Chances are the lake closest to you is a freshwater lake. But some lakes are extremely salty. These are called saline lakes. Although freshwater lakes often have minor amounts of dissolved salts in them (less than 1-3 g/L), saline lakes have more than this (between 3 and 300g/L).
Astronomical Unit (A.U.). An astronomical unit (A.U.) is the average distance between the Earth and the Sun, which is about 93 million miles or 150 million kilometers.Astronomical units are usually used to measure distances within our solar system.ne kiloparsec (kpc), is one thousand parsecs. One megaparsec (Mpc) is one million parsecs. SUMMARY 1 Astronomical Unit (A.U.) is the average distance between the Sun and the Earth. 1 A.U. = 93 million miles = 150 million kilometers 1 light-year (ly) is the distance that light travels in one year in a vacuum.
2. To demonstrate the distance between Sun and Earth at this scale, separate the images 65 feet (about 20 meters) apart. This distance represents approximately 93 million miles (150 million kilometers). This image of Earth is scaled to the proper size in relation to the image of the Sun below.o demonstrate the distance between Sun and Earth at this scale, separate the images 65 feet (about 20 meters) apart. This distance represents approximately 93 million miles (150 million kilometers). This image of Earth is scaled to the proper size in relation to the image of the Sun below.