[quote]Astronomers have come up with a novel way to look for circumstantial evidence of rocky planets around sun-like stars. The "stellar fingerprinting" technique points to the nearest star to our sun, Alpha Centauri A, and one of the top contenders for possessing an Earth clone.
What has become apparent over the past few years is that stars with planets can be very slightly anemic --containing less iron -- compared to stars where planets are not detected.
The conventional wisdom is that a small fraction of these elements are locked up in rocky planets and asteroids that condensed out of a disk of dust and ice that encircled the newborn star. The elements never manage to fall into their star to chemically enrich it. Even a planet as massive as just a few Earths will leave a telltale deficiency in the star's chemistry.
With extraordinary precision, Ivan Ramirez of the University of Texas at Austin studied the makeup of 11 target stars. The exact mix of elements the stars yield could betray the presence of terrestrial and gas giant planets, and tell of the episodes in the star's birth they formed.
Ramirez's spectroscopic survey found that 15 percent of solar type stars have circumstantial evidence for terrestrial planets according to his chemical recipe based on our sun's spectral fingerprint. This is a bit lower than estimates by detection from NASA's prolific Kepler space observatory.
He used the binary stars 16 Cygni as a good test case. The one companion star where a planet was found has a slight deficiency of heavier elements as compared to its apparently planet-less twin star.
By far the most exciting stellar candidate is merely 4.3 light-years away, Alpha Centauri A, the largest star in the triple star system. Compared to 85 percent of solar twins studied in Ramirez's survey, it has the closest temperature and iron abundance as our sun.
Ramirez says that this strongly argues for the presence of one or more terrestrial planets circling the star. Searches are underway, but no evidence for planets have been teased out of the data yet.
Regardless, given Kepler's trawl of rocky planets it would be much more surprising [I]not[/I] to find any rocky worlds orbiting Alpha Centauri A. Its closest companion star, Alpha Centauri B is far enough away to allow for stable planet orbits around either star.
Finding such a planet would send a seismic wave through the astronomical community. There would be a strong incentive to build ever-larger space telescopes to sample the planet's atmosphere, and in the much farther future, look for oceans and continents.
Because Alpha Centauri is as old as the sun, it would be natural to assume that a planet with atmospheric biotracers such as ozone, oxygen, methane and carbon dioxide would have time enough to evolve multicelled forms of life. If we found out that didn't happen on an Earth clone, it would strongly suggest that complex life is much more rare in the universe than some astrobiologists imagine.
This couldn't be answered without visiting such a world. And that could be accomplished within a reasonable amount of time if a probe could be built that could be accelerated to 10 percent the speed of light. Alpha Centauri A could be reached in a little over 40 years.
There is little doubt that microbes exist on other planets in our solar system. But being able to peruse a world to see Darwinian evolution played out over billions of years would be a scientific watershed of immeasurable impact.
The tremendous curiosity about such a place would only be offset by the cost of getting there, which would easily run many trillions of dollars. It could be the equvalent of the Apollo moon project for the next century -- for any nation and or group of nations ambtious and rich enough to undertake such deep space exploration.
[I]Image credits: NASA, NOAA[/I]
==============================================
Source:
[url]http://news.discovery.com/space/earth-like-planet-might-whirl-around-alpha-centauri-a-121003.html[/url]
[/quote]
:dance:
It's mathematically impossible for there to [i]not[/i] be another planet with life out there, based on how many billions of galaxies/stars/planets there are.
Would be cool if our nearest neighbor had some life.
"We choose to go to Alpha Centuri within this decade. Not because it is easy, but because it is hard!"
Artists representation of Alpha Centauri's might have planets:
[img]http://images2.wikia.nocookie.net/__cb20100822154549/halo/images/5/5e/Planet_Reach.png[/img]
Sad to think we can't go there in our lifetime.
Alpha Centuri is awesome because binary systems are beautiful.
Oh and planets are cool.
[QUOTE=Niklas;37907236]Sad to think we can't go there in our lifetime.[/QUOTE]
I know it's a pretty cliche'd thing to say, but never say never. It's definitely on the far side of unlikely that I'll ever see man set foot on a planet in an alien solar system, but who knows what could happen. Hell, in twenty or whatever years circumstances might lead to another space race - who knows what lies in the future?
[QUOTE=Niklas;37907236]Sad to think we can't go there in our lifetime.[/QUOTE]
knowing our collective luck, anything of interest there would probably be really weird and unknowable.
If there are blue people on the planet, don't shoot their trees.
[I]"And so whenever you are feeling very small and insecure, however unlikely is your birth.
Hope to hell there's intelligent life somewhere up in space, because there's bugger all, down here on earth"[/I]
I also feel like placing bets on whether they will actually get there in the decade.
I hate to be a pedant, but isn't Proxima Centuri our closest stellar neighbour?
Cue all the Catvatar freaks going ballshit insane looking for Pandora.
A valid argument today, as it was at the time:
[media]http://www.youtube.com/watch?v=ouRbkBAOGEw[/media]
[QUOTE=Camundongo;37907365]I hate to be a pedant, but isn't Proxima Centuri our closest stellar neighbour?[/QUOTE]
That's funny when considering that Alpha Centauri is actually our closest neighbor.
[QUOTE=Bomimo;37907386]That's funny when considering that Alpha Centauri is actually our closest neighbor.[/QUOTE]
[url]http://en.wikipedia.org/wiki/Proxima_Centauri[/url] ?
[QUOTE=Bomimo;37907386]That's funny when considering that Alpha Centauri is actually our closest neighbor.[/QUOTE]
Actually, it is Proxima Centauri.
[quote=Wikipedia]A third star, known as Proxima Centauri, Proxima or Alpha Centauri C (α Cen C), is probably gravitationally associated with Alpha Centauri AB. Proxima is at the slightly smaller distance of 1.29 parsecs or 4.24 light years from the Sun, making it the closest star to the Sun, even though it is not visible to the naked eye. The separation of Proxima from Alpha Centauri AB is about 0.06 parsecs, 0.2 light years or 13,000 astronomical units (AU); equivalent to 400 times the size of Neptune's orbit.[/quote]
[editline]4th October 2012[/editline]
Damn, ninja'd.
[QUOTE=Niklas;37907236]Sad to think we can't go there in our lifetime.[/QUOTE]
I wouldn't be too sure. Considering technology is advancing at an exponential rate, it's more than likely that you'll live to see 100. A lot can happen in 100 years, especially considering how fast we're advancing.
[QUOTE=chipset;37907571]I wouldn't be too sure. Considering technology is advancing at an exponential rate, it's more than likely that you'll live to see 100. A lot can happen in 100 years, especially considering how fast we're advancing.[/QUOTE]
It's a safe bet to say we won't be visiting in our life time.
Even with probs considering we'll be dead before they get there.
[QUOTE=NoDachi;37907612]It's a safe bet to say we won't be visiting in our life time.
Even with probs considering we'll be dead before they get there.[/QUOTE]
Unless we cheat the system somehow, it's impossible to go faster than light but there might be a way to bend the universe itself to make the path shorter, at least that's what I remember from an article not too long ago.
[QUOTE=Civil;37907170]Artists representation of Alpha Centauri's might have planets:
[img]http://images2.wikia.nocookie.net/__cb20100822154549/halo/images/5/5e/Planet_Reach.png[/img][/QUOTE]
That was Epsilon Eridani, dude.
[QUOTE=DeanWinchester;37907799]Unless we cheat the system somehow, it's impossible to go faster than light but there might be a way to bend the universe itself to make the path shorter, at least that's what I remember from an article not too long ago.[/QUOTE]
Centuri is only 4.3 light years away.
So it's not a case of 'going faster' than light.
It's just a case of reaching anything that isn't a pathetic fraction of the speed of light.
[QUOTE=DeanWinchester;37907799]Unless we cheat the system somehow, it's impossible to go faster than light but there might be a way to bend the universe itself to make the path shorter, at least that's what I remember from an article not too long ago.[/QUOTE]
Well let's hope we can cheat the system then, hopefully using the Alcubierre drive.
You'd think with all the planets they've discovered they'd have found the ones in the closest star to our solar system first
[QUOTE=Civil;37907170]Artists representation of Alpha Centauri's might have planets:
[img]http://images2.wikia.nocookie.net/__cb20100822154549/halo/images/5/5e/Planet_Reach.png[/img][/QUOTE]
Pretty sure that's the planet Reach, dude
I can tell from the craters, and from the fact that the filename is "Planet Reach" :v:
[QUOTE=latin_geek;37907900]You'd think with all the planets they've discovered they'd have found the ones in the closest star to our solar system first[/QUOTE]
The methods they have for detecting extrasolar planets are surprisingly limited. If the planets around Proxima Centauri were set up in just the right way, they could be nearly invisible to us.
[QUOTE=latin_geek;37907900]You'd think with all the planets they've discovered they'd have found the ones in the closest star to our solar system first[/QUOTE]
Yeah; you'd think that, since it's the closest couple of stars near Sol, but I guess their perceptions were focused elsewhere, or that the technology at the time wasn't truly advanced enough for wide-scale planet-hunting.
Also I do hope there's a true "world system" around the Centauri stars, so that if we do manage to get close enough to light-speed (even if we never discover the great loophole), it won't take too long to reach the Centauri systems, maybe like 10 years.
[QUOTE=Neo Kabuto;37908276]The methods they have for detecting extrasolar planets are surprisingly limited. If the planets around Proxima Centauri were set up in just the right way, they could be nearly invisible to us.[/QUOTE]
I know they usually use planetary transits to detect exoplanets (basically, if something has passed in front of a star, you can measure the drop in light) around nearby stars, but binary systems would make that hard to detect, since they'd also transit in front of each other.
It would probably effect gravitational lensing as well, so the only way to confirm the presence of planets in orbit would be to see if there's any anomalies in the binary system's orbit, and if there are use the data to calculate the mass and orbit of any planets.
This finger-printing method looks like a good way to detect possible candidate systems for exoplanets though, so if it's relatively fast it might be a decent way to let us focus more detailed searches in the right places.
[QUOTE=DeanWinchester;37907799]Unless we cheat the system somehow, it's impossible to go faster than light but there might be a way to bend the universe itself to make the path shorter, at least that's what I remember from an article not too long ago.[/QUOTE]
Relativistic faster-than-light travel.
It's hypothetically possible but requires a lot of energy. It will take some brilliant minds to make it feasible.
[QUOTE=yawmwen;37908399]Relativistic faster-than-light travel.
It's hypothetically possible but requires a lot of energy. It will take some brilliant minds to make it feasible.[/QUOTE]
NASA are actually working on the technology right now.
[QUOTE=Bomimo;37907378]Cue all the Catvatar freaks going ballshit insane looking for Pandora.[/QUOTE]
If we ever find Pandora I want it to be the Pandora with deserts, vaults, and psychos.
Sorry, you need to Log In to post a reply to this thread.
