Top 10 Earth facts Selected as the most interesting among geology related questions in Geology quiz Where is the saltiest lake in the world?In Antarctica. With a salinity level of over 40%, Don Juan Pond is the saltiest of the Antarctic lakes. This salinity allows the pond to remain liquid even at temperatures as low as −50 °C (−58 °F) due to the interference of salts with the bonding of water molecules. Don Juan Pond was discovered in 1961 by George H. Meyer.Created by: Tschukasalt facts » Why is the ozone hole dangerous?It increases UV radiation. In the ozone layer, ozone molecules absorb UV-B and UV-C radiation - short wavelength forms of ultraviolet that can disrupt organic molecules, producing cancerous changes in living cells.Created by: Riho Ishiiatmosphere facts » In which month is the Earth closest to the Sun?In January. Earth's perihelion occurs around January 3, and the aphelion around July 4. The distance change is about 3.5%, which gives 6.9% increase in solar energy reaching the Earth at perihelion relative to aphelion. Since the southern hemisphere is tilted toward the perihelion, the southern hemisphere receives more energy from the Sun than does the northern over the course of a year. Created by: globalquiz.orghard simple questions facts » If Earth's radius was larger by 1 meter, how much longer would its equator be?By approx 6 meters. For each circle, the length of the circumference is c=2πr. Hence, if a radius grows by 1 meter, the circumference grows by 2 π meters - no matter what the initial value of radius was.Created by: SpikeMemath facts » What is the rarest metal in the Earth's crust?Rhenium is a chemical element with symbol Re It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. Discovered in 1908, rhenium was the second-last stable element to be discovered. It was named after the river Rhine in Europe. Created by: Tschukametals facts » What is the most common element (by mass) forming the planet Earth?Iron is most abundant in the Earth's outer and inner core, and it is the fourth most common element in the Earth's crust.Created by: globalquiz.orgelements facts » What part of the Earth's surface is dry land?29,2%. It is currenlty 29.2% - but it may decrease in the near future due to global warming and sea level rise.Created by: Krzysztof Moskalwater facts » What is the tallest mountain in the world, when measured from its base?Mauna Kea is a dormant volcano on the island of Hawaii. Standing 4,207 m above sea level, its peak is the highest point in the state of Hawaii. Most of the mountain is underwater; when measured from its oceanic base, Mauna Kea is over 10,000 m tall and is the tallest mountain on Earth.Created by: Ninjaimountains facts » What object collided with Earth according to the giant impact hypothesis?A planet. According to the giant impact hypothesis Earth once collided with a planet of Mars size usually referred to as Theia, a titaness of Greek mythology, mother of Selene - Moon goddess, which is to reflect the believe the collision was an origin of the Moon. Created by: smyruuniverse facts » After what is the Jurassic period named?A mountain range in Switzerland. The Jurassic period is named for the Jura Mountains in between France and Switzerland, where many fossils have been found.Created by: MarcusXSwitzerland facts » Play geology quiz and see all the questions.