Weird Planets 9

How many are here for Leg 9 of the Weird Planets Tour? All of you? Okay, we’ll get started. Frankly, a lot of people stay in their hotel room for this day. After 8 straight days of viewing planets, they feel they’ve seen all the possibilities. I prefer to think that each planet has something that makes it unique. Everybody secured? Here we go.

Today we’re going to visit planets and systems discovered by the Kepler Telescope, which was the first unit designed and launched specifically to look for xenoplanets. Our first stop is the Kepler-11 system. Take a look; there are at least 5 planets, although sometimes I swear there’s 6. And they’re all packed in real close to their parent star. If this were the Earth system, all of them would be within Mercury’s orbit. And yet, this system is stable; they aren’t playing havoc with each other’s orbits. When this system was first discovered, a lot of scientists revisited the ideas about planet formation. And Kepler-11 also suggested that systems with multiple small planets might be common. It makes the Earth system a little less unique, but ups the possibility that other intelligent beings – or at least life of some kind – will eventually be found.

At about that same time, the Kepler Telescope discovered Kepler-10c, a mega-Earth planet that some called the “Godzilla of Earths”. 10c is 2.3 times the size of Earth, and 17 times heavier. I think that means if you weigh 100 pounds on Earth, on 10c you would weigh 1,700 pounds. You couldn’t stand up on 10c. You wouldn’t have enough muscles to do it. Now, 10c has a sibling, Kepler-10b, which is a lava world. We’ll catch a glance of that on our way out. The Kepler-10 system is 570 light years from Earth, and is located in the constellation Draco. Considering the naming practice, there should also be a planet called Kepler-10a. I keep asking about it, but they never add any notes about that planet, if it even exists.

In front of us, you can see a double star. Orbiting around both stars is a circumbinary planet, Kepler-16b, which some have nick-named “Tatooine”. You’ve already visited the other so-called “Tatooine”, haven’t you? In a trinary star system? Yes, that earlier 1 only orbits one of the 3 stars, so the chances of any occupants actually seeing 2 suns setting at the same time are pretty slim, but on Kepler-16b, that could be possible.

Our next planet is Kepler-22b. Yes, ma’am, I’m sure there were discoveries between 16 and 22, but they haven’t given me any information on them. They carefully pick which planets to have you view. I’m afraid we couldn’t possibly visit every planet that’s been discovered. At this point, there are thousands of them, and it would take years, even if we managed several in 1 day.

The next planet is Kepler-22b. This planet is in its system’s habitable zone, and could possibly be an actual water world, which we don’t have in Earth’s system.

A short hop away is the Kepler-36 system. Do you see the 2 planets? Just 2, and their orbits are extremely close to each other. At their closest, the distance between them is 1.2 million miles, which is only 5 times the distance between the Earth and her moon. That might make colonizing easier than Earth had in colonizing Mars.

And now we skip all the way to Kepler-186f. Does anything look familiar about this planet? Some people think there is, even if they can’t say what. Kepler-186f was the first rocky planet found in the habitable zone, so the temperature is right for liquid water. It’s also very close in size to Earth. It always makes me want to land and see what might live there. But we have to keep moving, or we’ll never get done.

Here we have the Kepler-444 system, the oldest known planetary system. Here we have no less than 5 terrestrial-sized planets, all in orbital resonance. This group shows that solar systems have formed and existed in our galaxy for nearly its entire life.

Kepler-452b is the first Earth-sized planet found in the habitable zone of a sun-like star. So it might look even more familiar than 186f did. 452b is only 60% larger than Earth, and 5% further from its star. Following our earlier logic, if you weigh 100 pounds on Earth, here you would weigh 160 pounds, which would be tiring, but do-able. And if a typical day on Earth got to 100°, here it might get to 95°. But there are a lot of things that have an influence on a planet’s temperature, so I’m not absolutely certain of that last statement. Still, at first glance, it certainly sounds inviting.

And now, just one last pause on our way back to the station. As you may know, the Kepler Telescope developed a technical problem, which scientists ‘fixed’, sort of, but its mission had to be modified to accommodate its somewhat limited capability. At that point, they stopped using ‘Kepler’ in the naming ritual and started using ‘K2’, to indicate these discoveries were made after its mission was modified.

This is the K2-3 system. We’re a bit late getting back, so we won’t stop here long. K2-3 has 3 super-Earths in orbit. If you check today’s pamphlet, the mass and radius of each is listed. The home office keeps promising to include updates on their atmosphere compositions, so if you see that information, I’d appreciate you letting me know.

And here we are. I apologize for a long day, but Leg 9 always takes longer than the home office thinks it should. Have a pleasant evening and get a good night’s sleep.

https://www.nasa.gov/feature/jpl/20-intriguing-exoplanets

www.space.com/159-strangest-alien-planets.html

Weird Planets 3

GJ 1214b is another exoplanet that I found on 3 of the 4 lists. Some have nicknamed it ‘Waterworld’ since its discovery in December of 2009. It orbits a red dwarf star some 40-42 light years from us and is a ‘super Earth’, a planet whose mass is between Earth and Neptune. It is triple the size of Earth, but its mass is about 6.5 Earths.

Waterworld - as you might guess - is probably covered in water, reaching depths far deeper than Earth’s oceans. It is assumed to have a solid core, but the lists disagree about that core. One assumed the core would be made of rock, one simply said the core was ‘solid’, and the third stated that with an ocean that deep, the pressure and cold could have formed a core made of different forms of ice.

The depths of this ocean might be frigid, but not the atmosphere, which it definitely has. This planet’s air is described as ‘thick’ and ‘steamy’. It is thought to be home to water in a medley of phases, such as steam, liquid, and plasma. Maybe even ice, down in the core region. Another scientist said that Waterworld’s high temperatures and high pressures could form some exotic materials, such as ‘hot ice’ or ‘superfluid water’.

The possibility of ‘exotic forms of water’ makes me think of an episode from the original series of Star Trek. Small bits of a freakish form of water would ‘infect’ people and make them behave as if they were drunk, even to the point of committing suicide. For most of the episode, Dr McCoy and his team could not figure out what had gotten into the victims... all the tests just considered this stuff water. But in the end, of course, they got it figured out and devised an antidote. There was a very similar episode in ST The Next Generation.

Hmm. I wonder if ‘Waterworld’s ocean consists of salt water, or something more closely resembling fresh water. If the only thing solid is the core - which at the very least might well be covered in ice, if not composed of ice - then where would it get any salt?

And if the ocean is fresh water, what are the chances that it managed to produce any life? Probably not life as we know it, because we need a whole bunch of stuff besides the hydrogen and oxygen found in water. Stuff like iron, carbon and potassium, just to name a few.

Now, let’s all think about this and try to figure out how plain water might manage to create living creatures. And when we’re done with that, let’s tackle the intelligence question.

Dione

I thought we’d talk about Dione today. That was before I found out there were 4 ‘Dione’s’ in Greek mythology and one in the Phoenician mythology of Sanchuniathon. Rather than try to sort through all those, I changed my mind and decided to discuss Dione, a moon of Saturn. (What or who is Sanchuniathon? I may have to come back to that one sometime.)

This moon was discovered by Giovanni Domenico Cassini in 1684. It is also sometimes called Saturn IV.

Dione’s orbit around Saturn is an ellipse, and at its closest approach, it is slightly closer to Saturn’s center than our own moon is to the Earth’s center. Because Saturn is a lot bigger than Earth, Dione races around it, taking 2.74 days to complete an orbit, as well as a Dione ‘day’. It never turns its face away from Saturn. It’s interesting that every time Dione completes one orbit, Enceladus (another Saturn moon) completes two. Each time they pass each other, the gravimetric tugging generates internal heat in both moons.

Also interesting is that Dione is one of a set of triplets. Two other moons of Saturn, Helene and Polydeuces, share the same orbit as Dione. They run around Saturn in single file, one 60° ahead of Dione, and the other 60° behind.

Who knew this kind of stuff could actually happen ‘naturally’? May I should have stuck with mythology after all.

It is believed that Dione is about 2/3 water in various forms, and the remainder is a dense core of silicate rock. The top of the ‘water’ is an ice crust, probably as thick as 99 kilometers ( 62 miles). The temperature at Dione’s surface is about -121°F, which would make the ice so hard, it would act like rock. Between the rock core and the ice crust is about 65 km ( 41 miles) of liquid ocean. The crust does have various features, such as chasms, ridges, long narrow depressions, craters and crater chains.

Dione is pretty well covered in craters, as large as 100 km (62 miles) across. However, most of the craters are on the opposite side as scientists expect them to be. The theory is that on something the size and mass of Dione, anything big enough to make a 35 km (22 mile) crater would be able to spin the moon about. There are enough large craters to indicate Dione did a lot of spinning in the past. So maybe she keeps her back to Saturn, trying to see the next spin-inducing attacker before it hits?

Oh, and let’s not forget the ice cliffs (formerly known as ‘wispy terrain’ when it was discovered by the Voyager space probe). At the time, they were called ‘wispy’ because whatever they were, they didn’t hide the countryside in their vicinity. But more recent photos by Cassini show that these ‘wispy’ lines were, in fact, ice cliffs, fractures created by chasms. We now know that some of them are several hundreds of meters tall.

In 2010, the Cassini probe detected oxygen ions around Dione, but there were so few of them, scientists prefer to call it an exosphere rather than a tenuous atmosphere.

en.wikipedia.org/wiki/Dione_(moon)

https://solarsystem.nasa.gov/planets/dione

The Inner Goldilocks Planet

I've been thinking about those twin Goldilocks planets I mentioned last week. That article had more details that I found intriguing but hadn't included in last week's post. So this week, I'm going to explore that inner planet a bit more.

The article claimed the inner planet might have a climate reminiscent of Hawaii or of Washington DC in May. I have to assume they meant that would be the 'average', and most likely found in the 'temperate zone', roughly 30 to 60 degrees North and South of the Equator.

On Earth, Hawaii stretches from 18 to 28 degrees North. To move that climate to the middle of the temperate zone would be a shift of 21 degrees. What does that do to the rest of the planet's climate, compared to Earth?

So I looked up Barrow, Alaska, which is located at 71 degrees North. That town has temperatures below freezing about 8 months of the year, and during its warmest month, the temperature averages 47 degrees F. Now, if we move that kind of climate another 21 degrees North-- well, we get 92 degrees North, and planets only go up to 90 degrees North or South. So it's possible the Inner Planet would not have any permanent ice caps.

What about the equator? The temperatures Earth experiences at our equator would now be normal at 21 degrees North and South. The area of our equator is mostly tropical rainforest or ocean, with little variety in temperature (high 80s) around the year. And it rains. A lot. I tried to look up some cities approximately 21 degrees N/S, to see what kind of temperature differences occur in that 21 degree difference. Antofagasta, Chile has an average temperature of 63. (It also sits in a desert where the only 'precipitation' comes as a thick morning fog, but we'll ignore that.) That's a difference of about 25 degrees, so I extrapolate that the average equatorial temperature of the Inner planet might be around 113 degrees F. Yes, definitely warmer than us.

It was also hypothesized that this might be an ocean planet and that some type of 'flying fish' might have evolved into 'birds'. Of course, if there isn't any land, those birds would not be able to rest unless they were some type of water fowl.

None of that would keep us from colonizing, if we were at that stage. Cities, towns, even farms could be placed on floating rafts and left to drift on the currents. Or given some motors so they could move out of the way of approaching storms. There have been people here on Earth designing such structures, to be set loose on our oceans.

There's got to be a few stories in amongst all those ideas, don't you think?