Question

what is Oort cloud? plz explain

Answer 1

The Oort cloud, or Öpik–Oort cloud,[1] is a cloud of comets and other objects.Astronomers believe it is way beyond the orbits of Pluto and the Kuiper belt. The Oort cloud is believed to be the source of long-period comets in the Solar System.[2]
The Oort cloud may lie about 50,000 AU, or nearly a light-year, from the Sun.[3] This means the cloud is nearly a quarter of the way to Proxima Centauri, the nearest star to the Sun.
The Kuiper belt and scattered disc, the other two reservoirs of trans-Neptunian objects, are less than one thousandth of the Oort cloud's distance. The outer limit of the Oort cloud defines the boundary of the Solar System and the region of the Sun's gravitational dominance.[4]
The Dutch astronomer Jan Hendrik Oortpublished the Oort cloud idea in 1950. The Oort cloud was named after him, as were the Oort comet, and Oort constants.[

Answer 2

Answer:

The Oort cloud, sometimes called the Öpik–Oort cloud, first described in 1950 by Dutch astronomer Jan Oort, is a theoretical cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 2,000 to 200,000 au.