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http://www.universetoday.com/am/publish … 72004]Read me
*Very interesting article. Our Solar System, by comparison, may be unusually blessed!
"Astronomers have found that a nearby star, Tau Ceti, is surrounded by 10 times as many asteroids and comets as our own Solar System. Even if there are planets orbiting Tau Ceti, they would be unlikely to support life because of the frequent and devastating impacts by these objects. This discovery will help astronomers narrow down their search when looking for distant worlds that may support life; ones which have a small number of comets and asteroids...
Tau Ceti, only 12 light years away, is the nearest sun-like star and is easily visible without a telescope...
even though Tau Ceti is the nearest Sun-like star, any planets that may orbit it would not support life as we know it due to the inevitable large number of devastating collisions...
!--->It also suggests that the tranquil space environment around the Earth may be more unusual than previously realized<---!
Jane Greaves continues, 'We will have to look for stars which are even more like the Sun, in other words, ones which have only a small number of comets and asteroids. It may be that hostile systems like Tau Ceti are just as common as suitable ones like the Sun.'
The reason for the larger number of comets is not fully understood explains Mark Wyatt, another member of the team: 'It could be that the Sun passed relatively close to another star at some point in its history and that the close encounter stripped most of the comets and asteroids from around the Sun.'"
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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Wow, compelling finds!
The high prevalence of asteroids might indicate a relatively young star. There seems to be some confusion about the age of Tau Ceti. In time most of the stellar material should be swallowed up by the star, gasgiants and other planets, like around Sol.
Yes, Tau Ceti is the closest stand alone G-type star in the stellar neighbourhood, but Alpha Centauri A is a G2 with Alpha Centauri B being a K0. Stable orbits around both stars have been inferred despite their proximity (Sun-Saturn at their closest).
Also, it has something to do with what you prefer to call sunlike, only "yellow" G-stars or higher range "orange" K's and lower range "yellow-white" F's as well. To me there's no reason not to include the two latter types.
Another promising stand alone object is for example Epsilon Indi (well, there are two brown dwarf companions at over 1 000 AU) which is a K4 at 11.83 lightyears, almost at the exact same distance as Tau Ceti (11.90 ly).
In fact our sun is quite massive and belongs to an uncommon type as far as stars go. Being so large it spews out radiation. Perhaps most aliens originate from calmer orange type stars that lives longer and are a lot more common. Their only marked disadvantage seems to be a tighter liquid water zone.
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Wow, it's a good thing I moved Delos out of there over to Chara. It makes sense that Tau Ceti would have more asteroids and comets, it's a much younger star than the Sun. In fact, it's a lousy place to look for life in general right now, the place is only about one or two billion years old, really not enough time for life to get started. The Sun probably looked a lot like Tau Ceti three billion years ago, so anyone from Delta Pavonis (older G-type star) wouldn't have come here to look for life.
Alpha Centauri is a pretty bad place to look for life, or planets, too. Sure, they have stable orbital zones, but what happens when a gas giant forms outside the zone? It will come crashing through breaking up any planet-forming activity that happened to be going on, we're not going to find anyone around there. There was a list made of the best stars to look for life around, and it mostly included stars like Chara and 18 Scorpii, single G-classers similar to the Sun. However, I agree with you that K-class stars are probably good places to look. Who knows? In two billion years, after all the chaos around Epsilon Eridani is over, it might be a nice place to live.
A mind is like a parachute- it works best when open.
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