what is the procedure to measure distance to space objects?

Question

what kind of instrument or range finder is needed to measure the distance to an object in space,when we are talking about billions of light years,the object may not even be there anymore.?

Answer 1

One primary method is stellar parallax, which is basically using apparent motion to triangulate distance.

Answer 2

The answers so far are excellent. The overall answer involves coordinating observable information and integrating it into a mathematical model which involves all the above listed factors. Without the math, relying on just the observations, we would be far more vague about positions of deep space objects.
It sounds wacky to many, but I am convinced that coherent light does not travel between stars. This means, for all of the observations, the electromagnetic spectra (light) you perceive is a by-product of another phenomenon. When this viewpoint is integrated into the current mathematics and observations they will still be as valid, but the values for their distances may change. If something is now found to be farther away than another, it would still be farther away.

Answer 3

The mass of an object is the quantity of matter it contains! It is a measure of hw heavy or light the object is. The unit is Kg and grammes. Use a balance to measure mass ( e.g. beam balance). Infact, use any instrument calibrated in Grammes. When most people talk about "weight," they are infact refering to mass without knowing it! It may be conventional but it is wrong. The reason for the exixtence of such was that people innitially associated "weight" with Kg and grammes before science could come up with a distinction. Any time you see these units, the values are those of mass: kilogram, centigrams, decigrammes e.t.c In contrast, weight is a force, measured in Newton. Use a force meter( calibrated in Newton) for this... or multiply as follows: Weight = Mass x Acceleration due to gravity

Answer 4

A relativistic universe has four distinct distances: luminosity (inverse square), angular diameter, parallax, and proper motion. No two of them need agree to maintain consistency. Clocks can only be synchronized by being local.

In general, astronomy uses redshfit to determine distance. Redshift is calibrated by Cepheid variable stars and Type I supernova as standard candles plus inverse square law.

The universe is expanding at a rate of 70 (+/-)2 km/sec per megaparsec.

Answer 5

For distances like what you're talking about, one usually infers it from the Doppler shift of spectral lines. At these scales, galaxies are receding at a rate approximately proportional to their distance. The proportionality (Hubble) constant is calibrated by comparing the red shift to the apparent brightness of supernovae whose intrinsic brightness is known from more local observatons of supernovae of the same type whoses distances are easier to determine.

Answer 6

for stars they usually use a scale of brightness. they have a general idea of how bright each type of star is, so say if a white dwarf, should be this bright at this distance than they can compare it to the rest of the white dwarfs out there.

then they can use the motion of the earths orbit around the sun to trianglate closer planets and stars, while they use circular motion of planets to pinpoint their position.