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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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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Calculating Angle Between Two Planets In Heliocentric Orbit

My goal is to calculate the retrograde of Mercury. What I've been working from is the book, Practical Astronomy With Your Calculator 3rd edition. I've made some progress, but I seem to be stuck with ...
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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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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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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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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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Measured values of the solar irradiance at other values than 1 AU?

It is straight forward to estimate the total solar irradiance of a planet using the Earth's solar constant, and scaling it according to the (mean) distance of the planets. But for which planets have ...
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What is the naming convention for craters on Mercury?

The two largest craters on Mercury are names Caloris (meaning "hot") and Rembrandt (for the painter). So there doesn't seem to be a pattern. By convention, craters on Mars are named for ...
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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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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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What would the Earth's peri- and aphelion have to be in order to have the same seasons due to its orbit?

Imagine the Earth had no axial tilt but had seasons due to a very elliptical orbit. How elliptical would the Earth's orbit have to be in order to have about the same seasons as it has now (just with ...
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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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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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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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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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Gravity on Mercury's highest elevation?

This post answers what is Mars' gravity at its highest point (Olympus Mons) compared to the Earth's and Mars' standard, it's 0.3736 g (Mars standard is 0.3794 g). This also seems to be the lowest ...
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What is preventing cave formation on Mercury?

The answer to this question suggested cave formation on other planets in the solar system especially on terrestrial planets. There are suspected lava tubes on Mars, Venus and Moon where lava flows ...
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Is it still the case that the transit of Mercury can't be measured with sufficient accuracy to determine the Sun's distance?

The book Transits -- When planets cross the Sun, Maunder & Moore, page 44 states that Legentil [was] one of the first to realise that transits of Mercury could never be observed with sufficient ...
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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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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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What effects does the motion of the Sun have on the perihelion precession of Mercury?

According to the wikipedia page, there are multiple effects contributing to the perihelion precession of Mercury. Of course, according to this link and this link we know that the Sun is itself ...
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How did Arecibo make radar images of ice on Mercury's poles?

update: I still haven't been able to get my hands on the Icarus paper linked below (I'll try other libraries) but these are newer and quite interesting!: Constraining the thickness of polar ice ...
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How was the Messenger spacecraft used to measure Mercury's orbital precession to such accuracy? Could this have been done using radar?

This comment under an answer to Path of Mercury and general relativity mentions that the Messenger spacecraft was used to measure the precession of Mercury's orbit to such accuracy that the tiny ...
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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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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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Path of Mercury and general relativity [duplicate]

I have read that many physicists challenge the theory of general relativity, and it has been proved many times that it is correct; my question is on Mercury's orbit. And we know that many of ...
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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 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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Are many exoplanets synchronously 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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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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How to write a normalized, dimensionless form of Binet's relativistic equation?

$$\frac{\delta^2 u}{\delta \theta^2} + u = \frac{\mu}{h^2} + 3 \mu u^2$$ This is Binet's relativistic equation. Here $u = 1/r$ where $r$ is the radial distance, and $\mu$ is the reduced mass of the ...
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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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Where can I find data on Mercury's orbit to fit a model to? [duplicate]

I have a project in which a Monte-Carlo method is used to find the optimal parameters for some model that is fit to a data set. I want to fit a model for the orbit of Mercury using this methods, but I ...
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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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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 ...
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Historical Distance of Planets to Earth [duplicate]

I'm curious if there is a readily accessible tool available, or simply a reliable way to find out what the distance of the planets in the solar system were on a given date. For example, if I am ...
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If Mercury and Venus where to collide would it make a habitable planet? [closed]

I have been wondering for a while now about a scenario of where if you combined Venus & Mercury would it be habitable if located in the goldy locks zone? I have found in my little research that ...
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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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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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Why does in-the-sky.org say that Mercury is not visible from Taipei these days?

I know that viewing Mercury is a challenge, but I'm fairly close to the equator and Mercury was at greatest elongation just a week ago. In-the-sky.org says: All around the world, Mercury is visible ...
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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 ...
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What is the temperature under the surface of Mercury?

What is the temperature under the surface of Mercury? I know at the surface the temperature varies greatly (-297 F to 801 F). I also realize that the answer would likely depend on depth. Do we know ...
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Mercury mapping attempts before Mariner 10?

Mercury's surface was not mapped up-close until Mariner 10 passed by in 1974. This was followed by MESSENGER in 2008. I have seen several attempts of mapping Mars that came before space exploration, ...
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What is the inclination of Mercury's orbit w.r.t. the Sun's equatorial plane?

What is the inclination of Mercury's orbit w.r.t. the Sun's equatorial plane? Additionally, what is the orientation of Mercury's orbit (long axis) w.r.t. the Milky Way?
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Orbit of Mercury

As observed from the earth, the sun appears to move in an approximate circular orbit. For the motion of another planet like mercury as observed from the earth, would this be true? If not, why? What ...
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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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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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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 ...