SOLAR SYSTEM

Detailed explanation-1: -Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the only naked-eye comet that can appear twice in a human lifetime. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. 0.2–1.5 g/cm3 (est.)

Detailed explanation-2: -comet: An object made mostly of ice and dust, often with a gas halo and tail, that sometimes orbits the sun.

Detailed explanation-3: -The C stands for carbon and the surfaces of these asteroids are almost coal-black. These asteroids contain large quantities of carbon molecules as well as the more usual rocks and metals. They are very similar in composition to the carbonaceous chondrite meteorites that sometimes fall on Earth.

Detailed explanation-4: -Halley’s Comet Halley’s Comet is the most famous of all comets. British astronomer Edmund Halley was the first to realise that comets are periodic, after observing it in 1682 and tallying it to records of two previous comet appearances. He correctly predicted it would return in 1757.