Five potential habitable exoplanets now

Phys.org ^ | July 20,2012 | Staff

[Red Badger]

New data suggest the confirmation of the exoplanet Gliese 581g and the best candidate so far of a potential habitable exoplanet. The nearby star Gliese 581 is well known for having four planets with the outermost planet, Gliese 581d, already suspected habitable. This will be the first time evidence for any two potential habitable exoplanets orbiting the same star. Gliese 581g will be included, together with Gliese 667Cc, Kepler-22b, HD85512, and Gliese 581d, in the Habitable Exoplanets Catalog of the PHL @ UPR Arecibo as the best five objects of interest for Earth-like exoplanets.

Doubts about the existence of Gliese 581g appeared only two weeks after its announcement on September 29, 2010 by astronomers of the Lick-Carnegie Exoplanet Survey. Scientists from the HARPS Team from the Geneva Observatory, which discovered all the previously known four planets around Gliese 581, were not able to detect Gliese 581g out of their own data, which included additional observations. Further analysis by others scientists also questioned the existence of Gliese 581g in the last two years.

Now the original discoverers of Gliese 581g, led by Steven S. Vogt of UC Santa Cruz, present a new analysis with an extended dataset from the HARPS instrument that shows more promising evidence for its existence. The new analysis strength their original assumption that all the planets around Gliese 581 are in circular and not elliptical orbits as currently believed. It is under this likely assumption that the Gliese 581g signal appears in the new data.

“This signal has a False Alarm Probability of < 4% and is consistent with a planet of minimum mass 2.2M [Earth masses], orbiting squarely in the star’s Habitable Zone at 0.13 AU, where liquid water on planetary surfaces is a distinct possibility” said Vogt.

Based on the new data Gliese 581g probably has a radius not larger than 1.5 times Earth radii. It receives about the same light flux as Earth does from the Sun due to its closer orbital position around a dim red dwarf star. These factors combine to make Gliese 581g the most Earth-like planet known with an Earth Similarity Index, a measure of Earth-likeness from zero to one, of 0.92 and higher than the previously top candidate Gliese 667Cc, discovered last year.

“The controversy around Gliese 581g will continue and we decided to include it to our main catalog based on the new significant evidence presented, and until more is known about the architecture of this interesting stellar system” said Abel Méndez, Director of the PHL @ UPR Arecibo.

Authors on the original paper are Steven S. Vogt, UCO/Lick Observatory, UCSC; Paul Butler, Department of Terrestrial Magnetism, Carnegie Institution; and Nader Haghighipour of the Institute for Astronomy and NASA Astrobiology Institute. Their research is published online on July 20, 2012 in the journal Astronomical Notes, 333, No. 7, 561-575.

[hoagy62]

Or a good archeological dig at Gisa.

Got the reference. Hee hee. :)

[TheOldLady]

I’m with you there, if it’s 100% cacao. Mmmm... “edible planets.”

[TheOldLady]

Yes, well. Haven’t we been wading through and ignoring media lies for forty years? Don’t worry, dear.

[MamaTexan]

As of right no, though, ‘warp 5’ will be simply 5 times the speed of light

Bubba -
I'm glad I saw your post before I went to the time and trouble of doing the math.

Badger -
Sorry, but Bubba's right. Warp speed is exponential. Warp 2 is twice as fast as warp one. Warp 3 is twice as fast as warp two....etc.

It's just one of those weird things you 'know' after watching Star Trek for 46 years. LOL!

[PIF]

If only Venus had a magnetic field and a moon it would probably be habitable.

—

Those and 800 degrees cooler, no sulfuric acid rain, and 10 or so less atmospheres of surface pressure.

[PIF]

At warp 5 we could get there in less than two months (one month if we have one of those new fangled 24th Century warp drive engines).

---

Two months? Why not just hitch a ride (via displacement - like teleportation, just not as dangerous and effective at interstellar distances) on any passing Culture General Service Vehicle (System Class)?

Not only would you enjoy all the comforts of upscale living, you and the other millions of fellow passengers would arrive within the week (assuming local displacement was within the ship's range).

If you were in a hurry, perhaps you could enlist the ship's avatar to request the services of a Superlifter and arrive within days ... if you were not bored by the vast ranges of entertainment aboard, and were not in a hurry, you might request to stop off an Orbital where you could do things like mountain climbing.

Those “Star Trek” vessels are so slow, small, cramped, generally limited, and awkward, why would any self-respecting traveler pick that form of travel?

Although why anyone would want to visit such backwaters like 667Cc, Kepler-22b, HD85512, Gliese 581d, and Gliese 581 is beyond me.

I've heard that the GSVs “Anticipation Of A New Lover's Arrival, The” (Plate Class), “Quietly Confident” (Plate Class), and the “Sleeper Service” (Plate Class) are in the neighborhood... perhaps they are going your way?

PS:
General Systems Vehicles (GSVs) are the Culture's largest type of ship, ranging between 25 km and 200 km in each dimension (including the fields protecting them and forming the exterior of their life-support system). GSVs which provide accommodation for biological members of the Culture generally have populations in the millions or even billions, and can be considered worlds in their own right.

System Class: (multiple separate components suspended in a force field up to 200 km long).

Plate Class: (53 km long, 22 km wide, 4 km thick, or, including fields, up to 90 km long, 60 km wide, 20 km thick).

If for some reason you suspect a spot of trouble, I suggest having the GSV: (System Class - Special Circumstances) “Hubris Knows No Bounds” (heavily militarized) along. and perhaps a Rapid Offensive Unit (Killer Class) along - just in case ...

[PIF]

As of right no, though, ‘warp 5’ will be simply 5 times the speed of light until further discoveries are made ...

—

5 Lights per Year? Why go Star Trek when you could go Culture - ships routinely travel at 100 KiloLightsHour and the Sleeper Service (if avallible) does upto 223 KLH (faster with a tow from a Superlifter) ... Those Trek ships are such antiques.

[wastedyears]

What lore are you getting that from?

[PIF]

The fictional universe of The Culture, created by Iain M. Banks:

Consider Phlebas
The Player of Games
Use of Weapons
Excession
The State of the Art
Look to Windward
Matter

Also but not in the Culture universe (perhaps adjacent): The Algebraist.

[America_Right]

The fictional universe of The Culture, created by Iain M. Banks

Gonna read at least one of those. Thanks!

[6ppc]

Warp speed is exponential. Warp 2 is twice as fast as warp one. Warp 3 is twice as fast as warp two....etc.

You are describing a geometric progression. Exponential is a factor of 10, not 2.

[Bubba_Leroy]

Those and 800 degrees cooler, no sulfuric acid rain, and 10 or so less atmospheres of surface pressure

If Venus had a magnetic field and a large moon its atmosphere and temperature would be much different. How different is subject to speculation, but the drastic differences between Earth's and Venus' atmospheres and temperatures cannot be explained simply based on Venus' closer orbit.

If Earth did not have a magnetic field and a moon it would likely resemble Venus.

[Bubba_Leroy]

If you are going to travel through space, Q Continuum travel is the way to go. Instantaneous transportation to any point in time or space.

[mrreaganaut]

Let’s talk about the most important thing: Gliese is a terrible name! Who is going to want to explore a system that sounds like a medical condition? I suggest something more marketable, like Chaucer, Laurier, or Gallifrey.

[Red Badger]

Depends on how you pronounce it.
If you say ‘Glee-ess’ it sounds really exotic and beckoning.
But if you call it ‘Gleece’, it sounds like a Japanese comedian talking about a movie musical..........

[PIF]

“If you are going to travel through space, Q Continuum travel is the way to go. Instantaneous transportation to any point in time or space.”

Unfortuantely, that method is limited to the Q. Culture travel methods are for everyone else. In “Excession”, several Culture ships instantaneously travel to another Universe - something the Q cannot do.

—

“If Venus had a magnetic field ...”

Albeit a weak one. But we are dealing in what is, not what might be. **If pigs could fly ...**