Haven’t found time to post this in a while. But today is a special day. (At least that’s what rumor would have you believe.) I’ll upload my thoughts live here:
RUMORS. Assuming this is all true, and based on a very first-order look at things, I think they’ve got it. A potentially Earth-like world beyond our solar system. How Earth-like is it? That’ll take a follow-up mission.
Pete Worden: “This is really cool.”
(YES! You bet it is.)
Worden now briefly going over the history of the Kepler mission. Alludes to the struggles Kepler met when it was first starting out.
He’s right… No one thought it would work at first, and now that it’s flying it’s working better than anticipated and might make one of the more historica scientific announcements in my lifetime.
They’re announcing the team now. The inclusion of Lisa Kaltenegger is why I originally suspected this being an announcement of a potentially habitable planet.
2:08-ish – Tweet with hashtag #askNASA If you have questions for the panel….
2:12 – Paul Hertz up now, also giving a shout-out to TESS, which will do things similar to Kepler but for planets around cooler stars but that are more capable of being studied in more detail with a future mission.
(I imagine we’ll talk more about “follow-up” or lack thereof later.)
2:13 – Roger Hunter (Project Manager) up now. Saying we have 2,740 planet candidates (WOW!) and lots of them are Earth or super-Earth sized (2 times Earth’s size or less.) Also going over how Kepler makes its measurements and how it can tell us its orbital properties. Most importantly: the planet’s size and distance from the star.
Hunter (paraphrased): today we’ll talk about two planetary systems with smaller planets in the habitable zone.
(WOOHOO! For me, this is a HUGE deal. I never believed Kepler 22b will be habitable because it was too big. These won’t be too big.)
Borucki: Puts up planets we’ll be talking about today, with sized 40% and 60% bigger than Earth.
(I can’t remember the planet names but in my opinion they might as well be called BFD-1 and BFD-2.)
2:16 – Borucki is now going over the concept of the habitable zone, and doing a pretty good job with it. Basically you can’t get too much energy from the star or else you’ll turn your oceans to steam… or you can’t be too far away or they’ll freeze over.
2:17 – Planets are over 1,200 light years away. Showing amazing video now. Three planets in the system. First one is Mars-sized and way too hot for life. Next one is “warm” (cue from me: probably means too hot for life, or may be a “habitable but ONLY IF…” type case). Next one is cooler and could have ice caps.
2:19 – (At this point planetary scientists are banging their heads on their desks at the lightning and oceans and continents being shown but that head-banging misses the point. These planets *COULD* be as imagined. That’s the point.)
2:21 – Borucki going over the importance of size. (This is good, because Kepler 22b (the last “potentially habitable planet” announced by the Kepler team) was probably too big for surface oceans. These are small enough for liquid water oceans.) Based on what I’m seeing so far, at least one of these will be the most habitable planet we know of outside Earth. In my opinion, that even includes Mars, Europa, Enceladus, Venus, etc…
2:22 – Thomas Barclay now talking about a second system, Kepler 69. This star is more Sun-like. Talking about candidate number 172.02 (that’s one that I had internally flagged as being habitable). System includes Kepler-69C, which is 70% bigger than the Earth. That’s pretty big, but still potentially habitable. (I certainly can’t rule it out.)
Barclay (paraphrased) None of these are Earth-sized, but we’re moving in that direction.
Lisa Kaltenegger (paraphrased) – Cutoff for “Earth-like” in size is 1.5 Earth radii. We now have planets smaller than this. Take models with a grain of salt…
As someone that runs those models, I’ll agree with that! Hehe. Now she’s showing the habitable zone… that looks like the one made by friend/colleague Ravi Kopparapu! Dr. Kaltenegger now saying that one of the planets is smack in the middle of the habitable zone. (This is critical, because even if some of the measurements are wrong it’ll still be potentially habitable.)
Lisa now putting in the grains of salt. For example, no cloud feedbacks in the models. Using that as an argument for why Kepler-62e could be habitable. (I agree, but with STRONG caveats. I’ll get to those later.) Now talking about another that’s a super-Venus. (I’m having trouble keeping up with the names. I’ll have to circle-back later.)
My eyeballing of the figure tells me Kepler-62f is the real star here. Kepler-62e is also interesting, but that’s the one with those caveats.
2:32 – Lisa now waxing poetic about the motivation here. Talking about the diversity of planets and how we might be able to learn something about rocky planets (like Earth) by studying them. And showing a graphical representation (artists rendering, NOT a real image) of what these planets *MIGHT* be like.
Dr. Kaltenegger – “For the first time, we found a system where potentially we could have more than one habitable planet.”
Q: Is there something special about Sun-like stars?
A (Lisa): What we’re basing out models on is the Earth. If you change the sunlight our models may not account for that. (Not exactly true… but there are other issues.) Other people, some people, want the exact Earth-Sun analog. (This is why Kepler was designed the way it was.) But the big point is the amount of energy you get. Just get closer to the dimmer stars like you would a dimmer fire.
A (Tom): The one planet we know of life on orbits a Sun-like star, so naturally the first planets we should first study in detail would be the ones around Sun-like stars.
A (Bill): IT should also “look like” the Sun from EArth walking around the surface of the planet.
Q: Could they be waterworlds?
A (Lisa): If you take a planet like the Earth with the same water content but bigger… you end up covering the planet with water. The reason is you get more water “faster” than you get more surface area as you go to bigger planets. So that more water will end up covering the Earth. Earth is very dry.
Q: Any reason to think planet inside the habitable zone would have a Venus-like atmosphere instead of Earth-like?
A (Bill): A planet that big you’d expect a lot of CO2. Could make planet even HOTTER.
(So basically, YES.)
Q: Confused… but what about clouds?
A (Lisa): If you make a little more clouds because you have more water vapor in the atmosphere you should be fine.
(They’re hand-waving here a bit, in my opinion.)
A (Lisa): Once you go Venus you don’t go back. It’s a runaway you don’t escape from.
Q: (I missed it, sorry)
A (Bill): You can look at the atmosphere and build an empirical habitable zone. You can also make a model-based zone, similar to what Lisa and others
(COUGH RAVI!!! COUGH) have done.
A (Lisa): Coulds are important here too, but they’re difficult to do.
(You bet they are.)
Q: Is more watery more conducive to early evolution of life? Or more rocky? What kind of life could we expect on them? What kinds of differences?
A (Bill): If we look at our ocean it’s just full of life. We think life started there. !Hints at another press release about getting chemicals needed for life from the subsurface! YOu might have flying fish and birds (??!?) evolved on this ocean planet. (OK you might also have nothing, right?)
Q: Has this been published yet? And can you go over why Kepler-69c might be habitable?
A: Paper was published in the Astrophsical Journal. The planet is in the habitable zone by the metrics for the mission. Probably this planet is “closer” to being Venus than Earth. But slightly farther from its star than Venus is from the Sun, and the star is a little dimmer. So this is “inbetween” the two.
(Basically, in my estimation this planet could be habitable but if AND ONLY IF it has massive cloud or aerosol cover.)
Q: Are there agreements on the habitable zones? Are there different ones? How do you come to agreement on that?
A (Lisa): We do agree. (Mostly.) We figure out how the models work and do our analyses and then come to conclusions. Now talking about how we can have different zones for different approaches (empirical vs. modeling). But either way, Venus is not habitable. There’s an “error bar” in where the planet actually is or how hot the star is. This leads to an “error bar” in how much energy the planet gets. For Kepler-69c you see this error bar and part of the error bar gets into the habitable zone.
(Ahhhh… now I see. If they’re wrong about how much energy this planet gets it *Could* be habitable. That’s actually not as crazy as it sounds. There’s a decent chance that could be the case.)
Q: Where do we go next? TESS? And what’s possible?
A (Bill): What could we do if we had more money? Kepler is the first step. TESS is another step. The next BIG step is something referred to is the Terrestrial Planet Finder. That would look at the atmospheres of the planets and look for water and CO2 and oxygen. Maybe freeons! But that’ll take a much more expensive, extensive mission. Kepler tells us how many planets are out there as a function of size and habitable zone and so on. That will tell us how big of a telescope we’ll need to look at the atmospheres. And then you’d need missions beyond that to confirm life. Missions through our children and grandchildren.
A (Lisa): Habitable zone is defined not where there’s life but where life can be found with a telescope. (This is an OUTSTANDING point by Lisa. This is really what we’re talking about when we talk about the habitable zone.)
Q: Where would Earth and Mars be in our habitable zone?
A (Bill): In our system we wouldn’t have seen anything yet because we haven’t been looking long enough yet.
OK I have to run. I’ll put up a post later with more fully-formed thoughts.