Posted on 03/25/2005 3:08:04 AM PST by snarks_when_bored
If Jupiter in its current position had become a star, then not only would there probably not be life on Jupiter's satellites (they'd be vaporized), but it would make a big, huge mess of the entire solar system. Sol and Jupiter would likely have pulled themselves into one another dragging much of the solar system - and certainly the inner planets if that happened - right along with them. It'd make for a spectacular explosion, but it would not be conducive to life as we know it (much less to civilization).
Even if that weren't the case, a Jupiter massive enough to ignite stellar fusion would wreak havoc on the current trajectories of the planets.
Mere arm waving. Even the political parties have drifted left. A number such as 5% is meaningless because untestable.
Didn't you see the movie 2001? Jupiter ignited and we had no problems. Get with the program!
That was just the example of an institution and the one most often cited whenever this question comes up. I imagine there would be a flurry of posts to FR for about a week and when nothing further develops it will be back to the arrogance of the courts or whatever other perennial topics are tweaking our noses.
hehe .. it'll certainly be a historic event if it happened. As it stands, I think of Jupiter as a brown dwarf myself, though that doesn't quite have the same flair, does it?
IIRC, Jupiter would need to be about 84 times more massive than it is right now in order to reliably ignite stellar fusion. That'd make for a rather dramatic alteration of the dynamics of our solar system.
BTW, I do grant your point that not all multiple star systems would be inherently hostile to the emergence of civilization, but what we know about them suggests this would comprise an exceedingly small fraction. The gravitational interaction of companion stars just seems too violent to permit the type of circumstances generally thought conducive. The Jupiter example underscores the point: so far as we can tell, you'd seemingly need a whole lot of fine-tuning to both turn Jupiter into a star and also produce technological civilization in our system.
That's not to say that multiple star systems necessarily preclude life of any kind whatsoever. As mentioned above, my personal view is that basic life can probably emerge in conditions extremely hostile by our standards.
We'll just have to stay alive long enough for the evidence to come in.
That's my plan!
Cats?
Thanks for the ping!
Nope. :-)
Check here:
http://www.wired.com/news/culture/0,1284,42009,00.html
How Many Habitable Planets Could Be Out There?
Here's the entire story:
Summary - (Apr 5, 2005) The chances of finding life somewhere else in the Universe depends on how many planets are capable of supporting life. Well, according to new calculations by astronomers at Open University, as many as half of all star systems could contain habitable planets. The team created mathematical models of known exoplanetary systems, and then added Earth-sized planets into the mix. They found that in half of all planetary systems they simulated, the gravity of the gas giants won't catastrophically affect the orbits of these smaller planets, giving life a chance to evolve.Full Story - How many planets like the Earth are there among the 130 or so known planetary systems beyond our own? How many of these ‘Earths’ could be habitable?
Recent theoretical work by Barrie Jones, Nick Sleep, and David Underwood at the Open University in Milton Keynes indicates that as many as half of the known systems could be harbouring habitable ‘Earths’ today.
Unfortunately, existing telescopes are not powerful enough to see these relatively small, distant ‘Earths’. Orbiting close to a much brighter star, these very faint worlds resemble glow-worms hidden in the glare of a searchlight.
All of the planets that have been detected so far are giants the mass of Neptune or larger. Even so, they cannot be directly seen with ground-based instruments. Almost all of the known exoplanets have been found through the “wobbling” motion they induce in their star as they orbit it, like a twirling dumb-bell in which the mass at one end (the star) is much greater than the mass at the other end (the giant planet).
Speaking today at the RAS National Astronomy Meeting in Birmingham, Professor Jones explained how his team used computer models to see if ‘Earths’ could be present in any of the currently known exoplanetary systems, and whether the gravitational buffeting from one or more giant planets in those systems would have torn them out of their orbits.
“We were particularly interested in the possible survival of ‘Earths’ in the habitable zone,” said Professor Jones. “This is often called the ‘Goldilocks zone’, where the temperature of an ‘Earth’ is just right for water to be liquid at its surface. If liquid water can exist, so could life as we know it.”
The Open University team created a mathematical model of a known exoplanetary system, with its star and giant planet(s), then launched an Earth-sized planet at some distance from the star to see if it survived.
By detailed study of a few representative exoplanetary systems, they found that each giant planet is accompanied by two ‘disaster zones’ - one exterior to the giant, and one interior. Within these zones, the giant’s gravity will cause a catastrophic change in the Earth-like planet’s orbit. The dramatic outcome is a collision with either the giant planet or the star, or ejection into the cold outer reaches of the system.
The team found that the locations of these disaster zones depend not only on the mass of the giant planet (a well known result) but also on the eccentricity of its orbit. They thus established rules for determining the extent of the disaster zone.
Having found the rules, they applied them to all of the known exoplanetary systems - a much quicker method than studying each system in detail. The range of distances from the star covered by its habitable zone was compared to the locations of the disaster zones to see if there was a full or partial safe haven for an Earth-like planet.
They discovered that about half of the known exoplanetary systems offer a safe haven for a period extending from the present into the past that is at least long enough for life to have developed on any such planets. This assumes that ‘Earths’ could have formed in the first place, which seems quite likely.
However, the situation is complicated by the fact that the habitable zone migrates outwards as the star ages, and in some cases this changes the potential for life to evolve. Thus, in some cases a safe haven might have been available only in the past, while in other cases it might exist only in the future.
These scenarios of past extinction and future birth increase to about two-thirds the proportion of the known exoplanetary systems that are potentially habitable at some time during the main-sequence lifetime of their central star.
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