Moon Definition and 1000 Threads

as we know that Newton's Motion of First Law state that everything will stay at stationary or uniform velocity unless an force act on it ..., the moon moves, as Earth gravitational field act as centripetal force on it , but how does the moon moves start from stationary ? unless it is start...

Hi! I was just wondering if anyone knows where I can find a software/algorithm that can give me the postion of the sun and the moon in ECEF coordinates? If not, do you have any clues to how I might start building one? I am an engeneering student, so I don't have a lot of knowlegde about...

Homework Statement The bird is fitted with a breathing apparatus, released on the moon could it fly? Homework Equations It doesn't violate any of Newtons laws, but I could be missing something. The Attempt at a Solution The best answer that is listed is that the question is in...

If during a solar eclipse the moon tapers one moon diameter, wouldn't a lunar eclipse taper one Earth diameter?

Suppose a rocket is hovering above the moon at a constant height, burning just enough propellant to stay at that height, and not move upwards or downwards. Viewed from an inertial frame, we have. Initial energy (just before ignition) : 1. Gravitational potential energy between rocket and...

Is there any way in relativity to mathematically compute what the rate difference would be between two identical clocks, one on the surface of the Earth and one on the surface of the Moon? The points on the surfaces to be considered are on the line joining the individual centers of gravity (i.e...

I'm just reading a book and it says: '' Humans are too small to be affected noticeably by the tides. The Earth has tides because its big, thousands of kilometres across. This gives the gravity from the Moon room to weaken.'' Why is it that the more massive an object is, the more it is...

Homework Statement There is a point on the line between the centres of the Earth and the moon where their gravitational fields have equal magnitude but are in opposite directions, effectively creating a point of zero gravity. Calculate the distance of this point from the centre of the earth...

First of all, I'm rather new to this forum and I didn't know where to put this thread, but I think General Discussion will do. Just recently I've been talking with my friend about how we can't sleep when the Moon is in its full stage, and I think some of you might also have this "problem". The...

why is the moon drifting away from the earth? isn't it general relativity suggests that itll move towards the earth?

Okay, first of all, sorry for not posting here, I unknowingly posted this q in the wrong section and got an infraction. Sorry againHomework Statement Question : Calculate the change in gravitational potential energy of the moon, when the radius of it's orbit increases by 4cm. Radius ...

Hello. I have been going through some old OU books on the sciences and started working through an excercise when I came to a stumbling block. I have come here in the hope that someone may be able to shed some light on my problem. This is all for personal study as I am not enrolled on any...

earth? Homework Statement Mass of moon - 7.3 x 10^22 kg Mass of Earth - 6.0 x 10^24 distance between moon and Earth - 356400 km change in distance 4 cm Homework Equations The Attempt at a Solution I just need to check if my answer is correct, I get some thing to the power...

Hey guys I have a question about central magnetic forces between the Earth-Moon system and how they would work at a very large scale similar to that of the central gravitational force. I don't know about electromagnetism as well as I do basic celestial mechanics, so I'm at a loss as to how I...

There is a lot of crazy conspiracy chatter, if its true, then what type of equipment do I need to see the moon bases or Mars bases? Thank you. I'm a real human, curious son of a b.

Hi, I've been doing a bit of independent study on Gravitation. What I find confusing is why the moon doesn't fall straight into the earth. I know that the moon has tangential velocity, but what exactly is tangential velocity? How does it apply to the moon not falling into the earth? Thanks,

I often hear that for planet to have life on it it must have proportionaly large moon to keep it's axial tilt small like Earth is between 21.5° to 24.5° and not like Mars that varies from 15° to 35° which makes destructive effect on possible life that could flourish. But doesn't Venus have...

Hello. I'm trying to write a book of fiction about a place where there is a moon much bigger than the one we have. The mass is probabbly at least double the one we have here circling earth. It could probably be called a case of double planets. My question is: How would the planet be affected...

Hi, I am trying to calculate if moon can possibly hold an atmosphere if we decide to terraform it. The assumption is that it is somehow miraculously completely shielded from Solar Wind, let's say by strong Earth like magnetic field. I found somewhere on the web, that atmosphere of any...

Hello everyone, I'm new here. I'm relatively familiar with some astrophysics calculations, but this particular equation is kicking my proverbial butt. I'm currently writing a sci-fi book series and there's an impact that happens on a moon, but I want to be able to realistically calculate what...

I know it has something to do with gravitational pull, but I don't know why.

I have 2 close friends who believe we've never been to the moon. I've tried explaining to them why the flag moved, why there is no need to go back, etc, and it falls on deaf ears. This morning i saw this video by NASA [...

Say we shoot the surface of the moon with various sized steel balls of size a cm and larger, say up to a km in size. Say the balls hit the surface of the moon moving at 20,000 mph. Is there a simple formula for the mass of the ejecta as a function of the mass of the projectile? Will the formula...

Hello, We had a Science test today and just after the test the teacher gave out the answers to all questions. I had a doubt which I wanted to ask. Hope you can help me... Homework Statement A person can lift 60 kg of weight on the Earth. How much weight will the respective person be...

This applet was used for the hw: http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/newt/newtmtn.html Explain or critique the following statement: “Just like Newton’s cannon ball, the moon orbits the Earth because it falls around the earth.” I agree with the statement. Is there...

Would launching spacecraft from the moon be more effective than from earth? I'm thinking that it would take less energy to escape the gravitational pull, and the added revolution would allow for a more significant slingshot effect on the craft. Granted the craft would either have to...

http://www.nasa.gov/mission_pages/LRO/news/lunar-graben.html A brief video from NASA showing curious geological features of the lunar surface. Graben indicate stretching of the Moon, lobate scarps tell a story of shrinkage. Respectfully submitted, Steve

I was trying to calculate possible orbit of a potential exomoon of a hot Jupiter within habitable zone of a red dwarf. Everything (heat absorbed, reasonably within Hill sphere, far from Roche limit) seamed reasonable. However, I encountered one problem - hot Jupiter should be tidally locked. It...

Why does the Earth orbit the Sun, but the Moon pull on Earth's tides? Earth orbits the sun, proving that the Sun has a greater gravitational pull on the Earth than the Moon. However, the Moon control's Earth's tides (unlike the Sun), which proves the opposite-the Moon has a greater...

I would like to know what the effects of a solar flare would be on equiptment used for lunar exploration, say a robot to be specific. What kind effects would this have on the electrical system? I also read a NASA article describing a large solar flare that created a long enduring proton...

Hi I've been scratching my head late into the night, and come up with some ideas for a moon pod, I could use a sanity check on the maths and basic idea. Very interested to hear feedback. Post comments here or on my blog... http://wellybob.blogspot.com/2012/01/travel-to-moon.html Thanks in...

The Wikipedia article on the moon says ithat "Ptolemy (90–168 AD)" calculated the distance of the moon as 59 times the Earth's radius and a diameter, which is about the modern value. But Wikipedia doesn't say how Ptolemy did that. An article at http://www.eso.org tells how to calculate the...

Homework Statement the radius of the moon is 1 over 3.65 of the radius of the earth, while the acceleration due to gravity of the moon is 1 over 6 of that on the earth`s surface. calculate the mass of the moon.

Homework Statement The Moon is 3.9*10^5 km from Earth's center and 1.5*10^8 km from the Sun's center. The masses of Earth and the Sun are 6*10^24 and 2*10^30 kg, respectively. a. The ratio of the gravitational fields due to the Sun and Earth at the center of the moon is: 1) 2300 2) 230...

In our Solar System, what is the best example of a planetary moon having its own satellite? What general properties do such satellites share?

I tried 5 times to get this problem, so I'm sort of heavily invested in it. Homework Statement How fast is the moon moving as it orbits Earth at a distance of 3.84 × 10^5 km?Homework Equations I'm using the kinematic equation: v = Δd/Δt Here distance will be 2∏r (I know that the moon's...

Found this on youtube, wasnt sure if this is actually possible, i never heard of the astronauts actually leaving stuff on the moon.

Hi everybody, I'm planning a 2016 mission to the moon similar to Apollo 8 (Orbital mechanics homework). I decided to start from a equatorial parking orbit, and then to perform a plane change. The problem is that I obviously need to know the position of the moon's orbit plane, which, as you know...

A pendulum on some moon has a length of 1.5meters and a period of 4.2seconds. On Earth a girl throws a rock 13meters in the air, if she was on that moon how high would that same rock go if she threw it with the same effect? (Ignore all air resistance)

1/2/2012 One new NASA spacecraft is orbiting the moon, another aproaching, to study moon structure via its gravity. 2nd NASA probe en route to moon on New Year’s Day http://www.washingtontimes.com/news/2011/dec/31/nasa- spacecraft -reaches-moons-orbit/

Hi , How could I calculate the acceleration of an object on the Earth's surface , say at the equator , from the influence of the moon , when the moon is directly overhead? I have calculated the force of attraction from the moon to be 1.99 x 10^(20) N. Now to find the gravitaional...

A UFO is observed just above the surface of the Earth moving at a constant velocity. An astronaut on the moon (3.8 x 10^8 m from earth) observes the UFO just above the surface of the moon 2.0s later. From the UFO's reference frame, how long did it travel from the Earth to the moon? The...

I understand that the moon doesn't fall down because it is in an orbit around the Earth. Is this orbit created by warped space due to the mass of the earth?

G'dday My name's Barry. I live in Sydney Australia. We got a reasonably good view of the eclipse of the moon last night. Was cloudy to start with, but cleared up later when the full eclipse happened. The event began about 11.45PM and ended about 2.45AM, so we were in a good position to...

Homework Statement does the moon orbit the Earth or the Center of mass of the earth-moon system. 2. Relevant ideas well, i think that it orbits the COM of the earth-moon system. If this is the case then is the radius of the moon from the Earth always constant. ie, if the moon...

Homework Statement I attached the problem to this post. I need help on the second question and I need to turn it in tomorrow. I'm not sure if I'm supposed to use anything from the first as they are both related. Homework Equations U + KE rvsinθ = rvsinθ These are all the equations...

So I'm working on homework, and encountered this problem. I thought I understood what to do, but I'm not getting the right answer. I'm so frustrated I decided to create an account, so this is my first post. I'll do my best to adhere to the PF format of questions. The Question is: A pendulum...

Homework Statement Using a modified version of Kepler's third law and data about Sinope calculate the mass of Jupiter. Keplers Third Law: p^2=a^3 Newton's Version: p^2=a^3 / M + M p^2 = a^3/M M=a^3/p^2 Sinope's period of orbit = 2.075 years Average orbital distance of Sinope is 0.158...

Homework Statement I'm stuck at one of my homework questions.Basically,it says there is a line EM between the Earth's and moon's centre of masses.The moon revolves around the Earth in circular motion.Point X(somewhere in between moon and earth)represents a point where the resultant...

what would happen if moon orbits around Earth were to be on the same plane as the earthe Earth's orbit around the sun?