Questions tagged [the-moon]

Questions regarding Earth's only natural satellite. For questions about the natural satellites of other planets, use the tag [natural-satellite].

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186 views

When will the last total solar eclipse occur?

Because the moon distance from earth grows, how long will it take, that it is no longer possible to see a total eclipse but only circular eclipses? And does it make a difference if you are on the ...
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117 views

“Lunar tropics”

The tropics is region of the Earth in which the Sun could be directly overhead. What is the corresponding region for the Moon? Is it the same or slightly larger? I live in the UK and hence have ...
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Can you see city lights on the Moon from Earth?

This is the opposite of another question. That question is about whether you could see cities on Earth if you were standing on the Moon. Let's there are cities on the Moon and you're standing on the ...
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Is it safe to view moon at daytime through telescope

I have a little 76mm Newtonian Reflector. I want to see the moon at daytime. Is it safe to look at sky at daytime when sun is shinning or there is any risk of sun.
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Why is the outline of a crescent moon brighter?

Some quick googling has given me the answer to whether seeing part of the moon that receives no sunlight is an optical illusion or not: it isn't. Earthshine lights the moon enough for the human eye to ...
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101 views

Why is the difference from a perfect sphere the same for the Earth and the Moon?

Wikipedia gives the following physical dimensions for the Moon: Physical characteristics ...
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285 views

Implementation of formulae for Meeus for the Moon

With Astronomical Algorithms by J. Meeus (1998) I have obtained the relevant illuminated fraction of the disk and position angle. But they're numbers (all Greek to me!) I know, Meeus explains that ...
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550 views

Connection between Earth, Moon, Theia, and asteroid belt?

Are there other fragments aside from the Moon that resulted from the collision of Earth and "Theia" (as it's called in recent main-stream press stories)? And if not, why not? And what happened to "...
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525 views

USNO moon images look quite different?

I visited: http://aa.usno.navy.mil/imagery/moon http://www.usno.navy.mil/USNO/time/moon-phase-images within seconds of each other, and saw two very different "current moon images": Is one of ...
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104 views

Are there pictures from a solar eclipse of the earth taken from a moon landing unit or orbiter?

Did any moon landing vehicle or orbiter took pictures of a solar eclipse happening on the earth, i.e. the moon's shadow on the earth? (Alternatively from other spacecraft showing the whole globe). A ...
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140 views

What is Earth believed to have looked like before the collision with Theia?

Let's assume the moon was formed because Earth collided into Theia. (There are numerous other theories, but this one is the most widely accepted.) In that case, are there theories that address what ...
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134 views

Solid-body tides on the Moon

There are various good models for solid-body tides on the Earth. Are there any recommendations for tides on the Moon?
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What stabilizes rings or accretion disks?

We think, more or less, that our Moon was formed from an accretion disk caused by a Mars-sized impactor. Cool. Tidal forces can break apart a moon, causing rings. Ashes to ashes, dust to dust: the ...
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92 views

Recommended papers

I am highly interested in how the moon originated. Theories suggest that the moon is a chunk of the earth, or rather, both were at one point one celestial body. Is there any literature out there with ...
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194 views

A [very basic?] question about light scattering and colors

Since the night two days ago, the moon here in Israel appears to be orange as it rises, and then gradually becomes white as it continues travelling across the sky. This phenomenon comes in a great ...
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186 views

Evidence behind Giant Impact hypthesis

The giant impact hypothesis is a theory to explain how the moon was formed. What evidence is there that supports the theory and led us to find the current theory?
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191 views

Total solar eclipse, supermoon, and spring equinox all happening at the same time: anything special about this?

Today (March 20, 2015) is seeing a rare combination of the spring equinox, a total solar eclipse, and a supermoon. I am wondering if there is anything special astronomically about all three of these ...
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Formulas to determine the illuminated phase and orientation of the Moon

The phase of the Moon (the bright limb) looks different depending on where on Earth the observer is located and the time of the observation. I've located this video and the accompanying spreadsheet ...
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586 views

How to calculate geocentric conjunction time and moon altitude at a given time

Umm al-Qura calendar of Saudi Arabia determine the new moon if these criteria meet at 29th day: The geocentric conjunction occurs before sunset. The moon sets after the sun. I've got the formula to ...
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227 views

Tide on the Moon

If the Earth's Moon had a water ocean of depth 2-4 Km, how high would the tides rise due to the Earth's gravity? (Just a hypothetical question.)
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Is the Ordovician meteor event detectable in the lunar cratering record?

Approximately 468 million years ago there were a large number of L-chondrite meteorites falling to Earth. This is called the Ordovician meteor event and was probably the result of a large collision in ...
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How open is China in sharing data from the Chang'e 4 mission?

It's really good to see that man (well, machine) has gone back to the moon again. Chang'e 4 is studying potential mantle material from the lunar depths and will be conducting radio astronomy in ...
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What is the relation between the saros (18 years, 11 days, 8 hours) and the period of lunar nodal precession (18.6 years)?

I am wondering. I am sure that they are related. How can we derive one from the other?
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When the Moon formed and early on, did it orbit over the Earth's equator?

Or was it always at about 5.14 degrees inclination or has the inclination changed over time? See diagram. James K's answer to this question got me thinking about this, and I don't mean to call him ...
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339 views

Is extraterrestrial mining more difficult or impractical for bodies without plate tectonics?

This article talks about the possibility of mining Uranium on the moon. Since the Moon lacks the geological forces that have created veins of concentrated minerals on Earth, would extraterrestrial ...
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How to calculate the moon phase [duplicate]

I need a way of to calculate the moon phase. Do you know resources for research the theory from behind this? I basically have searched in Google, but the results were not very satisfactory. Exists a ...
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861 views

Circular formation around the moon

I have seen a large circular formation of cloud around the full moon sometimes. Have anyone seen the same? What is the reason behind this formation? Due to lunar attraction? Most of the sky is empty ...
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205 views

Why does the Moon appear to be flat?

There's no way around it: when I look at the full moon at night it looks like a mostly flat disc, with at most a bit convexity in the middle. Phases of moon look like a full moon seen through a cut-...
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Moonrise after sunrise but moonset before sunset?

Today (1/24/2020) for Boston MA timeanddate.com lists the following four times: Sunrise 7:05 AM Moonrise 7:06 AM Moonset <...
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303 views

Is the moon's revolution speed increasing or decreasing

I've come across multiple answers to this question. So, the moon is moving away from the Earth a couple of centimeters per year and the Earth's rotation is slowing down. Here it says the moon's ...
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122 views

Different full moon face on different places on Earth same time

I have theoretical question. Let's assume that it is full moon and two different humans are looking at it at the same time. One human is for example in London and one in Beijing. It doesn't really ...
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277 views

Mountains on the moon during solar eclipse?

I ask myself the reason of why the sun in not uniform on the edge of the moon at this moment of the eclipse (cf. picture) is not unifom is because of the mountains of the moon ? Or can it due to ...
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407 views

Why is the Moon smooth near the equator and bumpy near the poles?

It looks as if it was polished by applying emery to its spinning equator. My initial guess was that it was simply an illusion caused by light direction, but the terrain map shows the same phenomena. ...
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338 views

Moon looks too small in 3D model

I'm not sure if this is more a question for a 3D graphics forum, but I'm trying here first in case the answer has more to do with astronomy than 3D. I am creating a model of the Earth and Moon in a ...
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Is this photocomposition of Andromeda's galaxy and the Moon accurate?

I recently saw the below image circulating around twitter/facebook/reddit. It is titled "Andromeda's actual size if it was brighter" One of the comments provides a link to another comparison provided ...
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608 views

Observed lunar distance data?

Where can I find free/open data for the observed (not calculated/theoretical) distance between the Earth & Moon? I want to see the observed distance of the Moon, hour by hour.
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181 views

Can radio telescopes such as arecibo image the subsurface of asteroids or planets?

This was done with the moon: Radio Dishes Peer Beneath Moon's Surface
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Is the boulder on the peak of Tycho Crater the core of the impactor, or is it a random rock?

There's a strikingly visible boulder sitting right at the top of the peak complex in the center of Tycho Crater on the Moon. Is it just a coincidence that this gigantic, bright rock is sitting dead ...
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Do we know the availability of any material suitable for solar cells on the moon?

Disclaimer: I have no formal training in any scientific field. Have we located any material suitable for solar panels already on the moon? Or does it appear that they would have be imported?
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179 views

Direction of major axis of moon's orbit

Does the major axis of the moon's orbit point in the same direction (with small deviations) throughout the year? or does it migrate along a path so that after a million years it might be 90° away from ...
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400 views

Why are tides high only on a full moon day?

As far as I've known, sea tides are higher on a Full moon day. And that is due to the "gravitational pull" of the moon. But we know that moon is visible because of reflection of sun's rays. So, even ...
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132 views

Why do some solar eclipses' umbra cross arctic/antarctic regions?

The ecliptic (Earth's orbital plane) is inclined 23.4 degrees. This is the same as Earth's axial tilt. The Moon's orbit is inclined 5.145 degrees to the ecliptic. Therefore, the maximum latitude ...
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When the moon eclipses the sun what direction is darkened first: left or right?

I saw the question and answer for the explanation of the direction of the moon's eclipse from left to right, but what about the direction of the moon as it passes over or between Earth and the sun? ...
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lunar calendar accuracy for predicting new moons

I wonder, how accurate the lunar calendar is? Can we predict the new moons precisely for tens of years in future? If we know all factors that affects the movement of the moon, then why it is not ...
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743 views

Could an asteroid knock the moon out of its orbit?

As describe in this CNN article, an asteroid is going to pass near the Earth on Halloween. The article says that As it misses Earth by about 300,000 miles (slightly farther away than the moon), ...
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225 views

Is there any man-made satellite orbiting our moon?

I am just wondering whether any man-made satellites are currently orbiting our Moon. If there is one, would I be able to see it using my telescope?
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Is it possible to see a spacecraft orbiting the moon with a pair of binoculars?

On this clear early morning over London, I was studying the moon with a pair of binoculars and noticed a tiny dot of light that appeared to trace a slow orbit around the moon. I reckon it moved ...
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Difference in time between sunset and moonrise on a full moon

So as a Sailor I have experienced some times where sunset and moonrise are very close together (this happens when it's full moon) which is particularly beautiful. I assumed that this was always the ...
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Is there a timekeeping word for the orbit of a moon?

For a planet, we can colloquially refer to its period of rotation as a "day" and its period of revolution around its parent star as a "year." Some worlds have unique terms, such as Martian days being ...
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What can a lunar-based telescope do?

What can a lunar-based telescope do? If the band is ultraviolet and it can do high time sampling exposure, maybe it can be used to get distance for a star with stable pulses. However, the star should ...