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Sat Sep 29, 2012, 04:32 AM

A periodic table of all 2,320 Kepler Exoplanet Candidates (

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Reply A periodic table of all 2,320 Kepler Exoplanet Candidates ( (Original post)
Ichingcarpenter Sep 2012 OP
longship Sep 2012 #1
Warpy Sep 2012 #3
eppur_se_muova Sep 2012 #5
littlemissmartypants Sep 2012 #2
Surya Gayatri Sep 2012 #4
muriel_volestrangler Sep 2012 #6
Odin2005 Sep 2012 #7
elbloggoZY27 Sep 2012 #8

Response to Ichingcarpenter (Original post)

Sat Sep 29, 2012, 06:30 AM

1. Understand confirmation bias.

Kepler Project is a space telescope like no other. It stares at the same area of the sky, roughly the area of the Big Dipper, and takes picture after picture. The Kepler scope has one of the largest digital cameras ever made and all it does is record, with exquisite precision, the light arriving from the same 150,000 stars. Minute by minute, day after day, week after week, month after month, year after year.

If a planet happens to go in front of the star it will dim slightly and Kepler's camera is sensitive enough to record that. It is like a tiny eclipse or, as astronomers call it, a transit. If the dimming happens at regular intervals, it may be a planet. The amount of the dimming and the period of the dimming gives the Kepler scientists an idea of the size and distance from the star of the planet. (See Kepler's Laws

Confirmation bias comes into this because the easiest planets to see with this method are the largest planets and those closest to their star. So Kepler's discoveries will inevitably be biased.

The cool thing is that the Kepler scientists are aware of the bias so they can factor it out. So far, they have found that planetary systems in our galaxy seem to be like our solar system, with plentiful earth-sized planets, even though the actual numbers do not say that. It's that damned confirmation bias.

This is a great project. I go onto the NASA Kepler site about once a month. It is awesomely cool, explicitly designed to find how many Earth-sized planets exist in our galaxy.

That's one of the factors in the Drake Equation. Here's Carl Sagan describing what that is:


Kepler's very, very cool, eh?

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Response to longship (Reply #1)

Sat Sep 29, 2012, 10:31 AM

3. That's why they're also striking out on cold zone planets

They transit their stars very seldom and are only spotted due to pretty dumb luck. They'd have to wait 163 years to see one the same distance out as Neptune and wait another 163 years to gauge its orbital distance and period.

Just confirming other stars have planetary systems is huge. All we need is one lonely bacillus on Mars to confirm that life is very likely out there.

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Response to Warpy (Reply #3)

Sat Sep 29, 2012, 12:12 PM

5. AND the farther the planet from its primary, the less likely it will be at the right inclination ...

... if the plane of the planet's orbit is not nearly parallel to our line of sight there will be no transit. The farther out the planet, the closer to parallel it must be.

The large orbit also makes gravitational perturbations harder to detect.

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Response to Ichingcarpenter (Original post)

Sat Sep 29, 2012, 10:00 AM

2. This must be kicked

it is high sci! Love it.

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Response to Ichingcarpenter (Original post)

Sat Sep 29, 2012, 10:37 AM

4. Love this stuff--the ultimate existential question:

"Helloooo! Is anybody there?"

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Response to Ichingcarpenter (Original post)

Sat Sep 29, 2012, 01:02 PM

6. Notable that 'superterrans' are the most common in candidates

(though a few more neptunians have been confirmed) although there's not a single example in our own solar system.

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Response to Ichingcarpenter (Original post)

Sat Sep 29, 2012, 02:05 PM

7. Kepler just astonishes me!

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Response to Ichingcarpenter (Original post)

Sun Sep 30, 2012, 02:11 PM

8. Way Out There

 

As a Cosmology inquisitive person I believe we so called human beings are not a one of a kind species. When you read that a Galaxy some 13 Billion Light Years away exists then anything is possible.

The only question I have is will we ever see a visitor from a World so far away.

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