MCQ Detailed View

The Oort Cloud is a vast, spherical region of icy bodies believed to surround the solar system far beyond the orbit of Pluto and the Kuiper Belt. It is considered a reservoir of long-period comets, meaning that many comets that enter the inner solar system likely originate from this distant cloud.

Scientists estimate that the Oort Cloud begins roughly at 2,000 astronomical units (AU) from the Sun and can extend up to 100,000 AU or possibly even further. One AU (astronomical unit) is the average distance between the Earth and the Sun, approximately 149.6 million kilometers (93 million miles). This means the Oort Cloud could be as far as 15 trillion kilometers (about 9 trillion miles) away from the Sun at its outer edge.

The Oort Cloud was first proposed by Dutch astronomer Jan Oort in 1950 to explain the source of comets with very long orbital periods, sometimes lasting thousands or even millions of years. Unlike the Kuiper Belt, which is a disk-shaped region beyond Neptune, the Oort Cloud is believed to be spherical and surrounding the solar system in all directions.

Objects in the Oort Cloud are composed mostly of ice, dust, and frozen gases, remnants from the early formation of the solar system. These icy bodies can be disturbed by the gravitational pull of nearby stars or passing celestial objects, sending some of them toward the inner solar system as comets.

Although no spacecraft has yet reached the Oort Cloud due to its extreme distance, its existence is supported by the behavior and origin of observed comets. Astronomers generally estimate its outer boundary to be about 100,000 AU away from the Sun, making this the most widely accepted figure.

The correct answer is 100,000 AU, as this is the approximate distance most scientists agree upon for the farthest edge of the Oort Cloud.