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Tom Kalbfus

Banned

Registered: 2006-08-16

Posts: 4,401

Terraforming an "Interstellar Venus"

Scientists think they just found the most important planet outside our solar system

This artist’s conception made by Dana Berry of SkyWorks and provided by NASA on Nov. 6 shows GJ 1132b, front, a rocky planet similar to the Earth in size and mass, orbiting a red dwarf star.
(Dana Berry / Associated Press)

Deborah NetburnContact Reporter

A small planet, just a bit bigger than Earth, has been spotted in our stellar neighborhood, just 39 light-years away.

Known as GJ 1132b, it is the closest rocky exoplanet to have ever been found, and astronomers say it could provide our most in-depth look yet at an alien world not so different than our own.

Drake Deming, an astronomer at the University of Maryland, was so excited about the findings, published this week in Nature, that he described the new world as "arguably the most important planet ever found outside the solar system" in an accompanying News and Views article.

See the most-read stories in Science this hour >>

The newly discovered planet is just 16% larger than Earth, and it is made of rock and metal like our own planet. However, scientists say it is not likely to host life as we know it.

Its small, dim, sun is just one-fifth the size of our own sun, but GJ 1132b circles it at a distance of just 1.4 million miles, completing a full orbit once every 1.6 Earth days. (For perspective, Mercury orbits the sun from a distance of 36 million miles.)

The exoplanet's close proximity to its host star keeps its temperature at a broiling 500 degrees Fahrenheit -- or about as hot as the highest setting on your home oven, said Zachory Berta-Thompson, a post-doc in MIT's Kavli Institute for Astrophysics and Space Research.

At that temperature, liquid water cannot exist on the planet's surface, although scientists say it is likely the planet still has an atmosphere.

An animation showing the distances to known transiting exoplanet systems, in units of light-years, puts the closeness of newly discovered GJ 1132b in perspective.

"Our best guess is that this planet looks like Venus," said Berta-Thompson, who was also the first author on the study. "But we won't have to guess for long. This is the first rocky planet for which we have the chance to go out and observe its atmosphere."

GJ 1132b was discovered with the help of the MEarth-South Observatory, a Harvard University lead array of eight 16-inch wide robotic telescopes stationed in the mountains of Chile. The array is specifically tasked with looking among nearby stars for exoplanets that in some way resemble Earth.

"The idea is if we can find the planet in a small telescope, we can study it in much more detail with a large telescope," said Berta-Thompson.

The researchers first detected  GJ 1132b in May 2014, when they noticed a telltale dip in the brightness of a small red dwarf star that suggested a planet had passed in front of it, blocking some of its light.

This cartoon shows the transiting planet GJ 1132b to scale against its host star GJ 1132.
(Zach Berta-Thompson)
After confirming the finding with a smattering of other telescopes, the researchers proceeded to do a series of measurements and calculations to characterize the exoplanet.

By measuring how much the star dims each time the planet passes in front of it they were able to determine the planet is just a bit bigger than Earth.

By looking at the frequency of the dips in the star's brightness they could say with certainty that the planet orbits its sun once every 1.6 Earth days.

The orbital period of the planet can also be used to calculate how far the exoplanet is from its host star, which in turn helped the researchers estimate how much the planet is likely heated by its star.

And there's more.

The MEarth-South telescope array, located on Cerro Tololo in Chile, searches for planets by monitoring the brightness of nearby, small stars.
(Jonathan Irwin)
Planets exert a slight gravitational pull on their host stars, causing them to wobble. By measuring how much a star wobbles, astronomers can determine an exoplanet's mass. Because they also know its size from looking at how much light it blocks, they can also figure out the planet's density.

"The density was telling us that this planet is for the most part a big ball of rock and iron, and not just big puffy ball," Berta-Thompson said. "For example, we could have measured that the density was the same as a bag of feathers."

But Berta-Thompson said these initial investigations of the newly found planet are just the beginning of what he hopes will be a lot more study yet to come -- especially once the powerful James Webb Space Telescope is launched in October 2018.

"We've come up with theories about rocky planets -- how they formed, how they got into their current orbits, what physical processes occur on them -- but we have not been able to test many of them," he said. "The discovery of this planet gives us the opportunity to switch our focus from imagining what is out there to testing our theories observationally."

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Looks like another planet to terraform. It gets plenty of red sunlight. and it is 39 light years away. Traveling at 10% of the speed of light would bring us there in 390 years, if we sent colonists their in a slow ship traveling at 1% of the speed of light, it would get there in 3,900 years. This would give us 3510 years to terraform this planet while the colonists are in transit. Terraforming would consist of building a shield between the planet and its Sun, the planet is probably tidally locked with its primary, as it is a red dwarf, this would make terraforming the planet even easier, as you simply block the red dwarf with the star shield, and then place a large mirror in a 24-hour polar orbit around the planet, the terminator of the planet would become its equator, the mirror would be a colored reflector, that is it would reflect more blue light than red light making the image of the red dwarf in the mirror appear white instead of red, the mirror would also be curved, to spread out the light so the planet would get the same amount as Earth.

Planets 39 light years away are probably easier to terraform than a planet like Venus, as people will tend to interfere with Venus over a 3510 year period during terraformation, we might want to do things with the planet like bombard it with comets to add water for oceans.

So what do you think?

Void

Member

Registered: 2011-12-29

Posts: 7,169

Re: Terraforming an "Interstellar Venus"

One interesting thing will be to find out if it does have an atmosphere.   Certain circles think that red dwarf stars in their infancies will strip away the atmospheres of their terrestrial planets, since those planets if they are warm enough will likely be tidal locked, and will perhaps have weak magnetic fields.

Our Venus must have had a magnetic field when Mars lost its field and much of it's atmosphere?  Otherwise, why would it still have an atmosphere like it does now?  Or did it bake out a new one?  Don't think so since it has lots of Nitrogen (As a total mass, relative to Earth).  Lots to find out.

Another item of interest is how many;
Venus Analogs
Mars Analogs
Titan/Earth(Without O2) Analogs

Type of planet are typical?

I think to find a True-Earth, then you almost have to presume that photosynthesis must exist on such a planet, and the habitable zone, blah, blah, blah.

So, I don't expect to find any True-Earths near by, but apparently we can hope for;

Venus Analogs
Mars Analogs
Titan/Earth(Without O2) Analogs

If we think humans might eventually become interstellar, then perhaps the methods we choose to modify Venus, Mars, and Titan, should be chosen for the potential that they could be used to inhabit analog planets.

Of these the Venus Analogs will be the easiest to observe I presume, but a great potential will exist to find;
Titan/Earth(Without O2) Analogs

That is cold Earths, with N2 dominated atmospheres, and sound magnetic fields.

Perhaps the solar system where the Venus analog has been found will also have one of those.  We are not able to  very well detect those yet.

But to terraform such a world, arranging a nice impact of a significant object, to warm it up temporarily could be the prelude to occupation, and the use of super greenhouse gasses to establish a human civilization.

Lets say an Earth 2 AU out in our solar system.  Imagine such a planet.  (If Jupiter did not object).

Last edited by Void (2015-11-14 00:41:28)

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Done.

Tom Kalbfus

Banned

Registered: 2006-08-16

Posts: 4,401

Re: Terraforming an "Interstellar Venus"

One interesting thing will be to find out if it does have an atmosphere.   Certain circles think that red dwarf stars in their infancies will strip away the atmospheres of their terrestrial planets, since those planets if they are warm enough will likely be tidal locked, and will perhaps have weak magnetic fields.

Our Venus must have had a magnetic field when Mars lost its field and much of it's atmosphere?  Otherwise, why would it still have an atmosphere like it does now?  Or did it bake out a new one?  Don't think so since it has lots of Nitrogen (As a total mass, relative to Earth).  Lots to find out.

Another item of interest is how many;
Venus Analogs
Mars Analogs
Titan/Earth(Without O2) Analogs

Type of planet are typical?

I think to find a True-Earth, then you almost have to presume that photosynthesis must exist on such a planet, and the habitable zone, blah, blah, blah.

So, I don't expect to find any True-Earths near by, but apparently we can hope for;

Venus Analogs
Mars Analogs
Titan/Earth(Without O2) Analogs

If we think humans might eventually become interstellar, then perhaps the methods we choose to modify Venus, Mars, and Titan, should be chosen for the potential that they could be used to inhabit analog planets.

Of these the Venus Analogs will be the easiest to observe I presume, but a great potential will exist to find;
Titan/Earth(Without O2) Analogs

That is cold Earths, with N2 dominated atmospheres, and sound magnetic fields.

Perhaps the solar system where the Venus analog has been found will also have one of those.  We are not able to  very well detect those yet.

But to terraform such a world, arranging a nice impact of a significant object, to warm it up temporarily could be the prelude to occupation, and the use of super greenhouse gasses to establish a human civilization.

Lets say an Earth 2 AU out in our solar system.  Imagine such a planet.  (If Jupiter did not object).

A Venus analog, might make a better colonization target, than an Earth analog, cause the Earth analog would have its own native life which might conflict with ours. Given a Venus analog, we simply modify the planet and add our own life. I was thinking of the above example:

Its small, dim, sun is just one-fifth the size of our own sun, but GJ 1132b circles it at a distance of just 1.4 million miles, completing a full orbit once every 1.6 Earth days. (For perspective, Mercury orbits the sun from a distance of 36 million miles.)

Its orbit is once every 1.6 Earth days, it already is getting too much sunshine., rather than have a reflector in Polar orbit as I originally thought, as such an orbit would have a similar period to the orbit of the planet around its Sun. What if we put the star shade at the L1 point to block most of the light, let just enough light filter through to give an average level of Earth daylight if you combine night and day on Earth, in other words a Mars level of light for the nearside. The L1 point should be fairly close to the planet since the star is so close.
Instead we have a separate reflector independently orbiting the star further out from the planet but in the opposite direction from that planet. That way we subtract the orbital period of the reflector from the orbital period of the planet to get 24 hour period for the reflector rising in the planet's sky and then rising again after sun set. Using photon pressure on a light sail, we can alter the orbital inclination of the reflector's orbit over time to produce seasons!

How does this idea strike you? The near side would be under constant daylight of filtered sunshine, while the far side would experience night and day as well as seasons. Both reflectors can be relatively thin and of low relative mass to the planet. This should be doable for a civilization which can build two starships. What do you think?

Void

Member

Registered: 2011-12-29

Posts: 7,169

Re: Terraforming an "Interstellar Venus"

It strikes me as rather good analysis of potential with very nice techniques.

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Done.