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.
Now, since the average distance between the Earth and the Sun over one Earth orbit is one AU (about 150,000,000,000 m), then it will take about 8 minutes for radiation from the Sun to get to Earth. Actually, the Sun does not only produce IR, visible light, and UV.Fusion in the core actually gives off high energy gamma rays. However, as the gamma ray photons make their arduous journey to the surface of the Sun, they are continuously absorbed by the solar plasma and re-emitted to lower frequencies.ow, since the average distance between the Earth and the Sun over one Earth orbit is one AU (about 150,000,000,000 m), then it will take about 8 minutes for radiation from the Sun to get to Earth. Actually, the Sun does not only produce IR, visible light, and UV.