# Tag Info

Accepted

### Can Pluto be seen with the naked eye from Neptune when Pluto and Neptune are closest?

No, it cannot. Far from it. The closest approach between both planets is roughly 16 AU due to the 3:2 orbit resonance. Pluto will even then be a tiny dot among many with a brightness around 14 mag. ...
• 10.7k

### Why is Neptune a darker blue than Uranus?

This is an intriguing question, with a solution suggested by the Irwin et al. (2022; arXiv:2201.04516) paper that inspired the YouTube, NewScientist, ScienceAlert, Phys.org, etc. coverage of the past ...
• 1,764
Accepted

• 113k

### Do tides occur on planets like Neptune, having water?

Neptune's largest moon, Triton, is about a third the mass of Earth's moon, and roughly the same distance away from its primary, so it will indeed have noticeable tidal effect on Neptune's atmosphere ...

### Why is Neptune a darker blue than Uranus?

Tl:DR: According to a team led by planetary physicist Patrick Irwin of the University of Oxford in the UK, an extended layer of haze dilutes the hue of Uranus, resulting in a paler color compared to ...
• 3,226
Accepted

### Why is the eccentricity of Triton so low?

Tidal circularization is indeed a plausible mechanism for why Triton's orbital eccentricity is so low, and I believe it is in fact the prevailing theory, at the moment. In short, tidal forces from ...
• 33.7k
Accepted

### Can Pluto and Neptune collide anytime in future?

It's hard to find a good 2 dimensional representation, but Pluto and Neptune's orbits don't actually cross. In fact, the orbits (not the planets but the orbits) never get within 100 million miles (...
• 22.9k

### Diamonds in Neptune?

People have demonstrated high-pressure diamond formation using laser-driven shocks, much in line with the original idea. The diamond rain idea seems to be doing well (popular science article about it, ...
• 10.2k

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

The inside of a giant planet is not like regular gas. First of all, it is hot. You are away of how it gets hot inside the Earth (causing volcanos). It is also hot inside Jupiter, but since Jupiter ...
• 87.5k
Accepted

### Dates of Passage of Neptune at Aphelion and Perihelion

The last perihelion passage of the Neptune system barycentre relative to the Solar System barycentre (SSB) was at 1881-Feb-02 10:00 TDB. Here's a plot (courtesy of JPL Horizons) of the distance from ...
• 8,862
Accepted

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

It is an image taken with the new narrow field mode of the MUSE instrument using the GALACSI Adaptive optics module on a single (UT4) VLT telescope using laser guide stars. I am having a great deal ...
• 113k

### Before Voyager 2, what were the highest quality photos of Uranus and Neptune?

As per the books referred to in comments: Both planets could be resolved as a disk, but no surface features could be observed on either. Spectrograms had been taken, so the general colour of the ...
• 87.5k
Accepted

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

The Nice model of solar system evolution proposes that both Uranus and Neptune migrated outward from their original orbits due to numerous encounters with planetesimals, stimulated by a temporary 2:1 ...
• 16.5k

### Neptune's Internal Heat Source

Neptune and Uranus have estimated core temperatures of 7273 K and 5255 K respectively. Uranus and Neptune however likely do not have liquid water oceans. The combination of pressure and temperature on ...