Questions tagged [mercury]
Questions about Mercury, the first planet from Earth's sun. Also the smallest major planet in the Solar System.
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Why doesn’t the Sun fill the sky on Mercury?
I’ve seen a lot of photos showing Mercury in front of the Sun when it passes by and you can see just how tiny it is in comparison.
Here’s a great example:
So I’d expect if I was travelling towards ...
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Why is the Sun's density less than the inner planets?
The density of the Sun is $1410~\frac{\text{kg}}{\text{m}^{3}}$ and Mercury's is $5430~\frac{\text{kg}}{\text{m}^{3}}$, but shouldn't the Sun be denser? Because when the Solar System was forming, ...
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Does anything orbit the Sun faster than Mercury?
Mercury's orbital period around the Sun is about 88 days. Comets and other things have gotten closer to the Sun than Mercury does. But has there ever been an asteroid or some other body discovered ...
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Why doesn't the IAU definition of "Planet" disqualify Mercury and Venus as planets?
Here's the IAU definition of a planet (source):
A celestial body that (a) is in orbit around the Sun, (b) has
sufficient mass for its self-gravity to overcome rigid body forces so
that it assumes a ...
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Why is Mercury's orbit so unusual?
Mercury's orbit has the most eccentricity, 0.2, of all the planets. And this orbit is also the most inclined relative to Earth, 7 degrees. Edit: And to the invariable plane, it is inclined 6.35 ...
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What rotational speed would Mercury need to have to achieve a temperature comfortable for humans
I wondered what rotational speed would Mercury need to have to achieve a temperature comfortable to humans, let's say 20 °C.
EDIT:
My idea was that if Mercury is so cold on the night side and so hot ...
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Are there auroras on Mercury?
Auroras on Earth are caused by interactions between the solar wind and the magnetosphere. I've also seen a few pictures of auroras on Jupiter and Saturn.
Mercury has a global magnetic field. Does it ...
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Is it possible that Mercury was originally the moon of Venus after a giant impact?
Mercury looks like the Moon, and so it makes me think about a question: is it possible that Venus and Mercury were the a same planet originally, and a giant impact with that planet made it split into ...
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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 ...
user8
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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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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 ...
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Mercury's spin-orbit resonance
When was it confirmed that Mercury has a 3:2 spin-orbit resonance and by whom (research group/radio observations...)? The first suggestion was made by Giuseppe Colombo in 1965.
Its proximity to the ...
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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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Can Mercury's core "boil over" if it gets to close to the Sun?
I was reading about how Mercury's core makes up most of the volume of the planet. I'm guessing this is both because of the small size and the distance to the Sun. If Mercury got too hot could it ...
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Are many exoplanets nonsynchronously tidally locked like Mercury?
The only tidally locked planet in the Solar system is 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 ...
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What are the "weather" (and other) implications of long "days" and short "years" on Mercury?
On earth, it takes a "day" for it to rotate on its axis, and 365 of these days for it to revolve around the sun. On Mercury a "day" that encompasses a rotation represents 59 earth ...
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Can we find rocks from Venus or Mercury on Earth?
As we know, we can find rocks from Mars on Earth, how about Venus and Mercury? Is that not found yet? Or it is impossible to find them because they are closer to the Sun, and debris won't go far away ...
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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 ...
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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?
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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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Did simultaneous transits of Mercury and Venus actually last occur in 373,173 BC?
According to the Wikipedia article for Transit of Venus, the last time a transit of Mercury and a transit of Venus occurred at the same time was 22 September of 373,173 BC. This is a Featured Article ...
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Why is Mercury's Density So Low?
I know the title sounds odd. You might be thinking "Doesn't Mercury have the highest uncompressed density of any terrestrial planet? Much higher than a planet its size normally should have?&...
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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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Watching the Mercury transit with improvised devices
I have learned that it is not possible to watch the upcoming Mercury transit with the plain eye (using special filter glasses).
Is it possible to watch the transit with improvised devices (like a ...
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What effects do CMEs have on planets like Mercury?
Some Background?
Coronal Mass Ejections, or CMEs for short are the topic of this question. Anyone new to this topic is sure to find some really interesting facts (and consequences) of CMEs and Solar ...
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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, ...
user21
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Will Mercury ever become locked to the Sun?
The Mercury year is between 1 and 2 days. Has it ever been greater, and will it eventually become "tidally locked" with the Sun?
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After what time interval do the closest approaches of Mercury to the Earth repeat?
The sidereal period of Mercury's revolution is 88 days and the synodic period — 116d.
my solution, but in the question featured "the greatest rapprochement." And this is no longer so easy. ...
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Can Mercury be seen from the 60th parallel north on Earth? Shetland, Faroe, Norway, St Petersburg, Alaska
I'm originally from a city in Spain which is 40 degrees north, and I used to watch Mercury (naked eye and telescope) every time I had the opportunity, that is, when Mercury was at maximum elongation ...
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How can Mercury's sodium tail be imaged?
I recently learned that Mercury has a sodium tail. Can this sodium tail be imaged with a ground based telescope? Is so, what is the minimum setup required to be able to take a picture of it? Do you ...
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What is wrong with this measurement of the synodic period of Mercury?
I'm measuring the synodic period of Mercury using Stellarium. When measuring the synodic period one needs to choose a reference point to start the measurement, and I choose the point when Mercury is ...
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How large was Mercury before it shrunk?
There's a theory that the reason Mercury has such an enormous iron core is that it was once a much larger planet before it got impacted by an object, resulting in most of its mass getting blasted away....
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How could one use the transit of Mercury to try and find the Astronomical Unit?
I am trying to use the transit of Mercury to estimate the distance between the Earth and the Sun, or 1 AU.
I know that I need to observe mercury from two antipodes, but I do not understand any of ...
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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 ...
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Does the axial tilt of Mercury and Venus vary?
The axial tilt of Mars varies greatly over time, with a tilt varying between 15 and 25° over the last million years, and varying even more over the last 5 million years. The Earth's tilt on the other ...
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What are the Time Zones on Mercury?
I normally post on worldbuilding, but this question is merely about facts of a planets orbit and spin. I am trying to figure out how time periods work on Mercury to possibly make a worldbuilding guide ...
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What are those long, smooth, longitudinally-opposing areas from pole to pole on Mercury?
Look at this model and spin it - Mercury 3d model
Are those artifacts of stitching together images, or does Mercury really have these opposing, huge pole to pole lines of smoothness?
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What could possibly save an atmosphere other than a magnetic field? Why can't a magnetic field save the atmosphere in certain cases?
Similar question here.
We know as a fact that the magnetic field protects planets from Solar Wind, a damaging, continuous, atmosphere-stripping wind of charged ions. Thus, a magnetic field protected ...
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Does the observed Perihelion precession of Mercury still deviate from prediction?
In Wikipedia section about the Perihelion precession of Mercury, we have the follwing table titled "Sources of the precession of perihelion for Mercury":
Amount (arcsec/Julian century)
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What is the highest point on Mercury?
Continuation of "Gravity on Mercury's highest elevation?"
Because when you Google that, you see "Caloris Montes" which is actually a mountain range consisting of mountains 1-2km ...
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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 ...
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Massive degraded impact crater on Mercury - chemical evidence?
The planet Mercury has a myriad of impact features - this has been known for some time. However, observe in the following images, a relatively large 'High-Mg region' detected on the planet (below):
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Is there an L2 Lagrange point for Mercury that lies in the shadow?
Or is it just too far away to be shadowed from the photosphere of the sun?
Just wondering if some futuristic science/observation station could ever be placed there.
I know about the polar craters that ...
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Exactly how elliptical is Mercury's orbit, visually, without exaggeration?
Reposting question from https://www.reddit.com/r/askscience/comments/5e1zhy/what_does_mercurys_orbit_really_look_like/ which reads:
First the full question: What does the orbit of Mercury really ...
user21
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Could Mercury be a some kind of Chthonian?
A recent news article mentioned that Mercury has an unusually large core - meaning it is denser than the other rocky planets in the solar system.
It made me wonder if Mercury could have started as an ...
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Pinhole projector for the Transit of Mercury
Very quick and simple one today. What would be the best/optimal pinhole size for a pinhole projector to observe the transit of Mercury on May 9th?
I want to get the optimum between resolution and ...
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Why aren't all planets in the same plane?
Obviously all planets are not in same perfect plane. Because if at all they were in the exact same plane, it would mean that Mercury transits and Venus transits would not be that rare.
Any ...
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κ₀ for Mercury—Formula (another definition)
Following my other question about a specific “hidden” formula in Ptolemy’s model for Mercury, I am now looking for yet another “hidden” formula, this time the one used to find $\bar\kappa_0$ so that $...
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Where can I build my house on Mercury so that I can see double sunsets (and sunrises)? Can I do it near the poles where it's cooler?
CNN'S Mercury mission flies by closest planet to the sun for the first time says at the end:
Mercury's unusual rotation and oval-shaped orbit around the sun (sic) means our star seems to quickly rise,...
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Planetary tails: How many have we observed yet?
Just recently I learned that Mercury has a sodium tail and it is actually well studied since long:
As a result, the planet has the appearance of a comet, with a tail that's been observed streaming ...
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