Earth-like Exoplanets - Discussions & Developments

[xXTheOneRavenXx]

Has anyone heard anything more on HD 40307 b? 41.6 ly's from earth. Magnitude 7.17, size: 4.2 Earths, discovered June 16, 2008. http://www.eso.org/public/outreach/press-rel/pr-2008/pr-19-08.html

 

[thnkrx]

Has anyone heard anything more on HD 40307 b? 41.6 ly's from earth. Magnitude 7.17, size: 4.2 Earths, discovered June 16, 2008

Full rundown from the 'extra-solar planets encyclopedia':

http://exoplanet.eu/planet.php?p1=HD+40 ... te#a_publi

11 articles, the most recent dating from this year.

 

[xXTheOneRavenXx]

Thank you for that thnkrx. Now the assumption is that the three planets are neptune-like... but they are still unclear.

 

[3488]

Thank you for that thnkrx. Now the assumption is that the three planets are neptune-like... but they are still unclear.

Hi TheOneRaven.

My educated guess is that the planets will be Uranus or Neptune like, rather than terrestrial like Mercury to Mars.

They are certainly not Jupiter or Saturn like as they lack that mass, but lower mass cousins of Uranus or Neptune would seem more like it IMO.

Andrew Brown.

 

[xXTheOneRavenXx]

What I kind of understood from the paper was that the planets could still be rocky bodies, however deficient in the amount of metals they may contain. I understand planet structure is also affected by the amount of metals they contain, however in this case the planets detected are also mass deficient which I interpreted as also lacking in metals. Not necessarily pointing to them being dubbed gaseous. However, your assumption at this point would not be an incorrect one. I think it can still go either way.

 

[bowman316]

If you could travel the speed of light, Time slows down. So the space travelers would not age at the same rate, so a 10 or 20 year journey might only age them 5-10 years. This would most likely be a one way journey, and the would never be able to return to earth.
I think we were never intended to have contact with other civilizations. They are most likely out there, but millions of light years away. Maybe one day the will receive radio communications from us, but we will be long gone by the time we get a response back.

Even radio waves only travel at the speed of light.

 

[xXTheOneRavenXx]

I'm not sure what that would have to do with the discussion.

 

[MeteorWayne]

I'm sure Raven.... Nothing at all

 

[xXTheOneRavenXx]

lol, what I meant MeteorWayne was that were discussing what type of planets they might be, not how long it would take to get there. I wasn't meaning to down bowman at all. Just pointing out the direction of the discussion.

 

[yevaud]

I suspect what Bowman was getting at was, we may discover they're there, but effectively we'll never visit them, so what's the difference.

I don't share in that myself. Merely trying to decode why he said it, and place it into context.

 

[xXTheOneRavenXx]

Could someone help resolve my state of confusion? In reference to COROT-EXO-7b. In one part of this article at: http://www.astronomy.com/asy/default.aspx?c=a&id=7888 it states that they estimate the surface temperature to be between 1,800° and 2,700° Fahrenheit (1,000° and 1,500° Celsius). However, later in the article they also state:

"The internal structure of COROT-exo-7b puzzles scientists. They are unsure if it is an 'ocean planet' — a kind of planet whose existence has never been proved so far. In theory, such planets would initially be covered partially in ice, and they would later drift towards their star, with the ice melting to cover it in liquid."

How can that be when the temperature is far above the evaporation point of liquid water?

 

[xXTheOneRavenXx]

My only guesses are that either the planet has a high enough atmospheric pressure to hold onto the water as it's evaporated, or it's not water at all but liquid methane. Something along those lines.

 

[dragon04]

My only guesses are that either the planet has a high enough atmospheric pressure to hold onto the water as it's evaporated, or it's not water at all but liquid methane. Something along those lines.

I think what they're saying is that prior to its spiraling in to such a close orbit that it may have been an "ocean planet". My take is that they're saying it started in a more distant orbit.

 

[xXTheOneRavenXx]

Ya, it was kind of confusing how they worded it.

 

[Dryden88]

Hello,

I have no doubt in my body with 5 years we will find a habibtable planet.

Don't ever say we can't. Certain people here are saying we cant or it's impossible. Doesn't the experience of human history prove to you that we will always find a way? I mean throught history there are examples of people saying things can't be done. They said we would never fly. They said you could never break the sound barrier. They said we couldnt go into space. They said we couldnt go to the moon. I can go on and on. The point is never say never.

As far as I am aware no one here talked about gas giants orbiting in the habitable zone? One of the Gas Giants moon's could support life in that scenario right? I mean even if it wasn't we have reason's to believe that moons around our Gas Giants might support life and they are not even in the habitable zone of our own solar system.

The future of the human race is colonization our solar system and out among the stars. One way or another it will happen. Human ingenuity knows no bounds. Perhaps there is someone out there with an innovative idea right know that will cause us to have FTL? (probably not ) But to lose hope is to lose oneself.

 

[thnkrx]

As far as I am aware no one here talked about gas giants orbiting in the habitable zone? One of the Gas Giants moon's could support life in that scenario right? I mean even if it wasn't we have reason's to believe that moons around our Gas Giants might support life and they are not even in the habitable zone of our own solar system.

I believe that the 'Extra-Solar Planets' Encyclopedia does list something on the order of forty or fifty Neptune to way larger than Jupiter size gas giants orbiting more or less in their stars habitable zones.

However, most of these planets have highly eccentric orbits; only a few...maybe a half dozen or so have orbits with eccentricity of less than 20% (which is still quite a bit).

I seem to remember reading a paper or two linked to off of that site that went into the mechanics of a habitable planet orbiting a gas giant. As I recollect, they seemed to be of the view that this was 'possible, but not likely'.

 

[xXTheOneRavenXx]

In between the kids keeping me very busy, I had a little time to surf my favorite subject in astronomy. I found the idea of this new technique most intriguing.

Caption: Using a new imaging technique on an 11 year old Hubble observation, an exoplanet has been discovered orbiting the young star HR 8799 (NASA/HST)

Like tiny jewels not yet uncovered, a trove of previously unknown extrasolar planets — perhaps as many as 100 — await discovery in a vast archive of images taken by the Hubble Space Telescope, the results of a new search technique suggest.

Using the new method, astronomers can more precisely model the amount and distribution of scattered light produced by young nearby stars suspected of spawning planets, and then subtract the light from images of those stars. Once the glare of the light from the parent stars is removed, young Jupiter-mass planets that emit faint but detectable amounts of heat may show up in images already taken by Hubble’s near-infrared camera.

That’s just what David Lafrenière of the University of Toronto and his colleagues found after examining old Hubble images to look for a planet known to exist around the star HR 8799. Last year, a team led by Christian Marois of the National Research Council of Canada’s Herzberg Institute of Astrophysics in Victoria, which included Lafrenière, used ground-based telescopes to image three planets around that star (SN: 12/6/08, p. 5).

Alerted that another group of astronomers had used the Hubble camera in 1998 to image the same star but had come up empty-handed, Marois, Lafrenière and two collaborators reanalyzed the 11-year-old Hubble images of HR 8799. After subtracting the scattered starlight estimated from the new model, the astronomers recovered the outermost of the trio of planets recently imaged, the team reports online at arXiv.org (http://lanl.arxiv.org/abs/0902.3247) and in an upcoming Astrophysical Journal Letters. The other two planets, which lie closer to the star, still could not be seen in the Hubble images.

The new study “definitely indicates that we should reanalyze all the existing Hubble images of young stars with the new approach — there's probably 100 to 200 stars where planets could be seen,” comments planet-hunter Bruce Macintosh of the Lawrence Livermore National Laboratory in California. Some of these stars, he notes, have already been examined by the high-resolution Keck telescopes atop Hawaii’s Mauna Kea. “But there's quite a few that are outside Keck's field of view or that have just never been looked at by anyone else. There's definitely a chance of finding more.”

The archival image of the planet, which lies about 70 times the Earth-sun distance from HR 8799 and takes more than 400 years to complete a single orbit, supplies evidence that confirms the body has a circular path. It also adds to evidence that the planet’s atmosphere contains water vapor and clouds of dust, notes study coauthor Travis Barman of Lowell Observatory in Flagstaff, Ariz.

The full range of infrared wavelengths recorded by Hubble literally puts the planet in a new light, since absorption by Earth’s atmosphere prevents some of the radiation from reaching telescopes on the ground.

But the most important result, says Lafrenière, is that the new image processing technique reaches “sensitivities 10 times better than what people have been obtaining for the past 10 years. We have seen a planet that had gone unnoticed before despite careful looks.”

The new technique’s success, he adds, “will certainly have a bearing on all future space-based direct imaging searches for extrasolar planets” including those with Hubble, the future James Webb Space Telescope and the proposed Terrestrial Planet Finder.

“The first thing it tells you is how valuable maintaining long-term archives can be. Here is a major discovery that’s been lurking in the data for about 10 years!” comments Matt Mountain, director of the Space Telescope Science Institute in Baltimore, which operates Hubble “The second thing its tells you is having a well calibrated archive is necessary but not sufficient to make breakthroughs — it also takes a very innovative group of people to develop very smart extraction routines that can get rid of all the artifacts to reveal the planet hidden under all that telescope and detector structure.”

I am wondering how many exoplanets this technique will reveal, and how far they have come in their research. If the various techniques are applied to each star being studied for exoplanets in the future, then I believe we should see a rapid growth in the amount being discovered. May also lead to more rocky planet's being revealed.

 

[EarthlingX]

http://www.physorg.com : Astronomers track long, strange voyage of distant planet

September 28, 2010

(PhysOrg.com) -- University of Pittsburgh planet hunters based at the Allegheny Observatory were one of nine teams around the world that tracked a planet 190 light-years from Earth making its rare 12-hour passage in front of its star. The project resulted in the first ground-based observation of the entire unusually drawn out transit and established a practical technique for recording the movement of other exoplanets, or planets outside of Earth’s solar system, the teams reported in The Astrophysical Journal.

The Pitt team, led by Melanie Good, a graduate student of physics and astronomy in Pitt’s School of Arts and Sciences, observed the planet HD 80606b for more than 11 hours on Jan. 10 as it passed in front of its star, HD 80606, located more than 1.14 quadrillion miles from Earth in the constellation Ursa Major. The Pitt group included Michael Wood-Vasey, a professor of physics and astronomy; Louis Coban of the Allegheny Observatory; and physics and astronomy undergraduate students Shane Cerutti, Korena Costello, Maya Hunt, Gary Lander Jr., Eric Roebuck, Chelsea Vincent, and Gwendolyn Weaver, all part of Good’s research group, Survey of Transiting Extrasolar Planets at the University of Pittsburgh, or STEPUP.

HD 80606b is among the strangest of the 500 exoplanets yet discovered, Good said. Approximately four times the size of Jupiter, the gaseous planet is scorchingly close to its star and follows an oblong orbit similar to that of Halley’s Comet. At its farthest, the planet is almost as far from its star as the Earth is from the Sun, while at its closest, it is just 3 percent of that distance so that the planet’s temperature jumps thousands of degrees as it nears HD 80606. And while most exoplanets complete their transit within a few hours, HD 80606b traipses along for nearly 12—and only makes the trip every 16 weeks.

Both characteristics of HD 80606b’s transit make it difficult for a single observatory to observe all of it, according to the article in The Astrophysical Journal. Coordinated by the Massachusetts Institute of Technology and the University of California at Santa Barbara, the nine-team project demonstrated that multiple observatories working together can capture such long transits in their entirety.

...

More information: Journal paper: http://iopscience.iop.org/0004-637X/722/1/880

Provided by University of Pittsburgh

Not really Earth-like, but a new technique.

 

[Sycamorefan]

bdewoody made a really good point that I would like to carry a little further:

On the other hand, if the speed of light ends up being (like the speed of sound) just an imaginary speed limit imposed by our current lack of knowledge of the big picture, mapping the location of stars that have rocky planets will be very important.

He's right, "Necessity IS The Mother Of Invention" If we find another world out there just like Earth, We WILL come up with a way to get there! The progession of events should go something like this:

1. Kepler discovers several worlds that are "maybes"
2. Terrestrial Planet Finder finally gets funded and built based on what kepler found.
3. TPF actually finds the" real deal", Another exoplanet/ exomoon that will support human life.
4. Getting to LEO with a reuseable/safe/moderately cheap to run vehicle system finally occurs due to a private company.
5. Radiation absorbing plastics finally get invented.
6. Interplanetary space travel finally becomes reality now that Radiation and Zero G gravity problems have finally been solved
7. The Moon, Mars & the Asteriod Belt are mined for for resources by private companies.
8. The Rare Earth Elements found in Quantity by deep sea/exo-mining now allow for the discovery of Room Temperature Superconductivity.
9. RTS now allows for sub- atomic particle research to begin on a much larger scale, now that they can do larger experiments and do them more than just once in a while as the power grid can handle it!
10. A way around the light speed barrier is discovered !

 

[EarthlingX]

http://www.universetoday.com : New Earth-sized Exoplanet is in Star’s Habitable Zone

Sep 29th 2010

by Nancy Atkinson


Artist illustration of a super Earth around Gliese 581

An enticing new extrasolar planet found using the Keck Observatory in Hawaii is just three times the mass of Earth and it orbits the parent star squarely in the middle of the star’s “Goldilocks zone,” a potential habitable region where liquid water could exist on the planet‘s surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one. The discoverers also say this finding could mean our galaxy may be teeming with prospective habitable planets.

“Our findings offer a very compelling case for a potentially habitable planet,” said Steven Vogt from UC Santa Cruz. “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”

Vogt and his team from the Lick-Carnegie Exoplanet Survey actually found two new planets around the heavily studied red dwarf star Gliese 581, where planets have been found previously. Now with six known planets, Gliese 581 hosts a planetary system most similar to our own. It is located 20 light years away from Earth in the constellation Libra.

The most interesting of the two new planets is Gliese 581g, with a mass three to four times that of the Earth and an orbital period of just under 37 days. Its mass indicates that it is probably a rocky planet with likely enough gravity to hold on to an atmosphere.

The planet is also tidally locked to the star, meaning that one side is always facing the star in sunlight, while the side facing away from the star is in perpetual darkness. One effect of this is to stabilize the planet’s surface climates, according to Vogt. The most habitable zone on the planet’s surface would be on the terminator, the line between shadow and light, with surface temperatures decreasing toward the dark side and increasing toward the light side.

“Any emerging life forms would have a wide range of stable climates to choose from and to evolve around, depending on their longitude,” Vogt said.

...

Source: University of California – Santa Cruz

 

[3488]

An amazing find, thanks EarthlingX.

3 to 4 times Earth mass. Likely to have a dense atmosphere & close eough to the red dwarf parent Sun to not freeze on the day side.

I wonder if this planet is indeed tidally locked to it's parent Sun as is likely the case, if any simulations could be carried out with a variety of possible atmospheres???

Also if Gliese 581 in it's youth was a flare star (like Proxima Centauri), if this planet was so close to it's parent sun & if so what effect the flaring would have had on it's original atmosphere.

I suspect if indeed this is a high mass terrestrial planet, the surface gravity will be rather strong & also if it is volcanically active with a super dense atmosphere, a cross between Venus & Io???????

Just a few thoughts.

Andrew Brown.

 

[robnissen]

I wonder if this planet is indeed tidally locked to it's parent Sun as is likely the case, if any simulations could be carried out with a variety of possible atmospheres???

Andrew Brown.

I also wonder if it has to be tidally locked? Could it be in some sort of resonance, perhaps 3:2? Also, if it was tidally locked, I assume there would be pretty serious winds as hot air from the star side and cold air from the night side flowed. This is soooo very cool. BTW, here is the SDC article:

http://www.space.com/scienceastronomy/e ... 00929.html

 

[Solifugae]

I also wonder if it has to be tidally locked? Could it be in some sort of resonance, perhaps 3:2? Also, if it was tidally locked, I assume there would be pretty serious winds as hot air from the star side and cold air from the night side flowed.

Perhaps the winds would allow life to live on the far side, due to evening out of temperatures with the flowing weather systems. Like in the large gas giants where the far side is nearly as hot as the locked side.

Maybe we will see a lot of heat and wind surviving life thriving on the planet's landmasses.

 

[grokme]

Sounds like a cool place, where you would travel to day and night instead of it traveling to you.

 

[Yuri_Armstrong]

Any civilization living there would certainly have a fascinating system to exist in. Not only does g look habitable, but d looks like it may be as well. I'd be willing to bet that if Mars was similar to Earth, we would have been there by now. Perhaps the Glieseans have made such a leap. What can we hope for in the way of new data about its atmospheric contents and possible oceans?