Showing posts with label Goldilocks Zone. Show all posts
Showing posts with label Goldilocks Zone. Show all posts

Wednesday, November 8, 2017

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

Thursday, October 5, 2017

Weird Planets 6

Some of these planets look familiar, which is how they get their nicknames. Is it a surprise that someone has imagined planets similar to actual exoplanets?

HD 188753 is sometimes called Tatooine. It is a Jupiter-sized planet located 149 light-years away from us… in a triple star system. One list explained that this meant the planet orbited a star, which orbited another star, which orbited a third star. They could be right that HD 188753 is set up this way, but it is not the only configuration available to 3 stars and 1 planet. How many other configurations can you come up with?

Whatever the configuration of this system, the gravitational fields would be complex, so scientists were surprised to find planets could be created in such a gravity maelstrom. Dr Maciej Konacki of CalTech feels the view from this planet would be spectacular, with ‘occasional’ triple sunsets. Yes, that’s possible; it depends on the distance between the triplet stars. Some ‘companion’ stars are so far apart that each appears as only a bright point to the other. But this Tatooine would definitely be hot; it completes an orbit around its star in 3.5 Earth days, so it is snuggled up real close.

CoRoT-7b was the first exoplanet to be dubbed a ‘Super Earth’. That means it’s a rocky planet, not a gaseous one. Knowing that other rocky planets exist, scientists can look for potentially habitable planets that reside in a star’s ‘Goldilocks’ zone.

However, this particular planet does not look like a pleasant place, as it is tidally locked to its star, meaning the same side always faces the star, and the temperature on that face is around 4,000° F. If you want to visit, consider that it may be the rocky core of a vaporized gas giant where it rains rocks. Be sure you take a strong umbrella with you!

Kepler-10b is the first rocky planet discovered by the Kepler equipment. It is the smallest known exoplanet; an Earth-sized world that may have a lava ocean on its surface. I love a hot tub, but that’s too hot.

OGLE-2005-BLG-390 is the first ‘cold super Earth’ exoplanet discovered, nicknamed Hoth. The thought is that it began to accumulate a Jupiter-like core of rock and ice, but didn’t stop with just a core. It is 5.5 times the mass of Earth, has a surface temperature of -364° Fahrenheit, and orbits a red dwarf star some 28,000 light-years away.

Well, on this trip, we’ve gone from Tatooine to Hoth. Have we gotten all the ‘extremes’ done? I’m not sure. But next week, we’ll start zipping through the planets that only appeared on 1 list. Bring your seat belt!

http://www.express.co.uk/news/science/643662/The-10-weirdest-planets-to-have-been-discovered-so-far
https://www.nasa.gov/feature/jpl/20-intriguing-exoplanets

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

Thursday, September 28, 2017

Weird Planets 5

Now we begin exploring the exo-planets that only appeared on 2 of the 4 lists. Does it seem like this series will never end? Cheer up; the process will get faster. The fewer lists that contained a particular planet, the less information I have to pass on to you. I’d like to get through several planets today, so let’s get started.

Earth Jr is only 20 light years away. It’s official name is Gliese 581d. Actually, there may be 2 planets around the same star, but only 581d is mentioned on both lists. 581g was a ‘shiny thing’ that briefly appeared in the same paragraph on the first list.

Gliese 581 is a red dwarf star located in the Libra constellation, and 581d sits on the outer edge of the Goldilocks zone, so it would be possible for water there to be liquid. In addition, the atmosphere produces a significant greenhouse effect, making it even more hospitable for life (more or less) as we know it. It is, however, 8 times the mass of Earth, so do you think any creatures living there would be Big and Strong? Or Short and Strong? I can’t decide, myself, and I assume it would depend - at least in part - on the biochemistry of the creatures.

If it exists, Gliese 581g sits in the middle of that same habitable zone. Some research says it does exist, other research says it doesn’t. This is only 20 light years away, so let’s go find out, shall we?

WASP-18b is 325 light years away. But since we don’t yet have light-speed travel, we aren’t likely to get there before it dies. Some scientists think it should have already died, before we ever got a glimpse of it. WASP-18b races around its sun in less than 24 hours, but its orbit is apparently degrading, so it’s getting closer and closer to its sun, and in 1 million years (or less?), it will plunge into that star.

WASP-12b is 870 light-years from us. I don’t think we’ll want to settle there, for it is rather warm - 4000°F or 2250°C. It sits only 2 million miles from its sun (Earth is 93 million miles from our sun), and takes just over 1 Earth day to make a complete orbit of that star. It’s also a gaseous planet, with 1.5 times the mass of Jupiter and about twice Jupiter’s size. Obviously, it’s less dense than Jupiter, right? So, even less chance that in all that gas there would be anyplace solid to build a new home. And can you imagine the air conditioning bill?


http://www.popularmechanics.com/space/deep-space/g1265/space-oddities-8-of-the-strangest-exoplanets/
http://www.express.co.uk/news/science/643662/The-10-weirdest-planets-to-have-been-discovered-so-far
www.space.com/159-strangest-alien-planets.html


Thursday, August 31, 2017

Weird Planets

A couple years ago, one of the panels I ‘moderated’ at mid-west sf conventions was about some of the definitely-odd exo-planets that had been found. Since astronomers are scientists and are never happy with what they know, they keep looking out into space. And they keep finding things, a certain percentage of which can be called ‘weird’. So I thought I’d take a fresh look at their current list of odd-balls. This could take more than one post, because I’ve found 3 different lists; one of 8 planets, one of 10 planets, and another of 20 planets.

Wait.

Yes, this is definitely going to take more than 1 posting, because I scrolled down the google page of search results, and found more lists. I decided I would not bother with other lists of 8 or 10, because they were probably just repeats or rewrites of one of the lists I already had. But I did decide to look at the list of 25 planets, because... well, I didn’t yet have a list that large.

That gives me - potentially - 63 planets to look at. Of course, I am hoping that there are some that are on more than 1 list, just to whittle that number down a bit. I mean, weird is weird, right? So each of the planets on the list of 8 should also be on the larger lists. Right?

Maybe. NASA’s list of 20 planets calls them ‘intriguing exoplanets’, and ‘intriguing’ does not necessarily equal ‘weird.’

Well, Jumping Jupiters. I spent so much time researching these planets that it’s time to post a blog, and all I’ve gotten written is this intro. Which is rather long for an intro to a blog post.

But, being an intro to a series of blog posts, maybe it isn’t too long. Okay, consider this the intro to the entire series of blog posts on ‘weird planets’. Next week, we’ll look at 1 - or maybe 2 - of the exoplanets that show up on the most lists that I’m working with. Exactly what will make them ‘weird’?

I can hardly wait!


http://www.popularmechanics.com/space/deep-space/g1265/space-oddities-8-of-the-strangest-exoplanets/
http://www.express.co.uk/news/science/643662/The-10-weirdest-planets-to-have-been-discovered-so-far
https://www.nasa.gov/feature/jpl/20-intriguing-exoplanets

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

Thursday, May 18, 2017

Planets Around Failed Stars

Stars can (but don’t necessarily) have a family of planets surrounding them. Planets can (but don’t necessarily) have moons surrounding them. What about the so-called ‘failed stars’? Do they have anything as a family?

Jupiter is sometimes called a failed star. If it had just a bit more mass, fusion could start, goes the argument. Well, not really. It would take 13 Jupiters combined to have enough mass to reach the minimum needed for a brown dwarf, AKA failed star. Also, Jupiter was created within the disk of dust that surrounded our infant sun, which is how planets are made, not stars. Not even failed stars. So we can’t take any clues from Jupiter about the possibility of planets around dwarf stars.

Okay, so exactly what is a failed star? A close apparent brown-dwarf-type object to Earth is SIMP0136. It lies 21 light-years away and is 13 times the mass of Jupiter. Theoretically, it could be a brown dwarf. Brown dwarves form like other stars, but fail to get big enough. They may have some fusion of deuterium for a relatively short time inside them, but it doesn’t last. Any light they produce tends to be in the red and infrared spectrums, so despite being called brown dwarves, they would probably appear magenta or possibly red-orange. And the older the brown dwarf is, the more it cools and contracts, until it can seem to be just another planet. Scientists have recently decided SIMP0136 is just a planet, after all. A rogue planet, big enough and close enough for them to study its weather patterns.

It could have gone the other way. The size of brown dwarves range from a minimum of 13 Jupiter masses to a maximum of 80 Jupiter masses. If it managed to gather more than 80X Jupiter’s mass, it would have made it to actual stardom.

Because brown dwarves are a type of star, at least some of them do have a family of planets, such as 2M1207b and MOA-2007-BLG-192Lb. This makes sense, because brown dwarves form the same way as other stars, just in the middle of a smaller dust cloud. Once the center of the cloud collapses into a proto-brown-dwarf, the remainder of the cloud thins into a rotating disk of dust, which would normally form planets. It is thought that this disk would not extend far, since the entire cloud was small to begin with, so any resulting planets would be fairly close to the brown dwarf. It is also believed that these planets would be rocky, like Earth and Mars, rather than gas giants like Jupiter, because most of the gas would be taken by the brown dwarf. So, let's look at some known brown dwarf systems:

170 light years from Earth, planet 2M1207b orbits a brown dwarf. Its mass is somewhere between 3X and 10X that of Jupiter, and it orbits its primary at approximately the same distance as Pluto from our sun. Although there is some indication of water, it is not likely to be habitable.

Occasionally shortened to MOA-192 b, MOA-2007-BLG-192Lb is about 3,000 light-years away. This small planet is 3.3X Earth’s mass, and circles a small brown dwarf in an orbit approximately 2/3 the size of Earth’s orbit around the sun. It is believed to have lots of ice and gases, more like Neptune than Earth.

And then there’s the quadruplets: a small brown dwarf (2MASS J04414489+2301513, with a mass 20X that of Jupiter) has a companion (5X to 10X the mass of Jupiter) that could be either a planet or a sub-brown dwarf. There are also two other brown dwarves in close association. All four objects together only have 26% the mass of our sun, making it the quad system with the least mass. It is 470 light years away.

So yes, it is entirely possible - almost probable - that ‘failed stars’ will have planets. Or possibly siblings, as in the quad system.


http://www.iflscience.com/space/one-of-earths-closest-failed-stars-may-actually-be-a-rogue-planet/
http://now.space/posts/gas-giant-planets-small-failed-stars-is-there-a-difference/
https://en.wikipedia.org/wiki/Brown_dwarf
https://en.wikipedia.org/wiki/2M1207b
https://en.wikipedia.org/wiki/MOA-2007-BLG-192Lb
https://en.wikipedia.org/wiki/2MASS_J04414489%2B2301513

Sunday, March 2, 2014

A 500 Year Summer

My husband has been re-watching Game of Thrones. As I've said before, I don't like political intrigue, nor a cast of thousands, so this is not my cup of tea. But the characters mention they are ending a summer of 500 years, and the winter will soon be on them. That comment has me intrigued.
What kind of solar system would they be in that a season could last for hundreds of years?
I read a book many years ago - I don't remember the title or the author, sorry - where the planet's orbit was a lop-sided elliptical around its sun. When winter came, everything hibernated, even the people. The length of their year did not equal one of ours, but a year - one revolution around their sun - did involve seasons. So that wasn't the answer.
I then thought about the planet NASA has discovered that has 4 suns. That in itself is mind-boggling. The planet revolves around one star, which is in a mutual revolution with a second star, and that pair of stars is in a mutual revolution with another pair of stars.
I don't have enough math and physics to do any computations, so I just have to use some logic to try and get a feel for it. The first pair of stars have to be far enough away from each other that they don't tear each other apart, and also so they don't burn the planet to a crisp when it passes between them. But when that planet is between them, it would be extra warm. As the stars go around each other, that extra warmth would move around their calendar, until the 'extra warmth' was actually during their winter. It might not seem like they were having any winter.
How long would it take for this 'extra warmth' to move around the planet, from producing warm autumns through not-really winters and into warm springs? I don't know. It would depend on how long it takes for those 2 stars to revolve around each other. A thousand years might be too fast.
That might help explain a REALLY LONG summer, but it doesn't explain an equally long winter. When both stars were on the same side of the planet, they would have hot summers and cold winters. Bummer. I thought I might be on to something.

Do we have any physicists in the audience who would like to weigh in on this?

Sunday, July 7, 2013

Billions of Possibilities


I ran across a headline a few days ago that stated that scientists now estimate that there may be billions of planets in the galaxy capable of supporting life. What took them so long to arrive at that conclusion?

The Science Fiction writers I grew up reading - Asimov, Clark, Bradbury, Biggles, Haldeman, to name a few - assumed there were plenty of planets that could support life, and that many of them had intelligent occupants. It seemed pretty logical to me.

This is the way I thought about it: solar systems like ours were created by the laws of physics. A star is born surrounded by swirling dust, the dust clumps together to form planets circling that star. Since that's how it happens, why wouldn't it happen around other stars as well? It happens because of physics, so it would.

So, plenty of planets out there.

Capable of supporting life? Some of those planets were certain to be in the 'Goldilocks Zone', where water could exist as liquid and not only as ice. And it didn't make any sense to me that out of all of those planets in the various Goldilocks Zones, ours was the only one that had an atmosphere, the only one that wasn't a gas giant or a small lump of rock. The math - in my mind - just didn't support the idea that out of all the solar systems in this galaxy, there was only one planet that could support life.

Supports an intelligent life? Why not? Whatever circumstances happen to create life, there are billions of possibilities for those circumstances to be replicated on other planets. And it actually only happens once? Again, the math doesn't support that outcome. And if we accept that has happened, then it only seems logical that some of that life would develop intelligence. Because, after all, even on Earth, man is not the only animal that has intelligence.

Perhaps, as scientists, they needed proof of the existence of all those other planets. This also seems strange to me. Why wouldn't they have followed the physics and math to the hypothesis that were many other planets out there that might be interesting? Instead, it seems to me that they went with the theory that we were the only planet with intelligent species, and now they are working to disprove that theory.

I think that's backwards.

Sunday, June 2, 2013

NASA News 2


NASA News 2

 

Now to get back to that informational talk NASA personnel gave at the Orlando Science Center. I believe the next subject was the Kepler telescope.

The purpose of the Kepler telescope is to examine one tiny section of this galaxy looking for planets. That's all. And it does a wonderful job of it, including some planets that are more or less earth-like AND in that star's Goldilocks Zone. Personally, I was surprised to learn that the Kepler telescope does not orbit Earth, but is actually located quite a distance from us. I was dismayed to hear that a short time ago, the second of its 4 stabilizers went out. It had been working 'okay' with only 3, but with 2, it is now rotating, unable to keep track of the section of the galaxy it's supposed to examine. Since it is so far away, chances are it will not be repaired. And that is a bummer.

Then we turned to Mars. I don't remember a specific number being mentioned, but there have been a lot of attempts to land a probe on Mars, by many different countries. The US is the only one who has managed to have any of their Martian probes still function after landing.

Apparently, Mars is very difficult to land on. It has enough gravity to pull things down really fast, but not enough air for wings or parachutes to do much good. If I remember correctly, the density of Martian air at the surface is only 17% of Earth's atmosphere density at sea level. It's why we've gotten so creative with our landing methods, from bouncey balls to floating cranes.

Discovery is our most recent probe sent to Mars, and it's about the size of a van. Can you imagine tooling around Mars in an intelligent van? It has to have some ability to make its own decisions, because calling for help, waiting for humans to figure out the answer and send it back takes too long.

Intelligent robots. The future is here. And we sent it to Mars.

Sunday, May 5, 2013

The Outer Goldilocks Planet



Last week I took a more detailed look at Kepler-62-e, one of two Goldilocks planets discovered recently. Today I'll give a few thoughts to its sibling, Kepler-62-f, which is a little further from their star.
The article said 62-f might have a climate rather like Alaska. Again, I'm going to assume that means the temperate zone. And Alaska stretches from 51 to 71° North. The middle, then, is 61°, and if we move that down to 45° (the midpoint between the equator and north pole), we are moving 16°.
If you remember from last week, Barrow AK sits at 71° North, so moving its climate 16° south would put it at 55°. This would mean the Alaskan panhandle, northern Ireland and the middle of Scotland/England would have 8 months of temperatures below freezing, and its warmest month would have an average temperature of 47. Brrr!
The climate at the equator of this outer planet could be approximately what Earth has at 16° north or south. Brasilia, Brazil, is at 15 3/4° south, so I looked at its climate. The average temperature is about 69°F. The record low has been 32°F, and the record high has been 99°F.
So that sounds intriguing, doesn't it? Nicely temperate around the middle. I'm thinking, though, that it could be pretty snow/ice bound around the poles, and extending about 1/3 of the way to the equator.
The article did not offer any guesses about the ratio of water surface to land surface, and that ratio could definitely influence the climate. We could imagine whatever ratio we would like. If it's a pretty dry planet, there wouldn't be enough water to moderate the temperatures, so the cold temperatures might migrate even closer to the equator. On the other hand, with so little water available, the 'polar caps' might be only designated by temperature, or perhaps a dusting of snow, rather than the vast ice fields that Earth has.
It's a nearly-blank slate, then. We have a little sense of what the climate might be like, the rest of the details are left for us to imagine. I can work with that.