Moon Definition and 1000 Threads

On 11th December 1972, almost 40 years ago, man set foot on the moon for the last time. The Apollo 17 mission manned by Eugene Cernan and geologist Harrison Schmitt was the last in the program, marking the end of, quite possibly, the most important era in space exploration. The Apollo...

Why does tidal force strectechs the Earth and creates two tidal bulges, like pulling on a rubber band, instead of pulling Earth and moon together?

Hello, I am an architect at UCL london and am currently looking at a hypothetical scene whereby the length of a day could be increased to something at least over a month (i.e. the Earth would be spinning so slowly that it would be in contact with the sun for 30 days and darkness for 30 days). I...

The moon is still there right? I understand how the act of measuring can cause subatoms to collapse into fixed positions but they do not have mass. And the moon is made of atoms not a flurry of electrons its made of atoms. My question is are atoms (which have mass) there even when they haven't...

Let's say that the Moon has a mass of 7.4 x 10^22 kg. What's the force that the Earth, and the Sun exerts on the Moon?

Homework Statement How far above the surface of the moon should a satellite be placed so that it is stationary with respect tot the moons surface. Radius of moon = 1737.4 kilometers mass of moon = 7.36 x 10^22 kilograms Gravitational Constant = 6.67 x 10^ -11 N x m^2/kg6@ Homework...

Homework Statement 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. Some information that will help during this problem: mearth = 5.9742 x 1024 kg rearth = 6.3781 x...

How do you calculate the centroid of the earth-moon system? Is it this exact point that the moon-earth system orbits? Is it an elliptical or circular orbit?

Homework Statement 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. Some information that will help during this problem: mearth = 5.9742 x 1024 kg rearth = 6.3781 x...

Colourful moon dog observed, or what?? Look at the following picture, taken 12/9 by Thomas Sannes: http://www.storm.no/nyheter/fotograferte-sjeldent-vaerfenomen-3583707.html He sent the picture to meteorologists, and they made their bet that this rainbow-coloured bright spot on the night...

Homework Statement The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force that the sun exerts on the moon is perpendicular to the force that the Earth exerts on the moon. The masses are: mass of sun=1.99 × 1030 kg, mass of earth=5.98 × 1024 kg...

Hi! When it comes to physics, I'm a total layperson (so, please, be kind ;-)), I actually study English, but recently my interest in physics has been growing more and more. So, yesterday I started watching the first of Feynman's Cornell University lectures. And that led me to the question: why...

A 3.07-kg object is thrown vertically upward from the surface of Earth, where the acceleration due to gravity is g1 = 9.81m/s2. The intial velocity is v1, and the object reaches a maximum height of y1. What is the maximum height, y2, if the object is thrown at a speed of v2 = 1.15v1 from the...

can we hear the sound of our steps in moon?

A bottle of water at 0'C is opened on the surface of moon. What happens and why?

It takes light roughly 1.3 seconds to travel from the Earth to the moon. I have read that even if you push on one end of a stick, the effect of the push cannot reach the other side of the stick faster than c. So suppose I held a stick in my right hand and one end of this stick is only 1cm...

my book says that the distance of the moon from the Earth was known in Newton's time but it doesn't say how they figured it out. it's 380,000 km. does anyone know how they knew it?

I understand orbit and why the moon doesn't collide with the earth, but why doesn't the Earth collide with the moon? Shouldn't the mutual gravitational forces attract each other, get stronger, until they eventually meet?

I was reading an article over the weekend that the Moon has evidence of a "final" volcano on it's "far side." I am working on something that suggests the Moon would be too small to have had volcanoes, and this didn't fit with my assumption. I then reasoned that based on size, and based on the...

Just saw this article here about it being announced on 20 July of this year, 2011! http://en.wikipedia.org/wiki/S/2011_P_1

Dear all, It's late in the night and I have some trouble in deriving the expression of the ratio of the illuminated disk to the whole disk. Is it a formula "by definition" ? See...

With current technology, could humans move Phobos to join with Deimos to create a single Mars moon? Move moon as a whole/cut it up and move it in peices, etc.

i mean when the moon is full like during 10-20 of lunar month the tides are higher but y?even when the moon isn't full its still there whole in sky? what is the reason?

Good morning, I've searched about this case in the internet but just found things about asteriods sharing the same orbit as Earth over the sun, but I wonder if an asteroid can get stuck in Earth's orbit like the moon. Thanks!

I'm not very fluent in how astral bodies are affected be gravity yet, or else I'd punch some numbers myself. But, what would be needed to knock the moon out of its current orbit and start it on an eventual collision course with the Earth? And what could (theoretically) cause this force?

Homework Statement A person can jump a maximum horizontal distance (by using a 45 ◦ projectile angle) of 4 m on Earth. The acceleration of gravity is 9.8 m/s 2 . What would be his maximum range on the Moon, where the free-fall acceleration is g 6 ? Answer in units of m...

1. Homework Statement Part One: Calculate the magnitude of the gravitational force between the Moon and an m = 6.45 kg mass on the surface of the Earth nearest to the moon. The distance to the center of the Moon from the surface of the Earth is 3.76×105 km and the mass of the Moon is...

I got to thinking about this recently, when thinking about various proposed "renewable energy" systems based on tidal energy capture. Tidal energy is, basically, caused by the interaction of the kinetic energy of rotation of the earth/oceans, the kinetic energy of the moon's orbit, and the...

Tides in sea are caused not by moon but by sun. Though the force of attraction caused by sun is much more than that by moon.

When calculating the mass of the Earth using the moon as a reference and Kepler's 3rd Law, is it correct to subtract the moon's mass after completing the sum: me = (4*(pi)2*r3) / (G*t2) me = (4*(pi)2*3850000003) / (G*23587202) me = 6.07E+24 Should I be subtracting the moons mass to get: me...

A) If the moon of mass mM has radius RM and the distance between the centers of the Earth and the moon is REM, find the total gravitational potential energy of the particle-earth and particle-moon systems when a particle with mass m is between the Earth and the moon, and a distance r from the...

A friend insist that gravity is due to Earth's rotation and that if it stopped spinning the moon would sease to orbit and would be lauched in space! Is that right? What pourcentage of Earth's gravity is caused by it's rotation? I thought the gravity came from it's mass! Thanks Eric

NASA have places a mirror on the Moon, and have thereby been able to measure that the Moon is moving 38 mm away from the Earth every year. Does anybody know more than this. Where to read about it? If measurement data are available ? etc..

Homework Statement A 6000 kg lunar lander is in orbit 80 km above the surface of the moon. It needs to move out to a 200 km -high orbit in order to link up with the mother ship that will take the astronauts home. How much work must the thrusters do? Homework Equations...

I have an iPad app almost complete that displays live weather data from my home weather station here in Hawaii for community use. I'm showing a picture of the moon phase, and a UPS freight pilot friend who flies at night pointed out that the conventional vertical phase orientation is...

I have always been curious about what would happen to the gravity at the center of the earth. After some googling I found some neat stuff. So IF it was possible to endure the heat and pressure to get there (impossible) it would feel weightless. So that answered my question but then I read it...

Hey rocket folks - In light of those artists that deal with massive art, like covering an outdooors area with cloth and the like I thought it would be interesting to propose a world shaking art project. Yes, I know this would never fly with the world and it might cause problems with the...

Hi, I'm an old biologist/naturalist who loves to go tidepooling, so this is not a homework question. Why do the lowest tides follow the full moon by a few days? For example, the "super" full moon of yesterday March 19, will pull the lowest tides (here in Maine) on Monday and Tuesday March 21...

My guess is that a small jovian can be a moon of a much larger jovian. Is this likely, and how would we detect it? Just something I've never seen before. It seems that the assumption is that all moons of jovian planets are terrestrial. Also possible are jovian binary planets, but I'm talking...

Please join with me this Sunday or Monday when the full moon of the vernal equinox rises over the east horizon just around or after sunset. Finally it will prove that the full moon appears biggest and brightest when it rises over the horizon while at Perigee, its closest approach to Earth. The...

Homework Statement Jupiter's moon Io is has an orbital radius of 421,000 km, around the planet Jupiter (MJ = 1.9 x 1027 kg). Io's radius is 1821 km and its mass is 8.93 x 1022 kg. Calculate the tensional force inside Io, as a result of Jupiter's gravitation.Homework Equations Fg= GMm / r2The...

Hi, I was wondering about an issue that we just started in my physics class: we learned that center of mass (CM) and center of gravity (CG) coincide in an object as long as the force of gravity is uniform over that object. So, for something near the Earth's surface we can say that CM and CG...

Moon rocks containing uranium 238, decays to lead with a half life of 4.5 billion yrs. The lunar rock sample you're invistigating contains half of the original uranium 238. How old is the rock? How would I go about solving this? What formula should I use?

I was wondering if there was a way to build something to see the surface of the moon easily like our satellites can zoom in on us... Is it possible to take a mirror and put it under a microscope that has say 10,000x magnification. Then take a second mirror and reflect the moon onto the mirror...

I understand that Libration allows us to see a total of about 9% of the far side of the moon, but what are the individual percentages of the far side of the moon that longitude, latitude, Diurnal and physical Libration allows us to see? I can't seem to "Google-up" these individual...

My son asked me if the moon is always full as seen from orbit. I think it is apreciably the same. E.g at new moon, the astronauts wouldn't see the moon. Is that true?

Hello there! When a motor is turning, if one applies a resisting torque on the rotor, the latter would brake, but then if one remove the torque, the motor recovers its initial speed. Is the same with Earth's spin and Moon's resisting torque on it (due to tidal effect)? ie: if, one day...

Homework Statement The gravitational field strength on the moon, which has a radius of 1.74 x 10^6 m, is approximately 0.17 as large as the gravitational field strength at the surface of the earth. The satellite is at an altitude of 100km above the moon. What is the radius of the orbit of...

I was just wondering why, if the gravitational force exerted on it by the Sun is greater than the one exerted on it by the Earth, the Moon stays in orbit around the Earth? Is it due to angular momentum or are there any other factors?