Trudy Myers's Blog, page 15

Why Jupiter Has No Rings

The title is false, Jupiter does have rings, but they are so thin, they are very hard to see, even in the best of conditions.

But why does Jupiter not have big, beautiful rings like Saturn? A recent article I read said Jupiter's moons are to blame. If it didn't have all those giant moons, it would have rings much bigger and more spectacular than Saturn's.

A new study says that giant moons destroy rings before they have a chance to form. And the Galilean moons of Jupiter, one of which is the largest moon in the solar system, seem to be good at it. Therefore, it is unlikely Jupiter ever had large rings at any point.

Massive planets form massive moons, which prevent them from having substantial rings.

Well, I thought the article had more to it than that, but that seems to be the sum total of it.

In a 'related' video, which I didn't watch for lack of time, the headline said Jupiter may have 'eaten' some sibling planets while it was growing. That sound interesting, so I'll keep my eyes open for more on that, but I suspect it will be as thin as Jupiter's rings.

 

https://www.msn.com/en-us/news/techno...

Wandering Jupiter

A few weeks ago, I explored the possibilities of what might happen if Neptune's orbit should get jiggled by a rogue sun wandering too close to our system. More recently, I read an article that explains that Jupiter has already done some wandering, in order to be in the orbit it's in.

Jupiter's current orbit averages 5.2 astronomical units (AU = the average distance between the sun and Earth). But researchers now say the gas giant started to form some 18 AU away, which is about twice as far out as present-day Saturn. Furthermore, Jupiter made that journey in about 700,000 years, which is the blink of an eye in astronomical terms.

The idea of a wandering Jupiter is not new; I've heard several theories about it. But this time there is some proof that Jupiter formed a long way from the sun and then migrated inward, and that proof came from the Trojan asteroids that share Jupiter's orbit.

Jupiter has 2 groups of Trojan asteroids that share its orbit around the sun. A large group is in front of the planet, and a smaller group follow it. Researchers ran numerous computer simulations that showed the early solar system through millions of years of evolution by 50-day increments.

The simulations showed that the inward migration of the giant planet always resulted in a larger swarm of Trojans in front of Jupiter than behind it. As Jupiter traveled inwards—propelled by gravitational interactions between the fledgling gas giant and the sun's protoplanetary disk—it created a wide zone of gravitational stability in front of it, leading to more asteroids being caught before it than behind it.

Other simulations that relied on Jupiter forming in its current position resulted in both groups of asteroids being the same size.

One more step to this becoming the solar system we know today.

I can't help but wonder what was happening to Venus, Earth and Mars during the 700,000 years that Jupiter came rolling so much closer.

 

"Trojan asteroids reveal Jupiter's great migration", Astronomy, July 2019

The Fun Never Stops

 

Let's take another look at that old adage about bad things happening in 3s. This time, it seems to be true. First, I had to take my car in to get its power steering looked at. I grew up with hydraulic power steering, but I couldn't find the power steering fluid reservoir, so I had to take it to the shop. I also asked about new tires, because I knew those were coming up on being bald.

In order to fix the power steering, they needed to get me a replacement steering column. Or for about half the price, a 'gently used' one. I opted for the used one. Plus, when they were looking underneath at my tires, they noticed all sorts of problems with the tire rods, and whatever else they found. My eyes kind of glazed over when they started listed all the things that needed attention. So, 10 days later, I finally got my car back, along with a whopping bill to go with it.

That was item #1.

Next, my 15-year-old computer turned itself off in the middle of a rainstorm. Now, when a computer is that old and is put through its paces nearly every day, you start expecting problems. For the life of me, I could not get the computer to turn back on and stay on. It wouldn't even get to the point where it wanted to know my password. That was on a Sunday, so the next day, I got up and disconnected the CPU from everything and ran it to Geek Squad, since it was under contract. Their 'make an appt now!' app gave me half an hour to get there, but their store is a pretty solid hour's drive away, so I was late.

Wouldn't you know it, they plugged it in, attached a monitor, keyboard and mouse, and the CPU behaved beautifully! Slow as molasses getting started, but that was normal. Just to be sure, I left it with them to do a diagnostic, and when I got home, I dug out a MacBook we only use when we're traveling. It works okay for checking email and composing rough draft, but is lousy at formatting or looking at Word docs you've already created.

But it would surf the net, so I kind of got through the 4 days my old computer was in the shop. When I finally got to pick it up, they had diagnosed it, updated it, and couldn't find any malware on it, so the bill was $0. I was so happy!

Still, I'm counting 'computer in the shop' as bad thing #2, because I got very little work done that week.

And it turns out that I went to the grocery store the day I was going to pick up my computer, and when I got home, I accidentally left my cell phone in the car. It was hot that day, and the windows were up, so when I climbed in in late afternoon to get my computer, I found my fone had been fried. Well, half fried. It still counts the steps I take (yea!), and it will still send and receive texts. But it won't send or receive phone calls. Won't even try.

I've done some preliminary research to find a replacement, and finding something that doesn't cost an arm and a leg and have all sorts of bells and whistles that I will never figure out how to use is not easy. I'm used to an android, and even those are getting pricey. I even looked at jitterbug and alcatel flip fones. I like the idea of a flip fone that won't spend its time taking pictures of the inside of my pocket. But the downsides of the alcatel add up to quite a bit; the screen size is 2.8 inches, so I'd have to carry a magnifying glass to try to read it. It's not water resistant. And the battery life is 6.5 hours. Okay, I guess I'm back to look at androids.

Actually, I'm not looking at the time. I've decided not to get a new one until after our vacation, about mid-August. I asked one of my sons to look at my carrier's website and see if he could find something I could live with. But this item is probably going to cost me. Not to mention all the left-over minutes I have that won't transfer to a new fone.

So, a semi-fried fone is Item #3.

That's it. That's 3 bad things. I'm done now. Everything is going to be smooth sailing and peachy fine for a while.

Won't it?

So Close!

I made a promise that my new website would be up and running today. So, what am I doing today? Trying to figure out how to use my domain name - which I bought via Godaddy - to work with my hosting company. They thought I had bought a hosting package from Godaddy, and when I said I didn't, that I only bought the domain name via them, and asked what did I need to do to get this domain to work for them? Crickets. Less than crickets.

Don't get me wrong, I am pleased with the support I've gotten from these people as I tried (for 3 months) to get my new website set up. I've occasionally had to ask them to dumb their explanation down, as I'm not the most computer-literate person in the world. Any one of my sons can attest to this, as I still call them up (long-distance) to ask computer questions.

It's possible that they are working on this. Or, depending where they are located, it may be past quitting time for them, in which case, I won't hear from them until Monday.

So... I suppose I should move on to other things, having done all I can do. I still need to work on my Mailchimp account. And go to the store and drug store to pick up groceries and prescriptions. Heck, there's some leatherwork I need to finish lacing, and make-up applications to practice. There's lots of stuff for me to do. (There always is.) I just need to make up my mind to move on.

I did the best I could. I guess it probably won't be live until Monday. Let's hope, okay?

Wandering Neptune?

I was perusing headlines the other day when I noticed one about Neptune. Normally, a headline about one of our planets grabs my attention and I read the article, but I was pressed for time that day, and decided to skip the article. Now I wish I'd read it.

The headline stated that all it would take to unravel our solar system was a star passing by and perturbing the orbit of Neptune. I have so-o-o many questions now about this possibly impending doom.

How big a star would it need to be? How big is the average rogue star? How close would the star have to get? How would that star appear to us here on Earth? Would we be able to feel any gravity or heat or radiation from that star? How much would it need to disrupt Neptune's orbit? What exactly would happen to the rest of the planets, once Neptune started to wander? How long would Earth have before it ultimately became uninhabitable?

So many questions, and no answers, because I didn't read the article. So I just now looked the article up, and read it.

Apparently, all it would take would be for the average distance between Neptune and the sun to be altered by 0.1%. Such a tiny change would increase the chance of the solar system descending into chaos 10 times higher. This 0.1% perturbation would be about 4.5 million kilometers (2.8 million miles). It would result in subtle changes to the orbits of the inner planets, reaching the Earth and Mars in about 20 million years. (Whew! I was afraid I might need to worry about it happening within my lifetime, or what's left of it.)

The team conducting the study ran 2,880 simulations with varying amounts of perturbations. 960 simulations had perturbations too small to be measured. In 4 of those, the resulting perturbation to Mercury's orbit resulted in it hitting Venus. In the remaining models, there were 26 that end in chaos; collisions between Mercury and Venus, Earth and Mars colliding, and some where Uranus, Neptune or Mercury were thrown out of the system.

They also estimated the chance of a star getting close enough to cause any of that, and concluded there were only about 20 chances over the next 100 billion years. So it doesn't seem very likely, given that our sun is only expected to last another 5 billion years.

 

https://www.iflscience.com/small-chan...

Death Throes

We've all heard that you can't take it with you. Well, scientists have discovered a dying star that is trying very hard to take its entire planetary system with it.

G238-44, a white dwarf located some 86 light-years away, seems determined it is not going alone. It's already made one attempt to end its system. You see, a white dwarf is what results when a star that is up to 8 times the mass of our sun reaches the end of its life. Once that star runs out of material to fuse, it puffs up to red giant size before ejecting its outer material. Then the core collapses to form a dense object that shines bright with the light of residual heat.

This process can put the inner planets right in the middle of that red giant until the outer shell is ejected and the core collapses. Scientists have discovered some planets that appear to have survived being gobbled up by a red giant phase, but not many, and they certainly don't appear to have any atmosphere or water left on them. When our sun hits that stage in a few billion years, the red giant produced could reach as far as Mars.

But we were talking about G238-44, which has reached the white dwarf stage, so it is currently much more dense than it used to be. Scientists studying it have been examining G238-44's atmosphere, and have found a plethora of 'heavy' elements, such as carbon, nitrogen, oxygen, magnesium, aluminum, silicon, phosphorus, sulfur, calcium, and iron. Most of these would have come from rocky worlds and inner system asteroids that probably 'survived' the red giant phase. The denser star is pulling them in and eating them.

But the nitrogen—and there seemed to be a lot of it—probably came from frozen worlds and asteroids such as exist in our Kuiper Belt. Apparently, the shift in gravity has perturbed their orbits, and the star is pulling them in and eating them also.

I wonder what the system will look like when all the planets and asteroids have been eaten, and the star cools into a massive hunk of... what? A huge rocky planet? A frozen gas giant with a big rocky core? What do you think it will be?

 

https://www.msn.com/en-us/news/techno... 

Hungry, Hungry Jupiter

Back when I was growing up, there was some debate whether Jupiter consisted only of gases, or if it had something more or less solid in the middle of it. At the time, scientists just didn't know. They had no way of seeing past the swirling vortexes of clouds that Jupiter presented to the universe.

Flash through the last few decades, and they finally came up with a way to 'see' past those clouds. NASA's Juno space probe gathered gravitational data about the planet in a variety of locations, and that data, combined with data by Galileo probe, indicates that yes, there is some solidity down in those depths.

The theory of Jupiter's creation is that it gathered vast amounts of gas and dust from what was left after the sun's creation, mainly hydrogen and helium. The more it gathered, the bigger it got, the more gravity it had, and thus the more it gathered.

This new data indicates there is a rich array of heavy elements in the rocky core of the system's biggest planet. Which suggests that Jupiter also gobbled up plenty of planetesimals (or baby planets) while it was gathering materials.

Planetesimals are space rocks spanning several miles, so larger than most of the asteroids. If they had been left alone, they might have grown up into planets. But alas, their fate was to be eaten and become just another piece of a huge planet. Just a bit like bits of gravel eaten by birds to help their digestion.

I hope those 'stones' at least gave Jupiter indigestion for a while.

But at least we now know that Jupiter has a rocky core.

 

https://www.msn.com/en-us/news/techno... 

What Size Is It?

Astronomers have been finding more and more planets outside our home system lately. I find that extremely exciting. But when I'm reading about these discoveries, I'm sometimes left wondering, just how big is this newly-discovered planet?

First, let's understand that because of the distances involved, and the methods currently in place for discovering planets, it takes a big planet to be noticed. I don't find that disappointing, because within our own system, we have 4 big planets (Jupiter, Saturn, Neptune and Uranus), an equal number of smaller planets, and a scattering of dwarf planets. So just because they haven't found lots of Mars- or Venus-sized planets circling other stars, doesn't mean they aren't there.

So, they are finding big planets, but they've developed a short of short-hand lingo to indicate a few tidbits of information just in what they call a new discovery. I recently read an article in Astronomy magazine that briefly explained what this lingo meant.

A Super-Earth sounds exciting, doesn't it? A planet like Earth! Well, up to a point. They are rocky planets like Earth, but remember that they are mostly finding big planets. A Super-Earth can range in size up to 10 times the Earth's mass. That means a lot of gravity, and I don't think we'd be colonizing that size a planet. But they are a rocky planet! Our system is not the only place where rocky planets exist. In fact, these may be the most common type of planet in our galaxy.

Then there are Mini-Neptunes. These ice giants range in size from 14.5 to 17 times the mass of Earth. (Neptune weighs in at 17 times Earth's mass.) These are also pretty common around other stars.

Which brings us to the 'Jupiter' class of planet, which come in 2 types.

A Hot Jupiter is a gas giant that orbits their star in under 10 days. (I can't name them, but I've heard of some that circle their star in a matter of hours.) A Hot Jupiter usually orbits at around 1/10 the distance between the Earth and the sun, or less. These are not common around stars like ours, occurring in only about 1% of systems having a star similar to ours.

A Cold Jupiter is a gas giant that—like our own Jupiter—lies beyond the ice line, where it's too cold for water to remain a liquid. There was no comment given about how common these might be. I assume Saturn is also a Cold Jupiter.

And then there are Brown Dwarfs, which is a type of star, not a planet. But they don't last long as a star, and then they cool off and they're just a big mass. It's not clear where the dividing line is between massive planets and dead brown dwarfs, but it seems to be somewhere around 10 times the mass of Jupiter.

Got that? Good. The next time you read about a newly-discovered planet, you can figure out a little something about it just by what they call it.

Getting Things Right

Have you ever had a project that you had to try several times to get it to come out correctly? It could be something you've done before, but in any case, you know the steps that have to be done, and you've done them, so why won't it come out right this time?

That's been me, this past month and more, trying to get 5 books correctly formatted as ebooks. Okay, yes, there were parts of that time when I couldn't work on them; the time we were on a cruise, the 2 weeks we were fighting covid, and a weekend spent in Kansas City. But when I could work on them, it felt like I was repeatedly slamming my head against a brick wall.

I studied the instructions each time before I started the process. I would work at the procedure for 2 hours and then take a break, because it was mind-numbing, repetitive work. 5 times I formatted these books and fed them through the converting software, only to open up the converted epub file and find mistakes.

Different mistakes each time. Where were they coming from? How could I be flubbing up that badly each time, in a different way from the time before? There was the time when most of the paragraphs were indented from the left margin by an inch. How could I have made such a stupid mistake and not notice it at the time? Another time, some paragraphs were in 12-pt font, but others were in 10-pt. And then there was the time when all the paragraphs were justified except one, and it was centered. And always, always, the 2 pictures that I had added to these books would float away during conversion and wind up as much as 3 pages from where they were supposed to be, making it impossible to read 2 or 3 paragraphs of the story!

Last week, I carefully went through each epub file and noted the problems. I actually wrote them down so I could remind myself what they were. I looked for answers in the instructions. I wrote the Help people with a couple questions. I considered hiring a professional to get it done right. But there were 5 books, and that would have involved a bit of money.

Last Saturday, I swept all my chores aside and devoted the day to formatting. I had stumbled across a way to 'anchor' the pictures to a particular location, and I was going to give it One Last Try, myself. I drank lots of caffeine that day, and when I took a break, I made sure I got some exercise as well as a change of scenery. I only got 4 of them done on Saturday, but I got the 5th one done on Sunday. Then I took the rest of Sunday off and forgot the whole project for a few hours.

Since then, I have fed them through the conversion software. I've checked the pdf files, and they look great. I'll be checking the epub files later today and tomorrow. Wish me luck!

Of Mice and Bananas

I just read an interesting article about mice. And bananas.

And no, it wasn't that bananas is a favorite food of mice.

It turns out that bananas stress mice out, particularly male mice. Stressed out as in they are ready to fight or run away.

Bananas can't even move on their own, or why would they be seen as a threat by male mice?

It all comes down to pheromones. Pregnant and lactating female mice produce a pheromone that tells stranger males to go away. It is their first line of defense to keep their pups safe, since stranger males are likely to try to kill pups. By producing this pheromone, the females are warning the males away, introducing the idea that a fight is imminent if they don't leave.

The pheromone in question is n-pentyl acetate, which occurs in the urine of late-term and lactating female mice.

So, where does the banana come in? Well, n-pentyle acetate is very similar to a compound found in many kinds of fruit, but that very similar compound is also used to produce banana extract. And sure enough, when the scientists brought in some banana extract bought from the local grocery store, and put some in the cage with male mice, they got some very stressed-out mice.

I'm glad n-pentyle acetate doesn't work that way on humans.