They are found within the bounds of the ocean floor and in the transitional zone and are divided into two morphological typesâflat, or subhorizontal, and hilly. Flat abyssal plains are confined to the margins of ocean basins or to the centers of the basins of epicontinental seas. Hilly abyssal plains occupy a large part of the bottom of the ocean floor. The surface of the flat abyssal plain is characterized by exceptional evenness, with floor gradients of less than 0.001. Starkly contrasting solitary seamounts, evidently of volcanic origin, are also found.
The first person to do so ever was as early as the 3rd century BC by Aristarchus of Samos. Unfortunately, his notion gained only few supporters and was summarily rejected. Later in the 16th century, Nicholas Copernicus presented a mathematical model. In the next century, Johannes Kepler made inclusions of elliptical orbits, and Galileo Galilei presented supporting observations made using a telescope.
Uranus was discovered by Sir William Herschel in 1781. Herschel was probably the most famous astronomer of the 18th century. In addition to discovering the planet Uranus, he also observed and cataloged over 800 double stars and 2,500 nebulae.luto was discovered by astronomer Clyde Tombaugh in 1930. A 9th planet had been looked for for some time. It was believed that such a planet had to exist in order to explain some odd things happening in the orbits of Uranus and Neptune.