Q 01/05

Who discovered Pluto in 1930?

A) Clyde Tombaugh

B) Edwin Hubble

C) Percival Lowell

D) William Herschel

Answer · why

A) Clyde Tombaugh

He was a 24-year-old self-taught farm boy from Kansas hired by Lowell Observatory to hunt for Planet X.

Q 02/05

What device did Tombaugh use to spot Pluto moving between two photographic plates?

A) A photometer

B) A blink comparator

C) A coronagraph

D) A spectroscope

Answer · why

B) A blink comparator

Flicking rapidly between plates makes anything that has moved appear to jump.

Q 03/05

Where was Pluto discovered?

A) Mount Wilson, California

B) Lick, California

C) Yerkes, Wisconsin

D) Lowell Observatory, Flagstaff

Answer · why

D) Lowell Observatory, Flagstaff

Percival Lowell had founded it in 1894 and started the search for a ninth planet in 1906.

Q 04/05

Who first suggested the name Pluto?

A) Percival Lowell's widow Constance

B) The astronomer who found it

C) An 11-year-old English schoolgirl

D) A Walt Disney animator

Answer · why

C) An 11-year-old English schoolgirl

Venetia Burney of Oxford proposed it to her grandfather over breakfast; he passed it to an astronomer who cabled Lowell.

Q 05/05

The name Pluto had an extra attraction: its first two letters were the initials of whom?

A) Percival Lowell

B) Pierre Laplace

C) Planet Lowell

D) Pickering and Leuschner

Answer · why

A) Percival Lowell

The planetary symbol became a PL monogram, still used in astrology.