Illustration©TobaisRoetschhatdoyougetifyoucrossthedinosaurs
withmillionsofcometsandaneviltwin
ofourSunthathasnotonlywreaked
havoconEarthmultipletimesbuthas
longbeenhiddenfromview?Anxious?Fearful?
Maybeboth?Forwhileitmaysoundlikea terrible
joke.Theintriguingpunchlineoncecausedsome
alarm– andraiseda mysterythathadastronomers
hookedforquitesometime.
WelcometoNemesis,theSun'shypotheticallong-
lostcompanionwhichhasbeenspeculatedtobe
circlingintheedgesoftheSolarSystem.Proposed
byRichardA.Muller,anAmericanphysicistand
professorofphysicsattheUniversityofCalifornia,
Berkeley,itgainedsomegroundinthe1980swith
thesuggestionthatitwasbehinda seriesofmass
extinctioneventshereonEarth.
Thetheorygrewfroma 1983studybytwo
palaeontologists,DavidRaupandJackSepkoski.
W
They had analysed the extinction rates of 27,000
marine animals which perished during the past
250 million years and pointed towards five mass
wipeouts since the Late Permian era, in which
more than 75 per cent of species disappeared.
They went on to suggest that these catastrophic
extinction events were uniformly spaced, taking
place every 26 million years, but scientists could
not quite fathom why.
Various studies emerged looking at phenomena
on Earth, but the belief that a large asteroid wiped
out the dinosaurs – a hypothesis by Luis and
Walter Alvarez in 1980 – suggested extraterrestrial
forces could be at play. It was on this basis that
Muller came up with the idea that the comet
which smashed into Earth 66 million years ago
had been among a humongous group of bodies
disrupted by a theoretical red dwarf star. He said it
affected the orbits of these objects and sent themNemesis