experimental verification of superionic water ice (suggested to be called ice XVIII, not sure if this nomenclature is official yet), which turns out to be a solid (or at ...
user avatar
5 votes
2 answers
325 views

Diamonds in Neptune?

In this publication from 1981, was shown that Neptune is raining diamonds: Many of the current models of Uranus and Neptune postulate a three-layer structure, consisting of an inner rocky core, a ...
roblox prisonlife's user avatar
2 votes
1 answer
226 views

Why do these Hubble images of Neptune look like Cheela?

The open access paper Formation of a New Great Dark Spot on Neptune in 2018 (cited in Gizmodo's Formation of Dark Vortex on Neptune Captured For the Very First Time and Phys.org's Hubble captures ...
uhoh's user avatar
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2 votes
1 answer
117 views

Could there be additional Neptunian satellites between Larissa and Hippocamp?

Plotting the moons of Neptune in terms of semimajor axis and eccentricity using the values given on the Wikipedia page for the moons of Neptune, there appears to be a fairly large gap between the ...
user avatar
4 votes
0 answers
140 views

Do tides occur on planets like Neptune, having water? [duplicate]

I mean, we experience tides here on earth because of combined effect of gravitational field of moon and sun. So I thought that tides could also occur on other planets. Let us consider Neptune where ...
Gamira's user avatar
  • 209
6 votes
4 answers
1k views

Do tides occur on planets like Neptune, having water?

I mean, we experience tides here on earth because of combined effect of gravitational field of moon and sun. So I thought that tides could also occur on other planets. Let us consider Neptune where ...
Gamira's user avatar
  • 209
10 votes
1 answer
237 views

Does the orbital decay of Triton affect Neptune's rotation?

Just a quick question regarding Neptune. Because Phobos is spiraling in towards Mars, Mars' rotation speeds up. Does the same thing happen with Neptune's rotation?
StellarExile's user avatar
5 votes
1 answer
329 views

Aren't there any rock or similar firm material on/in the gas giant planets?

Aren't there any rock or similar firm material on/in the gas giant planets? What happens if a rock asteroid hits one of these planets? Shouldn't the rock accumulate in the center of the planet due to ...
d-b's user avatar
  • 349
8 votes
1 answer
526 views

Why is Neptune true anomaly decreasing?

So I've been having fun with trying to determine where the perihelia of different planets are (using JPL Horizons). And by the time I got to Saturn, something weird started happening. I've noticed ...
Eugene B.'s user avatar
  • 158
5 votes
1 answer
856 views

Explanation of resonance stability and instability

I'm having some trouble grasping the idea of planetary resonances due to what seems to me like an ambiguity. It is known that the asteroid main belt is sculpted by the Kirkwood gaps, corresponding to ...
mysterium's user avatar
  • 811
6 votes
1 answer
413 views

How did VLT's adaptive optics obtain this resolution for Neptune? Is it really working in visible wavelengths?

This image of Neptune taken with the VLT is really impressive. The resolution is achieved by recent improvements in the adaptive optics. Gizmodo: New Super-Crisp Images of Neptune Show How Far Our ...
uhoh's user avatar
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10 votes
1 answer
3k views

Why do Uranus and Neptune have more methane than Jupiter and Saturn?

So the standard theory of the solar nebula is that in the region of the gas planets, ice and rock could condense to form planetesimals, which could then accrete hydrogen and helium to form the gas ...
cduston's user avatar
  • 255
15 votes
1 answer
2k views

Why does Neptune only have one major moon?

Neptune is profoundly anomalous when it comes to moons among the gas giants. Jupiter has its four massive moons, Saturn has a several large spherical bodies and Uranus, a world similar in size to ...
Mr Kusnetsov's user avatar
2 votes
2 answers
2k views

When and where are Pluto and Neptune closest to each other?

I found two sources sort of answering this question, but conclusions I made of them contradict each other. https://www.reddit.com/r/askscience/comments/29jrvq/...
TStancek's user avatar
  • 175
5 votes
1 answer
470 views

Why is the eccentricity of Triton so low?

Triton is very special, since its orbit is retrograde respect Neptune, its obliquity is near 0° and its orbit is almost circular (according to Harris (1984) is $5 \times 10^{-4}$). I'm familiar with ...
Carlos Vázquez Monzón's user avatar
-6 votes
1 answer
170 views

I have simple questions about neptunian system [closed]

I have two simple questions about Neptunian system. I understood the text just iterally, but I can't grasp the mechanism of them. Could you explain them?
Purple Rain Kim's user avatar
3 votes
2 answers
537 views

Does the lower mass of Uranus suggest it swapped position with Neptune?

As Uranus is less massive than Neptune, would this be evidence that it was formed further away from the sun than Neptune, and later it swaps orbit with Neptune to move closer to sun?
Gstestso's user avatar
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7 votes
1 answer
3k views

Have there been successful attempts at spotting Neptune with the naked eye?

As pointed out here, the limit of naked eye visibility for people with extremely good night vision is about magnitude 8.5. Neptune at opposition is much brighter at magnitude 7.7, so it should be ...
Count Iblis's user avatar
2 votes
1 answer
155 views

Does Triton trigger the active atmosphere of Neptune?

As we know the atmosphere of Neptune looks more active than Uranus', is this due to the tidal forces caused by the retrograde orbit of Triton around the planet?
Gstestso's user avatar
  • 2,209
1 vote
3 answers
205 views

Do great spot like features favour appear in south hemisphere?

As we know, both Jupiter and Neptune have great spot like features in South hemisphere, and Saturn has dragon storm in south hemisphere, is it true that great spot like features appear in South ...
Gstestso's user avatar
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