Slashdot Mirror
Sun's Twin Discovered — the Perfect SETI Target?
astroengine writes "There are 10 billion stars in the Milky Way galaxy that are the same size as our sun. Therefore, it should come as no surprise that astronomers have identified a clone to our sun lying only 200 light-years away. Still, it is fascinating to imagine a yellow dwarf that is exactly the same mass, temperature and chemical composition as our nearest star. In a recent paper reporting on observations of the star — called HP 56948 — astronomer Jorge Melendez of the University of San Paulo, Brazil, calls it 'the best solar twin known to date.' Using HP 56948 as a SETI target seems like a logical step, says Melendez."
First generation of stars create some heavier elements but still nothing for building life. They go nova and what have you. So after the first generation of stars, we're not at what? 5 Billion years?
Massive stars create elements all the way up to iron in their normal life span and all the heavier elements when they go supernova. They have lifespans measured in tens of millions of years.
It doesn't necessarily take a long time to go through several generations of stars. I thought I'd read recently that we'd found extremely old metal-rich stars indicating that they had in fact gone through several generations rapidly.
The enemies of Democracy are
There has been close to 4 billion years of life on Earth. All it would take is another world that started that chain of evolution just a few hundred years earlier, or to have, by chance, evolution form sentient life a few hundred years faster, or one of countless other variable changes, and we are not the first sentient life in the universe. When time lines are that long, you can't just hand-wave and say, "yeah, there was enough time for humans to evolve, but no way could it have happened already"
Although passive SETI does not send messages, Active SETI (ASETI) or METI does precisely that. As a planet, we have already sent messages to Gliese 581 and a number of other systems. If I'm successful I will even start sending such targeted messages full time from a 20 meter dish in Argentina. Unfortunately my power levels and antenna size probably limit my messages to a radius of about 50-100 light years, but with very large receiving antennas such messages could travel, much farther, possibly out to 200 ly. My goal is to start a full time. 24/7 targeted beacon. Now that has not been done before, but it's only a matter of time. If I'm not successful in my lifetime surely someone else will be eventually. Even some less cowardly government programs like that of the open minded Ukranians do not shy away from sending messages. They just don't do so as part of a permanent program. I believe that will be left to amateur projects like my own.
Does anyone know the declination and right ascension of this solar twin? I can't find any information on it from googling HP 56948. I'm guessing it probably has another more commonly used name.
Quite an experience to live in fear, isn't it? That's what it is to be a slave.