SOLAR SYSTEM

Detailed explanation-1: -Though long-period comets observed among the planets are thought to originate in the Oort Cloud, no object has been observed in the distant Oort Cloud itself, leaving it a theoretical concept for the time being. But it remains the most widely-accepted explanation for the origin of long-period comets.

Detailed explanation-2: -No known estimates of the mass of the inner Oort cloud have been published. If analyses of comets are representative of the whole, the vast majority of Oort-cloud objects consist of ices such as water, methane, ethane, carbon monoxide and hydrogen cyanide.

Detailed explanation-3: -Meteoroids are even found on the edge of the solar system, in regions called the Kuiper belt and the Oort cloud. Different meteoroids travel around the sun at different speeds and in different orbits. The fastest meteoroids travel through the solar system at a speed of around 42 kilometers (26 miles) per second.

Detailed explanation-4: -The Oort cloud is believed to be a potential source of meteorites that fall to Earth. During the planet formation process, smaller objects-including asteroids and comets-were drawn to the outer edges of the solar system.

Detailed explanation-5: -Beyond the Oort Cloud are the termination shock and heliopause. While the inner solar system is protected from many external forces, the Oort Cloud occasionally encounters large forces that affect the orbits of the icy bodies.