Why We Are Looking For Exo-Moons around Exoplanets

Views of and from a hypothetical habitable exo-moon around the nearby exoplanet Upsilon Andromedae d

So as I've said in the past I like to try to give you the interesting news and trends from the world of exoplanets and astrobiology before the mainstream media really catches on.

So that's why I'm posting a couple of excerpts here.

It seems like 2015 may indeed become the year of the habitable exomoon. Planet hunter extraordinaire, Sara Seager was recently quoted as saying this could be the year when one is confirmed:



Now David Kipping of Harvards HEK program (Hunt for Exomoons with Kepler) is about to up the ante:


Excerpts From Wired: Why We’re Looking for Alien Life on Moons, Not Just Planets

Think “moon” and you probably envision a desolate, cratered landscape, maybe with an American flag and some old astronaut footprints. Earth’s moon is no place for living things. But that isn’t necessarily true for every moon. Whirling around Saturn, Enceladus spits out geysers of water from an underground ocean. Around Jupiter, Europa has a salty, subsurface sea and Titan has lakes of ethane and methane. A handful of the roughly 150 moons in the solar system have atmospheres, organic compounds, ice, and maybe even liquid water. They all seem like places where something could live—albeit something weird.

So now that the Kepler space telescope has found more than 1,000 planets—data that suggest the Milky Way galaxy could contain a hundred billion worlds—it makes sense to some alien-hunters to concentrate not on them but on their moons. The odds for life on these so-called exoplanets look a lot better—multiply that hundred billion by 150 and you get a lot of places to look for ET. “Because there are so many more moons than planets, if life can get started on moons, then that’s going to be a lot of lively moons,” says Seth Shostak, an astronomer at the SETI Institute.

Even better, more of those moons might be in the habitable zone, the region around a star where liquid water can exist. That’s one reason Harvard astronomer David Kipping got interested in exomoons.


So far, no one has found a moon outside the solar system yet. But people like Kipping are looking hard. He leads a project called the Hunt for Exomoons with Kepler, the only survey project dedicated to finding moons in other planetary systems. The team has looked at 55 systems, and this year they plan to add 300 more. “It’s going to be a very big year for us,” Kipper says.

Finding moons isn’t easy. Kepler was designed to find planets—the telescope watches for dips in starlight when a planet passes in front of its star. But if a moon accompanies that planet, it could further lessen that starlight, called a light curve. A moon’s gravitational tug also causes the planet to wobble, a subtle motion that scientists can measure.

In their search, Kipping’s team sifts through more than 4,000 potential planets in Kepler’s database, identifying 400 that have the best chances of hosting a detectable moon. They then use a supercomputer to simulate how a hypothetical moon of every possible size and orientation would orbit each of the 400 planets. The computer simulations produce hypothetical light curves that the astronomers can then compare to the real Kepler data. The real question, Kipping says, isn’t whether moons exist—he’s pretty sure they do—but how big they are. If the galaxy is filled with big moons about the same size as Earth or larger, then the researchers might find a dozen such moons in the Kepler data. But if it turns out that the universe doesn’t make moons that big, and they’re as small as the moons in our solar system, then the chances of detecting a moon drop.

According to astronomer Gregory Laughlin of the University of California, Santa Cruz, the latter case may be more likely. “My gut feeling is that because the moon formation process seems so robust in our solar system, I would expect a similar thing is going on in an exoplanetary system,” he says. Which means it’ll be tough for Kipping’s team to find anything, even though they’re getting better at detecting the teeny ones—in one case, down to slightly less than twice the mass of the solar system’s largest moon, Ganymede.

a reply to: JadeStar

This makes sense and expands the logical idea that aliens DO exist in the cosmos even more. All we need now is the evidence to confirm our suspicions.

exoplanet moons might very well be home to intelligent life , not just the other planets

it's almost a 'given' that we are not alone in this solar system

some people care about stuff like that other people are more concerned with issues closer to home

a reply to: blacktie

Where do you get the idea that it is a "given" that we aren't alone in the solar system? The number of bodies in our solar system that can support life are ridiculously low. Sure we MIGHT not be alone in the solar system, but it is no where near a GIVEN that we aren't.

a reply to: Krazysh0t

well I believe space travel is possible and some people have been other places and lived to tell about it online

why, do you believe all planets and moons are empty void of anything human-like ?

originally posted by: blacktie
a reply to: Krazysh0t

well I believe space travel is possible and some people have been other places and lived to tell about it online

I believe space travel is possible too. Why wouldn't it be possible? Though no human has been anywhere but Earth or the moon. If you believe those accounts from people telling their stories online, then Mr. Chris Hansen in my avatar would like to have a word with you.

why, do you believe all planets and moons are empty void of anything human-like ?

Hmmm? Where did I say this? Go back and reread my posts carefully. I am only calling into doubt that other life exists in our solar system. I still think its highly possible that it exists elsewhere in our galaxy and I will even place the "given" label on it existing in other parts of our universe. And even with the solar system thing, I'm not saying it ISN'T there either, just that it isn't a given that it is.

originally posted by: blacktie
a reply to: Krazysh0t

well I believe space travel is possible and some people have been other places and lived to tell about it online

?

What people have been other places? Are you referring to a secret space travel team?

More info and links please....

Ever wonder why we don't have a base on the moon? It's been 40 years since man last went to the moon. Why is that?

a reply to:

well its boring here in my timemachine, gotta do something to pass the time

originally posted by: blacktie
a reply to: Krazysh0t

well I believe space travel is possible and some people have been other places and lived to tell about it online

I personally don't automatically believe everything I read online. Sure -- I suppose it's possible that these people's accounts are true, but people can say anything. I have yet to see one of these accounts have any credible evidence to back it up. They seem to read like fictional stories.

Would it be "really cool" if those stories were true? You betcha!
However, a story being "really cool" or a story being something that "I want to be true" does not make it any more likely to be true.

why, do you believe all planets and moons are empty void of anything human-like ?

I'm not Krazysh0t (the person to whom you were replying), but i'll throw my two cents in. In my case, I do believe that life probably exists elsewhere (similar to what Krazysh0t said in his reply to you).

Here are my thoughts:

Life elsewhere in the solar system --
I think there is a good chance that other life does exist in the solar system. I'm not automatically ruling out the chance considering there seems to be several places in the solar system that could have viable biosystems (Titan, Enceladus, Europa, under the soil of Mars, the clouds of Venus, etc.) However, I don't think other intelligent, or even complex animal-style life exists elsewhere in the solar system.


Live elsewhere in the galaxy --
I think there is almost certainly other life in the galaxy; there are just too many possible places for life to have begun to say that there isn't; not just exoplanets, but the exomoons that 'JadeStar' mentions in her OP. Plus, I'd say there is almost certainly complex (animal-like) life out there, a very high probability of other intelligent life in the galaxy (you said "human-like", but I'm not sure what you mean by "human-like"; I simply mean intelligent life). There may be life more intelligent than us, and life less intelligent than us, but I think it is less likely for that other life to look like us (i.e., Human-like in appearance).


Live elsewhere in the universe --
The universe is unimaginably huge. Even in the observable universe (which is not the entire universe), our Milky Way galaxy is almost a speck of nothingness compared to the totality of all of the other galaxies. I'd say it is virtually impossible (about as impossible as it gets) that we are alone. The probability that there are other intelligent beings in the universe is so high that is may as well be a certainty.

Could one of the super Jupiters we've found support an earth sized moon? If it could is there any chance it could orbit it's planet far enough away to avoid being tidally locked. I understand a planet being tidally locked doesn't necessarily preclude life, but i doubt a tidally locked planet would have the same diversity of life that a planet like earth would have.

a reply to: JadeStar

First and foremost we are trying to find the location where the new death star is being constructed.

Secondly - why not?

originally posted by: jefwane
Could one of the super Jupiters we've found support an earth sized moon?

Yes. Plenty. Including one of the first ones. Upsilon Andromedae d, discovered in April 1999 by Geoffrey Marcy (his favorite planet by the way), orbits in the habitable zone of the star Upsilon Andromedae, a star slightly hotter than our Sun could at least in theory have a Earth sized moon.

If it could is there any chance it could orbit it's planet far enough away to avoid being tidally locked.

There are plenty of candidates of super Jupiters which orbit Sunlike stars at habitable zone distances which wouldn't necessarily be tidally locked. In fact the types of stars which have their habitable zone so close that a planet would become tidally locked (small M-type red dwarf stars) don't typically even produce Jupiter sized planets much less Super Jupiters.

In general there are 107 known Warm Jupiters (Jovians) according to this chart with another 45 Kepler candidate planets (Around 90% of which will turn out to be real planets) in that category.



Also a Super Jupiter need not necessarily be in the habitable zone to have a habitable moon. It is possible that a planet could be in the cold region beyond the habitable zone but heat its moon to habitable temperatures through tidal heating like Jupiter slightly heats Europa and IO.

I understand a planet being tidally locked doesn't necessarily preclude life, but i doubt a tidally locked planet would have the same diversity of life that a planet like earth would have.

It might actually be more diverse as there would be isolated biomes where creatures might not venture far from if they were well adapted. The night side vs the day side vs the terminator might all be like separate worlds.

originally posted by: jefwane
I understand a planet being tidally locked doesn't necessarily preclude life, but i doubt a tidally locked planet would have the same diversity of life that a planet like earth would have.

originally posted by: JadeStar
It might actually be more diverse as there would be isolated biomes where creatures might not venture far from if they were well adapted. The night side vs the day side vs the terminator might all be like separate worlds.

Good point.

Earth has separate food chains for nocturnal and diurnal creatures based on time of day. A tidally locked planet or Moon could have separate food chains for nocturnal and diurnal creatures based on geography.

a reply to: Krazysh0t

Not true. First of all, Europa (Jupiter's moon) may very well have life. We know it's covered with ice, and most moons of gas giants tend to have active geology and magma. This is because the immense gravity of Jupiter pulls on the planet's structure, leading to a very active magma. Magma+ice? Water. Furthermore, we know that it's not all solid ice cause we've seen massive fissures in the ice, gigantic cracks across the surface? Why is it cracked? Cause the ice is smashing into other blocks of ice...how would that be possible if the sheets of ice weren't floating atop a medium of some kind...AKA WATER!! Furthermore, we know for a fact that geothermal vents under sheets of ice can support life cause we've seen it right here on Earth, in hydrothermal vents in the ocean. Furthermore, that magma could seed the PHONS (Phosphorous, Hydrogen, Oxygen, Nitrogen and Sulfur) that are necessary for carbon based life. Though there's no sunlight down there, all the energy can be chemosynthetic from the vents. For another potentially life filled moon in our solar system, look no further then Saturn's moon Enceladus, which we know also might have a sizeable ocean. And if that's not enough, look at Titan, which could have an ammonia based ecosystem. After all, perhaps the greatest difficulty in searching for alien life is the fact that we are only looking for carbon based Earthlike life. But what about other biochemistries? Titan could very well have it. Also, not all bets are off with Mars. Don't you know about the Viking lander controversy? The first test got positive results, and the second was nothing like the first. In science, you have to do experiments multiple times to prove or disprove something. For the scientific community to dismiss the first results even though the second one is nothing like the first is ridiculous. Until they do the test again, microbial life on mars remains a distinct possibility. But they will do it again. How do I know? I was on the phone with the lead engineer of the Mars Rovers at JPL and that's what he told me. The Mars 2020 mission will bring rocks back to Earth to be studied in a quarantined lab (after all, we don't want a war of the worlds pandemic). So yes sir, there very likely is life in our solar systems. Human like or intelligent? probably not...but microbial and possibly even complex ecosystems of animals and plants? Definitely.

a reply to: SpaceOverlord

Fine. Just as Krazysh0t said, other life in the solar system is certainly possible. However, it isn't a "given".

When something is a "given" then you are saying it is virtually a 100% probability of being true. I agree with you, Krazysh0t, and blacktie in as much as I also think other life in the solar system is certainly possible. But I also agree with Krazysh0t that it is not a "given".

Even though I'm not a scientist, I like to try to think like one, and a good scientist would not jump to a conclusion like that (i.e., saying that there is definitely life) until they find solid evidence of specific life someplace.

Sure -- there is plenty of good evidence that there are places in the solar system that may support life (Enceladus, Titan, Europa, Ganymede, the sub-surface of Mars, the clouds of Venus, etc.), but that is not the same as finding specific solid evidence of specific life someplace.

Personally, I believe there probably is other life in the solar system. However, I'm not ready to say that there definitely is life until I see specific evidence of that life in its specific environment.

originally posted by: Soylent Green Is People
a reply to: SpaceOverlord

Fine. Just as Krazysh0t said, other life in the solar system is certainly possible. However, it isn't a "given".

When something is a "given" then you are saying it is virtually a 100% probability of being true. I agree with you, Krazysh0t, and blacktie in as much as I also think other life in the solar system is certainly possible. But I also agree with Krazysh0t that it is not a "given".

Even though I'm not a scientist, I like to try to think like one, and a good scientist would not jump to a conclusion like that (i.e., saying that there is definitely life) until they find solid evidence of specific life someplace.

Sure -- there is plenty of good evidence that there are places in the solar system that may support life (Enceladus, Titan, Europa, Ganymede, the sub-surface of Mars, the clouds of Venus, etc.), but that is not the same as finding specific solid evidence of specific life someplace.

Personally, I believe there probably is other life in the solar system. However, I'm not ready to say that there definitely is life until I see specific evidence of that life in its specific environment.

Good point. I agree with that, I guess I misunderstood his point. I think there's a high probability but I also agree that we won't know till we send a submarine to the oceans of Europa or we actually address the Viking controversy. I'd say the probability is high, and it's very likely...but your right that it's not confirmed. As for intelligent life in the entire universe? The probability is so overwhelmingly high, I have to say I take it as a given. Just because when you look at the math, it's so incredibly likely.

Where do you get the idea that it is a "given" that we aren't alone in the solar system? The number of bodies in our solar system that can support life are ridiculously low. Sure we MIGHT not be alone in the solar system, but it is no where near a GIVEN that we aren't.

Not a "given", but certainly a most-likely scenario, just by sheer statistics. Personally, I think the Universe is literally "teeming" with life, with sentient life being "rare", but other life being just about statistically assured. The problem is just that the Universe is just too big, compared to our tech.

The real challenge with sentient beings is that we wouldn't even detect them until they had likely died out many years prior (depending on distance). Likewise, our earliest signals to the Universe are still likely on the way to any ET capable of detecting and interpreting them. Maybe in 1000 years, or 10000 years, they'll get them....

That said though, there are other places (than Earth) in our own solar system where there are likely vast oceans. Ask a biologist if they think a liquid water ocean is going to be devoid of life....doubt you'd get many agreeing with the idea of none.