Parsecs & Lightyears?
821198
persec is the largest unit of distance and is 3.26 times of a light year.Whereas one light year is equal to 9.45X10^12 km ,one persec is equal to 30.84X 10^12 km.This is the reason for using persec
286920
they're already in scientific notation!\nI think you mean decimal form..
613765
See in\nhttp://www.seds.org/nineplanets/nineplanets/nineplanets.html\nGood luck!
670041
There are a few measurements that astronomers/cosmologist use to describe the great distances of space.\n\nHere are a few:\n\nLightyear - The distance that light travels in a vacuum in one year, approximately 9.46 trillion (9.46 × 10^12) kilometers or 5.88 trillion (5.88 × 10^12) miles. \n\nAstronomical Unit - A unit of length used in measuring astronomical distances within the solar system equal to the mean distance from Earth to the sun, approximately 150 million kilometers (93 million miles).\n\nParsec - A unit of astronomical length based on the distance from Earth at which stellar parallax is one second of arc and equal to 3.258 light-years, 3.086 × 10^13 kilometers, or 1.918 × 10^13 miles.
773665
70 sextillion according to this site\nhttp://www.cnn.com/2003/TECH/space/07/22/stars.survey/
766153
pulsar \npulse\npulsing\npulses
488777
A light year is a measurement of distance, not time.  It's the distance light travels in a year.  For example it takes light about 8 minutes to get from the Sun to the Earth.  Alpha Centauri (the next nearest star) is 4 light years away.\n\nA light year is 9.4605284 × 10^15 meters (10^15 means 10 to the 15th power).  Basically, it's REALLY far and only good for measuring huge distances in space.
488135
A little over 4.35 light years.
905593
zee_prime's got a good answer there.  Very precise and correct.  I'm gonna take another approach to it, though, and try to make it intelligible for those who don't have a lot of math or physics behind them.  My answer'll be correct, too, it'll just use smaller words--and more of them!  (-;  \n\n~~\nPARSEC:\nA parsec is a standard unit of astronomical distance equal to 3.26 light years. It is also the distance a star has to be from earth so that its parallax is one arcsecond.\n\nOuch!  What the heck does all that mean? \n\nFirst off, we need to know about "parallax".  Parallax is easy.  It's just the change in the apparent position of an object when your position changes. \n\nA great example is easy to show: hold a thumb up in front of your face, about 20 centimeters away. Close your left eye, and move your thumb so that while looking through your right eye it is lined up with some distant object like a tree. Now close your right eye and look at your thumb through your left eye. See how it no longer lines up with the tree? That's because the angle formed by your eye, your thumb and the tree has changed. That angle is called the parallax angle.\n\nParallax angle depends on two things: (1) how far apart your eyes are (the baseline), and (2) how far away your thumb is. If your eyes are really far apart, the angle gets bigger. If the thumb is held farther away, the angle gets smaller. \n\nWhen you are in a car and you look at trees nearby, they appear to race past you. Far away trees appear to move slowly. This is because for the nearby trees the parallax angle is large and so it changes rapidly if the car moves a little bit. Trees farther away appear to change less as the car moves along. Their parallax angle is small. \n\nThis parallax method has been used for over a hundred years to find the distances to nearby stars. The Earth has an orbit about 300 million kilometers across. That's a long baseline! Even nearby stars will appear to change position due to parallax when you have such a long baseline. \n\nAstronomers needed some sort of unit to measure this change in position. What they decided was to make a standard unit for the distance. A star at that distance would change position by 1 arcsecond due to parallax. The distance is 3.26 light years, and is abbreviated parsec for PARallax SECond. (Ummm, one arcsecond is 1/3600 of a degree--which comes from 360 degrees of a full circle.) \n\nStars farther away than one parsec would shift by less than 1 arcsecond, and closer stars by more. The nearest star to the Sun is Proxima Centauri, which is about 4.3 light years away, or 1.3 parsecs away. That means that even the closest star has a parallax less than an arcsecond. Stars out to a distance of about 100 parsecs have had their distance measured this way. \n\nTo imagine how small a shift that really is, imagine someone standing 125 miles (about 200 kilometers) away from you and then moving to the left by one centimeter. That is the same shift! \n\nGot it?
1145113
This should help you:  http://www.le.ac.uk/physics/faulkes/web/stars/o_st_overview.html
818301
It's the distance light travels in a year, ie about\n\n5,878,625,373,183.61 statute miles.\n\n(Based on a reference year of exactly 365.25 days (each of exactly 24 hours). This is the value recommended by the International Astronomical Union. It is not a universal standard.)
327223
1 lightyear is the distance a beam of light can travel in a vacuum in one year.  Given that the speed of light is roughly 3*(10^8) meters per second, or about 670.6 million miles per hour, then 93 million miles is about 1.58*(10^-5) lightyears.  Another way to look at it, is that it takes about 7.21 minutes for light from the sun to reach earth, and they are roughly 93 million miles apart.
50566
A light-year is not a measure of speed; it is a measure of distance.  In particular, it is the distance traveled by light in one year.\n\nLight moves at 299,792,458 meters/second and there are 31,536,000 seconds in a year so a light year is:\n\n9,454,254,955,488,000 meters.\n\nBecause this number is so large, cosmologists use units similar to the light year to measure astronomical distances.  In particular, they tend to use parsecs to measure distance where 1 parsec = 3.26163626 light years.
267068
a light year isn't a speed, it's a distance, that's like asking how fast is a mile.\n\na light year is 5,865,696,000,000 miles
1151942
Metric system?????\n\nWe BARELY know the system we're using now!!! Anyone who knows their Multiplication Table is considered a Mathematical GENIUS!!!
591913
Despite it sounding like time, light year measures distance.\nIt's the distance that light travels in space in one year, a very long distance.\n\n186000*365*24*3600 = 5.87 x 10^12 miles.
224869
one light year = 9.4605284 × 10^15 meters \n  (go to google and type meters in one light year in the search box)