0_Wizard
the ocean composes most of the planets hydrosphere 
An ocean (, the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere.
chosen_Ocean_0
Ocean
chosen_topic_0_Ocean
Ocean
An ocean (, the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere. On Earth, an ocean is one of the major conventional divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans. The word "sea" is often used interchangeably with "ocean" in American English but, strictly speaking, a sea is a body of saline water (generally a division of the world ocean) partly or fully enclosed by land. Saline water covers approximately and is customarily divided into several principal oceans and smaller seas, with the ocean covering approximately 71% of Earth's surface and 90% of the Earth's biosphere.
Hydrosphere
The hydrosphere (from Greek ὕδωρ "hydōr", "water" and σφαῖρα "sphaira", "sphere") is the combined mass of water found on, under, and above the surface of a planet, minor planet or natural satellite. It has been estimated that there are 1386 million cubic kilometers of water on Earth. This includes water in liquid and frozen forms in groundwater, oceans, lakes and streams. Saltwater accounts for 97.5% of this amount. Fresh water accounts for only 2.5%. Of this fresh water, 68.9% is in the form of ice and permanent snow cover in the Arctic, the Antarctic, and mountain glaciers. 30.8% is in the form of fresh groundwater.
Modern Mars habitability
One of the central questions of modern Astrobiology is whether there is, or ever has been life on Mars. Mars probably had oceans in the past, and it definitely had lakes and a thicker atmosphere. Modern Mars has become cold, dry, and almost uninhabitable, yet, if life did ever arise on Mars, some hardy microbes and perhaps even multicellular life might survive there right through to the present. The only missions to search for life on Mars, the two Viking missions, returned results that were inconclusive . However the instruments were not designed to cope with the unusual conditions which Viking discovered on Mars, which may have confused the results of the experiments.
Geology of solar terrestrial planets
The geology of solar terrestrial planets mainly deals with the geological aspects of the four terrestrial planets of the Solar System, Mercury, Venus, Earth, and Mars, and one terrestrial dwarf planet, Ceres. Only one terrestrial planet, Earth, is known to have an active hydrosphere. Terrestrial planets are substantially different from the giant planets, which might not have solid surfaces and are composed mostly of some combination of hydrogen, helium, and water existing in various physical states. Terrestrial planets have a compact, rocky surfaces, and Venus, Earth, and Mars each also have an atmosphere.
Earth
Earth is the third planet from the Sun and the only object in the Universe known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4 billion years ago. Earth's gravity interacts with other objects in space, especially the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in 365.26 days, a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times. Earth's axis of rotation is tilted, producing seasonal variations on the planet's surface. The gravitational interaction between the Earth and Moon causes ocean tides, stabilizes the Earth's orientation on its axis, and gradually slows its rotation.
Circumstellar habitable zone
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. The bounds of the CHZ are based on Earth's position in the Solar System and the amount of radiant energy it receives from the Sun. Due to the importance of liquid water to Earth's biosphere, the nature of the CHZ and the objects within it may be instrumental in determining the scope and distribution of Earth-like extraterrestrial life and intelligence. The habitable zone is also called the Goldilocks zone, a metaphor of the children's fairy tale of "Goldilocks and the Three Bears", in which a little girl chooses from sets of three items, ignoring the ones that are too extreme (large or small, hot or cold, etc.
Abiogenesis
Abiogenesis (British English: , ), biopoiesis, or informally the origin of life, is the natural process by which life arises from non-living matter, such as simple organic compounds. On Earth, the transition from non-living to living entities was not a single event but a gradual process of increasing complexity. Abiogenesis is studied through a combination of paleontology, chemistry, and extrapolation from the characteristics of modern organisms, and aims to determine how pre-life chemical reactions gave rise to life on Earth. The study of abiogenesis can be geophysical, chemical, or biological, with more recent approaches attempting a synthesis of all three, as life arose under conditions that are strikingly different from those on Earth today.
1_Apprentice
I knew it was a lot - the oceans are still so unexplored