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Viewing a total solar eclipse from an airplane

posted by Jason Kottke   Aug 18, 2017

On March 8-9, 2016, a total solar eclipse swept across the Pacific Ocean for more than 5 hours. About a year before the eclipse, Hayden Planetarium astronomer Joe Rao realized Alaska Airlines flight 870 from Anchorage to Honolulu would pass right through the path of totality…but 25 minutes too early. Rao called the airline and convinced them to shift the flight time.

Alaska’s fleet director, Captain Brian Holm, reviewed the proposed flight path and possible in-route changes to optimize for the eclipse. The schedule planning team pushed back the departure time by 25 minutes, to 2 p.m.

On the day of the flight, Dispatch will develop the specific flight plan, to find the most efficient route and account for weather and wind. Maintenance and maintenance control will help make sure the plane is ready to go — they even washed all the windows on the right side of the plane.

Captain Hal Andersen also coordinated with Oceanic Air Traffic Control, to make them aware that the flight might require a few more tactical changes then normal.

“The key to success here is meeting some very tight time constraints — specific latitudes and longitudes over the ocean,” Andersen said. “With the flight management computer, it’s a pretty easy challenge, but it’s something we need to pay very close attention to. We don’t want to be too far ahead or too far behind schedule.”

The video was shot by a very excited Mike Kentrianakis of the American Astronomical Society, who has witnessed 20 solar eclipses during his lifetime.

July 11, 2010. That was the eclipse over Easter Island, the one for which hotel room rates were so high that there was no way Kentrianakis could afford it. Instead, he considered attempting a trip to Argentina, where experts predicted there was a 5 percent chance of clear skies. His wife at the time, Olga, urged him not to go — it’s not worth the expense, she insisted. Reluctantly, Kentrianakis stayed home.

“It was the beginning of the end for us,” Kentrianakis says. There were problems in the marriage before that episode, “but it affected me that I felt that she didn’t really appreciate what I loved.” They were divorced the following year.

Kentrianakis doesn’t like to dwell on this, or the other things he’s given up to chase eclipses. He knows his bosses grumbled about the missed days of work. Friends raise their eyebrows at the extremes to which he goes. He’s unwilling to admit how much he’s spent on his obsession.

“There is a trade-off for everything, for what somebody wants,” he says.

A camera on the Deep Space Climate Observatory satellite captured the eclipse’s shadow as it moved across the Earth:

For this year’s eclipse, Alaska Airlines is doing a special charter flight for astronomy nerds and eclipse chasers. Depending on how this eclipse goes, seeing an eclipse from an airplane might be on my bucket list for next time. (via @coudal)

Infographic of the fascinating timeline of the far future

posted by Jason Kottke   Aug 17, 2017

Timeline of The Far Future

Timeline of the far future is one of my favorite pages on Wikipedia. It details what might happen to humanity, human artifacts, the Earth, the solar system, and the Universe from 10,000 years from now until long past the heat death of the Universe. Information is Beautiful has made a lovely infographic of the timeline.

Reading through the timeline is a glorious way to spend time…here are a few favorites I noticed this time around as well as some from my first post.

August 20, 10,663: “A simultaneous total solar eclipse and transit of Mercury.”

20,000 years: “The Chernobyl Exclusion Zone, the 1,000 sq mi area of Ukraine and Belarus left deserted by the 1986 Chernobyl disaster, becomes safe for human life.”

296,000 years: “Voyager 2 passes within 4.3 light-years of Sirius, the brightest star in the night sky.”

1 million years: “Highest estimated time until the red supergiant star Betelgeuse explodes in a supernova. The explosion is expected to be easily visible in daylight.”

1 million years: “On the Moon, Neil Armstrong’s ‘one small step’ footprint at Tranquility Base will erode by this time, along with those left by all twelve Apollo moonwalkers, due to the accumulated effects of space weathering.”

15.7 million: “Half-life of iodine-129, the most durable long-lived fission product in uranium-derived nuclear waste.”

100 million years: “Future archaeologists should be able to identify an ‘Urban Stratum’ of fossilized great coastal cities, mostly through the remains of underground infrastructure such as building foundations and utility tunnels.”

1 billion years: “Estimated lifespan of the two Voyager Golden Records, before the information stored on them is rendered unrecoverable.”

4 billion years: “Median point by which the Andromeda Galaxy will have collided with the Milky Way, which will thereafter merge to form a galaxy dubbed ‘Milkomeda’.”

7.59 billion years: The Earth and Moon are very likely destroyed by falling into the Sun, just before the Sun reaches the tip of its red giant phase and its maximum radius of 256 times the present-day value. Before the final collision, the Moon possibly spirals below Earth’s Roche limit, breaking into a ring of debris, most of which falls to the Earth’s surface.

100 billion years: “The Universe’s expansion causes all galaxies beyond the Milky Way’s Local Group to disappear beyond the cosmic light horizon, removing them from the observable universe.”

A tour of our solar system’s eclipses

posted by Jason Kottke   Aug 16, 2017

In a meditative video for the NY Times, Dennis Overbye takes us on a tour of eclipses that happen in our solar system and beyond.

On the 21st day of August, 2017, the moon will slide between the Earth and the sun, painting a swath of darkness across North America. The Great American Solar Eclipse. An exercise in cosmic geometry. A reminder that we live on one sphere among many, all moving to the laws of Kepler, Newton and Einstein.

Humans have many more vantage points from which to observe solar eclipses than when the last solar eclipse occurred in the US in 1979. I had no idea that the Mars rovers had caught partial solar eclipses on Mars…so cool. (via @jossfong)

What if the Earth suddenly turned flat?

posted by Jason Kottke   Jun 23, 2017

Disc Earth

We all know the Earth is (nearly) spherical. Wellllll, not everyone does. So what if our planet did suddenly turn flat? Gizmodo recently asked a bunch of scientists this question and the answer came back: certain death for all life on Earth. More specifically, seismologist Susan Hough says:

If the earth were to suddenly flatten, presumably all sorts of hell would break loose. I guess it would depend on how flat is flat. If we’re talking pancake flat, gravity would be an immediate problem: gravitational attraction goes as G(m1*m2)/r^2, where G is the gravitational constant, m1 & m2 are two masses, and r is distance. A sphere is the 3D shape that maximizes surface area relative to volume, which kind of gives gravity the biggest bang for its buck. If you flatten the sphere, the far side gets closer to the new center point, but the ends spread way out, so surface gravity goes down at the center, and way down at the edges. Lose gravity and bye-bye atmosphere.

Other first-order problems: heat, radioactivity, etc. In our spherical earth, both of these are concentrated in the core. If the earth were flattened, they would have to go somewhere-presumably a lot closer to the surface.

Here’s how we know the Earth is round

posted by Jason Kottke   May 23, 2017

Flat-Earthers aside, people have known that the Earth is round since at least the 3rd century BC. This quick video explores a few of the ways we know the world is spherical, some of them quite simple to recreate as experiments. See also Top 10 Ways to Know the Earth is Not Flat.

(5) Seeing Farther from Higher

Standing in a flat plateau, you look ahead of you towards the horizon. You strain your eyes, then take out your favorite binoculars and stare through them, as far as your eyes (with the help of the binocular lenses) can see.

Then, you climb up the closest tree — the higher the better, just be careful not to drop those binoculars and break their lenses. You then look again, strain your eyes, stare through the binoculars out to the horizon.

The higher up you are the farther you will see. Usually, we tend to relate this to Earthly obstacles, like the fact we have houses or other trees obstructing our vision on the ground, and climbing upwards we have a clear view, but that’s not the true reason. Even if you would have a completely clear plateau with no obstacles between you and the horizon, you would see much farther from greater height than you would on the ground.

This phenomena is caused by the curvature of the Earth as well, and would not happen if the Earth was flat.

Update: Carl Sagan explains how Greek astronomer and mathematician Eratosthenes figured out how the Earth was round in ~200 BC.

(via @preshit)

The Earth’s five energy revolutions

posted by Jason Kottke   May 22, 2017

Five Energy Expansions

Since life first formed on Earth billions of years ago, the ability of organisms to use more powerful and efficient energy sources has been key in driving the diversity and complexity of life. According to this provocative piece in Nature by Olivia Judson, the history of life on Earth can be divided into five energetic epochs characterized by the following energy sources: geochemical energy, sunlight, oxygen, flesh and fire.

The first two were present at the start, but oxygen, flesh and fire are all consequences of evolutionary events. Since no category of energy source has disappeared, this has, over time, resulted in an expanding realm of the sources of energy available to living organisms and a concomitant increase in the diversity and complexity of ecosystems. These energy expansions have also mediated the transformation of key aspects of the planetary environment, which have in turn mediated the future course of evolutionary change. Using energy as a lens thus illuminates patterns in the entwined histories of life and Earth, and may also provide a framework for considering the potential trajectories of life-planet systems elsewhere.

Organisms formed on Earth and changed the planet, which led to the formation of new organisms more suited to the new environment. For instance, when a type of bacteria evolved to turn sunshine into oxygen, it completely changed the planet.

In the absence of a biotic source of oxygen, trace quantities of the gas can be generated abiotically: water molecules can be split by sunlight or radioactive decay. However, these abiotic processes are much less efficient than their biotic equivalent. Had cyanobacteria, or something like them, never evolved, oxygen would never have built up in the atmosphere of the Earth.

But build up it did. Between 2.45 and 2.32 Ga, significant quantities of oxygen began to accumulate in the air, an episode known as the Great Oxidation Event. Before the Great Oxidation, atmospheric oxygen levels were less than 10^-5 of the present atmospheric level of ~21%. By ~2 Ga, they had risen to perhaps 0.1-1% of the present atmospheric level. Although the subsequent history of oxygen is complex and many details are uncertain, Earth’s atmosphere has contained an appreciable level of the gas ever since. (Full oxygenation of the oceans, however, would not happen until around 1.8 billion years after the Great Oxidation.)

The original piece in Nature is fairly readable for a science journal, but this summary in The Atlantic is worth a look if you’re short on time or attention. (via @CharlesCMann)

NASA’s new nighttime map of the entire Earth

posted by Jason Kottke   Apr 13, 2017

Night Map Earth 2017

Night Map Earth 2017

For the first time since 2012, NASA has released a new map of the entire Earth at night. Of course, you don’t see the Earth so much as the activity of humans in well-lit cities.

Today they are releasing a new global composite map of night lights as observed in 2016, as well as a revised version of the 2012 map. The NASA group has examined the different ways that light is radiated, scattered and reflected by land, atmospheric and ocean surfaces. The principal challenge in nighttime satellite imaging is accounting for the phases of the moon, which constantly varies the amount of light shining on Earth, though in predictable ways. Likewise, seasonal vegetation, clouds, aerosols, snow and ice cover, and even faint atmospheric emissions (such as airglow and auroras) change the way light is observed in different parts of the world. The new maps were produced with data from all months of each year. The team wrote code that picked the clearest night views each month, ultimately combining moonlight-free and moonlight-corrected data.

Scientists are planning on providing “daily, high-definition views of Earth at night” starting later this year. It’s worth clicking through to play with the interactive India map…it’s astounding to see how much light the country has added in the past 5 years. And see if you can spot North Korea at night:

Night Map Earth 2017 03

Barely…just a tiny dot for Pyongyang. You can play around with a fully zoomable version of the entire map here. (via @JamesJM)

If only 100 people lived on Earth…

posted by Jason Kottke   Mar 06, 2017

Because many people have trouble with very large numbers, what if you reimagined the billions of humans on Earth as a slightly more manageable number? Say, 100? If 100 people represented the current population of the Earth:

25 people would be 0-14 years old
31 would be Christian
23 would be Muslim
15 would be Hindu
6 would speak Spanish
5 would speak English
54 would be urban dwellers
11 would live on less than $1.90 USD per day
95 live in an area with a mobile-cellular network

And some that are not on that page:

1 person would die every 15 months
2 people would be born every 6 months
1350 people would have died, all-time

What if the Earth were a middle-aged adult and other comparisons

posted by Jason Kottke   Feb 28, 2017

Sometimes big distances, long time periods, and large numbers can be difficult to grasp. So it helps to contextualize them with comparisons. When you do so, you realize that a billion is much much more than a million:

But when he linked these numbers to time, it brought things in perspective: 1 million seconds is nearly 12 days, whereas 1 billion seconds is almost 32 years. “Everybody gets it when you say it like that,” he wrote in an email. “If you just said 1 billion is three orders of magnitude greater than 1 million, I don’t think it would make the same impression.”

Tim Urban’s Life Calendar emphasizes the relative shortness of human life and the importance of using your time well by reorganizing a human lifespan into weeks.

Each row of weeks makes up one year. That’s how many weeks it takes to turn a newborn into a 90-year-old.

It kind of feels like our lives are made up of a countless number of weeks. But there they are — fully countable — staring you in the face.

High school chemistry teacher Keith Karraker recently imagined the Earth having the lifespan of a typical human, which is a useful way of thinking about young humanity is in comparison.

Earth’s about half-way through its life. If it were a middle-aged adult of 40, its last mass extinction happened about 7 months ago.

To 40-yr-old Earth, humans have been using tools for a week and a half, and just left Africa 8 hours ago to settle around the globe.

All of human history is the last half hour. It’s been an exhilarating and disastrous half hour. But we figured out some really cool shit.

We figured out quantum, relativity, and DNA. A randomly mutating and replicating molecule built a machine to figure itself out.

Even much older evolutionary changes are surprisingly recent on this scale. Spines debuted just over 4 yrs ago. About when iPhone 5 did.

For more on the visualization of large scales, see also Powers of Ten, the leisurely pace of light speed, the size of supermassive black holes, and this comparison of the sizes of things from the Moon to galactic superclusters and beyond:

You want to talk about human insignificance? If Betelgeuse, one of the largest stars shown in the video, were in the Sun’s place, it would nearly reach the orbit of Jupiter, from which light takes 43 minutes (on average) to reach the Earth. (via @stevesilberman)

The Earth and I

posted by Jason Kottke   Oct 18, 2016

Earth And I

From James Lovelock, The Earth and I is a look at our planet and the living things on it…how Earth came to be, what we understand about our planet, and how we live today. Lisa Randall, Martin Rees, Edward O. Wilson, and Eric Kandel have contributed writing to the book.

Planet Earth II

posted by Jason Kottke   Oct 10, 2016

I reported back in February that the BBC was doing another season of Planet Earth with David Attenborough (aka the voice of nature). Now there’s a trailer out (with a Sigur Ros soundtrack) and the show is set to debut in the UK on BBC One later this month. In US? Who knows… probably in 8 months with Ellen Degeneres narrating.

Update: Planet Earth II, a massive hit in Britain already, will debut on US television tomorrow (Feb 18). You can catch the first episode on AMC, BBC America, and Sundance TV. And unlike the original Planet Earth, they’ve thankfully kept the original Attenborough narration for the US version of Planet Earth II.

A year-long time lapse of the Earth rotating in space

posted by Jason Kottke   Jul 22, 2016

NASA recently released a time lapse video of the Earth constructed from over 3000 still photographs taken over the course of a year. The photos were taken by a camera mounted on the NOAA’s DSCOVR satellite, which is perched above the Earth at Lagrange point 1.

Wait, have we talked about Lagrange points yet? Lagrange points are positions in space where the gravity of the Sun and the Earth (or between any two large things) cancel each other out. The Sun and the Earth pull equally on objects at these five points.

L1 is about a million miles from Earth directly between the Sun and Earth and anything that is placed there will hover there relative to the Earth forever (course adjustments for complicated reasons aside). It is the perfect spot for a weather satellite with a cool camera to hang out, taking photos of a never-dark Earth. In addition to DSCOVR, at least five other spacecraft have been positioned at L1.

L2 is about a million miles from the Earth directly opposite L1. The Earth always looks dark from there and it’s mostly shielded from solar radiation. Five spacecraft have lived at L2 and several more are planned, including the sequel to the Hubble Space Telescope. Turns out that the shadow of the Earth is a good place to put a telescope.

L3 is opposite the Earth from the Sun, the 6 o’clock to the Earth’s high noon. This point is less stable than the other points because the Earth’s gravitational influence is very small and other bodies (like Venus) periodically pass near enough to yank whatever’s there out, like George Clooney strolling through a country club dining room during date night.

And quoting Wikipedia, “the L4 and L5 points lie at the third corners of the two equilateral triangles in the plane of orbit whose common base is the line between the centers of the [Earth and Sun]”. No spacecraft have ever visited these points, but they are home to some interplanetary dust and asteroid 2010 TK7, which orbits around L4. Cool! (via slate)

Earth has a new(ish) quasi-moon

posted by Tim Carmody   Jun 17, 2016

About a hundred years ago, a tiny asteroid making its way around the sun got caught in Earth’s gravity well. Now it’s locked in an irregular orbit far around our planet, between 38 and 100 times the distance between the Earth and its proper moon.


As it orbits the sun, asteroid 2016 HO3 spends about half of the time closer to the sun than Earth, and passes ahead of our planet. The other half of the time it falls behind.

It’s also in a tilted orbit, which causes it to weave up and down on the orbital plane like a bob on choppy waters. As NASA’s Paul Chodas put it in a press statement, “In effect, this small asteroid is caught in a little dance with Earth.”

In another couple of centuries, the asteroid will probably get far enough away that it’ll leave Earth behind forever. I wonder how many times this has happened — how many times the asteroids have been bigger, closer, but still not big or close enough to stay.

What would happen if all humans disappeared?

posted by Jason Kottke   Jun 03, 2016

If all humans just up and disappeared one day, life on Earth would suffer in the short term but fare much better in the long run.

A view of the Earth from the ISS in ultra high def 4K

posted by Jason Kottke   Apr 25, 2016

Full-screen this baby on the biggest high-definition screen you can find. A 5K iMac works spectacularly well.

Scientists warn of dramatic climate shift much sooner than expected

posted by Jason Kottke   Mar 22, 2016

A new paper by climate scientists, including ex-NASA scientist James Hansen, warns that our climate could dramatically change within decades, not centuries.

Virtually all climate scientists agree with Dr. Hansen and his co-authors that society is not moving fast enough to reduce emissions of greenhouse gases, posing grave risks. The basic claim of the paper is that by burning fossil fuels at a prodigious pace and pouring heat-trapping gases into the atmosphere, humanity is about to provoke an abrupt climate shift.

Non-linear systems, man. Gradually, then all at once.

Update: Slate’s Eric Holthaus has more on the paper and its potential implications.

In addition to the risk of “several meters” of sea level rise this century, which Hansen calls the most important finding, the final version of Hansen’s paper gives new emphasis to the possibility that the ocean’s heat circulation system may be in the process of shutting down. The circulation shutdown would precede the rapid increase in global sea levels. If the shutdown happens, simultaneous cooling of the waters near Greenland and Antarctica and warming in the tropics and midlatitudes could spawn frequent strong storms on the order of Hurricane Sandy or worse.

If that sounds a lot like the plot of The Day After Tomorrow to you, you’re not alone.

Hansen also released a 15-minute video about the paper:

Satellite view of a total eclipse

posted by Jason Kottke   Mar 09, 2016

The Japanese satellite Himawari caught yesterday’s total solar eclipse as it moved across the Pacific Ocean.

Update: @paulmison sent along some better views of the eclipse: here and here. I tried to find a better YouTube embed, but no dice. This one, taken of the eclipse in Micronesia, is pretty amazing though…you can see the solar flares coming off the surface of the Sun as it reaches totality. Holy shit, I’m getting excited for Eclipsathon 2017!

The Breathing Earth

posted by Jason Kottke   Nov 18, 2015

From NASA, an animation of the yearly cycle of the Earth’s plant life. The data is taken from satellite measurements (plant density for land and chlorophyll concentration for the ocean) and averaged over several years.

From December to February, during the northern hemisphere winter, plant life in the higher latitudes is minimal and receives little sunlight. However, even in the mid latitudes plants are dormant, shown here with browns and yellows on the land and dark blues in the ocean. By contrast the southern ocean and land masses are at the height of the summer season and plant life is revealed with dark green colors on the land and in the ocean. As the year progresses, the situations reverses, with plant life following the increased sunlight northward, while the southern hemisphere experiences decreased plant activity during its winter.

If you’re anything like me, about 2-3 times into the video’s cycle, you’ll be breathing in tune to the Earth. Oxygen in, carbon dioxide out. Carbon dioxide in, oxygen out. Oxygen in, carbon dioxide out… (via @EricHolthaus)

Living in a thin moist layer on a small wet rock

posted by Jason Kottke   Nov 03, 2015

Here’s everything you need to know about the Earth, in a snappy 7-minute video. I am trying very hard not to watch the rest of Kurzgesagt’s videos this afternoon, but I did make time for this one on the Big Bang — key quote: “time itself becomes wibbly wobbly” — and how evolution works.

Beautiful hand-painted globes

posted by Jason Kottke   Aug 25, 2015

Bellerby & Co. Globemakers are one of the world’s last remaining makers of globes by hand. Their Instagram account is chock full of their handiwork.



If I could afford it (£2000!), I’d get The Livingstone globe in Prussian blue. Beautiful and wonderful craftsmanship.

Supermassive black holes are *really* massive

posted by Jason Kottke   Aug 19, 2015

How massive are they? The Sun is 1 solar mass and as wide as 109 Earths. Sagittarius A, the black hole at the center of the Milky Way, weighs 4.3 million solar masses and is as wide as Mercury is far from the Sun. The black hole at the center of the Phoenix Cluster is one of the largest known black holes in the Universe; it’s 73 billion miles across, which is 19 times larger than our entire solar system (from the Sun to Pluto). As for how much it weighs, check this out:

I also like that if you made the Earth into a black hole, it would be the size of a peanut. (thx, reidar)

The Moon crossing the sunlit face of the Earth

posted by Jason Kottke   Aug 05, 2015

This is just flat-out incredible… NASA’s Deep Space Climate Observatory satellite captured a series of photos of the Moon as it moved between it and the Earth.

Earth Moon Anim

The image shows the “dark side” of the Moon, which we can’t see from Earth because it’s always pointed away from us.

The lunar far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side. The largest far side features are Mare Moscoviense in the upper left and Tsiolkovskiy crater in the lower left. A thin sliver of shadowed area of moon is visible on its right side.

“It is surprising how much brighter Earth is than the moon,” said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Our planet is a truly brilliant object in dark space compared to the lunar surface.”

I don’t know why, but this image gives me chills up my spine! Is anyone else freaking out about this?

A musical journey away from Earth

posted by Jason Kottke   Jul 14, 2015

Lightyear FM

Taking inspiration from the opening sequence of Contact, lightyear.fm is a musical journey away from the Earth. As you get farther out (say, 10 light years away, just past star Ross 154 in the constellation of Sagittarius), you hear music that was broadcast on the radio at that time (Gold Digger by Kanye West).

Radio broadcasts leave Earth at the speed of light. Scroll away from Earth and hear how far the biggest hits of the past have travelled. The farther away you get, the longer the waves take to travel there — and the older the music you’ll hear.

This is the coolest.

Earth Primer

posted by Jason Kottke   Feb 02, 2015

Earth Primer is an upcoming iOS app that bills itself as “A Science Book for Playful People”. It looks amazing:

Earth Primer is a science book for playful people. Discover how Earth works through play-on your iPad. Join a guided tour of how Earth works, with the forces of nature at your fingertips. Visit volcanoes, glaciers, sand dunes. Play with them, look inside, and see how they work.

Earth Primer defies existing genres, combining aspects of science books, toys, simulations, and games. It is a new kind of interactive experience which joins the guided quality of a book with open ended simulation play.

Here’s a quick preview of the app. Can’t wait to explore this, with and without the kids.

Update: The Earth Primer app is now available on the App Store.

Infrared Planet Earth

posted by Jason Kottke   Jan 30, 2015

This is an ultra-HD time lapse of planet Earth in infrared. Infrared light is absorbed by clouds and water vapor, so the result is a sphere of roiling storms and trade winds.

Here’s a video with both hemispheres at once and another offering a closer view. If you’ve got a 4K display, this will look pretty incredible on it. James Tyrwhitt-Drake has done a bunch of other HD videos of the Earth and Sun, including Planet Earth in 4K and the Sun in 4K.

Around the World in 92 Minutes

posted by Jason Kottke   Oct 29, 2014

Hadfield Venice

Canadian astronaut Chris Hadfield became a celebrity while aboard the International Space Station. Now he’s publishing a book of photographs he took during his time in orbit: You Are Here: Around the World in 92 Minutes.

During 2,597 orbits of our planet, I took about 45,000 photographs. At first, my approach was scattershot: just take as many pictures as possible. As time went on, though, I began to think of myself as a hunter, silently stalking certain shots. Some eluded me: Brasilia, the capital of Brazil, and Uluru, or Ayers Rock, in Australia. I captured others only after methodical planning: “Today, the skies are supposed to be clear in Jeddah and we’ll be passing nearby in the late afternoon, so the angle of the sun will be good. I need to get a long lens and be waiting at the window, looking in the right direction, at 4:02 because I’ll have less than a minute to get the shot.” Traveling at 17,500 miles per hour, the margin for error is very slim. Miss your opportunity and it may not arise again for another six weeks, depending on the ISS’s orbital path and conditions on the ground.

In an interview with Quartz, Hadfield says the proceeds from the book are being donated to the Red Cross.

The polar flip

posted by Jason Kottke   Jul 16, 2014

Earth Magnetic Field

According to data collected by a European satellite array, the Earth’s magnetic field is shifting and weakening at a greater pace than previously thought. One of the reasons for the shift might be that the magnetic North and South poles are swapping positions.

Scientists already know that magnetic north shifts. Once every few hundred thousand years the magnetic poles flip so that a compass would point south instead of north. While changes in magnetic field strength are part of this normal flipping cycle, data from Swarm have shown the field is starting to weaken faster than in the past. Previously, researchers estimated the field was weakening about 5 percent per century, but the new data revealed the field is actually weakening at 5 percent per decade, or 10 times faster than thought. As such, rather than the full flip occurring in about 2,000 years, as was predicted, the new data suggest it could happen sooner.

You can read up on geomagnetic reversals on Wikipedia. A short sampling:

These periods [of polarity] are called chrons. The time spans of chrons are randomly distributed with most being between 0.1 and 1 million years with an average of 450,000 years. Most reversals are estimated to take between 1,000 and 10,000 years. The latest one, the Brunhes-Matuyama reversal, occurred 780,000 years ago. A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years. During this change the strength of the magnetic field dropped to 5% of its present strength.

What is Mother Earth worth?

posted by Jason Kottke   Jun 12, 2014

A group led by Dr. Robert Costanza has calculated the value of the world’s ecosystems…the group’s most recent estimate puts the yearly value at $142.7 trillion.

“I think this is a very important piece of science,” said Douglas J. McCauley of the University of California, Santa Barbara. That’s particularly high praise coming from Dr. McCauley, who has been a scathing critic of Dr. Costanza’s attempt to put price tags on ecosystem services.

“This paper reads to me like an annual financial report for Planet Earth,” Dr. McCauley said. “We learn whether the dollar value of Earth’s major assets have gone up or down.”

The group last calculated this value back in 1997 and it rose sharply over the past 17 years, even as those natural habitats are disappearing. This line from the article stunned me:

Dr. Costanza and his colleagues estimate that the world’s reefs shrank from 240,000 square miles in 1997 to 108,000 in 2011.

Coral reefs shrank by more than half over the past 17 years…I had no idea the reef situation was that bad. Jesus.

The Moon, closer

posted by Jason Kottke   May 19, 2014

If the Moon orbited the Earth at the same distance as the International Space Station, it might look a little something like this:

At that distance, the Moon would cover half the sky and take about five minutes to cross the sky. Of course, as Phil Plait notes, if the Moon were that close, tidal forces would result in complete chaos for everyone involved.

There would be global floods as a tidal wave kilometers high sweeps around the world every 90 minutes (due to the Moon’s closer, faster orbit), scouring clean everything in its path. The Earth itself would also be stretched up and down, so there would be apocalyptic earthquakes, not to mention huge internal heating of the Earth and subsequent volcanism. I’d think that the oceans might even boil away due to the enormous heat released from the Earth’s interior, so at least that spares you the flood… but replaces water with lava. Yay?

The sixth extinction

posted by Jason Kottke   Feb 12, 2014

About 250 million years ago, Earth suffered its fifth (and worst) mass extinction event. Nearly seventy percent of land species disappeared. And they got off easy compared to marine species. Are we headed for another mass extinction on Earth? I’m not ready to break that news. But something unusual is definitely going on and extinction rates seem to be speeding up. Here’s an interesting chat with Elizabeth Kolbert, author of The Sixth Extinction.

The worst mass extinction of all time came about 250 million years ago [the Permian-Triassic extinction event]. There’s a pretty good consensus there that this was caused by a huge volcanic event that went on for a long time and released a lot of carbon-dioxide into the atmosphere. That is pretty ominous considering that we are releasing a lot of CO2 into the atmosphere and people increasingly are drawing parallels between the two events.