Philips Atlas of the Universe

THE SOLAR SYSTEM

It also was visible at the same time as the Sun, and it had a

long, imposing tail. The orbit is elliptical, but we will not

be seeing the comet again yet awhile, because the estimated

period is of the order of 4 million years. Obviously we

cannot be precise; we can measure only a very small seg-

ment of the orbit, and it is very difficult to distinguish

between a very eccentric ellipse and a parabola.

Comet Skjellerup–Maristany of 1927 was also very

brilliant, but its glory was brief, and it remained incon-

veniently close to the Sun in the sky. This was also true,

though not to so great an extent, of Comet 1965 VIII, dis-

covered independently by two Japanese observers, Ikeya

and Seki. From some parts of the world it was brilliant for

a while, but it soon faded, and will not be back for at least

880 years. Kohoutek’s Comet of 1973 was a great dis-

appointment. It was discovered on 7 March by Lubos

Kohoutek at the Hamburg Observatory, and was expected

to become extremely brilliant, but it signally failed to do

so, and was none too conspicuous as seen with the naked

eye. Perhaps it will make a better showing at its next

return, about 75,000 years from now.

Of lesser comets, special mention should be made of

Arend–Roland (1957), Bennett (1970) and West (1976).

Arend–Roland was quite conspicuous in the evening sky

for a week or two in April 1957, and showed a curious

sunward spike which was not a reverse tail, but was due

merely to thinly spread material in the comet’s orbit

catching the sunlight at a favourable angle. Bennett’s

Comet was rather brighter, with a long tail; the period here

Year Name Date of Greatest Mag. Min. dist. from

discovery brightness Earth, 10^6 km

1577 1 Nov 10 Nov 
 494

1618 16 Nov 6 Dec 
 454

1665 27 Mar 20 Apr 
 485

1743 De Chéseaux 29 Nov 20 Feb 1744 
 7 125

1811 Flaugergues 25 Mar 20 Oct 0 180

1843 5 Feb 3 Jul 
 7 125

1858 Donati 2 June 7 Oct 
 180

1861 Tebbutt 13 May 27 June 0 20

1874 Coggia 17 Apr 13 July 0 44

1882 Great Southern Comet 18 Mar 9 Sept 
 10 148

1910 Daylight Comet 13 Jan 30 Jan 
 4 130

1927 Skjellerup–Maristany 27 Nov 6 Dec 
 6 110

1965 Ikeya–Seki 18 Sept 14 Oct 
 10 135

1996 Hyakutake 30 Jan 1 May 
 121

1997 Hale–Bopp 22 July 1995 30 Apr 
1.5 193

SELECTED LIST OF GREAT COMETS

is about 1700 years. West’s Comet was also bright, but

suffered badly as it passed through perihelion, and the

nucleus was broken up. No doubt observers will be inter-

ested to see what has happened to it when it returns in

around the year AD559,000.

The only really bright comets of very recent years

came in 1996 and 1997 – Comet Hyakutake and Comet

Hale–Bopp. When the next will appear we do not know,

but we hope it will not be too long delayed. At least

the appearance of two bright comets so near the end of the

20th century is encouraging.

▲ The Great Comet of 1843,

as seen from the Cape of

Good Hope on the evening

of 3 March. This may have

been the brightest comet

for many centuries.

▲ De Chéseaux’s Comet of

1744, with its multiple tail;

this is a famous impression

of it, but it did not remain

brilliant for long, and is not

well documented.

▼ Donati’s Comet of 1858,

often said to have been

the most beautiful comet

ever seen; it had tails of

both types.

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