Q 01/05

Roughly how often does Halley's Comet return to the inner Solar System?

A) Every 12-15 years

B) Every 33-36 years

C) Every 74-79 years

D) Every 150-160 years

Answer · why

C) Every 74-79 years

Every 74-79 years: that steady beat has let astronomers match the comet to old sky records of its visits going back more than 2,000 years.

Q 02/05

Why was Halley's Comet so faint in 1986?

A) Behind the Sun

B) No tail formed

C) It broke apart

D) Beyond Mars

Answer · why

A) Behind the Sun

Behind the Sun: at its brightest in February 1986 the comet sat on the far side of the Sun from Earth, and it never came nearer to us than 63 million ...

Q 03/05

When is Halley's Comet next expected to reach perihelion?

A) 2038

B) 2049

C) 2054

D) 2061

Answer · why

D) 2061

Perihelion is predicted for 28 July 2061, and this time Earth will be on the same side of the Sun, so the show should be far better than 1986.

Q 04/05

What does 1P in 1P/Halley record?

A) First probe target

B) First shown to return

C) First telescope find

D) First comet sampled

Answer · why

B) First shown to return

First shown to return: when it came back in 1758 as forecast it proved that comets can circle the Sun, so it heads the list of periodic comets as numb...

Q 05/05

What convinced Edmond Halley that three past comets were one?

A) Similar tails

B) Similar orbits

C) Similar brightness

D) Similar colours

Answer · why

B) Similar orbits

Similar orbits: the comets of 1531, 1607 and 1682 followed nearly the same path, so in 1705 he forecast a return in 1758.