Pluto''s Mass Was Poorly Known Before 1978

question 32

Multiple Choice

Pluto''s mass was poorly known before 1978.What happened in that year to change this?

• A) The Hubble Space Telescope was launched.
• B) The new Keck II telescopes became operational.
• C) Charon was discovered.
• D) The return echo of a radar pulse, sent many years before, .returned to Earth, allowing a Doppler shift measurement of its rotation rate.

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Definitions:

Nerve Impulses

Nerve impulses are electrical signals that travel along neurons, facilitating communication within the nervous system.

CN VIII

Cranial Nerve VIII, also known as the vestibulocochlear nerve, which is responsible for hearing and balance.

Cerumen

The scientific term for earwax, a substance produced in the ear canal that protects the ears from dust, foreign particles, and microorganisms.

Eczema

A condition causing inflamed, itchy, cracked, and rough skin patches, sometimes accompanied by blisters.