Orbital perturbations caused by passing stars might very well have caused past extinctions
According to new computer simulations, scientists now think that any calculations of the long term changes in the orbits of the planets in our solar system must include the orbital perturbations caused by passing stars, perturbations that might very well have caused past extinctions. From their paper’s introduction:
Simulations of the long-term orbital evolution of the Sun’s planets have nearly always modeled the solar system as an isolated system. For many purposes, this is a very good approximation, but the solar system is of course part of the Milky Way Galaxy. Consequently, it occasionally suffers close encounters with other field stars, and solar neighborhood kinematic studies predict an average of ∼20 stellar passages within 1 [parsec] of the Sun each [million years].
Because the solar system cross section scales with the square of heliocentric distance, the large majority of these encounters will be distant and inconsequential to the planets’ dynamics, but this is not guaranteed. In fact, there is a ∼0.5% chance that a field star passage will trigger the loss of one or more planets over the next 5 [billion years], and such passages may actually guarantee the disruption of the planets’ orbits many [billion years] after the Sun becomes a white dwarf. Yet, encounters need not trigger an instability for them to have dynamical consequences for the planets. For instance, it has been suggested that ∼one-third of Neptune’s modern eccentricity has been generated through past stellar encounters, but many of the long-term dynamical effects of stellar passages remain unknown.
Their simulations as well as other data suggest that for computer models to have any chance of accurately calculating the orbital evolution of the solar system’s planets, those models must include the passing of nearby stars.
Or to put it in more blunt terms, the uncertainties here are so great that it is unlikely any computer model will ever be able to reconstruct our solar system going back further than 50 million years.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
According to new computer simulations, scientists now think that any calculations of the long term changes in the orbits of the planets in our solar system must include the orbital perturbations caused by passing stars, perturbations that might very well have caused past extinctions. From their paper’s introduction:
Simulations of the long-term orbital evolution of the Sun’s planets have nearly always modeled the solar system as an isolated system. For many purposes, this is a very good approximation, but the solar system is of course part of the Milky Way Galaxy. Consequently, it occasionally suffers close encounters with other field stars, and solar neighborhood kinematic studies predict an average of ∼20 stellar passages within 1 [parsec] of the Sun each [million years].
Because the solar system cross section scales with the square of heliocentric distance, the large majority of these encounters will be distant and inconsequential to the planets’ dynamics, but this is not guaranteed. In fact, there is a ∼0.5% chance that a field star passage will trigger the loss of one or more planets over the next 5 [billion years], and such passages may actually guarantee the disruption of the planets’ orbits many [billion years] after the Sun becomes a white dwarf. Yet, encounters need not trigger an instability for them to have dynamical consequences for the planets. For instance, it has been suggested that ∼one-third of Neptune’s modern eccentricity has been generated through past stellar encounters, but many of the long-term dynamical effects of stellar passages remain unknown.
Their simulations as well as other data suggest that for computer models to have any chance of accurately calculating the orbital evolution of the solar system’s planets, those models must include the passing of nearby stars.
Or to put it in more blunt terms, the uncertainties here are so great that it is unlikely any computer model will ever be able to reconstruct our solar system going back further than 50 million years.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I somehow just do not believe this.
First off how far out of our present orbit would we have to move to cause an ice age?
And how would we get back to this pretty nice orbit afterward?
Why wouldn’t it move all the other planets or at least some of them?
And if it could have moved Neptune a large distance why not Pluto? Instead of Pluto being a captured asteroid it could have started off as a regular planet in a more normal orbit.
Pluto is a planet dang it!
The “passing star effect” would probably reduce the number of planets that are hospitable to life. Thus, slightly reducing the potential for other life forms, especially in crowded galaxies.
Computer-driven dynamical models should have been discredited since Eddie Lorenz published his butterfly. That was what. 1968?
We’re decent at proxies for past temperature and, say, how long our own day was, since the “boring billion” 1800-800 Mya. For two billion years our Earth hasn’t budged much from 1 AU. Mars is well-enough explored by now, we know that it hasn’t Velikovsky’d, either, since like 3500 Mya. I expect similar for Vesta. And for Jupiter and its moons.
Saturn’s system is a problem and it’s exactly the outer planets as would be most-affected by a Gliese 710 in our past.
To upset the inner planets any passing body would have to either pass through the solar systems orbital plane or parallel to it and so close that it would be closer to the inner than the outer planets.
Once I can see as possible but multiple times and only causing ice ages on Earth? Or even the great extinctions?
Gliese 710 set to do a very close pass.
So a few million solar storms doesn’t have an effect?
One would have to wonder at how the Oort Cloud and the Kuiper belt would be affected by such encounters. Would they still exist or would they have been stripped off or otherwise disrupted into significantly eccentric orbits?
On the other hand, we haven’t discovered that many objects in these regions of solar space, so maybe they have been largely stripped off.