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11 New Extra-Solar Planets Announced
Shooter6947 writes: "The European planet hunting team, including Mayor and Queloz who first found 51 Pegasus b in 1995, have just announced
the discovery of 11 new extrasolar planets. The new list includes 2 multiple planet systems, one planet with an orbital eccentricity of .93, and another in a nearly circular orbit near its star's habitable zone. Kickass!"
We are broadcasting less and less radio power into space as time passes. More and more data is being transmitted on narrow beams, or by wire or fibre or at high frequencies that don't escape the atmosphere much. Even without some "magical" replacement for radio, it is imaginable that higher tech civilizations would radiate relatively little radio energy omnidirectionally into space.
Also, our present detection systems would not detect Earth's boradcast emmision at stellar distances. The SETI experiments hope instead to detect a deliberate beacon transmission aimed at us.
So, we're a Sun-3.
If tits were wings it'd be flying around.
Neptune was the only planet to be found by mathematical prediction from anomalies in Jupiter and Saturn orbits. The first six planets were known from ancient times by eye. Uranus was accidently discovered with early telescopes. Mathematicians predicted another planet beyond Neptune. Pluto was found during a search for this planet, but it was too small and in the wrong place compared to mathematical predictions. A few die-hards hold out for another solar planet.
That's not entirely accurate, but it's close enough to get the point across. Another way is by observing the brightness of the star. A planet (of any size, though obviously this also works best with large planets) passing between the star and our telescope causes the star to dim. If this occurs periodically, and a few other things check out, it's very likely a planet.
High-speed Road Trip (18.000KPH)
It's pretty much accepted that we're all made of dead stars. What I hadn't realized is that mere supernovas don't readily explain the relative abundance of heavy metals we seem to have in the solar system.
Yesterday on NPR they had a piece about a researcher who has apparently determined that the more abundant heavy metals come from a collision between neutron stars. The elemental distribution we enjoy in our solar system requires both previous supernovas and neutron star collisions in order to exist. At least according to this researcher.
Makes you wonder about SETI. Also makes you wonder if the more abundant heavier elements are necessary for life, for advanced life, for intelligent life, or for technology-using (maybe intelligent too, unlike Earth) life.
The living have better things to do than to continue hating the dead.
The Dark Ages were a factor in this. Had we not been held back by religious fundamentalism for several hundred years we might very well be well into the galactic empire stage by now. Another civilisation may not have had these problems, nor had a space race that depended more on nationalism and value for tax money than scientific advancement and exploration. Only time will tell. I doubt that the Star Trek future is very likely for us, since learning from history is not a human trait.
The new list includes 2 multiple planet systems, one planet with an orbital eccentricity of .93, and another in a nearly circular orbit near its star's habitable zone.
p lanets/ecc.html for more information on this.
For those of you who don't know what orbital eccentricity is, it is a measure of how much an orbit deviates from being a perfect circle. IOW, the planet in question here has a very elliptical orbit, which is not close at all to being circular. See http://www-astro.phast.umass.edu/courseware/java/
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The AOL-Time Warner-Microsoft-Intel-CBS-ABC-NBC-Fox corporation:
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Humans have been on the earth and been sentient a tiny fraction of the age of the earth, and the earth is a relatively young planet. We orbit a young star. We have only been seriously broadcasting radio waves for 50 years, which means only civilizations within 50 light years of us have any chance of knowing we exist. Only civilizations within 25 light years could have responded by now. This is a very small portion of just the Milky Way galaxy, there are countless other galaxies surrounding us. With the huge number of stars just by us around which life could originate, to think that if we haven't been contacted yet means "they ain't coming" is illogical.
Enigma
Enigma
There is a new technique, which relies on gravitational lensing, which should allow us to find smaller planets than we can using gravitationaly-induced wobbles in a star's motion.
It works like this: If you get a reasonably sized dark object (say a rogue planetoid or any object hypothesized by the MACHOS theory of dark matter) between the Earth and a star, then gravitational lensing will cause a larger proportion of the light's star to be sent in Earth's direction, causing an effective amplification in the brightness of the star. Plot this amplification over time, and you get a characteristic curve, known as a Paczynski curve (I think I splet that right), which is basically just a bell-curve.
If there are any planets in the system, chances are a similar lensing effect will occur as the focusing object passes them, creating another Paczynski curve. Superimpose that curve with the star's, and you get a curve with a spike to one side of the maximum or the other. Find this spike in your observation, and chances are you've got yourself a planet.
Of course, you have to get lucky and have a suitable object pass between you and the star, but if the MACHOS theory is correct, there's plenty of such objects out in deep space.
First Planet: God.
Second Planet: ...
Well, that exhausts those possibilities. So much for monotheism.
Mod me Mad
Even if we say that we'll never find anything better than radiowaves in the spectrum SETI is searching to communicate with, SETI have still listened to a narrow time band of only a few decades for each star.
It doesn't take much imagination to see how large the chances of civilizations occuring that had either not reached a radio sending age at the point where the signals SETI are now processing originated, or that had either found some other way of communicated by then, or been destroyed in some way by then.
And that is assuming that life may exist or existed in places where SETI might have detected life in had it existed and been at a radio-sending stage at the right time.
We've only looked at a microscopic part of the universe for an incredibly short time period. There's still a chance ;)
Given the last item -- "a giant planet moving in an orbit around its Sun-like central star that is very similar to the one of the Earth and whose potential satellites (in theory, at least) might be "habitable"" -- I wonder not about how we humans might live there, but how life might evolve there.
In particular, I wonder if advanced space travel might develop at a faster evolutionary rate given several habitable planet-sized moons in close proximity. After all, great advances in technology are usually composed of thousands of small steps and an occasional leap. Starting from Earth, there are no close-by habitable locations, so we focus on making one great leap after another. Our drive to explore overrides reasons to return to the same spots again and again. That's not very efficient or productive in terms of developing travel technology. If the Moon, Mars, and Venus were all habitable, the amount of repetitive space travel we'd be engaged in would result in rapid incremental improvement in travel technology.
Racetrack demons start by going really fast around the block when they're little kids, and speeding up with every step. But here we are, stuck in a celestial backwater with nowhere to go nearby, so our first toddling steps involve building and driving the equivalent of a long-haul truck. I'd lay my money on us being visited far sooner than us finding/visiting another travel-capable race.
I think not...(*poof*)
well, i can answer the first question. scientists find planets by studying an effect called "red shift" in a star's motion in our sky. by studying this, we can determine if there is a planet acting with gravitational force on the star. Basically a star with a large enough planet orbiting around it will make the star appear to wobble. Unfortunately, this techinique is only useful for finding planets the size of jupiter (at least), because smaller planets don't "pull" on the star enough to cause a noticable wobble.
The naming planets after Greek Gods thing has been done to death. I say we adapt it to modern times and start naming planets after modern Gods. Planet Carmack, anyone?
I'm still waiting for the new, better detection methods that will allow us to actually find Earth-sized planets in their normal orbits. Not only that, but future missions will be able to tell the composition of the atmosphere around these planets - and if they find an atmosphere a lot like ours, that would be the first concrete evidence towards extrasolar life.
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Take a look at Geoff Marcy's website at exoplanets.org. Marcy is a professor here at Berkeley who leads one of the two teams which has done most of the planet finding thus far. This most recent announcement is by Michel Mayor, a Swiss astronomer who leads the other major extrasolar planet hunt. I think the two teams have a fairly friendly rivalry going on, and often both end up observing/discovering the same planets. One of Geoff's graduate students (who I think reads /.; Jason, you reading this?) told me that this latest batch was all discovered by using southern hemisphere telescopes, so none of these were discovered by Marcy et al's search, since that is conducted solely with Northern hemisphere telescopes.
Right now, we're finding Jupiter-sized planets around roughly 5% of the stars we've looked at - 60-ish planets around about a thousand stars. It's expected that the actual numbers of stars with planets is much higher than that, potentially as much as 50% or so, but smaller planets or ones further from their parent star are much harder to detect, so we have not yet identified any.