Can anyone explain what the Oort cloud exactly is?

Answer 1

A vast region of space far beyond the orbit of Pluto where millions of comets are believed to reside.

Comets are in highly elliptical orbits, sometimes approaching closer to the Sun than Earth or even Mercury and sometimes passing far beyond the orbit of Pluto. Since the speed of any object in an elliptical orbit is slow at the high point and fast at the low point, it is easy to calculate that a comet we see taking a year or two to pass through the inner solar system has to have spent thousands or even millions of years in the slow distant part of it's orbit. If every comet that we see spending a year or two close to the Sun also spends thousands or even millions of years too far away to see, then there must be thousands or even millions of times more comets than we have ever seen lurking out past Pluto. That collection of comets is called the Oort cloud.

Answer 2

The Oort cloud is an immense spherical cloud surrounding the planetary system and extending approximately 3 light years, about 30 trillion kilometers from the Sun. This vast distance is considered the edge of the Sun's orb of physical, gravitational, or dynamical influence.

Answer 3

Jan Oort was a Dutch professor astronomy in Leiden university.
He suggested as the first person, that the comets in and outside our solar system all come from a hugh cloud around this solar system.

Answer 4

The Ooort Cloud is a region of the solar system beyond the orbit of Pluto, which is believed to be where comets are born.

Answer 5

This site will give your answer and give you a picture to see how OORT cloud is about.
http://www.issp.ac.ru/iao/ap/index.html

Answer 6

basically, just ice, rock, a conglomeration of "****" so to speak.