Influential Prose

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Posts Tagged ‘science

Fire in the Sky


From a letter to a friend shortly after 9/11

Date: Sun, 11 Nov 2001 10:03:47 -0500
To: Dave
From: DeafScribe
Subject: Fire in the Sky

That was 3 hours well spent.

I just returned from the beach. Got the bike out at 3:30, mounted the night light, added a bit of air to the front tire, and set off for the shore. It’s a straightforward trip – one block over to 16th St., then follow that for about 3 miles to the ocean. There’s just one hurdle – the Indian River and the bridge that vaults over it.

As much as I love my Schwinn 10-speed, it has one glaring flaw – the gearshift is old and totally unreliable. Despite the occasional adjustment, it inevitably slips back into a state where shifting gears will lock it up, jam the chain between the chainrings, and force a miserable roadside battle with an stuck chain and grease-coated hands. To avoid this fight, I leave the bike in 10th gear, which is great for keeping my legs strong, but not so fun for honking up a big bridge.

Still, it could be worse. I’m not smoking anymore, so I was able to reach the bridge top without gasping too badly. Sixteenth Street is lined with bright lights nearly the whole way, but even peering through them, I could see the meteors streaking down from the east. Beyond the lights, the conditions could not be better. The sky was crystal clear, the stars were blazing and the night was comfortably cool.

The bridge plays out to A1A, the highway that runs alongside the Florida coast. Crossing that, it’s another 1/2 mile to South Beach park. I could have stopped there, and it would have been a fine choice since it’s very dark, but I pushed north toward Humiston Beach. This meant a winding ride through silent streets unmolested by lights.

I turned off the bike lamp and let the stars light the way. The Big Dipper hung in the northeast, pointing the way to Polaris, the north star. The belt of Orion flew nearly overhead, escorted by Betelgeuse and Rigel, and Capella was a blazing beacon. To the east, where breezes carried the scent of the sea, bright streaks of burning dust and pebbles were flying down like psychedelic raindrops.

I reached Humiston, which was nearly deserted. An elderly couple made their way toward the boardwalk, where a smoker fired up a cigarette and three young girls chattered together, swaddled in sleeping bags. I parked the bike and locked it near Crusty’s, a casual restaurant propped up on posts over the sand. Went directly down to the beach, found a dark spot, and settled back to watch the show. It was 4:30.

The Leonid meteors come from a comet, the Tempel-Tuttle comet. It’s a big dirty ball of ice, a flying mountain about 2.5 miles wide. It swings around the sun every 33 years. As it passes through our neighborhood, the sun warms it and melts some of the ice. All the gravel and dust locked into the ice is released, leaving a long trail of debris in its path, much like the contrail of a jet flying through the sky.

The trail gets pushed around some by solar wind and radiation, but it mostly just hangs there in space. There’s no real wind to break it up and scatter it, so the trail we’re plowing into this year has been hanging around for three centuries, since Tempel-Tuttle passed through in the 1700’s. The comet leaves a long half-donut of dust and gravel around the sun every time it passes through. Some years it dumps more than others, and some years we hit a denser part of it than others. This year the prediction is that we’d hit an especially dense part.

Not all meteors are created equal. Some just skim past the earth in the upper atmosphere, like a flat rock skipping over the surface of water. Some hit the earth at an angle, and some crash in head first. Some come from behind our motion around the sun, catching up to the earth, and almost float into our atmosphere.

The Leonids mostly come screaming in head first. This means they come in very, very fast. There’s no sound on the ground, of course, since these are pretty small meteors and all the action is going on about 60 miles overhead.

If a fireworks show is rock and roll, then a meteor shower is understated classical symphony. It’s not an in-your-face explosion of light and sound. It’s more of a subtle, unpredictable rhythm, one surprise following another on a deep velvet void inlaid with fiery diamonds.

Even when there’s no meteor shower expected, most nights you’ll see 2 or 3 if you watch the sky for a while. The trick to seeing meteors is not to look for them. Just lie back and let your eyes relax, not seeking, not focusing on anything especially. Once you have that trick down, your side vision picks up everything in view that moves, and your eyes will dart in the direction of any movement. That way you seldom miss anything, even the really short, fast meteors.

Tonight, though, it was impossible to miss anything. At 4:30, they were appearing in a steady parade, one at a time, perhaps 2 or 3 each minute. Some were tiny and dim, some were bright and sharp. They left lines of light in varied colors and shades – red, blue, white, purple, even green. Nearly all were wicked fast, ripping by in an eyeblink. Sometimes they burned with the intensity of a welder’s torch, so bright they cast shadows.

In 20 minutes’ time, the parade began to moving faster. They flew down in quick bursts of 4 and 5, appearing within seconds of each other. Mixed in with Leonids were slower meteors coming from other directions. A steady stream of larger green trails were left by slow earth grazers coming from the north. Quick white wands of neon winked on and off past Orion’s belt.

It’s easy to imagine ancient people being awed by nights like this. They must have wondered if the very stars were falling to the earth.

By 5 a.m, the single notes of individual meteors were being replaced by whole chords appearing together. 4-5 would spray down at once, usually entering from different directions, sometimes flying in formation. Seeing 10 to 15 meteors a minute was not unusual. Anywhere you looked, a gentle celestial rain was falling. It would not have been surprising if a rock thudded into the beach and sat there, steaming, a relic possibly older than the Earth itself. Above us, fragments just as old spent their final moments of existence tortured by a sudden impact with an ocean of air, turbocharged fireflies smashing into our atmospheric windshield.

It was hypnotic, relaxing, transcendent, beautiful. Sounds like hype for a trip through a cloud of dust and gravel, but it was all that and a side of fries, too.

At 5:30, meteors were still coming fast and furious while dawn was making itself felt in a ghostly gray light over the waters. It was time to start back for home. I stood and brushed off the beach sand, thinking that many of the meteors that appeared tonight were not much larger, and not so very different, than these same grains.

It’s of a piece, really, what lies out there and what we work with every day. It’s all connected, a tapestry woven from elements forged in the heart of stars.

The rain of fire will return next year.

Be there.

Written by Influential Prose

December 20, 2021 at 9:50 pm

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The Inner and Outward Gaze

Ever seen those delightful Russian matryoshka dolls, the ones where each doll opens to reveal another, smaller but identical doll, which opens to reveal yet another smaller, identical doll, and down it goes to a doll the size of a peanut?

Likewise, the films Inception and the Matrix portray realities within realities within realities, scrambling our perception of reality.

There’s an everyday analogue to this – a simple mirror. You gaze at the mirror through your eyes, which are reflected in the mirror, so your view includes the thing you are viewing through.

Both are real, the view and the reflection, and neither can exist without the other.

This image is another example, taken from the International Space Station.

What you see is an orbital sunset, looking out the back view as the ISS circles the globe. Two Russian ships can be seen docked with the sun’s glare between them, a Soyuz crew capsule in the foreground and Progress cargo capsule in the background, with the earth’s horizon outlined by a thin layer of atmosphere.

You can also see the dim outline of a camera lens. This can only be seen when the angle of the sun’s light is such that the transparent cover over the camera acts like a mirror and reflects an image of the camera.

And so it is that the instrument we use to see the earth is mirrored back to us. Our own eyes gaze back at the manufactured eye we ordinarily look out from.

This demonstrates in a concrete way something that a wise man once noted:

 

Written by Influential Prose

September 19, 2016 at 6:07 am

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Three Bright Lights

Last night the sky over Washington, DC was unusually clear, so we had a spectacular view of three planets low in the pre-dawn east. Venus, Jupiter and Mars were all pointed toward the coming sunrise. It reminded me of one of the early geometry puzzles I sorted through while learning astronomy.

Venus orbits closer to the sun than we do. When we’re on the earth’s night side, it’s orbit is “behind” us. When we look up and out, we’re looking toward the orbits of the outer planets – Mars, Jupiter, Saturn, etc.

So it makes sense that we see the outer planets at night, when we face away from the sun; but how is it we can see them and the inner planet Venus *at the same time*?

If all the planets remained aligned and orbited in lockstep, then that would be an issue. But of course planets are at different parts of their orbits at different times, and this gives us windows when we can see them together.

My phone is most definitely not an astronomy camera. Please accept this simulated view from Stellarium, matching the exact time I saw it last night. The actual view was more impressive. Click on images to enlarge.

 

Celestia provides real-time simulated snapshots of our solar system. The view below is tilted sideways because you’re standing on a ball looking east. See the string of lights in the middle of the ocean? Hawaiian islands. Top center of Earth, the lights of the California coast. Look up, and what do you see? Same planets, same alignment.

 

Same image, with orbital paths added:


And an overhead view of the solar system at the same time:

.

..and that’s how you see three planets, one inner, two outer, together on cool fall night.

Written by Influential Prose

May 5, 2016 at 4:22 am

Posted in astronomy, science, space

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Farmland Volcanoes

 

The mound you see here is Mole Hill in Northern Virginia, a bit over an hour away from Thomas Jefferson’s Monticello. 48 million years ago it was a volcano.

It has obviously worn down quite a bit since then, but the geological processes that gave it birth are still active. The Journal of Geophysical Research released results of a study that found parts of the mantle below this region are peeling off, weakening and destabilizing the crust above. This is what set off the 2011 earthquake that rattled Washington, DC and a good chunk of the Southeastern U.S.

The area sits close to the middle of the North American plate and because of that it’s normally stable. But the evidence revealed by the study suggests the mantle erosion is continuing and will eventually produce more earthquakes. No timetable on that – it might not even happen in our lifetimes.

But the slow grind of plates and the interaction of mantle and crust will continue, and as sometimes happens in these things, can open up fissures that allow hot magma to rise to the surface – giving birth to a new volcano.

http://blogs.agu.org/geospace/2016/05/03/scientists-find-likely-cause-recent-southeast-u-s-earthquakes/

Scientific American summarizes the history of east coast volcanoes, presented as detective story that takes you through time and shifting landscapes.

http://www.scientificamerican.com/article/recent-east-coast-volcano/

There are two extinct volcanoes in Virginia. Mole Hill is one; Trimble Knob is the other.

Trimble Knob
https://en.wikipedia.org/wiki/Trimble_Knob

Drive-by video of Trimble Knob
https://www.youtube.com/watch?v=TQm8mvBXvPI

Overhead view of Trimble Knob

 

Written by Influential Prose

May 5, 2016 at 3:26 am

How to Pop a Parachute on Another Planet

The Martian atmosphere lies low and thin. There’s not enough of it to land softly by parachute alone. But when you come screaming in a little over 3.5 miles per second, it’s almost more like water than air.

The Mars Science Laboratory hit the atmosphere at 13,000 mph and slowed to 900 mph on atmospheric friction alone. Peak heating during this period is twice as hot as melted rock, or lava.

Then it popped a parachute. There’s enough atmosphere at the altitude of six miles – about the same height as a jet airliner over Earth – for a parachute to slow everything down a lot.

Here’s that parachute during indoor testing on Earth:

 

Even in a very thin atmosphere, popping a chute at 900 mph creates a lot of stress, about 9 Gs. How do you test for that? With a helicopter, a rocket sled and a lot of very strong cable. Watch to 4:00 to see the big picture:

The parachute worked. It was used less than two minutes. But that was long enough for the Mars Reconnaisance Orbiter to capture a photo of the rover under parachute with the HiRise camera:

 

You can do more than see this parachute. You can ride it down. Twenty seconds after the parachute was deployed, the heat shield was dropped while the rover was 5 miles above the surface and falling a bit over 500 mph. That’s where the ride begins:

 

Images have been captured of the parachute in its final resting place.

It’s still blowing in the Martian winds.

Written by Influential Prose

July 3, 2015 at 4:31 am

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Physics for Curious Teenagers

[One of 50 articles written and published for Demand Media in 2013]

Physics is often an intimidating subject because it encompasses so much – it is the foundation for how everything else works. Our understanding is advanced and growing, but not yet complete. There are still holes, and this is where the excitement lies – exploring the unmapped territories, standing on the shoulders of giants and seeing farther than any have seen before. The easy parts have been mapped, and the hard parts beckon. Teens with the academic capacity for this subject can benefit from strong parental encouragement and support. STEM (Science, Technology, Engineering and Math) programs are proliferating, and physics provides a reliable foundation for these areas. Check your teen’s school to learn about local courses.

Particle Physics
The most fundamental questions have been asked for centuries. Where are we from? How did we get here? Physics is part of our pursuit for answers. By examining the most basic building blocks that everything is made of, we discern the properties of both matter and energy, and how matter is essentially a form of energy. Chemistry, organic chemistry and biochemistry, the basis for life, all originate in particle physics. It’s like the “CSI: Crime Scene Investigation” shows, but this is the detective work of reality – physics underlies a lot of criminal investigative work.

Fermilab, the U.S. Department of Energy’s powerhouse of particle physics, offers a solid list of books on physics for regular people, and the Carnegie Library in Pittsburgh offers a selection of engaging physics books for teens — such as the “Manga Guide to Physics” — that are accessible without being dumbed down.

Electromagnetism
Fundamental particles carry positive and negative electrical charges, and these charges regulate the interaction of matter. As the Encyclopedia Britannica notes, at the particle level electrical charge is so powerful that the absence of only one electron out of every billion molecules in two 70-kilogram (154-pound) persons standing two meters (two yards) apart would repel them with a 30,000-ton force. If you want to understand how that works, “Physics for Idiots” has good explanations, even if you’re not an idiot. Teens looking for the story behind the science can also enjoy “Electric Universe: How Electricity Switched on the Modern World,” an overview of the history and human drama behind electromagnetism’s discovery.

Physics of Motion
Energy and matter together becomes motion. Isaac Newton formulated the Three Laws of Motion on an English sheep farm in the mid-17th century and revolutionized our understanding of the cosmos. He worked out how the motion of the moon affects the oceans on Earth and creates tides. The same laws that govern the fall of an apple from a tree form the basis of our understanding of orbital mechanics – how the planets orbit the sun through the principles of inertia and mass. The online Physics Classroom presents these laws in a clear, accessible way for teens.

Physics of Relativity
Einstein’s Special Theory of Relativity picked up where Newton left off by showing that space itself is warped by gravity, and that even light is affected by it. This effect is so powerful it enables us to see galaxies hidden behind clusters of other galaxies because the galaxies in front create a lensing effect, warping the light around them. Relativity also gave us light’s speed limit – 186,000 miles per second. By this measure, the sun is 8 minutes distant, Saturn is 15 minutes away, and the Voyager 1 space probe at the edge of the solar system is over 17 hours out. Cornell University, the workplace of renowned astronomer Carl Sagan, has a good overview of Einstein’s theory, and yes, there’s a “Manga Guide to Relativity” too.

Written by Influential Prose

June 26, 2015 at 3:24 am

Cultural Differences in Moral Reasoning

[One of 50 articles written and published for Demand Media in 2013. Published version here.]

Cultural differences in moral reasoning are driven by various influences — history, leadership, religious belief, experiences with peace and warfare, available resources and the strategies for extracting and distributing those resources. These cultural differences are not limited to the scale of nations. There can also be differences in the culture and moral reasoning between schools, communities, companies, even families. Moral reasoning has a way of adapting to or being shaped by people’s needs and perceptions.

Absolutes vs. Relativism
There’s an ongoing, cross-cultural debate on whether moral values are absolute or relative. Are there universal morals that apply to all regardless of culture, or are moral values a negotiation between the environment, natural selection and social conditions? It’s a hotly debated topic, but clearly moral reasoning diverges among cultures. In some areas, gay marriage is accepted and not in others. Some countries permit personal firearm ownership, in others you can be jailed. The same is true for possession of certain plants.

National Differences
Overpopulation has led China to impose some restrictions on family size. Today it has over 1.35 billion people and most Chinese live with an average density of 326 people per square mile. People living at that density calls for, and perhaps requires, a moral system that emphasizes cooperation and harmony — exactly what Confucianism teaches. In China, conditions and moral reasoning lead to limits on family size.

In Russia, conditions and moral reasoning lead to an opposite conclusion. Russia’s population density is slightly below 14 people per square mile, with about 143 million total population. Government policy encourages families to have as many children as they can (which also requires cooperation and harmony).

Japan’s situation is complex. They face a rapidly aging population and steep decline in fertility, in part because strong Confucian values demand marriage before children, but marriage rates are dismally low. Japan is caught between cultural values and an inevitable economic decline unless fertility and immigration increase; thus Japanese moral reasoning is now forced to resolve this conflict to maintain national prosperity.

Economic Differences
Consider a simplified example of conflicting interests between a factory owner and a farmer. To remain in business, the factory owner must balance costs and expenses. This may mean discharging pollutants in the atmosphere because it is the lowest-cost way to eliminate wastes. If costs are not well-controlled, the factory could fail and people would lose jobs. From this perspective, cost control is a moral good.

From a farmer’s perspective, if crops are contaminated by mercury particulates from the factory, the moral good of cost control becomes the evil of food poisoning. Similarly, an agricultural society will have a different moral perspective on some issues than an industrial society. Cultural values — morals — tend to dovetail with practical needs.

On the issue of global warming, there’s a clear clash between the view in academic culture, which is driven by several lines of evidence pointing toward anthropogenic climate change, and the views of fossil fuel and other industries, a culture that tends to combat any conclusion that will affect profits. When scientific facts and self-interest diverge, the effect on moral reasoning is illuminating.

Humanitarian Differences
Cultures vary in how they value others in their midst. Slavery is a stark example, and had its advocates. It is now widely condemned, yet persists in the form of human trafficking, or sex slavery. Sexual slavery victims tend to flow from economically insecure areas to regions of relative stability. When times are hard, the young women who comprise the majority of victims can be manipulated and entrapped with promises of phony jobs. Some locales, most famously Bangkok and Amsterdam, tolerate the sex trade by reasoning that it’s a matter between consenting adults. This blurs the line between consent and coercion and complicates enforcement against human trafficking.

Social Stratification
Other forms of devaluation persist, cutting across lines of ethnicity, gender, age and disability, resulting in societies stratified by economic class (U.S.), social castes (India, Pakistan) and ethnicity (U.S, Japan). Social stratification is inherently hierarchical, a pre-rational behavioral pattern, and proactive moral reasoning is working to reduce it through affirmative action programs in the U.S. and India.

Moral reasoning varies by culture in accordance with what the culture values. As noted American author Robert A. Heinlein pointed out, “Man is not a rational animal. He is a rationalizing animal.” It’s clear that moral values are relative in practice. If there are also absolute universal moral values, no clear consensus has yet emerged that identifies them.

Written by Influential Prose

June 26, 2015 at 3:20 am

Educational Science Games for Teenagers

[One of 50 articles written for Demand Media in 2013]

Educational games can be competitive – teams can vie to build a better tool, such as a water balloon catapult or battling robots. More often, educational games are cooperative activities. You may build something with others, or construct something virtually based on real-world physics using a computer. Learning by doing is the essence of applied science – we experiment, we guess what approaches will solve problems. When we fail, we apply lessons learned and try again. For the games and activities described here, see the Resources listed at bottom to access instructions, videos and links to more fun.

Cooperative Exploration
Some science tasks are too large for small teams to tackle. Crowdsourcing helps break down enormous tasks into smaller chunks, then presents them in a game format that anyone can grasp and play. These games help analyze cancer cells, explore the surface of the moon and ocean floors, find planets around other stars, sort the meaning of whale and bat calls, and classify animals in Africa. There’s much to explore at the Zooniverse.

Electrical Engineering
If you’re interested in building a robot warrior, you needn’t wait to form a team, join a class or enter a competition. There are numerous sources for parts and do-it-yourself guides for beginners. Servos, cameras, motors, controllers, transmitters, batteries, tools – building a robot today is like Legos on steroids. (Lego is also a player – see their Mindstorms NXT kits).

Not all robots are ground-based – some fly. While radio-controlled cars and aircraft have been around for years, it’s possible to build personal autonomous aircraft. You tell them where to go, they fly off and do it. DIY Drones has plenty of guides to get you started. Build for your own pleasure or compete with other local hobbyists to fly faster, higher and longer.

Mechanical Engineering
Building a bridge demands an understanding of materials, their strengths and limitations, the requirements of the site and loads – dead, alive and dynamic. In Bridge Builder, you can test different construction approaches and learn what works. Unlike the real world, when you fail, nobody gets hurt.

Water balloon battles are a summer favorite. You can take it to the next level by building a large slingshot, catapult or trebuchet. Now you can learn the physics of parabolas with real-world target practice. Aim well, or you may soon be all wet! Make magazine has detailed step by step instructions.

Geography
Google Earth is a lot of fun all by itself – you’ve got a whole planet to play with (more, actually – the Moon and Mars is included). At Planet In Action, there’s a collection of games that work together with Google Earth. If you’re looking for multiplayer action, look at Google Earth War, where the entire planet becomes your battlefield.

Want to do a bit of near-space photography? It’s not especially difficult or expensive. Dedicated teams have lofted small weather balloons equipped with cameras 20 miles up to capture astonishing views of earth’s curvature and black skies. Tutorials abound. Create rival teams to see who can fly higher or gather the most interesting photos and videos!

Astronomy
As long as you’re looking up, try running the Messier Marathon. Every spring, conditions are favorable for surveys of 100 deep sky objects. These galaxies, star clusters and nebulae were first discovered and cataloged by Charles Messier, an 18th century French astronomer. Your challenge is to view them all in one evening. You’ll need a good telescope, clear skies and patience. You’ll learn a lot along the way.

Aerospace
Here is a trio of games all built to reflect real-world physics. Two of them emulate real-world vehicles. X-Plane is a sophisticated flight simulator that offers an amazing range of aircraft that you can fly over real-world terrain in real-world weather conditions, with authentic failure scenarios. In Orbiter, you can pilot an Apollo command module to the moon, dock with the International Space Station from a Space Shuttle or Soyuz, then re-enter and land. In the Kerbal Space Program, you build your own spacecraft subject to real-world limitations of materials, weight and fuel. You can build your own moon base, ferry supplies and discover what happens when you run short.

Written by Influential Prose

June 22, 2015 at 10:04 pm

Grenville Rocks

Just outside Baltimore, there’s a trail in a state park that winds down toward a small river. The river descends down a short rapids, gliding over rock. The rock is unique; it’s over a billion years old. It’s known as the Baltimore gneiss. This is what it looks like:

The DC metro area has been through four mountain-building periods in the past billion years, give or take a few hundred million. The first one raised the Grenville mountains. Over eons, they drifted around the Earth aboard a tectonic plate, eroding, worn down by wind, water and ice. There were four global glaciation events between 900 and 600 million years ago. The ice certainly extended as far as the DC area during these events, and may have girdled the entire planet. In any event, the Grenville mountains were scoured down and the roots that remained became the “basement rock” of the east coast.

Later there was a rifting, a sort of splitting of the Grenville rock, with some blocks being dragged out to sea. Magma welled up and spread, then cooled to form a new layer of rock 2,000 feet thick in some areas. These flows formed the Blue Ridge province, and you can see exposures of that rock at Catocin mountain.

Later another plate began converging on the North American continent, with the ocean floor diving beneath the plate. This generated a chain of underwater volcanoes topped by islands running north and south called the Chopawamsic Arc, similar to the arc of islands in southern Alaska. The plate and these volcanoes eventually converged on the eastern North American coast, sweeping up everything on the sea floor in between, carrying it all back onto the continent where it was raised and mashed and mixed with existing rock. This event created the Taconic mountains.

The Taconics wore down. The Acadian mountains formed when continental fragments collided with the east coast. This episode created much larger mountains than the Taconic. To give you a sense of scale, the erosion of the Acadian mountains created pile of sediment to the west. That pile was 9,000 feet high in central Pennsylvania, sloping down to 1,000 ft in Ohio. That was just the stuff left over after the mountains wore down.

The last period of mountain-building was the biggest one. This time, 250 million years ago, Africa and North America collided as all the other continents came together and formed a single supercontinent known as Pangea. This created the Appalachian mountains, and they were as tall as the Rockies and the Alps when fully formed. They’re much smaller now, of course – that’s what 250 million years of constant erosion does to mountains.

 

Throughout all of this, the billion-year-old Grenville basement rock has been squeezed, heated, folded and torn apart. It’s metamorphic rock, with complex layers. Most of it still lies deep beneath layers of other rock. But there are some areas around Baltimore where you can see it, and Dylan and I did that today.

This rock is older than multicellular life, at least 400 million years older. It was here 500 million years before land plants existed. Our solar system, along with the entire Milky Way galaxy, completes one rotation around the galactic center every 250 million years. This rock has made the trip four times.

Dylan found some rock fragments at the site and brought them home. The rock has been in the water, it’s hydrated and its age shows. It’s very brittle and flakes easily. As we were leaving, one of the rocks he collected split in half. In that moment, he was gazing on the surface of rock that no one, anywhere, had ever seen before – formed a billion years ago, and only now exposed to light and a 16-year-old’s wondering eyes.

 

It’s been a good day.

Written by Influential Prose

June 22, 2015 at 7:11 pm

Martian Geology

This image from India’s MOM mission highlights a region with stress fractures – cracks – in Mars’ crust that can run as much as 3 miles deep.  They’re called fossa, sometimes grabens, and they exist on Earth too. Yes, you are riding on a cracked surface. Have a good day.

http://www.isro.gov.in/pslv-c25-mars-orbiter-mission/breathtaking-pictures-mars-colour-camera-mcc-of-india%E2%80%99s-mars-orbiter

Elsewhere on Mars, there’s a volcano notable for being about the same height as Mount Everest. (It’s tiny compared to other Martian volcanoes). The linked image shows a forked valley sloping down from the volcano.

https://en.wikipedia.org/wiki/Ceraunius_Tholus

Studies of the valleys suggest they were originally formed by lava flows and later altered by water flow. Think about that. It would require an atmosphere that was warm, wet and large enough to rain down into the caldera at the altitude of Everest’s peak.

Obviously the water cycle and atmospheric dynamics are different on a young planet with about 1/3 of earth’s gravity.

The best estimate of when the volcano’s caldera and channels began filling with water date back to the Late Heavy Bombardment, right about the same time bacterial colonies begin to appear in Earth’s fossil record.

http://onlinelibrary.wiley.com/doi/10.1029/JB095iB09p14325/abstract

Written by Influential Prose

May 25, 2015 at 6:59 pm