Questions tagged [mercury]
Questions about Mercury, the first planet from Earth's sun. Also the smallest major planet in the Solar System.
82 questions
0
votes
4
answers
231
views
Does the Sun drag space after it as it spins?
I am trying to explain why Mercury's orbit precesses more than expected, to children, in plain English, in simple terms, they can actually understand, without invoking GR, which they cannot possibly ...
user54537
2
votes
1
answer
60
views
What was the last simultaneous total solar eclipse and Mercury transit?
An old revision of the transit of Venus page on Wikipedia (the current revision doesn't have this info), says that the last simultaneous total solar eclipse and transit of Venus (currently) occured in ...
user59421
3
votes
1
answer
689
views
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 ...
3
votes
1
answer
272
views
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 $...
- 7,659
1
vote
1
answer
280
views
Why is Mercury visible
How is it possible that Mercury can be seem from Earth if it is such a small planet, it has the lowest albedo of any planet, and it is so close to the Sun?
- 383
15
votes
1
answer
4k
views
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 ...
- 2,000
21
votes
6
answers
5k
views
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 ...
- 511
1
vote
1
answer
75
views
At what exact date and location does Mercury appear at the highest altitude from Earth in history?
I have been messing around with the elongation for Mercury, and I have been getting 27.8 degrees at maximum in https://www.heavens-above.com/PlanetSummary.aspx. Is there any history record that ...
4
votes
1
answer
257
views
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)
...
- 1,707
12
votes
1
answer
2k
views
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 ...
- 223
5
votes
2
answers
1k
views
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?
- 670
7
votes
1
answer
916
views
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 ...
- 349
5
votes
2
answers
286
views
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 ...
- 325
3
votes
1
answer
185
views
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,...
- 30.7k
3
votes
2
answers
852
views
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 ...
- 183
2
votes
0
answers
64
views
Surface composition of Mercury?
I've been doing research on the surface composition of Mercury, but it doesn't seem that there are many helpful results online from ArXiv. One article from PNAS describes the composition of Mercury as ...
- 6,733
1
vote
0
answers
106
views
Is the asteroid belt made up of Mercury's former crust?
Mercury has an unusual composition: It seems to consist mostly of metal, which is otherwise common in the cores of planets. Also, Mercury's rocks are rich in volatile materials, which could not have ...
0
votes
1
answer
230
views
When will Mercury have rotated an extra round around its axis?
It is well known that Mercury orbits slightly differently from a pure Newtonian orbit. Every year a slight deviation is found.
Now if we observe a lot of these orbits then Mercury should at one point ...
3
votes
1
answer
96
views
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 ...
- 5,657
1
vote
0
answers
278
views
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 ...
- 11
6
votes
1
answer
1k
views
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?&...
- 403
4
votes
2
answers
324
views
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 ...
- 309
4
votes
2
answers
212
views
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?
- 203
0
votes
1
answer
143
views
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 ...
- 17.7k
3
votes
0
answers
88
views
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 ...
- 5,657
7
votes
0
answers
262
views
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 ...
9
votes
1
answer
219
views
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 ...
- 1,105
3
votes
1
answer
166
views
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 ...
- 397
22
votes
4
answers
5k
views
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 ...
- 16.7k
5
votes
2
answers
655
views
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. ...
- 153
4
votes
1
answer
767
views
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 ...
- 5,253
3
votes
0
answers
125
views
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 ...
- 113
6
votes
1
answer
231
views
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 ...
1
vote
1
answer
99
views
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 ...
- 17.7k
5
votes
4
answers
716
views
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 ...
- 17.7k
12
votes
1
answer
928
views
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 ...
- 17.7k
2
votes
2
answers
244
views
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 ...
- 265
5
votes
1
answer
461
views
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 ...
- 17.7k
36
votes
10
answers
18k
views
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 ...
- 479
5
votes
1
answer
247
views
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 ...
- 63
2
votes
1
answer
178
views
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 ...
- 30.7k
0
votes
1
answer
177
views
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 ...
- 405
5
votes
2
answers
479
views
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 ...
- 4,851
2
votes
0
answers
81
views
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 ...
- 139
3
votes
0
answers
144
views
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 ...
- 30.7k
2
votes
1
answer
132
views
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 ...
- 21
4
votes
3
answers
2k
views
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 ...
- 1,882
2
votes
1
answer
331
views
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 ...
- 123
1
vote
1
answer
2k
views
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 ...
- 77
5
votes
1
answer
1k
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 ...
- 831