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.
Therefore, the distance between the earth and the sun varies throughout the year. At its nearest point on the ellipse that is the earth's orbit around the sun, the earth is 91,445,000 miles (147,166,462 km) from the sun. This point in the earth's orbit is known as perihelion and it occurs around January 3.The earth is farthest away from the sun around July 4 when it is 94,555,000 miles (152,171,522 km) from the sun. This point in the earth's orbit is called aphelion.herefore, the distance between the earth and the sun varies throughout the year. At its nearest point on the ellipse that is the earth's orbit around the sun, the earth is 91,445,000 miles (147,166,462 km) from the sun. This point in the earth's orbit is known as perihelion and it occurs around January 3.