Earth-sized planet around nearby star is astronomy dream come true
Source: Nature
Proxima Centauri, the star closest to the Sun, has an Earth-sized planet orbiting it at the right distance for liquid water to exist. The discovery, reported today in Nature1, fulfils a longstanding dream of science-fiction writers a potentially habitable world that is close enough for humans to send their first interstellar spacecraft.
...snip...
Humanitys first chance to explore this nearby world may come from the recently announced Breakthrough Starshot initiative, which plans to build fleets of tiny laser-propelled interstellar probes in the coming decades. Travelling at 20% of the speed of light, they would take about 20 years to cover the 1.3 parsecs from Earth to Proxima Centauri.
Proximas planet is at least 1.3 times the mass of Earth. The planet orbits its red-dwarf star much smaller and dimmer than the Sun every 11.2 days. If you tried to pick the type of planet youd most want around the type of star youd most want, it would be this, says David Kipping, an astronomer at Columbia University in New York City. Its thrilling.
Earlier studies had hinted at the existence of a planet around Proxima. Starting in 2000, a spectrograph at the European Southern Observatory (ESO) in Chile looked for shifts in starlight caused by the gravitational tug of an orbiting planet. The resulting measurements suggested that something was happening to the star every 11.2 days. But astronomers could not rule out whether the signal was caused by an orbiting planet or another type of activity, such as stellar flares.
Read more: http://www.nature.com/news/earth-sized-planet-around-nearby-star-is-astronomy-dream-come-true-1.20445
Dale Neiburg
(698 posts)...if its year is only 11.2 earth days long?
PJMcK
(22,045 posts)SPACE has a good article that includes the answer to your question:
For comparison, Earth orbits about 93 million miles (150 million km) from the sun. But Proxima b's relatively tight orbit puts it right in the middle of the habitable zone, because red dwarfs are so much cooler and dimmer than sun-like stars, team members said. Not much else is known about Proxima b, so it's unclear just how hospitable the planet may be to life.
The complete article is here: http://www.space.com/33834-discovery-of-planet-proxima-b.html
Fast Walker 52
(7,723 posts)Very cool:
What is more interesting is the history of the planet whether in the early ages, the young ages, of this planet the star was so active, and the star emitted so much high-energy radiation, that it blew away the atmosphere and may have blown away the water also," he said.
Other aspects of the planet's history also have a bearing on just how wet Proxima b may be. For example, if the alien world formed far from the star but then migrated inward, it is likely water-rich; if it formed near its present position, it likely started out much drier, study team members said. (But even this latter scenario doesn't preclude the existence of large amounts of water on Proxima b, Anglada-Escude stressed; comet and/or asteroid strikes could deliver the substance, as apparently happened here on Earth, he said.)
Tidally locked planets were once regarded as inhospitable to life baked too hot on the star-facing side, and freezing cold on the dark side. But recent research suggests that such worlds may indeed be habitable; winds in their atmospheres could distribute heat, smoothing out temperature extremes.
And if Proxima b is potentially habitable, life-forms have a long time to gain a foothold there: Red dwarfs keep burning for trillions of years, in contrast to stars like the sun, which die after 10 billion years or so.
"Proxima Centauri will exist for several hundreds or thousands of times longer than the sun," Hatzes wrote in his "News and Views" piece. "Any life on the planet could still be evolving long after our sun has died."
The sun is 4.6 billion years old. Proxima Centauri is thought to be slightly older perhaps 4.9 billion years or so, study team members said.
longship
(40,416 posts)Over 3/4 of the stars in the universe are red dwarfs. They are, by far, the longest lived star type. Many will go on slowly burning their hydrogen for up to a trillion years, or more.
Yes, they are dim, but once they get out of their adolescence they are stable.
The habitable zone being so close in is worrying though, because any planet there will very likely be tidally locked to the star, showing only one face to it. Not sure if that is conducive to life.
cstanleytech
(26,317 posts)caused all the water to have evaporated from the light side like what happened to Venus with any remaining water (if it ever had any) frozen on the dark side?
PJMcK
(22,045 posts)The article indicates that the planet could be in danger from solar flares.
"Energetic particles associated with the flares may erode the atmosphere or hinder the development of primitive forms of life," Hatzes wrote. "We also don't know whether the exoplanet has a magnetic field, like Earth, which could shield it from the dangerous stellar radiation."
But the higher X-ray flux is not a "showstopper" for life, Anglada-Escude and his colleagues said.
"None of this does exclude the existence of an atmosphere, or of [surface] water," co-author Ansgar Reiners, a professor at the University of Göttingen's Institute of Astrophysics in Germany, said during Tuesday's news conference.
It's possible that the most important things from this discovery will be for improving the scientific techniques to use in other planetary searches. Still, it's very cool news! In the 1960's science fiction television show "Lost in Space," the Robinson family was supposed to visit Alpha Centauri:
Life imitates art, although the TV show was pretty un-artful!
byronius
(7,400 posts)Twenty years? Let's do this.
Fast Walker 52
(7,723 posts)0rganism
(23,965 posts)good news everyone!
Orrex
(63,220 posts)0rganism
(23,965 posts)humanity's comin your way universe, deal with it!
Buckeye_Democrat
(14,856 posts)The stars are very distant. Even the closest ones are about 4.5 light years away. With our current rocket technology, it would take over 100,000 years to get there.
There's hypothetical future technology to cut down that travel time dramatically, but then there's collision risks at high speed. The galaxy is full of gas and dust between the stars, and they can be lethal as a traveler approaches even a fraction of the speed of light. When distant galaxies collide, it's mostly the gas and other particles that strike each other. The stars mostly pass right by each other. When the Andromeda galaxy hits the Milky Way in a few billion years, it's believed that none of the hundreds of billions of stars will collide because they're so sparsely distributed. The gas in between will heat up and glow, however.
Here's a recent article about using laser-powered small sails to fly past the solar system mentioned by the OP and the risk of collisions through the interstellar medium (which doesn't mention the greater risk closer to each solar system): http://arstechnica.com/science/2016/08/could-breakthrough-starshots-ships-survive-the-trip/
By the way, I seriously doubt that warp drives will ever be achieved, at least anything that achieves FTL travel. Why? Inevitable causality paradoxes.
This is the technology being referenced in this thread:
Here's another video about other travel ideas:
Hortensis
(58,785 posts)a child reading science fiction than...Cincinnati or Baltimore. Whoops, forgot jump rope, c-i-n-c-i-n-n-a-t-i, cross off Cincinnati.
"Lisa Kaltenegger, a Cornell astronomer: "A planet next door. How much more inspiring can it get?"
Scientists even now think planets in binary star systems (in general) might be habitable, although this one doesn't exactly look like Kansas. What Proxima b might look like:
https://img.washingtonpost.com/wp-apps/imrs.php?src=
Wonder if Jeff Bezos is planning an interstellar space ship already.
Cirque du So-What
(25,965 posts)to fuck up.
Frank Cannon
(7,570 posts)There is only one that we know right now that we are messing up, and that's the one we seem to be stuck on.
snooper2
(30,151 posts)Would have been involved LOL
n2doc
(47,953 posts)Getting up to 20% of light speed using lasers? Photons are not all that strong an accelerant (little mass) and the light levels would have to be astounding to punch through the atmosphere and provide the thrust.
Electronics can't be too small because they have to be able to send data back. and survive long periods of time in space.
I'll believe it when I see them get a probe up to escape velocity.
VWolf
(3,944 posts)But they do carry momentum, albeit not much
(Sorry for being so picky, just wanted to clarify)
Buckeye_Democrat
(14,856 posts)And this is about visiting the NEAREST star to us other than our Sun.
There's collision risks too:
http://arstechnica.com/science/2016/08/could-breakthrough-starshots-ships-survive-the-trip/
That article mentions the very low probability of striking dust that's large enough to destroy a sail in one blow, at least through the interstellar medium between the systems, but the risks from striking smaller dust particles and gas molecules are inevitable.
Interstellar travel certainly isn't easy. No visits from ET? Maybe they realized it's incredibly difficult and not worth the effort. (Or maybe they're simply not out there in our Milky Way, but I doubt it.)
VMA131Marine
(4,145 posts)If you know where to point it, you can use a laser to measure the distance to the moon by bouncing the beam off one of the mirrors left by the Apollo missions. The thrust produced by the laser would be very low, but a craft could achieve huge speeds by operating the beam continuously. Theoretically, the speed would asymptotically approach the speed of light itself, although it could never quite get there, of course.
The momentum of a photon is h/wavelength, where h is Planck's constant. If you have an ideal mirror, the momentum imparted to the spacecraft by one photon would be double the initial momentum of the photon.
According to my (non-relativistic) estimates, a 10GW red laser at 633nm could accelerate a 1000kg spacecraft so that it reached Proxima Centauri in 34 years. The spacecraft would be travelling at 25% of the speed of light at that point so it would not spend much time in that neighborhood as it would have no way to slow down.
You would not want to get in the way of the laser beam unless you were highly reflective.
n2doc
(47,953 posts)What would such a thing look like from the ground? It would probably blind you just from the scatter.
VMA131Marine
(4,145 posts)If I assume a 1kg probe then 35 gigawatts of power are needed to accelerate it to 0.2c in 3 days. That's considerably more than the 1.21 gigawatts needed to propel Marty McFly back to the future in a deLorean.
Yavin4
(35,445 posts)**Whew**
Blue_Tires
(55,445 posts)tclambert
(11,087 posts)jtuck004
(15,882 posts)63splitwindow
(2,657 posts)For comparison sake, here is a picture of earth taken by a rover on the surface of Mars, just 250,000,000 miles away:
Fast Walker 52
(7,723 posts)RapSoDee
(421 posts)freebrew
(1,917 posts)I'm getting dizzy just thinking about it.
Oh, the vertigo.