Yeah, no. Even if we discover habitable planets, warp drive, and aliens tomorrow, there will *always* be people complaining about space exploration funding. If there's one thing people love to do, it's complain.
Proxima Centauri has an earth like planet!
- Thread starter Romulan_spy
- Start date
Some talk about our "pale red dot"
https://twitter.com/mustapipa/status/754669650286379008
https://forum.nasaspaceflight.com/index.php?topic=39533.80
http://www.seeker.com/could-proxima-centauri-be-our-interstellar-getaway-1977439925.html
I've heard it described as a warm Mars. It doesn't help that it orbits a flare star:
These flares can grow as large as the star and reach temperatures measured as high as 27 million K[41]—hot enough to radiate X-rays.[50] Indeed, Proxima Centauri's quiescent X-ray luminosity, approximately (4–16) × 1026 erg/s ((4–16) × 1019 W), is roughly equal to that of the much larger Sun. The peak X-ray luminosity of the largest flares can reach 1028 erg/s (1021 W.)
https://en.wikipedia.org/wiki/Proxima_Centauri#Habitable_zone
Still, perhaps better than any other planet we have in our system--save Earth.
You might have something on the farside--or could deposit some genetically engineered something. Life would need help there.
Still--a good extrasolar object not all that far away--in the cosmic sense.
The best bet isn't starshot, but something like this:
https://en.wikipedia.org/wiki/Sunjammer_(spacecraft)
I'd propose two SLS missions. One with a massive solar sail--and at least another with an NTR.
This would launch the folded sail near Jupiter, when opposite the Sun from target--on a trjectory similar to this: https://en.wikipedia.org/wiki/Solar_Probe_Plus
Early conceptual designs for the Solar Probe mission used a gravity assist maneuver at Jupiter to cancel the orbital speed of the probe launched from Earth, in order to drop onto a trajectory close to the Sun.
Now, as the solar sail falls inward, close to 200 km/s (120 mi/s), then the sail will deploy.
The sail will then slingshot out and get a last gravity assist from Saturn in Opposition, and angle towards Proxima Centauri in such a way as light from that system can slow it down.
That's about as good as I can come up with. You need a lot of surface area for this--and the sail doubles as a comm dish perhaps.
http://space.stackexchange.com/ques...blems-with-using-the-sun-for-oberth-maneuvers
https://twitter.com/mustapipa/status/754669650286379008
https://forum.nasaspaceflight.com/index.php?topic=39533.80
http://www.seeker.com/could-proxima-centauri-be-our-interstellar-getaway-1977439925.html
I've heard it described as a warm Mars. It doesn't help that it orbits a flare star:
These flares can grow as large as the star and reach temperatures measured as high as 27 million K[41]—hot enough to radiate X-rays.[50] Indeed, Proxima Centauri's quiescent X-ray luminosity, approximately (4–16) × 1026 erg/s ((4–16) × 1019 W), is roughly equal to that of the much larger Sun. The peak X-ray luminosity of the largest flares can reach 1028 erg/s (1021 W.)
https://en.wikipedia.org/wiki/Proxima_Centauri#Habitable_zone
Still, perhaps better than any other planet we have in our system--save Earth.
You might have something on the farside--or could deposit some genetically engineered something. Life would need help there.
Still--a good extrasolar object not all that far away--in the cosmic sense.
The best bet isn't starshot, but something like this:
https://en.wikipedia.org/wiki/Sunjammer_(spacecraft)
I'd propose two SLS missions. One with a massive solar sail--and at least another with an NTR.
This would launch the folded sail near Jupiter, when opposite the Sun from target--on a trjectory similar to this: https://en.wikipedia.org/wiki/Solar_Probe_Plus
Early conceptual designs for the Solar Probe mission used a gravity assist maneuver at Jupiter to cancel the orbital speed of the probe launched from Earth, in order to drop onto a trajectory close to the Sun.
Now, as the solar sail falls inward, close to 200 km/s (120 mi/s), then the sail will deploy.
The sail will then slingshot out and get a last gravity assist from Saturn in Opposition, and angle towards Proxima Centauri in such a way as light from that system can slow it down.
That's about as good as I can come up with. You need a lot of surface area for this--and the sail doubles as a comm dish perhaps.
http://space.stackexchange.com/ques...blems-with-using-the-sun-for-oberth-maneuvers
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A new BBC article references the researchers and the paper published in Nature.
http://www.bbc.co.uk/news/science-environment-37167390
http://www.nature.com/news/earth-si...rby-star-is-astronomy-dream-come-true-1.20445
Seems there are hints of a second planet in the system. Note that a subscription is required to read the paper in Nature. The following text is the abstract from the paper:
http://www.bbc.co.uk/news/science-environment-37167390
http://www.nature.com/news/earth-si...rby-star-is-astronomy-dream-come-true-1.20445
Seems there are hints of a second planet in the system. Note that a subscription is required to read the paper in Nature. The following text is the abstract from the paper:
Get yer ass to mas
No subscription to Nature, which leaves me out.
http://www.space.com/33841-living-on-proxima-b.html
-Researchers think the planet is likely rocky, and it has a surface one could walk on
- "One side is always sunny, the other is gloomy and dark,"
Warm enough to host water.
- Without an atmosphere, the planet's surface could hover at around minus 40 degrees Fahrenheit (minus 40 degrees Celsius). But that's no cause for alarm, the researchers said during the briefing — Earth itself would hover at around minus 4 F (minus 20 C) without an atmosphere. If this planet has an atmosphere, too, it could range from minus 22 to 86 F (minus 30 to 30 C) on its dark and light sides, making it warm enough to host liquid water on its surface.
Whether it has that atmosphere and water, though, depends a lot on the planet's history.
"It strictly depends on the initial conditions," Anglada-Escudé said. "Either this planet's dry, or it formed very far away and brought a lot of water from beyond the ice line [far away in the star's system, where comets and debris are icy rather than just rocky], or maybe started dry but comets rain every once in a while on the planet and make it water again."
"This is open for speculation, but chances are good — there are viable models and stories that lead to a viable, Earth-like planet today,"
Another thing to consider is the radiation beaming off the nearby star, researchers said — because Proxima Centauri is so close, strong enough X-ray and ultraviolet radiation would stand a chance of boiling off the water and stripping the planet's atmosphere. While the current high-energy radiation — about 100 times that of modern-day Earth, the researchers estimated — isn't enough to have that effect or to preclude life, it's possible that earlier in the star's lifetime it could have been violent enough to take a toll.
The researchers also mentioned other signals in the star's wobbles whose source was unsure — it may just be the star itself, or it might indicate another planetary neighbor, or one large planet with an entourage of smaller ones around it, the researchers said in a second press conference. That planet, though, would be farther out, larger and well away from the zone where liquid water can exist.
Researchers think the planet is likely rocky, and it has a surface one could walk on — it's probably not a tiny gas planet.
-Researchers think the planet is likely rocky, and it has a surface one could walk on
- "One side is always sunny, the other is gloomy and dark,"
Warm enough to host water.
- Without an atmosphere, the planet's surface could hover at around minus 40 degrees Fahrenheit (minus 40 degrees Celsius). But that's no cause for alarm, the researchers said during the briefing — Earth itself would hover at around minus 4 F (minus 20 C) without an atmosphere. If this planet has an atmosphere, too, it could range from minus 22 to 86 F (minus 30 to 30 C) on its dark and light sides, making it warm enough to host liquid water on its surface.
Whether it has that atmosphere and water, though, depends a lot on the planet's history.
"It strictly depends on the initial conditions," Anglada-Escudé said. "Either this planet's dry, or it formed very far away and brought a lot of water from beyond the ice line [far away in the star's system, where comets and debris are icy rather than just rocky], or maybe started dry but comets rain every once in a while on the planet and make it water again."
"This is open for speculation, but chances are good — there are viable models and stories that lead to a viable, Earth-like planet today,"
Another thing to consider is the radiation beaming off the nearby star, researchers said — because Proxima Centauri is so close, strong enough X-ray and ultraviolet radiation would stand a chance of boiling off the water and stripping the planet's atmosphere. While the current high-energy radiation — about 100 times that of modern-day Earth, the researchers estimated — isn't enough to have that effect or to preclude life, it's possible that earlier in the star's lifetime it could have been violent enough to take a toll.
The researchers also mentioned other signals in the star's wobbles whose source was unsure — it may just be the star itself, or it might indicate another planetary neighbor, or one large planet with an entourage of smaller ones around it, the researchers said in a second press conference. That planet, though, would be farther out, larger and well away from the zone where liquid water can exist.
Researchers think the planet is likely rocky, and it has a surface one could walk on — it's probably not a tiny gas planet.
Anyone have access to that Nature article?
The main pieces of information - that *might* be possible to determine from here? - that I would like to see are mass and the strength of gravity at the planet's surface. It can be all sorts of "Earth-like" - liquid water, habitable temperatures, breathable atmo mix, heck, even native life - and that will all be very fascinating and worth study. And *I* would even regard it as worth visiting. But if the surface gravity would make it impossible for a human to stand up for any real period of time, I just can't see us colonizing it. And getting all of our eggs out of this one basket (planet and preferably solar system) is a big part of my interest in exoplanets.
I read an article on CNN. But I sent them an email pointing out an error in their article. That said:
Because of its location, the researchers hope it provides an opportunity for possible "robotic exploration in the coming centuries."
They misspelled a word. It should be spelled D-E-C-A-D-E-S not C-E-N-T-U-R-I-E-S. Why? 'Cause ain't no one got time fo' dat.
Because of its location, the researchers hope it provides an opportunity for possible "robotic exploration in the coming centuries."
They misspelled a word. It should be spelled D-E-C-A-D-E-S not C-E-N-T-U-R-I-E-S. Why? 'Cause ain't no one got time fo' dat.
In the news:
http://hpf.psu.edu/2016/08/25/the-plot-thickens/
Some talk here: http://www.nextbigfuture.com/2016/08/earth-mass-world-in-habitable-zone.html
http://forum.nasaspaceflight.com/index.php?topic=40996.0
https://palereddot.org/
http://www.centauri-dreams.org/?p=36210
http://www.americaspace.com/?p=95085
Very nice graphics here:
http://www.americaspace.com/?p=95000
http://hpf.psu.edu/2016/08/25/the-plot-thickens/
Some talk here: http://www.nextbigfuture.com/2016/08/earth-mass-world-in-habitable-zone.html
http://forum.nasaspaceflight.com/index.php?topic=40996.0
https://palereddot.org/
http://www.centauri-dreams.org/?p=36210
http://www.americaspace.com/?p=95085
Very nice graphics here:
http://www.americaspace.com/?p=95000
I am going to have to point out the incorrect sentence structuring "Why? Cause ain't no one got time fo'dat." Fo' dat should be "For that" as well as Cause being Cuz.
Proxima Centauri b and Proxima Centauri comparisons:
https://en.wikipedia.org/wiki/Proxima_Centauri_b
From what I have read is that Proxima b might be tidally locked with some sparse pockets of water on its surface in the sunnier regions as well as having 400 times more x-ray exposure than Earth which is what I would be most concerned about.
It concerns me, too, and would certainly be a challenge - but at the basic level, at least, we know how to block x-rays. We would overcome it if we put our minds to it. We *don't* know how to negate an unacceptable surface gravity *at all* that I'm aware of (short of some stunts with using forces in involved in flight to make it *seem* greater or less for brief periods that don't seem like they'd be very useful for trying to establish a presence on the surface). Our essential knowledge of the mechanism of gravity is... rudimentary... to be generous.
Wear helium balloons? Genetically engineer humans to adapt them to a higher gravity? The planet might be more massive than Earth but we don't know its density or radius. The surface gravitational acceleration is proportional to M/r^2 or to ρr where M, ρ, and are the mass, average density, and radius of the planet (M = ρ4πr^3/3). A higher radius and lower density than the Earth's could yield a similar surface gravity -- that is, the product ρr need only be similar to that of the Earth.
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http://www.cnn.com/2016/08/24/healt...neighbor-star0401AMVideoVideo&linkId=28070146
Proxima Centauri b and Earth comparisons:
https://en.wikipedia.org/wiki/Proxima_Centauri_b
From what I have read is that Proxima b might be tidally locked with some sparse pockets of water on its surface in the sunnier regions as well as having 400 times more x-ray exposure than Earth. The x-ray exposure is what I would be concerned about regarding life being present on Proxima b.
https://en.wikipedia.org/wiki/List_of_nearest_terrestrial_exoplanet_candidates
I was looking at the chart from the Wiki and found the distances from Earth to other planets be rather interesting.
Promixa Centauri b - 4.22 ly
Wolf 1061b,c and d - 13.8 - 8.78 ly from Proxima Centauri b
Gliese 876 d - 15 ly, 10.78 ly from Proxima Centauri b and 1.2 ly from Wolf 1061b,c and d
Gliese 682 b - 16 ly, 11.78 ly from Proxima Centauri b, 2.1 ly from Wolf 1061b,c and d and 1 ly from Gliese 876 d
Gliese 832 b - 16.16 ly, 11.94 ly from Proxima Centauri b, 2.26 ly from Wolf 1061b, c and d and 1.16 ly from Gliese 682 b
The further away from Earth the planets discovered seem to be grouped more closely together until Gliese 667C c that is 22 ly from Earth and six ly from 61 Virginis b. Eight ly separates 61 Virginis b from HD 85512 b where the distance then settles into a two ly distance.
It could be theorized that when large groups of planets are found based on the above distances that somewhere in the chain there would be an Earth like planet possible of sustaining life or already has life on it.
A grouping of planets like those around Earth could be a sign a habitable planet is located somewhere in the middle that the exo-planets would provide a shield for against asteroids and other cosmic events.
If life is formed in the center of a protective shell, be that shell a womb or the shell of an egg then life on a planet would function in the same way where a habitable planet would have layers of protective planets orbiting it much like the womb and chicken egg shell does for the developing life in the center.
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Venus all over again.
Next to nothing is known about this planet, yet you're already counting the jungles and dinosaurs. It might be tidally locked. It might have an atmosphere. It might have water on the surface. It might have life. "Earth-like planet found next door!" That's called "give us grant money" hype. In other business it's known as a pig in a poke. Next you'll be telling us about the postal rates and library cataloging methods used on Proxima Centauri b.
What I want to know is: does Proxima dim when this planet swarms in front of it?
Next to nothing is known about this planet, yet you're already counting the jungles and dinosaurs. It might be tidally locked. It might have an atmosphere. It might have water on the surface. It might have life. "Earth-like planet found next door!" That's called "give us grant money" hype. In other business it's known as a pig in a poke. Next you'll be telling us about the postal rates and library cataloging methods used on Proxima Centauri b.
What I want to know is: does Proxima dim when this planet swarms in front of it?
In other news, some talk about a SETI signal from the direction of Vega/Hercules:
http://up-ship.com/blog/?p=32996
http://www.centauri-dreams.org/?p=36248
“HD 164595 is a star of 0.99 solar masses at a distance of roughly 95 light years in the constellation Hercules, and an estimated age of 6.3 billion years. Its metallicity is almost identical to that of the Sun. A known planet in this system, HD 164595 b, is 0.05 Jupiter mass with a period of 40 day”
We do live in interesting times.
Time to breathe new life into the ashes of the treasure fleet, Zheng He.
http://up-ship.com/blog/?p=32996
http://www.centauri-dreams.org/?p=36248
“HD 164595 is a star of 0.99 solar masses at a distance of roughly 95 light years in the constellation Hercules, and an estimated age of 6.3 billion years. Its metallicity is almost identical to that of the Sun. A known planet in this system, HD 164595 b, is 0.05 Jupiter mass with a period of 40 day”
We do live in interesting times.
Time to breathe new life into the ashes of the treasure fleet, Zheng He.
Just remember -- Klaatu barada nikto.
The odds of its orbit being aligned in such a way that the transit is visible from Earth are pretty low.
The probability is easy to calculate:
http://kepler.nasa.gov/Science/about/characteristicsOfTransits/
The probability is D/2a (*) for a transit greater in duration than half of a central transit, where D is the stellar diameter and a is the orbital radius. For Proxima, D = 0.14 of the sun's diameter (0.0093 AU) and a = 0.05 AU for the candidate planet, therefore D/2a = 0.14 x 0.0093 / 0.05 = 0.026 or 2.6% or about 1 in 40. If more grazing transits can be detected, the probability is as high as 5.2%.
(*) ETA: A more accurate formula is (d +D)/2a where d is the planetary diameter, which is probably similar to the Earth's diameter -- about 1/109th of the Sun's diameter or 1/15th of Proxima's -- so the probability increases to between 2.77% and 5.54%.
http://kepler.nasa.gov/Science/about/characteristicsOfTransits/
The probability is D/2a (*) for a transit greater in duration than half of a central transit, where D is the stellar diameter and a is the orbital radius. For Proxima, D = 0.14 of the sun's diameter (0.0093 AU) and a = 0.05 AU for the candidate planet, therefore D/2a = 0.14 x 0.0093 / 0.05 = 0.026 or 2.6% or about 1 in 40. If more grazing transits can be detected, the probability is as high as 5.2%.
(*) ETA: A more accurate formula is (d +D)/2a where d is the planetary diameter, which is probably similar to the Earth's diameter -- about 1/109th of the Sun's diameter or 1/15th of Proxima's -- so the probability increases to between 2.77% and 5.54%.
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