Moon Definition and 1000 Threads

Homework Statement Saturn’s moon Titan is the only moon in the solar system with an atmosphere, which is 95% nitrogen molecules (N2), similar to Earth’s atmosphere. At Saturn’s distance from the Sun, the temperature of the atmosphere is only 95 K (−180◦ C), and the molecules have an average...

I have recently come across a new theory about the formation of the moon. It says that the Earth was rotating faster than it is now and was side-swiped by an object larger than Mars. Is it possible that object was Venus and the collision caused the Earth to slow down and the rotation of Venus...

Homework Statement What was the diameter of the object that impacted the moon 3 to 4 billion years ago and created Mare Humorum Homework Equations N(t) = N0(1/2)n The Attempt at a Solution I'm completely lost by this question so I haven't attempted a solution yet but I think I'm...

This question is really starting to bug me!:bugeye: Consider for example Io is orbiting Jupiter and the force of the gravity pulling the moon towards the planet vs the momentum pulling in the other direction creates friction in the moon's core. First of all, this should heat up the moon. But...

Homework Statement The force of attraction between Mars and its moon, Phobos, which has a mass of 1.072 x 10^16kg and a radius of 11.1km is 5,18 x 10^15 N Find the height of Phobos above the surface of the moon. Homework Equations f=G(m1)(m2)/d^2 d(mars-phobos surfaces)= d (moon-phobos...

Homework Statement Part 1(complete and correct. I'm including this for context's sake) You plan to take a trip to the moon. Since you do not have a traditional spaceship with rockets, you will need to leave the Earth with enough speed to make it to the moon. You leave the surface of the...

Hello everyone, I have one simple question. How quickly moves the terminator on the Moon? It is the same speed as the Moon rotates? I can't imagine it a lot. Thank you very much.

Homework Statement This is third and last part of a question whose first part was solved on here earlier. Given the spin angular momentum of the Earth and the Orbital (around Earth) angular momentum of the moon calculate the mass of an object that if it hit the Earth at it's radius (glancing...

Homework Statement During Apollo 14, Alan Shepherd hit a golf ball on the Moon. If he hit the ball at an angle of 15° and an initial velocity of 30m/s, what was the time in the air? Homework Equations 30 m/s / 1.6 So it takes 18.750 seconds to get to the top where you start at...

If so, how??

Hi everybody, I've registered to PF because after searching the web and this forum too, I couldn't find a clear answer to my dilemma. I've read this article but something seems wrong: http://www.scientificamerican.com/article.cfm?id=half-mass-moon What if the mass of the Moon would be...

I know there there has to be a simple answer to this, but I can't understand where it's at. Here is the question. Find the apparent magnitude of the Moon [Earth's] as seen from Mercury. Assume Mercury is 0.52 AU from the Moon and that Mercury sees the Moon fully [it's a full moon]. Okay...

Homework Statement So basically I'm given the distance to the moon (384,000,000 meters), and I need to find out how many degrees per second I'd need to move the laser for the spot touching the moon to move faster than the speed of light. Homework Equations w=\frac{v}{r} The Attempt...

Homework Statement Moon's gravity is 5.31ft/sec^2 An object has the weight of 3.5 lb-f on the moon. What is its lb-m What is the lb-m and lb-f on Mars with gravity of 12.1 ft/sec^2. Homework Equations w=mg=mg/gc gc= gravitational constant----> 32lbm*ft/sec^2 for earth The...

amateur question. referring to the following link Lunar phase - Wikipedia, the free encyclopedia (particularly the video on the bottom right) I understand what's going on except one thing, why don't the phases of the moon change overnight? is it the scale of the video that is probably...

Can a moon orbit close to its host planet and have no tidal heating? Say there is a moon with 0.5 Earth masses and 0.8 Earth radii orbiting a Jupiter mass planet every 18 hours with an eccentricity of 0.00001. There are no moons within 3 million miles of the exomoon in question. Could this moon...

Hi! I looked up on the sky today while arriving home from work. There was the moon but only exactly half of it was being visible. With exactly half I mean, with regard to my poor english, that it was like a folded circular disc. Seeing a "new-moon" like we call it here in Sweden, the...

In the recent hubbub centring on Despicable Me 2 (bear with me), I recall the first film when the protagonist stole the moon by using a shrink ray to shrink it to fit in his palm. My question is, what would happen in real life if such an absurdity was committed? For one, shrinking the moon would...

Homework Statement Imagine a cyclist (in spacesuit) cycling on the level on the Moon (so no drag). The external forces acting on them are contact force upwards (from Moon) and weight downwards (from Moon), which balance. Plus an unbalanced friction force forwards (from Moon on the tyres). I...

Anyone else seen this somewhat low budget Scifi movie? Its not that old, say maybe 3-5 years. Called "Moon" Very cool with a lot of atmosphere. If you haven't seen it yet, do yourselves a favor and do so. Anyone else a fan?

Homework Statement What multiple of the distance between the centre of the Earth and that of the moon is the distance between the centre of the Earth and a geostationary satellite which above a fixed location on the equator?Take the cycle of revolution to the moon around the Earth to be 27...

I've heard two hypothesis: 1. The air causes the image of the moon to literally appear larger 2. The increased size of the moon comes purely from illusion of perspective Which one is it?

So we know that for every action force there is an equal and opposite reaction force, but these forces act on different objects. And we know that the gravitational force acting on the Moon by Earth and the gravitational force acting on Earth by the Moon is equal. But what amount is this equal...

Hello Physics Forums, this is my first thread here. My daugher of 9 years is getting interested in the moon and tides and those things. And she askes me a peculiar question which I could not answer. It goes as follows: If you put a strong rockets on the moon which turn/spin it on the spot...

Which of them larger? The gravity of the Earth to the moon or the gravity of the sun to the moon?

Homework Statement gravitational potential at surface of the Earth = -63MJkg-1 gravitational potential at surface of the moon = -2MJkg-1The attempt at a solution I thought gravitational potential was a scalar, so in which case, you would surely just add up the potential due from both masses...

I have always wondered why the moon doesn't look blurred to us if Earth is spinning so fast, or are we spinning so fast that the image of the moon or everything else in the cosmos for that matter, looks clear? Like when a picture is taken of the Earth it looks still, is it because the thing used...

This seems like a pretty simple question, but I haven't been able to find an answer yet. It has to do with gravity, so even though it's not really about special relativity, this seems like the best place to post it. My question is; if an object were free-floating in perfectly still water...

Hi, consider a Moon Crater hidden from direct sunlight that has an average temperature about -60 Celcius (213 K). It is quite possible that somewhere on the Moon such crater exists. I choose -60 Celsius because it is the average Winter temperature at the South Pole and thus possible lowest...

Homework Statement Homework Equations The Attempt at a Solution Parts I'm unsure of: Sketching of graphs in (a) and (b). I know increasing its energy will shift the entire graph upwards. But does it shift it rightwards if the angular momentum is increased? Last part, they said to ignore the...

I'm a writer, damn it, not a physicist! My imagination takes me to a world where a moon can be a habitable planet that orbits the largest planet possible that could be completely engulfed by liquid water.

A meteorite crashed into the moon on March 17, http://news.yahoo.com/huge-rock-crashes-moon-sparks-giant-explosion-152049489.html Apparently, NASA astronomers have been monitoring the moon for lunar meteor impacts for the past eight years.

Not homework here but merely curiosity. I was reading that on Titan there are rivers of methane, and that at least one is 400km long. Now I was thinking about the Earth and moon; imagine that the moon becomes a copy of Earth exactly, keeps all of it's features and becomes the diameter of the...

We have two tides because of the moon's attraction on the front and back side of the earth. I can understand the reason for the attraction of the moon on the front side which causes the water to move towards the moon but I can't understand the reason that the thing happens in the backside. I...

If you had a planet orbiting a double star and the planet had a moon similar to Earth's moon. Would it result in an eclipse that looks like the eye of a cat/snake? Wondering for a SF/F book project where that world's religion would hinge upon this phenomena.

I've been reading on how the distance to the moon is calculated by bouncing a laser signal on the retro-reflectors and measuring the time it takes the light to return to Earth, but what I've seen is that the retro-reflectors do a good job of minimizing scattering by returning the signal along...

Homework Statement Io (pronounced “EYE oh”) is one of Jupiter’s moons discovered by Galileo. Io is slightly larger than Earth’s Moon. The mass of Io is 8.92*1022 kilograms and the mass of Jupiter is 1.9*1027 kilograms. The distance between the centers of Io and Jupiter is r =...

In my reading about Astronomy, I have encountered two seemingly different scenarios for the origin of the Moon: (A) Planet Gaia (unsure of spelling) crashed into the Earth. It nearly destroyed the Earth, but from that collision, debris formed into the Moon. (B) Planet Orpheus crashed into...

From observation I believe that the moons of Mars may provide a landing and lift off platform . The moon Deimos is near to geosynchronous orbit and drops a tether to dangle over the orbit of Phobos above the surface of Mars . From Phobos a shoe swing is tethered out and dropped onto Mars as...

I am not that great in physics, but I put a lot of effort in trying to learn it. I would really appreciate any help on this problem, since I am not even sure where to start. An asteroid is about to fly past the moon (about 384,000km away) and is on a collision course with the earth...

Homework Statement Experts recommend a release angle of 35 degrees for javelin throwing, use this as the release angle. Determine what the length of the equivalent throw on the moon would be. Clearly communicate the procedure you followed, and fully justify your answer. Homework...

Homework Statement Io - mass: 8.9x1022kg period: 1.77 days mean distance from Jupiter: 422x103km Find the mass of Jupiter using the data for Io. Homework Equations ƩF=ma Fc=mv2/r GmM/ro2 v=2∏r/TThe Attempt at a Solution I am just unsure what should I put the time in?? Seconds...

Homework Statement It is possible to determine the mass of a planet or large moon by using a ‘pendulum bob’ horizontal circular motion experiment. A cosmonaut on the moon finds that a 25 cm long ‘pendulum bob’ moving in uniform horizontal circular motion makes an angle of 22° to the vertical...

The fact the moon always faces us the same way fascinates me. Apparently the explanation is that our tidal bulge, and its tidal bulge "sync", which sort of makes sense. I wanted to know a bit more about this, if you guys don't mind helping a layman understand it all. Do we have evidence...

Question: The Moon has an albedo of 0.05. What is the total power of the solar radiation reflected from the Moon in units of 10^15 W? My Answer: - To get my answer i multiplied the flux density of the sun measured on the moon, then multiplied it by half of the moon's total surface area...

>>>If the mass of the moon were tripled and it was moved to half as far from the centre of the Earth as it now rests, what would the new gravitational force between the Earth and the moon be? Can someone confirm with me that the answer is 12 times the original? >> A 12 kg box is...

There is no real debate about the moon haux in the scientific community and evidence for the moonlanding that would be quite hard to fake, like the pendulum swing. Why is it that many people believe in the moon haux although there is no real evidence that the moonlandings were faked?

How does conservation of energy relate to Gravity? The moon seems to rotate around the Earth for eternity (so it seems). But intuitively I would think that the energy of Gravity would eventually deplete and the moon would drift off into space. This apparently isn't the case. I know that...

Hello, The problem is quite simple.You are an astronautics engineer in an established colony on europa,one of jupiter's moons and your boss asks you what would be the minimum velocity so that a cargo full of wastes or garbage is placed on a parbolic (neglecting the mass of europa versus the...

Homework Statement How much charge in Coulombs is required to levitate a motionless grain of dust 10 cm above the surface of the moon? Assume the dust grain is a point mass with mg = 1*10^-9g. The gravitational acceleration at the surface of the moon is 1.6m/s^2. Assume charge on the surface...