The Nemesis Theory: Is there a Second Sun in Our Solar System?
The Nemesis Hypothesis
Nemesis is a theoretical second sun in our solar system, a dwarf star named after the Greek goddess of vengeance. In the English vocabulary the word nemesis has come to mean downfall, or ruin, and surely nothing good can result from a celestial body bearing this moniker. According to some, Nemesis will indeed bring about our ruin one day by setting in motion an extinction event that will wipe us off the face of the Earth.
Proponents of the Nemesis theory say it has happened before. In fact, every twenty-six million years the Earth has a little problem. Some horrible and mysterious catastrophe brings about a mass extinction, destroying a large percentage of life on the planet and altering the balance of nature.
It happened with the dinosaurs sixty-five million years ago. It’s happened since. In fact, it happens reliably, about every twenty-six million years. The question is not if the Earth will see another cataclysmic extinction, but when.
This pattern of destruction baffled paleontologists, until science began to consider causes not of this world. Astronomers arrived at the Nemesis Hypothesis, a theory that says our Sun has an evil little brother called Nemesis who orbits at a great distance.
Every twenty-six million years the orbit of Nemesis brings it through the Oort cloud, a mass of comets and debris out on the far reaches of space. Nemesis disrupts the comets, sending them hurtling toward the inner planets on a rain of destruction that can last decades. Comets smash into Earth and cause these mass extinctions at a regular and predictable rate.
Nemesis may not have the same size and power as our Sun, and it's not likely to come anywhere near the Earth, but it has enough of a push to cause havoc from afar. The concept of Nemesis is chilling to say the least, the stuff of nightmares. So what are the chances that Nemesis really exists, and if Nemesis does come calling is there anything we can we do about it?
Where is Nemesis?
Nobody has ever seen Nemesis, nor has it been located using current technology. Theoretically, this is because Nemesis is a red or brown dwarf, a star with very little brilliance, which explains why it is so hard to detect.
You might think it would be easy to spot an extra sun in our own solar system, but a dark object out there among millions of other dark, moving celestial bodies is hard to track. Even with our advanced technology and powerful telescopes, Nemesis has yet to reveal itself.
Some astronomers are currently hard at work trying to locate Nemesis using calculations based on past extinctions. They think they know where to look, but they haven’t spotted it as of yet. The use of infrared technology may help. The heat of a dim star will be easier to see in infrared than it would with the naked eye.
But does it even make sense that there could be two suns? How likely is it that there could be a second star in our solar system, even if it is undetected?
The theory of a second sun in our solar system is not as bizarre as it might sound. Binary star systems (two stars orbiting the same center of mass) are quite common. In fact, Alpha Centauri, our solar system’s nearest neighbor, is a binary system. Astronomers estimate that around half of all stars in our galaxy have at least one companion. Therefore, the existence of Nemesis would not be surprising at all, at least statistically.
A Look at Trans-Neptunian Objects
The Gas Giant Tyche
As if Nemesis weren’t enough, in 1999 astrophysicists hypothesized there may be a massive gas planet present in the Oort cloud. Similar to the Nemesis hypothesis, some people jump to the conclusion that the gravitational influence of this planet known as Tyche sends comets hurtling toward the inner solar system at a predictable rate. Evidence of Tyche’s existence, it is argued, can be shown in the way comets tend to cluster rather than disperse randomly. This seems to point to some powerful force ejecting the comets from the Oort cloud.
The orbit of the bizarre trans-Neptunian celestial body called Sedna offers more food for thought. Sedna is one of the furthest known objects in our solar system, and it follows an elongated orbit which takes longer than any other large body in our solar system. There are several theories to explain this orbit, one being the presence of a massive planet at the fringes of our solar system.
Nemesis or Tyche, it appears some astrophysicists are convinced there is something causing mayhem in the outer solar system. Is it an overreaction to attempt to correlate this information with the extinction events which first led to the Nemesis hypothesis?
Nemesis Theory Debunked
Of course, in opposition to the relatively small number of astronomers and astrophysicists who find the Nemesis theory valid, there are those who have done their best to debunk it. In fact, since 1984, when the idea of Nemesis first came to light, researchers have not been able to find hard evidence of the existence of such a star. Our sun, it seems, is alone.
More recent studies of impact craters even call into question the idea that comets rain down on Earth at predictable intervals. Even the idea that extinctions occur reliably every twenty-six million years is now uncertain. Extinction events, Nemesis skeptics say, can be caused by any number of reasons, including disease, volcanic upheaval, and natural changes in the Earth’s climate. Associating them with some far-off death star isn’t necessarily logical.
But what about Tyche? For some, Tyche has replaced Nemesis as the theoretical companion to the sun, which will one day threaten the Earth. For others, they associate Tyche more closely with the Nibiru legend that says a rogue planet is out there somewhere at the far reaches of our solar system. But most researchers say, unlike Nemesis, Tyche’s theoretical orbit wouldn’t mean such a massive disruption of the Oort cloud, or destruction here on Earth.
What to Do about Nemesis?
Though some astronomers still hold on to the Nemesis theory, as frightening as Nemesis is the majority of researchers agree it is nothing to lose sleep over. As for right now it is a theory, one that is increasingly losing its luster, and nothing more. But it is an interesting hypothesis, and a stern reminder of the power of the universe. Sometimes it's hard to remember that mankind is but a blip in the life of the universe, the blink of an eye in cosmic time. Like the dinosaurs, we could be wiped away at any time.
With the array of cosmic dangers lurking out in space, Nemesis might be the least of our problems. From gamma ray bursts to supernovas to solar flares, when you think about it we’re lucky to be here at all. Maybe we were better off back in the dark days of astronomy when threats like Nemesis were as unfathomable as the idea of a round earth.
The good news is that, even if Nemesis exists, it isn’t due back for many millions of years. Not that an asteroid or comet can't demolish the Earth at any time, but if it does don't blame Nemesis.
The bad news is, if Nemesis exists, it is coming, and our planet will be forever altered. Maybe someday we’ll have some kind of defense against a barrage of comets crashing down to earth, but as for right now we may as well enjoy the night sky without worrying too much about what might be hurtling at us.