Question

explore directions: read the information below. then use the information to answer the questions. water is an abiotic factor that is essential for life on earth. its properties are very unique! in fact, it is made of only two gases: oxygen and hydrogen. these gases bind together to make a liquid molecule. before we further explore the chemistry of water and other molecules that make up the abiotic and biotic factors on earth, lets discuss the origin of water. earth is called the water planet because its approximately 80% water! it is the only planet in our solar system with liquid water on the surface. but, where did earths water come from? in the following excerpts, you will read about evidence supporting different claims regarding the origin of earths water. after you read the excerpts, answer the questions. article excerpt 1: in trying to understand the formation of the early earth, some researchers have suggested that the planet was dry and inhospitable to life until icy comets pelted the earth and deposited water on the surface. wendy panero, associate professor of earth sciences at ohio state, and doctoral student jeff pigott are pursuing a different hypothesis: that earth was formed with entire oceans of water in its interior, and has been continuously supplying water to the surface via plate tectonics ever since. researchers have long accepted that the mantle contains some water, but how much water is a mystery. and, if some geological mechanism has been supplying water to the surface all this time, wouldnt the mantle have run out of water by now? because theres no way to directly study deep mantle rocks, panero and pigott are probing the question with high - pressure physics experiments and computer calculations. “when we look into the origins of water on earth, what were really asking is, why are we so different than all the other planets?” panero said. “in this solar system, earth is unique because we have liquid water on the surface. were also the only planet with active plate tectonics. maybe this water in the mantle is key to plate tectonics, and thats part of what makes earth habitable.” gorder, pam f. “study hints that ancient earth made its own water—geologically.” the ohio state university news room. ohio state university, 17 dec. 2014. 1. according to the article, where did earths water come from?

Explanation:

The article presents two hypotheses. One is that icy comets deposited water on Earth's surface. The other is that Earth was formed with water in its interior and supplies water to the surface via plate tectonics.

Answer:

There are two main hypotheses: 1. Icy comets deposited water on Earth's surface. 2. Earth was formed with water in its interior and supplies water to the surface via plate - tectonics.