Can the Sirius Star System Support Life?
In 1976 a book was written by Robert Temple called 'the Sirius Mystery'. This book suggests that the Dogon tribe of Africa had advanced astronomical knowledge given to them by extraterrestrials from Sirius. There was certainly a lot of anomalies surrounding the knowledge of the Dogon tribe. They knew of the existence of a second star that was not visible to the naked eye, and the Dogon had no telescopes. It was postulated that they also knew the existence of a third star in the Sirius system that is completely undetected to this day. The existence of this knowledge as well as several other pieces of information were cited as proof that the Dogon tribe had been visited and influenced by extraterrestrials (Called the Nommo - an amphibian race)
The book is well written and quite extensive and it would take awhile to properly research all the data to determine its validity. Rather than go over this, and all the following books written on the subject since 1976, I have decided to first determine if the Sirius star system, based on the scientific data I have been able to find, is actually capable of sustaining life.
So What Do We Know for Sure?
For that, let's first look at what we know for sure. Sirius is a known binary star system. This means that there are two stars in this system. The main star is a Class A (White) star called 'Sirius A', there is a companion star - 'Sirius B' - which is a white dwarf star roughly 20 AU (astronomical unit) away from Sirius A currently and has a orbit of 49.9 years. The system is roughly 300 million years old. (1) Sirius A has a habitable zone of between 2 and 5 AU , otherwise known as the 'goldilocks zone'. Any planet closer than 2 AU and it would be too hot, farther out than 5 AU and it would be too cold to support life.
Let's look first at the age of the star system. Scientists have put the age of the Sirius system at roughly 300 million years old. Our solar system is 4.5 billion years old to give an idea of how long it MAY take for life to develop normally to the stage it has on Earth, but be careful when making this comparison as Earth has suffered numerous extinction level events such as asteroid impacts throughout its history that may or may not be common in other star systems. However, even keeping that in mind, 300 million years is barely long enough for planets to form never mind life forming on that planet.
This means that any planet orbiting Sirius A would be a young world. It would have warm, shallow oceans and any continents formed already would be small, with little or no erosion and volcanic. The planet would have a thick and very humid atmosphere, and this environment would be dominated by a bright, violent sun beaming out sterilizing ultraviolet light. At the bottom of these oceans, protected from the white sun's detrimental effects, simple forms of bacterial life could gain a toe hold, nourished by hydrothermal vents from the planet's interior. How long this life would take to develop and evolve into more complex life is variable.
Add to this the fact that Sirius A lifespan in its current configuration - otherwise known as its main sequence lifetime (MSL) - is only 1 billion years and 300 million years have already passed and we can assume that no life that formed on any planet in the habitable zone would live long as in 700 million years all planets in existence today around Sirius A will be destroyed when it reaches the end of its MSL.
So the age says that the prospect of life in the Sirius star system is low but what about the stars themselves?
As stated, it is known for sure that Sirius has two stars, with a possibility for a third, but let's focus on the two Science knows about for sure right now. Sirius A is a spectral type A star - also known as a white star. These stars have a high mass and burn brighter and hotter than our sun, which is a class G (yellow) star, because of this they tend to consume the supply of hydrogen faster and thus are shorter lived. They tend to give off a lot of ultraviolet light and, due to all of this, biological evolution is severely restricted in Sirius. (2) (3)
Sirius B is a white dwarf on a 49.9 year orbit of Sirius A and during that orbit is between 8 and 31 AU distance from Sirius A. This star would give off similar brightness and radiation to Sirius A and, when it is closest to Sirius A would be a very strong 'second sun' for any planet near the outer rim of the goldilocks zone for Sirius A. The existence of a second white dwarf star in the Sirius system would seem to suggest that the possibility of life is extremely remote indeed.
But wait, there is a supposed third star in the Sirius system. According to Robert Temple's Dogon information, this should be a red dwarf star. He was so certain of it that he made the following quote:
"If a Sirius-C is ever discovered and found to be a red dwarf, I will conclude that the Dogon information has been fully validated."
So, what about that third star? Well, funny you should ask that. According to gravitational studies done in 1995 showed a possible Brown Dwarf star orbiting Sirius A every 6 years. Could this be the elusive Sirius C spoken about by the Dogon?( 4)
A brown dwarf star is a sub-stellar object whose mass is too low to sustain a hydrogen fusion reaction in its core. So it never becomes a full blown star and resembles a large Jupiter like gas giant.
However, before we lose ourselves too much in determining the effects this third star would have on any planets in the goldilocks zone it should be noted that a more recent study published in 2008 and using advanced infrared imaging technology came to the conclusion that Sirius PROBABLY did not have a third star. I say probably as the survey of the entire system was not fully complete having a region roughly 5 AU from Sirius A being unexplored during this study. (5)
So, in conclusion, I would have to say that due to the relatively young age of the Sirius system, combined with the extreme challenges to life development in a Class A star system and the problems presented by Sirius B roaming through the system every 49.9 years makes the probability of even simple life in the Sirius system highly unlikely never mind an advanced aquatic species capable of traveling the 8.6 light years to Earth. I do not say it isn't there, just that it is highly unlikely that the Sirius star system can support life in any advanced form unless of course this life took the form of a purely aquatic life form capable of 'breathing' in the same way a fish does on our beloved Earth.
I don't fully understand how the Dogon got the knowledge they got regarding Sirius, was it actually from 'The Nommo' - that aquatic species that is supposed to be native to Sirius? Was it a wandering band of astrologists that came to the Dogon territory to sky watch who gave them the info? After all, the Dogon has been around since the Sumerians and there have been many civilizations since then that had astrological capabilities in that part of the world, they could have picked that up from them. How they got it is unknown, that they had it is pretty much undisputed. Did the info come from Sirius itself? I would have to say no based on my current knowledge of the environment present in that star system.
In the future, more info may reveal more insights. In 1976, when Robert Temples book was written, it was dismissed outright by other scholars as nonsense. But is it? Since his writing of his book the second star has been 100% confirmed and the third star has not been mathematically ruled out and indeed, gravitational studies in the 90s did show that something was there.
The Sirius Mystery continues...
Do you think humans have been visited before?
Do you believe in Extra-Terrestrial life?
Given Humanity as it is today, if you were an alien species would support or oppose first contact with humans?
For further Reading on this Fascinating subject...
- The Mysterious Connection Between Sirius and Human History - The Vigilant Citizen
A look at the importance of the star Sirius in ancient civilizations and today's secret societies. Is there more to this astral body than meets the eye?
- The Sirius Star System
- Sirius - Wikipedia, the free encyclopedia
(1) Liebert, J.; Young, P. A.; Arnett, D.; Holberg, J. B.; Williams, K. A. (2005). "The Age and Progenitor Mass of Sirius B". The Astrophysical Journal )
(2) BENEST D., 1989: Planetary orbits in the elliptic restricted problem. II - The Sirius system. Astronomy and Astrophysics, 223, 361
(3) BENEST D., 1993: Stable planetary orbits around one component in nearby binary stars. II Celestial Mechanics, 56, 45
(4) Benest, D., & Duvent, J. L. (1995) 'Is Sirius a Triple Star'. Astronomy and Astrophysics 299: 621-628
(5) Bonnet-Bidaud, J. M.; Pantin, E. (October 2008). "ADONIS high contrast infrared imaging of Sirius-B". Astronomy and Astrophysics 489: 651–655. arXiv:0809.4871. Bibcode 2008A&A...489..651B. doi:10.1051/0004-6361:20078937.
© 2013 Robin Olsen