Kepler Mission Options

[Greg Hullender]

Nice update on Spaceflight Now, with some new (to me) information:

http://www.spaceflightnow.com/news/n1007/28kepler/

"A lot of the misunderstanding occurred because he used the inappropriate term for talking to the public. He should not have said Earth-like. He should have said Earth-sized," Borucki said in an interview Tuesday.

I think Earth-sized is a very fine term.

Kepler is currently only searching for planets with orbital periods of less than three months . . .

Borucki said Kepler scientists will expand their search for planets in the habitable zone once they finish writing an advanced software program to analyze stars over longer periods of time.

Kepler rotates on its axis every three months, meaning light from a specific star falls on a different set of CCDs inside the telescope's 95-megapixel camera.

"The different CCDs have different sensitivities, so it looks to us as if from three months to three months there's a big change in all the brightnesses of the stars," Borucki said.

A computer progarm has to stitch together observations from each three-month period to find planetary transits occurring at longer intervals.

"The computer program can't do that yet," Borucki said. So we can't find anything with significantly longer periods. We simply can't find things in the habitable zone until we finish the computer program. That's what we're working on.".

I suppose this shouldn't surprise me, but it does. I'd have expected them to have produced this software before they launched Kepler. I realize they had more CCD problems than originally expected, but still.

The data only covers 43 days of observations because it takes about four months to process observations into usable formats, according to Borucki.

That seems like an unbelievable amount of time for a data-conversion operation. I suppose that includes heavy-duty things like wavelet transforms, but even so. Also, this makes it sound like they are gathering data about ten times as fast as they can convert it. Maybe they should write it so it can run on a home PC and then invite ordinary enthusiasts to help. Yeah, it'd take time to write the software to do that too, but if they're looking at 40 years to convert the data, that might not seem so bad.

Or maybe I'm just entirely misunderstanding it. :-)

--Greg

[stevesliva]

Given that Gravity Probe B is still tinkering with their software, it's quite alright for Kepler to be debugging...

[Habitable Zoner]

I think that a Kepler@Home project, if technically feasible, would be a fantastic idea. Not only would it make a ton of computation power available, it would give the scientifically literate public a chance to take some kind of ownership of exoplanet discovery. And that could be a very powerful thing, boding well for future missions.

[Reed]

That seems like an unbelievable amount of time for a data-conversion operation. I suppose that includes heavy-duty things like wavelet transforms, but even so. Also, this makes it sound like they are gathering data about ten times as fast as they can convert it. Maybe they should write it so it can run on a home PC and then invite ordinary enthusiasts to help.

I would be surprised if that was limited by raw CPU time, and also surprised if it was just data conversion rather than analysis. My guess is that the pipeline is still being developed, and the four months isn't how long it will take in general, but how long it has taken to date. Rolling out a "kepler@home" would before the process is nailed down would involve significant extra development effort.

The text you quoted does suggest your interpretation, but notice that it's the reporters words and not a direct quote from the mission team.

[Habitable Zoner]

Another opportunity to hear Bill Borucki speak will be coming up August 5-8 in Dayton, Ohio, at the Mars Society Convention. Borucki will deliver the plenary address. For more information, see http://www.marssociety.org/portal/kepler-m...iety-convention.

[hendric]

Well, I assume there will be a Kepler II mission at some point. It would be a great idea for someone with copious free time to take the raw Kepler data and develop a BOINC workflow, calibrating etc along the way, so that the application can double-check the final results, and also prepare for follow on transit searches. Hopefully there will be a fleet of Kepler follow-ons to search the rest of the sky for transits. Perhaps there is no need though. None of the Kepler stars is really close enough for imaging planets even with TPF, right?

[nprev]

IIRC, the high-end version of TPF could potentially resolve large-scale surface features on planets out to something like 20 light-years. (Gotta admit that still sounds implausible to me, though.) Kepler's target stars are all well over a thousand light-years away.

[brellis]

Google Galaxy!

[Hungry4info]

IIRC, the high-end version of TPF could potentially resolve large-scale surface features on planets out to something like 20 light-years.

You can watch the light curve over the course of a planet's rotation period to resolve surface features longitudinally.

If the planet rotates several times per orbit, you can watch the light curve over the course of the planet's orbital period to resolve surface features latitudinally.

It's kind of how they build the map of Pluto, an indirect method.

[scalbers]

IIRC, the high-end version of TPF could potentially resolve large-scale surface features on planets out to something like 20 light-years.

Yes, I recall the Planet Imager (PI) that had been proposed as a network of TPF style interferometers that could image some nearby Earth-sized planets with 25 pixel resolution.

[tacitus]

I think it's all but inevitable that we will end up probing other planetary systems to the limit of the physically possible eventually, even if it's not within the next 25 years. Given the near impossibility of interstellar travel, the only means of exploring our galactic neighborhood that will be available to us for decades, and very likely for centuries, will be telescopic missions, be they in Earth's orbit, at L2, in the outer reaches of the solar system, beyond the zodiacal dust cloud, and even to the focal point of the Sun's gravitational lens at a distance of 550AU.

And yes, there will be fleets of interferometric telescopes one day, because unless we quickly reach the theoretical viewing limits, it will continue to be our only means of imaging and gathering more information about extrasolar planets.

So Google Galaxy is right. We're almost certainly going to have a catalog of millions of planets one day, even if we can only take images sharp enough to create maps of the surface features of the nearest few thousand or so.

Good times...

[Syrinx]

http://www.seti.org/colloquium

Beyond Kepler: Direct Imaging of Earth-like Planets
08/25/2010
Location: conference room adjacent Symantec Cafe at 360 Ellis St. Mountain View, CA.

Ruslan Belikov, Space Science Division, NASA Ames

Is there another Earth out there? People have been asking this question for over two thousand years, and we finally stand on the verge of answering it. The Kepler mission (which was featured in several of the past SETI talks) will likely find the first ever Earth-sized planet around the habitable zone of another star. This talk is about the next step after Kepler, which might be a mission to directly image Earth-like planets and analyze their spectra for biomarkers such as oxygen, water, and atmosphere. The talk will cover the technology of direct planet imaging, focusing on the work done at NASA Ames, as well as the science we might get out of it and some repercussions.

[Habitable Zoner]

Almost six weeks since the last manager's update. Wonder if that means they are gearing up for a big announcement in September? Waiting for another batch of papers to finish peer review? I hope so. But then again, maybe they just forgot about the update thing.

[Greg Hullender]

Here it is!

http://www.kepler.arc.nasa.gov/news/mmu/in...s&NewsID=55

Says their propellant use is lower than expected, so they could go 10 more years, if they got funding. That'd be nice. Confirms the CCD that failed in January is still dead, but says that has only a small impact. They do have an issue that their data transmission rate drops over time as the spacecraft gets further and further away.

They talk at some length about how the Followup Observation Program (FOP) helps them vet the hundreds of planet candidates to eliminate false positives.

--Greg

[Drkskywxlt]

Have they considered looking at a different field-of-view during the extended mission? Or would the goal be just to find longer period planets in the current FOV near Cygnus?