Questions about Mercury, the first planet from Earth'd sun. Also the smallest major planet in the Solar System,

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Could Venus or Mercury have a moon that we haven't detected?

Let's consider Mars' two moons for a moment. They're small, not even spherical, and most likely are captured asteroids. They weren't discovered until the late 1800's. Telescopes are much more powerful ...
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1answer
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What does the surface of Mercury look like?

What does the surface of Mercury look like? What color is it (I have seen some images portraying it grey and some a light brownish color), and would the surface be dusty like the Moon, smooth, or ...
5
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81 views

Are there ever any simultaneous transits of both Mercury and Venus as seen from the Earth?

Transits of Mercury happen fairly frequently due to its short period, but transits of Venus are less frequent. I've looked over the data available to me and found that there have been transits of ...
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2answers
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Delta-v from Mercury surface to Venus surface

What it says on the tin: using the most efficient launch opportunity afforded by orbital mechanics, what delta-v would you have to impart to a payload to send it from the surface of Mercury to crash ...
7
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184 views

Are we sure there are no planets inside Mercury's orbit?

Currently, most explorations about new planets are pointing to area outside Neptune's orbit, but how about inside Mercury orbit? Can we say for certain there are no planets inside Mercury's orbit?
4
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Do sungrazing comets leave a field of meteoroids near the Sun?

A large fraction (a third?) of all comets found (with observational bias thanks to SOHO) have been sungrazers, breaking up with perihelion of a few of Sun's radius. Is there reason to believe that ...
3
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1answer
97 views

What is the format of the data from the JPL's HORIZONS system?

I'm looking for accurate positions and velocities of the planets in the solar system over several decades. I want to simulate their trajectories using Newtonian laws of motion, and compare the ...
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25 views

attractors of Mercury's spin-orbit relation

Mercury rotates at such a rate that the Sun appears to stand nearly still at perihelion, when the tide is strongest. Is there a mechanism that tends to adjust the orbital eccentricity to improve the ...
2
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427 views

Shall we say now that Pluto is “larger than Mercury” ?

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150717-3 "Scientists working with NASA’s New Horizons spacecraft have observed Pluto’s atmosphere as far as 1,000 miles (1,600 kilometers) ...
5
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119 views

Is Mercury's core liquid?

A very basic question, but one to which I keep finding different answers: does Mercury have a liquid core, or is it all solid? Whatever the reason, what are the causes of it being so?
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What are the exact physical parameters used to calculate Mercury precession with Einstein theory?

NASA measured 43,13 arc seconds per century. General relativity predicts 42,98 arc seconds per century. I try to find out what the parameters' values such as $G$, $M_{sun}$, $\omega_{min}$ at ...
6
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1answer
44 views

When do Mercury/Venus reach greatest elevation at sunset/twilight for a given location?

On what day does Mercury reach its greatest elevation (in degrees from the horizon) at sunset a given location? The obvious answer is the day of Mercury's greatest elongation from the Sun, but, ...
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Motion of the sun as observed from mercury

I recently found this animation which shows the motion of sun as observed from mercury. It seems as if the sun stops in between, retraces a bit and then continues towards the west. What is the reason ...
0
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219 views

Can Mercury hit Earth or Mars in the next 5 billion years?

Mercury is the most unstable planet of the solar system, with an oscillating orbital eccentricity (between 0 to 0.45). It seems there is a 1% probability in the next 5 billion years Jupiter and ...
4
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1answer
75 views

Are many exoplanets synchronously tidally locked like Mercury?

The only tidally locked planet in the Solar system i Mercury. But it is synchronously tidally locked 3:2, because of the relatively high eccentricity of its orbit, so doesn't turn the same side ...
9
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What is the current accepted theory as to why Mercury, despite its size, has a similar density to Earth?

According to the NASA web page overview about Mercury, despite the planet being just a bit larger than our moon, it's density is about 98.4% of Earth's. This high density suggests a comparatively ...