1000 parsecs. A parsec equals 3.26 light years. LIGHT YEAR The distance light can travel in one year, which is 9,500,000,000,000 kilometers. MAGNETIC FIELD The area in which an attractive or repelling force exists between two magnets or in association with the element iron. The Earth's magnetic field is thought to be due to the liquid iron-nickel which is in its core. This magnetic field protects Earth from constant bombardment by high-energy charged particles.