Astronomy

50 ASTRONOMY • JANUARY 2018

the most inf luential bands of the 1960s.

He’s also an enthusiastic — if not always

well-informed — astronomy fan. With col-

laborator Bob Hippard, McGuinn wrote

“C.T.A.-102.” The space-themed song

appeared on the group’s early 1967 album

Yo u ng e r T h a n Ye s t e rd ay.

In a 1973 interview, McGuinn said

of the inspiration for the song, “At the

time we wrote it, I thought it might be

possible to make contact

with quasars.” It was not

until later, he added,

that he learned they

“were stars which are

imploding at a tremen-

dous velocity ... sending

out tremendous

amounts of radiation.”

He mistakenly thought

that the signals were

audible as an electronic

impulse detected by

radio telescopes “in

rhythmic patterns.”

The song’s tune is

jaunty, the lyrics upbeat:

“We’re over here receiving you / Signals

tell us that you’re there ... on a radio tele-

scope / Science tells us that there’s hope.”

And the group went to considerable lengths

to produce some spacey sound effects. At a

time when computers weren’t yet available,

they got creative. They used audio feed-

back, an oscillator connected to a telegraph

key, a piano keyboard repeatedly pounded

with their fists, and nonsense sounds

laid down on audiotape that was speeded

up or played backward to achieve the

desired effect. As McGuinn later said,

“That was a big fad at the time, to play

things backwards.”

A 1968 paper published in The

Astrophysical Journal (“Quasi-Stellar Radio

Sources: 88 GHz Flux Measurements”)

actually referenced McGuinn and The

Byrds. Referring to aspects

of CTA-102’s spectrum, the

authors wrote: “The spec-

trum ... [gives] no indica-

tion of an upturn at short

wavelengths. ... [W]e have

been unable to detect it.” In

a wry reference to the rock

band’s song they added,

“Therefore we are unable to

comment on the discussion

by McGuinn, Clark, Crosby,

Clarke and Hillman.”

“C.T.A.-102” isn’t the only

science- or science-fiction-

inspired rock song. David

Bowie’s 1969 “Space Oddity,”

Elton John and Bernie Taupin’s 1972

“Rocket Man,” Brian May and Queen’s 1975

space-travel folk song “ ’39,” and Rush’s

1977–78 two-part “Cygnus X-1” are other

examples. But “C.T.A.-102” is the first song

inspired by a quasar, the first to reference a

radio telescope in music — and possibly the

first to garner a rock band a mention in a

refereed scientific journal.

An account of a comet

1P/Halley is arguably the most famous

comet of all time. Its regular visits to

the inner solar system have been reli-

ably recorded since at least 240 B.C. In

1066, the comet was seen in England and

its appearance recorded in the famed

Bayeux Tapestry, a 230-foot (70 meters)

textile depicting the Norman conquest

of England. None of its apparitions were

identified contemporaneously as the same

comet, however, until its appearance in

1682, when English astronomer Edmond

Halley successfully predicted its return in

1758. Halley’s Comet returned again in
      1835, and then again in 1910.
      That was actually a year of two great
      comets. Halley’s was one, and people
      around the world were eagerly awaiting its
      return to our cosmic neighborhood after 75
      years. But C/1910 A1, better known as the
      Great January Comet of 1910 or the
      Daylight Comet, dazzled the world first. It
      was already a magnitude 1 naked-eye
      object when it was spotted January 12. The
      comet was visible in broad daylight in the
      Southern Hemisphere, and by February it
      was visible at twilight in the Northern
      Hemisphere as a spectacular object with a
      long, curved tail.
      Two months later, Halley’s Comet was a
      naked-eye object in the night sky, reaching
      perihelion April 20. It then passed within
      0.15 AU (13.9 million miles [22.4 million
      km]) of Earth. So while not quite as

The Great January Comet of 1910 (pictured) grew brighter than Venus and dazzled viewers with a
long, arcing tail visible in daylight; Halley’s Comet would appear just months later. The close timing
of the comets could have confused people’s later recollections — including those of John S. Stewart.
UNIVERSITY OF CHICAGO PHOTOGRAPHIC ARCHIVE, [APF6-02103], SPECIAL COLLECTIONS RESEARCH CENTER, UNIVERSITY OF CHICAGO LIBRARY