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.
The orbit of the Earth around the Sun is an ellipse. The distance is not fixed, but varies throughout its orbit. The average distance is about 150 million kilometers (149,597, â¦ 890 km) or about 93 million miles (92,955,820 mi.). The distance at perihelion is 147,098,290 km, the distance at aphelion is 152,098,232 km.e receive the same amount of solar radiation year-round. during the winter that radiation is spread over a larger surface and so it is less effective, during the summer the same radiation is on a smaller surface and so it is warmer.