Giants of Gas and Ice

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GIANTS OF GAS AND ICE

We pass by, as if we fly, or if you wish to sail the sky, within your craft a sailboat be, atop the solar sea beside. Remember Apollo 8 and the first picture of “Earth-Rise” beyond the moon. You are farther away now. In the realm of giants!

They are planets, too. And they are big! But it’s not them you want. It is their moons! But first you must navigate through the asteroid belt to reach them. Hundreds of miles of space, just beyond Mars, and thick with shooting stars and meteorites. Come on. You can do it! But be careful. Remember the fate of the dinosaurs.

THE GAS GIANTS

Jupiter is so big, so bright, and so obvious. It seems to float across our night sky. A thousand times bigger than Earth, all of the bodies in the solar system could comfortably fit inside its circumference. But it is a gnarly, gaseous ball. Powerful winds, and lightning with ten times the power of that found on Earth. And the giant, swirling red spot? It is three times the size of Earth. What’s up with that?

The pressure of the planet’s mass of gas is so great that methane is crushed into diamonds and hydrogen becomes molten, metallic, and electric. That is why Jupiter has the most powerful magnetic field of any planet!

And that field is full of plasma torn away from its closest moon, Io, which is constantly fuming in volcanic eruption, drawn out by the sweeping gravitational tides of Jupiter and its other moons. We have seen plumes of yellow, green, and red shades of sulfur thrust out 300 miles into space from Io!

The four largest moons of Jupiter are known as the Galilean Moons. Io, Europa, Ganymede, and Callisto. They are what got Galileo in trouble with the Church. You know, the heresy that planets revolve around the sun and not Earth. Galileo saw the moons first on one side, and then the other side of Jupiter. You can see them yourself tonight in a powerful set of binoculars!

The Church issued an apology in 1992. A little late for Galileo, who died under house arrest in 1642. Although it took 350 years to do it, the Church, like science, can be self- correcting.

And of the Galilean moons, maybe life can be found under the smooth water-ice surface of Europa. You should go look! If you could fly there on a commercial jet, it would take you just 100 years!

Saturn would float on water, so light is this giant ball of gas. But its seven rings are what excite our view. Look at them through an inexpensive telescope. The planet varies its tilt for our visual enjoyment. If its rings were highways, you could drive around one in 258 days! In fact, all of the gas giants have some sort of ring system.

Saturn has many moons. The one that excites us the most is Titan. It is the largest⎯bigger than Mercury⎯and has a dense atmosphere of nitrogen and methane. On its surface are flowing rivers and seas of natural gas, cooled to a temperature of minus 300 degrees. Winds there contain tempting indications of organic material in the surface soil. Alien, for sure, but surely interesting!

THE ICE GIANTS

Something big must have hit Uranus. Instead of rotating on an axis perpendicular to the plane of the solar system, it lies on its side. This was the planet unknown to the ancients. It was discovered by William Herschel with his famous telescope in 1781. And don’t forget his sister, Caroline. Together, they were quite a team.

Neptune is the farthest planet away. That body has a thick atmosphere of hydrogen and helium, with evidence of hydrocarbons, ammonia, and methane. It is methane that gives it a blue color. Its core is composed of various ices and rock. And it is so far away that it takes light four hours to reach us. And that is traveling at 186,000 miles per second! You do the math. The distance will expand your imagination.

Neptune’s largest moon is Triton⎯not Titan, that’s Saturn. Triton is solid, but its core is geologically active. That must mean radioactive decay and internal heat. Maybe there is a buried ocean that is liquid and harbors primitive life forms. Is that why some of the volcanic ejecta contain what may be a black mixture of organic compounds? But Triton’s surface is exceptionally cold, a frozen nitrogen crust at minus 391 degrees Fahrenheit. That is pretty close to absolute zero⎯minus 460 degrees Fahrenheit!

I know that Pluto is still farther out, but so is a lot of other stuff out there. Eris, Haumea, Makemake, Ceres. They are all bodies in the Kuiper Belt or beyond. And many of them are comets! Why, even farther out in interstellar space is the Oort Cloud of icy planetesimals. So we will stop at Neptune for this essay.

So, if you want to get out of here⎯up there, that is⎯maybe there is a Mars, or Titan, or Triton that you might eventually explore. But I think I will stay here and work to take better care of this place. It has been my job for more than 40 years now.

 

The Rocky Planets

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THE ROCKY PLANETS

Why do you want to get off this one?

There are no gods to visit on those spinning orbs, and they are not very nice places on which to live. Let’s take a quick look in our scientific shuttle.

THE SUN

Nope. Don’t want to go there. Nuclear explosions. Fusion. The conversion of hydrogen gas to helium. You know. Energy equals the quantity of mass multiplied by the speed of light squared. The loss in mass equal to the weight of one million elephants every second.

If you heated the head of a pin to the temperature of the center of the sun, it would instantly vaporize everything within 60 miles. And loops of energy extending off the sun’s surface have the power of millions of volcanoes. Yikes!

Sun God? Phooey! But if the sun were mysteriously extinguished, you wouldn’t know it for eight minutes. That’s how far away it is. And those would be the last eight minutes of your life. Without it, we are lost. Sun God? Maybe!

A MNEMONIC

I wonder if they still teach it in school. I do. Here goes, in order of planetary position: My Very Educated Mother Just Served Us Nine Pizzas.

Yes, I still consider Pizza a planet!

 

MERCURY

 

An iron ball with a thin crust and gravity one-third of that on Earth. Stand on the surface at midday and you will melt. It’s 800 degrees Fahrenheit! But at nighttime, the shadows will bring on the deep freeze. Minus 290 degrees Fahrenheit! No atmosphere. No wind or rain. No home for us!

VENUS

Now this planet is different. The very word Venusian conjures up all kinds of romantic images. And in alternate months, it puts us to bed and wakes us up as the evening and morning star. Mysteriously cloaked too, to keep away prying eyes. Edgar Rice Burroughs went there three times in the 1930s, and Flash Gordon in 1955. Let’s go there now!

Ah, no, I don’t think so. Those clouds are made of sulfuric acid. Burning rain drops. Yikes! Isn’t that like what Anne McCaffrey writes about on her planet, Pern?

And the air you breathe in is choking you with carbon dioxide. Ninety-six percent CO2! Doesn’t that cause a greenhouse effect? Yup, big time.

That is why it is 900 degrees Fahrenheit on that planet. Hotter than Mercury! Canyons of molten rock, and volcanoes spewing forth boiling phloem and belching out gas. You will suffocate, assuming you are not crushed by the atmosphere with a pressure ninety times that on Earth at sea level. Assuming that there is enough of you left after the sulfuric acid burns you. And get this. There is little water in the sky, but when it gets there, it explodes on contact with the sulfuric acid. Yikes!

MARS

Ah, now that’s a planet. Burroughs sent John Carter there in 1912. His books were Ronald Reagan’s favorites as a summer lifeguard in his youth.

Mars was named after the mythological God of War. Why war? Because it appears red. Like the color of blood? That’s the color of iron oxide in the soil of Mars. Rust to you. And what of its two moons, Phobos and Deimos? Fear and terror in Greek mythology!

There’s not much atmosphere on Mars. But there was once. And there is still enough to generate a wind. Dust devils. Pictures have been taken of them by our landers. Robotic extensions of our laboratories and sense. And those machines are almost like humans. Well, not that much like us, I suppose, but I still think of them as friends. The United States has sent four Rovers to Mars: Sojourner (1997), Spirit (2004-2010), Opportunity (2004-2018), and Curiosity (2012 and still rolling). They are wonderful machines. I build models of them!

There is no magnetic field on Mars to hold its atmosphere or deflect the high-energy radiation from the sun. You would be assaulted there by blistering solar blasts, burning you as you stood on the surface. No magnetic shield to sweep that radiation aside and into polar auroras. Earth does that trick very nicely.

And there is no oxygen-derived ozone barrier on Mars to bar further harmful solar and cosmic radiation from penetrating to the surface. Like we have on Earth.

But it wasn’t always so on Earth. Free oxygen is new here. And so is ozone. Life began generating free oxygen on Earth about 2.5 billion years ago. That’s right. Earth wasn’t ready for us. Life had to “terraform” Earth to its liking. Just like we will have to do on Mars if we move there. And there is water hidden there. Maybe then we can soar through the Valles Marineris⎯the biggest canyon in the solar system. Or climb Mons Olympus⎯the tallest mountain amongst our rocky planets!

 

EARTH

Ah, home. I like it here. An earthly paradise, I think. Blue oceans with earth-colored continents. And sweeping slips of white clouds adding a curtained proscenium to our stage in life!

 

The Family Human-part 3


THE FAMILY HUMAN – part 3

Neanderthal People

The excitement began when bones were first discovered in the Neander Valley in Germany in 1856. It was Homo neanderthalensis, a cousin that evolved in Eurasia about 450,000 years ago.
Neanderthal People had been widespread in Europe and Asia, and living strong and long before our species arose in the cradle of humankind in East Africa about 200,000 years ago. Only later did we begin to migrate out, first into the regions of the Middle East. Perhaps to those oasis along ancient rivers bordering the Levant and the mountains of Iran. Lands where we encountered the Neanderthal People.
Savage brutes, you say? Well, think on this. If you are of European descent, 1%-4% of your genetic structure is probably from Neanderthal People. And how do you think that happened?
So what did these Neanderthal people look like? A little or a lot like you. But probably with a larger brain.
What kind of tools did they make? “Mousterian” tools, we call them. Fine- edged flakes, points and scraper. And now attached to wooden spears or bone handles as knives. Beautiful tools. And weapons.
Did they draw, make art? Look at the cave paintings in Spain dated to 65,000 years ago. We, Homo sapiens, did not arrive there until 20,000 years later.
Did they bury their dead? At least some did. And not just to dispose of a corpse. Were they spiritual? These are questions that I leave for your own research. That’s how confident I am that I have caught some of your interest.


Denisovans

Until 2010, they didn’t exist. At least not in our minds. So arrogant is our hubris in the possession of limited knowledge. It was in that year that a single finger bone from a young girl was found in the Denisova Cave in the Altai Mountains of Russia. Scientists, by then, had developed skills at sequencing all of the genes in a cell’s mitochondria⎯energy generating organelles inherited only from your mother. And when that was done for the still viable mitochondria found in that bone, a stunning discovery was made. That girl was from an entirely new species of humans! Homo denisova.
Yikes! What is going on here? Oh, we have found a few teeth, too. That was enough to sequence more of her genome. And now we find that as much as 6% of the genes of Melanesians, Australian Aborigines, and Papua New Guineans may be of her Denisovan stock.
From a few teeth and a finger bone? You’re kidding! No. The science is good. Your genome is your history, and that of those who went before you. And the structure of its basic code is not complicated. I teach it in my class and build models of its scaffold. Your genes bear a mystery that is not hidden. And, like the Mayan glyphs, we can read them. Glory to be. That is exciting! God’s handwriting, if you will.

Homo Sapiens

We appeared in Africa by 200,000 years ago. We were surely smarter than Homo erectus. Made better tools. But were we smarter than the Neanderthal People? They had bigger brains, stockier frames, and were stronger. One-on-one, we mostly lose. But something happened about 70,000 years ago. Happened in the brain of one of our forebears. Maybe that is the time that God touched our species. No one knows for sure.
But our larynx had settled further down in our throats. We know from the brain impression in old skulls that Broca’s area, the region of our brain controlling speech in our frontal lobe, was well developed. We were primed. Then something happened. Not just speech sounds now. Group action. Gossip. And out of Africa, we surged.
150,000 years ago, we shared the planet with at least four other species of humans. Homo erectus, Homo neanderthalensis, Homo denisova, and Homo floresiensis. More maybe? There might have been one million humans represented by multiple species alive then. But by 30,000 years ago, there was just one. Us. You. Homo sapiens. I wonder why.
Gossip! You’re kidding. No, I am not. It is our ability to talk about things not before us, people that we know, that enable us to form larger groups of people that we trust. Groups who can work together. Groups with people that you can talk about behind their backs!

By 16,000 years ago, we invaded the American Continent to face the last remnant of Pleistocene megafauna that evolved there. It appears that, with the help of climate change, we did them in too. Sobering. Are there lessons here?