Planet discovered in Alpha Centauri system

[Bardo]

I thought this was neat, finding a planet system in the closest star system to ours has been an astronomer's dream for who knows how long.

The star system closest to our own sun hosts a planet with roughly Earth's mass and may harbor other alien worlds as well, a new study reports.

Astronomers detected the alien planet around the sunlike star Alpha Centauri B, which is part of a three-star system just 4.3 light-years away from us. The newfound world is about as massive as Earth, but it's no Earth twin; its heat-blasted surface may be covered with molten rock, researchers said.

The mere existence of the planet, known as Alpha Centauri Bb, suggests that undiscovered worlds may lurk farther away from its star — perhaps in the habitable zone, that just-right range of distances where liquid water can exist.



"Most of the low-mass planets are in systems of two, three to six or seven planets, out to the habitable zone," study co-author Stephane Udry, of the Geneva Observatory, told reporters today (Oct. 16).

So the discovery "opens really good prospects for detecting planets in the habitable zone in a system that is very close to us," Udry added. "In that sense, this system is a landmark."

Alpha Centauri Bb zips around its star every 3.2 days, orbiting at a distance of just 3.6 million miles (6 million kilometers). For comparison, Earth orbits about 93 million miles, or 150 million km, from the sun.

http://www.space.com/18089-earth-siz...-centauri.html

[Zeus the Moose]

Someone alert Sid Meier!

[PC LOAD LETTER]

This is great. I hope in my lifetime we identify a rocky, earth-like planet in the habitable zone. That'd be nice.

[ÑóẊîöʼn]

If a sufficiently massive rocky planet is found in the habitable zone, then the prospects for interstellar colonisation look a hell of a lot better.

Even if that turns out to not be the case, there may still be an Earth-size planet orbiting in the habitable zone of Proxima Centauri.

[Mather]

If a sufficiently massive rocky planet is found in the habitable zone, then the prospects for interstellar colonisation look a hell of a lot better.

Even if that turns out to not be the case, there may still be an Earth-size planet orbiting in the habitable zone of Proxima Centauri.

We are kind of lucky to have these two stars (Proxima and Alpha Centauri) really near us.

Sadly the planet they found is not in the habitable zone but now that we have found the first planet in this system, it won't be long (hopefully) before we start finding others.

[Igor]

if it's anything unlike the sid meier game i'm going to be pissed

[Q]

We are kind of lucky to have these two stars (Proxima and Alpha Centauri) really near us.

"Really near us" is a rather optimistic formulation. Although the Alpha Centauri system is closest to our solar system, "just" being a little over 4 lightyears away, it would still take us around 40 000 years to reach that system with a manned mission at our current technological level.

But if we're fine sending robots that don't care about gigantic acceleration forces, it might "just" take a lifetime to send a probe.

With all these scifi series, a lot of people don't realise how fucking hugely big space really is.

[Mather]

"Really near us" is a rather optimistic formulation. Although the Alpha Centauri system is closest to our solar system, "just" being a little over 4 lightyears away, it would still take us around 40 000 years to reach that system with a manned mission at our current technological level.

But if we're fine sending robots that don't care about gigantic acceleration forces, it might "just" take a lifetime to send a probe.

With all these scifi series, a lot of people don't realise how fucking hugely big space really is.

I meant near in astronomical terms. Compared to the rest of the galaxy or even our local star cluster, four lights years is no distance at all.

Before we start sending humans to other solar systems, I think we will start with our own solar system first. But for that to even happen, we will need to develop our space infrastructure and space transportation technologies as what we have today is nowhere near sufficient.

I think your right though in that for the time being, we will most likely explore neighbouring solar systems with probes and robotic technology.

[Lynx]

If they can refine the technique to detect smaller planets orbiting at greater distances, then many more potentially habitable worlds may be discovered.

[ÑóẊîöʼn]

"Really near us" is a rather optimistic formulation. Although the Alpha Centauri system is closest to our solar system, "just" being a little over 4 lightyears away, it would still take us around 40 000 years to reach that system with a manned mission at our current technological level.

I assume that's with chemical rockets? You are aware that there are many proposals for more efficient and powerful engines that don't require new interpretations of physics, right? I find it really irritating that people keep saying throwing out such figures as if they really mean anything. If we ever go to the stars, we certainly won't be doing it with chemical rockets like those on the Space Shuttle, no matter how we end up doing it.

But if we're fine sending robots that don't care about gigantic acceleration forces, it might "just" take a lifetime to send a probe.

Nope. If we can build an engine capable of maintaining an acceleration of just one Earth gravity throughout the voyage, then from the point of view of the crew on board, a journey to Alpha Centauri would only take three and a half years, due to relativistic effects. From the point of view of observers on Earth, the journey would have only taken 5.9 years, plus the 4.3 years it would take for a "we've arrived!" signal to get back. That's well within the potential lifetime of most people.

As a nice bonus, the constant acceleration would obviate the need for rotating sections.

With all these scifi series, a lot of people don't realise how fucking hugely big space really is.

I don't think we can expect FTL this side of the next decamillennium, but if we can work out how to extend human lifespans indefinitely, then travel between the stars merely becomes a question of avoiding boredom.

Failing that, we can work on ways of storing passengers and crew in a static condition for decades at a time, thus bringing more star systems within the potential reach of a baseline human lifetime.

[Q]

I assume that's with chemical rockets? You are aware that there are many proposals for more efficient and powerful engines that don't require new interpretations of physics, right? I find it really irritating that people keep saying throwing out such figures as if they really mean anything. If we ever go to the stars, we certainly won't be doing it with chemical rockets like those on the Space Shuttle, no matter how we end up doing it.

Be that as it may be. All these proposals are so far unproven technology or very much still in the "beta" phase (like ion engines).

Nope. If we can build an engine capable of maintaining an acceleration of just one Earth gravity throughout the voyage, then from the point of view of the crew on board, a journey to Alpha Centauri would only take three and a half years, due to relativistic effects. From the point of view of observers on Earth, the journey would have only taken 5.9 years, plus the 4.3 years it would take for a "we've arrived!" signal to get back. That's well within the potential lifetime of most people.

As a nice bonus, the constant acceleration would obviate the need for rotating sections.

Would you mind pointing me to some more background on this? I find it kinda hard to believe that it would take only 5.9 "Earth years" to cross 4+ lightyears.

I don't think we can expect FTL this side of the next decamillennium, but if we can work out how to extend human lifespans indefinitely, then travel between the stars merely becomes a question of avoiding boredom.

Failing that, we can work on ways of storing passengers and crew in a static condition for decades at a time, thus bringing more star systems within the potential reach of a baseline human lifetime.

Again, scifi so far. We have no idea how to put humans in "stasis" as far as I'm aware.

[ÑóẊîöʼn]

Be that as it may be. All these proposals are so far unproven technology or very much still in the "beta" phase (like ion engines).

We built and tested nuclear fission-based NERVA engines in the 1960s, and since nuclear fission is now a more mature technology it should be even better if picked up again for rocket vehicle applications now or in the future.

Would you mind pointing me to some more background on this? I find it kinda hard to believe that it would take only 5.9 "Earth years" to cross 4+ lightyears.

It all comes down to acceleration:

T = 2 * sqrt[ D/A ]

where

T = transit time (seconds)
D = distance (meters)
A = acceleration (m/s2)
sqrt[x] = square root of x

Remember that

AU * 1.49e11 = meters
1 g of acceleration = 9.81 m/s2
one-tenth g of acceleration = 0.981 m/s2
one one-hundredth g of acceleration = 0.0981 m/s2

Divide time in seconds by

3600 for hours
86400 for days
2592000 for (30 day) months
31536000 for years

Now, using a distance of 4.3 light years, converting that to seconds and running it through the above equation using (A = 1 g) gives T a value of 128748854.78 seconds, or 4.08 years. Now that was not a relativistic equation because it gives a single value T which is the same for all observers. It fails to take into account time dilation due to the massive relative velocities accrued by years of constant acceleration.

Using the calculator here (under "Long Relativistic Journeys"), we get two results, one an observer on the ship, and one for an observer on Earth.

Of course, it would be remiss of me to fail to mention that such vehicles, if they were ever built, would have nasty mass ratios (basically kilos of propellant versus everything else), the best we can expect being 22, about equivalent to the Saturn V. I am not expecting travel between the stars to be casual within the forseeable future. Even as a one-off special we would still need to establish the kind of space-based industrial infrastructure required to build such vehicles. I'm in agreement with those who advocate colonisation of the Solar system initially.

Again, scifi so far. We have no idea how to put humans in "stasis" as far as I'm aware.

That the first premise of cryonics is generally accepted by scientists suggests that it may be possible to revive people from such a state. Less extreme would be experiments to determine if hibernation-like states are able to be induced in organisms that do not naturally hibernate (I'm pretty sure I remember some experiment being done on monkeys that was exactly that but I can't seem to find it ). This is of course assuming that attempts at prolonging human longevity do not pan out.

[ÑóẊîöʼn]

Not exactly what I was looking for, but interesting and relevant nonetheless:

New hibernation technique may work on humans

A new trick could one day put humans into a hibernation-like state without all the frigid antics of an Austin Powers movie or an Arthur C. Clarke story.

Using a natural chemical humans and other animals produce in their bodies, scientists have for the first time induced hibernation in mammals, putting mice into a state similar to suspended animation for up to six hours and then bringing them back to normal life.

The breakthrough suggests humans along with other mammals might harbor a mostly unused ability to hibernate on demand. Further research into the phenomenon could lead to medical advances, such as buying time for humans awaiting an organ transplant, scientists said.

"We are, in essence, temporarily converting mice from warm-blooded to cold-blooded creatures, which is exactly the same thing that happens naturally when mammals hibernate," said lead researcher Mark Roth of the Fred Hutchinson Cancer Research Center in Seattle.

During the induced hibernation, cells virtually stopped working, reducing the rodents' need for oxygen.

"We think this may be a latent ability that all mammals have - potentially even humans - and we're just harnessing it and turning it on and off, inducing a state of hibernation on demand," Roth said.

The results are detailed in the April 22 issue of the journal Science.

Humans already hibernate

Squirrels, bears, snakes and many other animals hibernate naturally, some more deeply than others. Humans have been known to hibernate by accident, Roth and his colleagues point out.

A Norwegian skier was rescued in 1999 after being submerged in icy water for more than an hour. She had no heartbeat and her body temperature was 57 degrees Fahrenheit (normal is 98.6). She recovered.

Canadian toddler Erika Nordby wandered outside at night and nearly froze to death in 2001. She wore only a diaper and T-shirt. It was minus 11 Fahrenheit (-24 Celsius). When found, her heart had stopped beating for two hours and her body temperature was 61 degrees. She suffered severe frostbite but required no amputations and otherwise recovered.

"Understanding the connections between random instances of seemingly miraculous, unexplained survival in so-called clinically dead humans and our ability to induce - and reverse - metabolic quiescence in model organisms could have dramatic implications for medical care," Roth said. "In the end I suspect there will be clinical benefits and it will change the way medicine is practiced, because we will, in short, be able to buy patients time."

Back from the dead?

Already there are companies that will gladly freeze the dead in hopes some way of curing and reviving them might develop in the future. The field is called cryonics. So far, no one has been brought back.

The trick with the mice didn't require freezing. Instead, the rodents breathed air laced with hydrogen sulfide, a chemical produced naturally in the bodies of humans and other animals. Within minutes, they stopped moving and soon their cell functions approached total inactivity.

Humans use hydrogen sulfide to "buffer our metabolic flexibility," Roth explained. "It's what allows our core temperature to stay at 98.6 degrees, regardless of whether we're in Alaska or Tahiti."

In extreme doses, the hydrogen sulfide is thought to bind to cells in place of oxygen. The organism's metabolism shuts down. Upon breathing normal air again, the mice "quickly regained normal function and metabolic activity with no long-term negative effects," the researchers report. They plan to test the technique on larger mammals next.

Practical uses

"Hibernating humans and space travel aside," Roth told LiveScience, "we hope that 'metabolic flexibility' can be used to enhance trauma care, surgical outcome, and organ transplant."

Among the first applications in humans might be to reduce severe fevers, when a patient is near death. Clinical trials for such a procedure could begin in five years, the scientists say.

"We believe we know how to flip the breaker on the patient's furnace," Roth said. "If they have a fever, we believe we know how to stop it on a dime."

For cancer patients, Roth speculated that temporarily eliminating oxygen dependence in healthy cells could make them less vulnerable targets to radiation and chemotherapy.

"Right now in most forms of cancer treatment we're killing off the normal cells long before we're killing off the tumor cells," he said. "By inducing metabolic hibernation in healthy tissue we'd at least level the playing field."

Eric Blackstone, a graduate research assistant in Roth's laboratory, was lead author of the journal paper.

[Fnord]

It would be quite interesting to live in a triple multiple star system, one thing that I noticed that no one is taking note of, is the consequences of living in such a system.
With three stars, there would be massive temperature difference on different parts of the orbit, in our current biological form, it would probably be best if we were to colonize a habitable planet in this system, to do it deep underground. Another thing to note is that it would be much easier to colonize a permanently frigid planet than a molten one, perhaps instead of searching for the often difficult to find "goldilocks" planet, we should instead send a probe to investigate such a system and terraform an ice covered or even barren planet or even just make it easier and just make a bio-dome with earth-like conditions on any planet you want.

[ÑóẊîöʼn]

It would be quite interesting to live in a triple multiple star system, one thing that I noticed that no one is taking note of, is the consequences of living in such a system.
With three stars, there would be massive temperature difference on different parts of the orbit, in our current biological form, it would probably be best if we were to colonize a habitable planet in this system, to do it deep underground.

Doesn't that all depend on the sum total of stellar energy falling on the planet?

For example, you could have a planet orbiting a close binary pair which have a combined luminosity equal to the Sun, while a tiny little red dwarf star might provide a little more light and heat depending on its orbital semi-major axis from the binary pair and planet. A habitable planet in such a system may be similar to Earth temperature-wise, but would most likely still have unusual cycles of light and dark depending on the exact orbital arrangement.

I think that could have interesting implications for any life on such planets, since a lot of life on Earth organises itself according to a daily cycle of light and dark. I wonder what it would be like if a living world had varying light levels throughout the year?

Another thing to note is that it would be much easier to colonize a permanently frigid planet than a molten one, perhaps instead of searching for the often difficult to find "goldilocks" planet, we should instead send a probe to investigate such a system and terraform an ice covered or even barren planet or even just make it easier and just make a bio-dome with earth-like conditions on any planet you want.

Ever heard of paraterraforming? You can basically think of it as doming over the whole surface of a planetary body.

[Fnord]

Doesn't that all depend on the sum total of stellar energy falling on the planet?

For example, you could have a planet orbiting a close binary pair which have a combined luminosity equal to the Sun, while a tiny little red dwarf star might provide a little more light and heat depending on its orbital semi-major axis from the binary pair and planet. A habitable planet in such a system may be similar to Earth temperature-wise, but would most likely still have unusual cycles of light and dark depending on the exact orbital arrangement.

I think that could have interesting implications for any life on such planets, since a lot of life on Earth organises itself according to a daily cycle of light and dark. I wonder what it would be like if a living world had varying light levels throughout the year?

The following information is from wikipedia, so I'm not sure how true it may be to the facts. If it were a close-binary pair, the temperature would probably change very little, if only a few degrees in difference depending on how close it is, the problem is that if it was too close it would probably merge together over time. Regardless, that's kind of not applicable to this thread as much because the distance between the two main stars of Alpha Centauri is on average larger than the distance between the sun and Saturn which would cause a massive temperature difference if the planet orbited both stars at the same time. It would still suffer a dramatic change in temperature even if it orbited only one star, because periodically the planet would line up between the two stars causing a heat surge and at other times the second star would be behind the other one causing a drop in heat.
The third star is so small and over 400 times the distance between the sun and Neptune, as well as the fact they are not 100% sure if it's gravitation is associated with the binary system, it would not have any significant effect on the temperature of the planet.

Ever heard of You can basically think of it as doming over the whole surface of a planetary body.

Oh, this is very interesting, I have not heard of this, it would probably require immense amounts of material to create a dome over the entire surface though, unless the materials to make the dome were directly accessible on the planet.

[Silas]

Alpha Centauri Bb? For people who are intelligent enough to know how to search for and find planets in nearby star-systems, they are not terribly imaginative when it comes to actually naming what they discover when they do.

[ÑóẊîöʼn]

Alpha Centauri Bb? For people who are intelligent enough to know how to search for and find planets in nearby star-systems, they are not terribly imaginative when it comes to actually naming what they discover when they do.

It might be better to think of it as a catalogue entry rather than a name.

Presumably we'll get round to naming it properly when it becomes something more socially significant than just an astronomical data point.

[Domela Nieuwenhuis]

How bummed would we be if we after years of spacetraveling we got there and it turned out they were very badly into capitalism...

[TaylorS]

Hurry, get the spaceship built so we can win a science victory!