New Earth-sister Kepler 452b announced by NASA

[DaveC426913]

http://www.nasa.gov/keplerbriefing0723

As I type this, NASA is announcing discovery of a new planet Kepler 452b that is
- small and (probably) rocky like Earth
- orbits a G2 star
- is in the star's habitable zone
This is the first candidate that meets all three criteria. (Most Earth-twins so far discovered are around tiny red dwarfs, and orbit in a matter of days) It has a 385 day long year, almost exactly the same as Earth.

Kepler 452b is a slightly older sibling of Earth - it has lived in its habitable zone for 6 billion years. It's a little bigger, surface gravity is about 2x Earth, but it probably has a thick atmosphere as well as volcanism.

One implication of this discovery is that these are surely common. We only detect 1 in 50 planets because of alignment issues, so detection of one suggests another 50 out there we can't see with current equipment.

The one imperfection in this otherwise ideal Earth-sister is that it is more than 1300 light years away.

 

[rootone]

The Kepler telescope is luckily still operational due to an ingenious solution which was found that compensates for the loss of two of it's reaction wheels.
Is there any similar telescope planned to replace it eventually?, - or is the Kepler data sufficient in itself to answer a number of important questions.
Anyway now that this planet has been found, I'm sure that other existing telescopes will be used to glean better information about it's composition.

 

[berkeman]

Aim the radio telescopes at it!

 

[tom aaron]

Aim the radio telescopes at it!

Why?

 

[berkeman]

Why?

To listen. Didn't we use radio telescopes to listen for ETI in the past? (I'm no expert in this by any means)

 

[rootone]

Why?

They might be broadcasting their own version of Star-Trek!

 

[davenn]

Aim the radio telescopes at it!

would be interesting to do ...

keeping in mind any tech advanced civilisation there would have to be well ahead of ours
We didn't have radio 300 yrs ago, let alone 1300 yrs ago any radio signal you received would have
been broadcast 1300 yrs ago Dave

PS ... unless of course, they advanced faster than we did

 

[rootone]

Aside from radio scopes, I guess that now we have found a planet which really does resemble Earth in some respects, we should want to do as best we can to determine what state it's atmosphere is (was) in.
Do we have any technology at present which could provide a clue at that kind of distance?

 

[Evo]

would be interesting to do ...

keeping in mind any tech advanced civilisation there would have to be well ahead of ours
We didn't have radio 300 yrs ago, let alone 1300 yrs ago any radio signal you received would have
been broadcast 1300 yrs ago Dave

PS ... unless of course, they advanced faster than we did

But their planet is over a billion years older than earth, any advanced civilization could be long gone, that is if there ever was one.

 

[Evo]

Aside from radio scopes, I guess that now we have found a planet which really does resemble Earth in some respects, we should want to do as best we can to determine what state it's atmosphere is (was) in.
Do we have any technology at present which could provide a clue at that kind of distance?

StevieTNZ sent me this link this morning, it goes into some detail.

http://www.stuff.co.nz/science/70502227/nasa-discovers-earthlike-planet

 

[tom aaron]

I suppose Mars and Venus are Earth twins if this is an Earth sister. Seems more like an Aunt.

What incredible technology! Wah! Makes me wish I was born a hundred years from now. We're on the cusp of discovering so much stuff at the macro and micro level.

 

[rootone]

Yes, and the whole plan with Kepler was to look at what possibly is out there in a very narrowly focused area of space.
I'm not sure offhand, but think the area of sky it focuses on is well less then 1% of the total sky visible from Earth, and now we find a solar system comparable to the one we are living in.
It can only get more interesting, I want an immortality pill!

 

[DaveC426913]

Aside from radio scopes, I guess that now we have found a planet which really does resemble Earth in some respects, we should want to do as best we can to determine what state it's atmosphere is (was) in.
Do we have any technology at present which could provide a clue at that kind of distance?

Well to put it in perspective, we don't yet even know if it's rocky. There is a "better than even" chance that it is, but that tells you how little we know so far.

 

[Astronuc]

Other articles put the star at 1400 ly.

http://www.npr.org/sections/thetwo-...ope-introduces-earth-to-a-very-distant-cousin

The planet is about 1.6 times the size of earth. It would be interesting to know the mass.

http://www.nasa.gov/keplerbriefing0723
Technical paper - http://www.nasa.gov/sites/default/files/atoms/files/ms-r1b.pdf

 

[Byron Brubaker]

I'll guess the mass at 9,555,504,000,000,000,000,000,000 kg for starters.

 

[CalcNerd]

When we started SETI or using radio telescopes to listen in, we were certain ALL intelligent advanced civilizations would transmit some type of radio signal that we might be able to listen in. We ourselves have been broadcasting for a century or so. But our new methods of signals (cellular) are encoded and might just look like noise to even our own civilization 30 years ago. And a lot of our data is now transmitted over fiber.
.
To summarize, we would never find a civilization that used fiber or copper or used a complex signal that we could mistake for a noise source. Our own civilization might not be visible to anyone if they look for us and are outside of our 150 year transmission window (assuming we advance to where we are not transmitting over the open air in 50 years).

 

[newjerseyrunner]

But their planet is over a billion years older than earth, any advanced civilization could be long gone, that is if there ever was one.

Or so evolved that we wouldn't recognize them as life, perhaps the entire population has uploaded their minds to Kepler 452b's virtual reality Facebook and exist in a tiny computer in a bunker on the planet.

 

[rootone]

To summarize, we would never find a civilization that used fiber or copper or used a complex signal that we could mistake for a noise source. Our own civilization might not be visible to anyone if they look for us and are outside of our 150 year transmission window (assuming we advance to where we are not transmitting over the open air in 50 years).

First off, no I don't anticipate signs of intelligent life being found on the first Earth-like planet we discover, that does seem very improbable.
However, a species that had got as far as radio would probably have also got as far as having communications and other orbiting satellites.
Those can't use fiber connections, so there could be at least some radio transmission still in use (hypothetically)

 

[mheslep]

Interesting discovery, but I find it annoying that the artist's concept drawing of the "sister" circulating with the story has been appearing in the media without being labeled as an artist's drawing. NASA certainly includes "artist's concept depicts one possible appearance" prominently in its captions (figure 4)

 

[mheslep]

Kepler 452b is a slightly older sibling of Earth - it has lived in its habitable zone for 6 billion years. I,...

Speculation? As I understand it, what's known with some scientific basis is the age of Kepler 452b's star, the temperature of that star, and know with this observation we know the period of 452b's orbit from which other orbital mechanics calculations can be made. After that, yes it's fun to speculate and assume that the planets formed around that star at the same rate as did the planets in our solar system, but any number of factors could wildly change that assumption, like another planetesimal colliding after initial formation and forming moon as happened with the Earth.

 

[DaveC426913]

Interesting discovery, but I find it annoying that the artist's concept drawing of the "sister" circulating with the story has been appearing in the media without being labeled as an artist's drawing.

Laypeople are certain to misjudge science news no matter how careful you are. Artists' concepts are kind of the least of our collective problem.
A guy here at work thought they were saying that Kepler has discovered over 1000 planets in that solar system.

 

[DaveC426913]

Speculation? As I understand it, what's known with some scientific basis is the age of Kepler 452b's star, the temperature of that star, and know with this observation we know the period of 452b's orbit from which other orbital mechanics calculations can be made. After that, yes it's fun to speculate and assume that the planets formed around that star at the same rate as did the planets in our solar system, but any number of factors could wildly change that assumption, like another planetesimal colliding after initial formation and forming moon as happened with the Earth.

That factor wouldn't change the assumption. The fact that [a planetesimal collision made the Moon] has not changed our estimate of the age of the planets in our system.

Do you know a reason why their estimation is based on shaky logic? Or are you merely speculating?

 

[Chronos]

The assumption a planetary system is roughly the same age as its host star appears reasonable given the limit of our knowledge on the age of planetary systems.

 

[mfb]

First off, no I don't anticipate signs of intelligent life being found on the first Earth-like planet we discover, that does seem very improbable.
However, a species that had got as far as radio would probably have also got as far as having communications and other orbiting satellites.
Those can't use fiber connections, so there could be at least some radio transmission still in use (hypothetically)

We might switch to lasers in the future - the test a while ago was successful and it allows to increase the transmission rate by orders of magnitude. Lasers are much more collimated which makes it rare to get hit by the signal by accident, and we would see it for a very short period only - no chance to listen to it for a while.

 

[DaveC426913]

We might switch to lasers in the future - the test a while ago was successful and it allows to increase the transmission rate by orders of magnitude. Lasers are much more collimated which makes it rare to get hit by the signal by accident, and we would see it for a very short period only - no chance to listen to it for a while.

I think there's a principle here that transcends any given technology.

In order for us to detect a signal, that means that signal's energy has been lost - wasted - as far as the source civilization is concerned. The more advanced they get, the less likely signal energy will be broadcast in such an inefficient way such that it is simply lost to space to great enough degree that it is still detectable 1000 light years away.

Thus, technology aside, I posit that categorically, we won't detect an advanced civilizations' communications unless they have deliberate reason for spraying the galaxy with it.

 

[mfb]

Thus, technology aside, I posit that categorically, we won't detect an advanced civilizations' communications unless they have deliberate reason for spraying the galaxy with it.

I think deliberate emissions are the main hope for all those search programs.
For an advanced civilization on planets we can see it should be easy to spot Earth, and if they can measure the atmospheric composition this should be a clear indication of life. We cannot have responses to our radio emissions from planets more than ~50 light years away, of course, assuming the limiting speed of light cannot be avoided.

 

[mheslep]

The fact that [a planetesimal collision made the Moon] has not changed our estimate of the age of the planets in our system.

I mean the age since the surface of the planet stabilized, and hence the time available for life to theoretically occur.

 

[mheslep]

We cannot have responses to our radio emissions from planets more than ~50 light years away, of course, assuming the limiting speed of light cannot be avoided.

Via that network of worm holes.

 

[mfb]

Those collisions are much more frequent in young planetary systems - it is hard to make a rough planetesimal orbit around for billions of years in a stable orbit, and then suddenly crash into a planet. Not completely impossible, but unlikely.

Via that network of worm holes.

I cannot exclude magic.

 

[DaveC426913]

I mean the age since the surface of the planet stabilized, and hence the time available for life to theoretically occur.

I beg to differ. You were explicitly talking about the age at which planets formed, and it was in response to me commenting on how long it has been in its habitable zone.

Review the thread:

Kepler 452b is a slightly older sibling of Earth - it has lived in its habitable zone for 6 billion years.

As I understand it, what's known with some scientific basis is the age of Kepler 452b's star, the temperature of that star, and know with this observation we know the period of 452b's orbit from which other orbital mechanics calculations can be made. After that, yes it's fun to speculate and assume that the planets formed around that star at the same rate as did the planets in our solar system, but any number of factors could wildly change that assumption, like another planetesimal colliding after initial formation and forming moon as happened with the Earth.

That factor wouldn't change the assumption. The fact that [a planetesimal collision made the Moon] has not changed our estimate of the age of the planets in our system.[addendum: nor would it change our estimate of the age of Kepler 452b]

If you want talk about when the surface was stable enough for life, that is a completely different question - because now you're speculating about events that we can only guess may have happened.

 

[lpetrich]

Wikipedia's contributors have added it: Kepler-452, Kepler-452b

Its star, Kepler-452, is very Sunlike.

Mass = 1.04 Msun, Radius = 1.1 Rsun, Lum = 1.2 Lsun, Temp = 5905 K, Age = 6 billion years, Distance = 1400 ly / 450 pc

Its planet, Kepler-452b, is the most Earthlike that the Kepler team has found.

Its size is 1.63 times the Earth's, the only observable physical feature of it so far. It orbits its star with a period of 385 days, meaning that it was likely seen transiting only 3 times during Kepler's 4-year primary-mission run. Its mean distance is about 1.04 times the Earth's. Scaling from the Earth's mean surface temperature of 15 C gives one of 21 C. So it may be close to having a Venus-like runaway greenhouse effect.

The Wikipedia article quotes a mass estimate of 5 times more than the Earth's, and I'll use it. That is presumably from it being all-rocky. If it had an ocean several thousand km deep, then it would be much less massive.

Surface gravity = 1.9 * Earth's or 18 m/s^2, orbital/escape velocity = 1.8 or (14 km/s, 20 km/s)

So while that planet can retain an atmosphere better than the Earth, it is more difficult to escape from. One will likely need an additional rocket stage to get into orbit.

 

[mfb]

So while that planet can retain an atmosphere better than the Earth, it is more difficult to escape from. One will likely need an additional rocket stage to get into orbit.

If intelligent life has developed there, they could have been at that stage a billion years ago. Enough time to find better techniques. The atmosphere is probably more dense, but it also falls of more quickly with height, even some non-rocket spacelaunch ideas we have today should work.

 

[Raman Choudhary]

Why is it that suddenly(why not earlier,is it because kepler is not fixed in space??) we found it as the telescope is there for many years??
How is the identification of the surface type(terrestrial,gaseous etc.) done from such a long distance??

 

[mfb]

Kepler needed to observe at least three transits to make sure it is a repeating pattern. With an orbital period of about one year, that takes two to three years of data-taking even in the best case. Add some telescope down-time and it can take four years. And that is just data-taking. There are many other effects that can mimic a planet signal (double stars, background stars, ...), so scientists have to look at the data in more detail. Often follow-up observations by other telescopes are necessary to rule out all other possible interpretations of the signal. All that takes a while.

How is the identification of the surface type(terrestrial,gaseous etc.) done from such a long distance??

The radius can be measured based on the amount of light the planet blocks. The orbital period also allows to determine the orbit. For Kepler 452b, everything else is educated speculation for now. It is too small to be a pure gas giant. It is possible to set upper limits on the mass based on radial velocity measurements, a direct measurement is not yet possible with the available telescopes. If other planets are found in the system, the mutual interaction between them can allow to measure the mass precisely.

 

[castor]

would be interesting to do ...

keeping in mind any tech advanced civilisation there would have to be well ahead of ours
We didn't have radio 300 yrs ago, let alone 1300 yrs ago any radio signal you received would have
been broadcast 1300 yrs ago Dave

PS ... unless of course, they advanced faster than we did

Not to mention, any intelligent life that may have developed over there wouldn't have much incentive to beam anything towards the Earth. Remember, the distance of 1400 ly works both ways. If any hypothetical life sent out signals 1400 years back, they would have done so following data they received from Earth, which is 1400 ly away from them. And the Earth was quite quiet in 785 BC.

Anyway, calling Kepler 452b Earth's sister or cousin or whatever is stupidity. Remember, they used to call Venus Earth's twin before the Venera probes crashed on its' surface.