Mass is the quantity of matter in an object. Weight is the amount of gravitational force acting on an object. Hope the answer was helpful. ;-)

mass - 1 a: a quantity or aggregate of matter usually of considerable size b (1): expanse, bulk (2): massive quality or effect <impressed me with such mass and such vividness — F. M. Ford> (3): the principal part or main body <the great mass of the continent is buried under an ice capitalized — Walter Sullivan> (4): aggregate, whole <men in the mass> c: the property of a body that is a measure of its inertia and that is commonly taken as a measure of the amount of material it contains and causes it to have weight in a gravitational field2: a large quantity, amount, or number <a great mass of material>3 a: a large body of persons in a compact group : a body of persons regarded as an aggregate b: the great body of the people as contrasted with the elite — often used in plural <the underprivileged and disadvantaged masses— C. A. Buss> weight - 1 a: the amount that a thing weighs b (1): the standard or established amount that a thing should weigh (2): one of the classes into which contestants in a sports event are divided according to body weight (3): poundage required to be carried by a horse in a handicap race2 a: a quantity or thing weighing a fixed and usually specified amount b: a heavy object (as a metal ball) thrown, put, or lifted as an athletic exercise or contest3 a: a unit of weight or mass — see metric system table b: a piece of material (as metal) of known specified weight for use in weighing articles c: a system of related units of weight4 a: something heavy : load b: a heavy object to hold or press something down or to counterbalance5 a: burden, pressure <the weight of their responsibilities> b: the quality or state of being ponderous c: corpulence6 a: relative heaviness : mass b: the force with which a body is attracted toward the earth or a celestial body by gravitation and which is equal to the product of the mass and the local gravitational acceleration7 a: the relative importance or authority accorded something <the weight of her opinions> b: measurable influence especially on others <throwing his weight behind the proposal>8: overpowering force9: the quality (as lightness) that makes a fabric or garment suitable for a particular use or season — often used in combination <summer-weight>10: a numerical coefficient assigned to an item to express its relative importance in a frequency distribution11: the degree of thickness of the strokes of a type character yes it is as far as i know astronauts can move objects in large mass in outer space the way everyone can move most objects under water lessening half of its weight but this depends on the situation.. but yes possible..

As Terminator said, mass is the quantity of a thing and weight to do with gravity. Massy objects have great inertia and so are hard to stop and start moving, even in space. Incidentally, there is no weightlessness in space. In an orbiting frame of reference like the ISS, because the occupants are in free fall while orbiting, and the station is too, the occupants feel weightless. "Microgravity" is a better term for this state of affairs.

mass= weight/acceleration due to gravity But weight= mass*acceleration due to gravity

1) "In the physical sciences, mass and weight are different properties. Mass is an inertial property; that is, the tendency of an object to remain at constant velocity unless acted upon by an external force. Weight is the force created when a mass is acted upon by a gravitational field. While the weight of matter is entirely dependent upon the strength of local gravity, the mass of matter is constant (assuming it is not traveling at a relativistic speed with respect to an observer). Accordingly, for astronauts in microgravity, no effort is required to hold objects off the cabin floor since such objects naturally hover; they are “weightless.” However, since objects in microgravity still retain their mass, an astronaut must exert ten times as much force to accelerate a 10-kilogram object at the same rate as a 1-kilogram object." Source and further information: http://en.wikipedia.org/wiki/Mass_versus_weight Further information: http://www.answerbag.com/a_view/2429890 http://www.answerbag.com/a_view/5127636 http://www.answerbag.com/a_view/5127733 2) "Weightlessness is a phenomenon experienced by people during free-fall. Although the term zero gravity is often used as a synonym, weightlessness in orbit is not the result of the force of gravity being eliminated or even significantly reduced (in fact, the force of the Earth's gravity at an altitude of 100 km is only 3% less than at the Earth’s surface). Weightlessness typically occurs when an object or person is falling freely, in orbit, in deep space (far from a planet, star, or other massive body), in an airplane following a particular parabolic flight path (e.g., the “Vomit Comet”), or in one of several other more unusual situations." "Often, the terms zero gravity or reduced gravity are used to mean weightlessness as it is experienced by orbiting spacecraft, but this is not technically accurate. Spacecraft are held in orbit by the gravity of the planet which they are orbiting. The sensation of weightlessness experienced by astronauts is not the result of there being zero gravitational acceleration, but of there being zero difference between the acceleration of the spacecraft and the acceleration of the astronaut." "Weightlessness can also be simulated with the use of neutral buoyancy, in which human subjects and equipment are placed in a water environment and weighted or buoyed until they hover in place. NASA uses neutral buoyancy to prepare for extra-vehicular activity (EVA) at its Neutral Buoyancy Laboratory. Neutral buoyancy is also used for EVA research at the University of Maryland's Space Systems Laboratory, which operates the only neutral buoyancy tank at a college or university. Neutral buoyancy is not identical to weightlessness, but it is similar in that the astronaut is free to move all parts of their body. This is because the net buoyancy force that supports the astronaut is distributed widely over their body. Drag is also a significant factor when moving in a neutral buoyancy environment, whereas astronauts on EVA do not experience any drag." Source and further information: http://en.wikipedia.org/wiki/Weightlessness 3) "Imagine yourself out is space away from any gravitational field, with a bowling ball in your hands. Let it go and it just floats in front of you. Without gravity, it has no weight. Now grab it again and shake it back and forth. That resistance to being moved is inertia, and mass measures how much inertia an object has. Inertia does NOT depend on gravity." Source and further information: http://www.physlink.com/Education/askExperts/ae321.cfm "If you are in a spaceship far between the stars and you put a scale underneath you, the scale would read zero. Your weight is zero. You are weightless. There is an anvil floating next to you. It's also weightless. Are you or the anvil mass-less? Absolutely not. If you grabbed the anvil and tried to shake it, you would have to push it to get it going and pull it to get it to stop. It still has inertia, and hence mass, yet it has no weight. See the difference?" Source and further information: http://www.exploratorium.edu/ronh/weight/ 4) Notice that if you want to apply a force to move a massive object, it is necessary for you to be fixed somehow on a still less unmovable object. Because of the principe of action and reaction, it will be very dificult for you to move a pickup truck if you stay on it without grasping the ground, but you could move it by pushing it if you stay on a solid ground. The same applies for a boat: it will be difficult to move if you stay on it (except, maybe, by pushing the water), but you could tow it from the shore. A donkey could tow a massive boat that way.