Kepler: The Era of Exoplanets Has Arrived - Jeff Coughlin & Geert Barentsen (SETI Talk 2017)

NASA’s Kepler space telescope was launched in 2009 and measured the brightness of 200,000 stars at unprecedented precision for over four years, with the prime mission goal of detecting Earth-sized exoplanets. Now after another four, Kepler’s final planet catalog is complete --- over 4,000 planet candidates have been found, with 50 of them possibly rocky and capable of having liquid water. For the first time in human history, we can calculate how common planets the same size and temperature as Earth are, a key component to SETI’s goal of figuring out how common life may be in the universe.

The K2 mission began three years ago, and uses the Kepler spacecraft to stare at many different parts of the sky for 80 days at a time. A broad portion of the Astronomical community chooses what targets to observe, resulting in a wide variety of science, including supernovae, galaxies, stars, and of course exoplanets. K2 has found over 300 confirmed exoplanets and an additional 500 candidates. Some of these are likely to be habitable, and many of them are prime targets to be observed by future missions, such as the James Webb space telescope. We'll discuss what we may learn about these worlds over the next few decades, and what future missions are being planned to find planets to which our descendants may one day travel.

[chromabotia]

Yea! SETI Talks returns after what seems like a long time. This presentation was informative and entertaining. The new venue is nice (no more microsoft) and there was a good turnout. My favorite talks go back to the SETI auditorium when Adrian was hosting - wow some outstanding speakers. Was a little disappointed to hear that the talks would only be given monthly not weekly. But I'm happy to have that. I did contact Seth via email when SETI talks went silent but alas I heard nothing back. But I understand that Seth is very busy doing stand up at Yuk-Yuks and the Comedy Castle. But seriously, thanks to everyone at SETI, UC Berkeley and NASA Ames. I am a huge supporter of your work and have been so for a very long time. ~ Mike McManus

[chrismacp]

Great to to see the talks back on. Thanks for the update on the Exo-planet data!

[centavitagris]

That Kepler orbit ROCKS! Can you imagine, in light of the Deep Space Field of Hubble, if we had geo stationary outer atmosphere observation stations to record as many deep space fields all the way around our sun AND earth with upgraded Kepler instruments???? Too kewl!!!

[SwissMilk]

hi seti please can you get a sound engineer or something to keep an eye on audio levels, getting extreme highs and lows, thx

[willi-fgdh]

please fix the sound levels . . . i couldn't hear the introductions at all, the speakers were OK, but the audience applause at the end of the second speaker's segment was so loud that i think i'm going to be traumatized for at least a month . . . if i miss xmas i'm going to blame our sound guy!

[Jenab]

For planets orbiting in the habitable zone of their stars, the odds of a transit are about one third of a percent (P=0.0033) for a G2 star like the sun, but the odds of a transit are about 2% (P=0.02) for an ultracool red dwarf. So it's a pretty good guess that, averaged over many carefully watched stars, there are at least 100 habitable-zone planets that are not observable by the transit method for each planet in the habitable zone that has been observed by the transit method.

[Jenab]

Kepler's third law, as Isaac Newton presented it, is

P² = 4πa³/(GM)

P is the period of the exoplanet's orbit
a is the semimajor axis of the exoplanet's orbit
G is the gravitational constant
M is the combined mass of the star and the exoplanet

If you know the star's mass (which you can infer from its effective temperature to a fairly good approximation) and the period of the exoplanet's orbit, then you can estimate the semimajor axis of the exoplanet's orbit. Until you can determine the exoplanet's eccentricity — there is a way to do that from doppler shifts in the star's light, if you have sufficiently good spectral resolution — you'd assume zero eccentricity. The flux of radiation from the star at the exoplanet is found and a (wide) range of possible surface conditions for the planet becomes known. When you are able to determine, from spectroscopic observations of the exoplanet during a transit, the chemical constitution of its atmosphere, then you can narrow the range of possible surface conditions. As you might expect, how much you can find out depends a lot on how good your instruments are.

[SwissMilk]

how do we find life on exoplanets in real time with the distances involved or are we looking at signs of extinction maybe?

[danievdw]

I'm always excited to see new videos from SETI/Kepler...., but somehow they always manage to produce the worst sound quality videos. I don't get how all these smart people can't ever manage to normalize sound and use proper sound equipment.

[dipi]

25:38 Up to a quarter of stars may have Earth-sized planets around the habitable zone — a really remarkable result. But: the relative dearth of Jupiter-sized gas giants may indicate that those goldilocks Exoplanets may be getting pummeled by debris constantly, making life harder to emerge.

[searchingformyself]

Can't wait for the newer, better planet-hunting telescopes and the like to be launched in the early 2020's. Kepler discovered quite a few planets, but only looked at a small area of the sky, discovering planets that could either be directly observed as viewed from Earth or inferred from the dip in the star's light, i.e. transit or from the wobble a large planet produced on the small star.

[Norman]

Exciting times indeed. Just imagine when TESS and JWST join the fray.

[drew]

quiet parts followed by loud parts are pretty annoying. A shame..

[redventrue]

We should be designing these things to be refueled by drones. Maybe have them upgradable by units we could just send up and plug in by remote.

[HebaruSan]

Does that mean Kepler is at the Earth-Sun L4 or L5?

[InfiniteUniverse]

What percentage of "Earth-like" planets have opaque atmospheres? If the atmosphere is opaque like Titan or Venus, then photosynthesis is impossible. Also, why isn't TESS contributing as much as Kepler to the exoplanet count? For the last decade or so, post-Kepler, the rate of exoplanet discovery has been slow compared to the thousands of exoplanets discovered by Kepler. Why hasn't the Kepler design been reproduced or a better version created?

[Jenab]

Life probably isn't common in the universe. The biggest filters (after the astrophysical requirements have been met) occur early. However hardy life might become after several hundred million years of evolution, it is fragile to begin with. Life is difficult to kick-start, and it is easily killed off at the outset. Your "most pessimistic estimate" of 2% of planets meeting all astrophysical requirements as bearing life is, itself, much too _optimistic._ Before you begin making probability estimates, wait until you have more than one life-bearing planet in your statistical population.

[enriquejorge]

Adios Benardette. please dont come back.

[politicallycorrectredskin]

I don't want to complain, but this stuff is far too interesting and important for poor sound quality and a twenty minute backslapping sesh, of at most even slight interest to maybe three people in attendance and no one else, before the content starts.

[Jenab]

EDIT THE VIDEO to remove the preliminary blah-blah. Nobody cares about that stuff. Thirteen minutes of verbiage of merely local or temporary interest is too darn much to wade through.