kottke.org posts about Earth
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)
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.
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.
Full-screen this baby on the biggest high-definition screen you can find. A 5K iMac works spectacularly well.
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:
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!
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)
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.
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.
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)
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.
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?
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 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.
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.
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.
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.
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.
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?
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.
In a fly-by of Earth on its way to Jupiter, NASA’s Juno probe took a short movie of the Moon orbiting the Earth. It’s the first time the Moon’s orbit has been captured on film.
Scientists from an advanced alien society have discovered a potentially remarkable planet that turns out to be “completely hostile to life”.
“Theoretically, this place ought to be perfect,” leading Terxus astrobiologist Dr. Srin Xanarth said of the reportedly blighted planet located at the edge of a spiral arm in the Milky Way galaxy. “When our long-range satellites first picked it up, we honestly thought we’d hit the jackpot. We just assumed it would be a lush, green world filled with abundant natural resources. But unfortunately, its damaged biosphere makes it wholly unsuitable for living creatures of any kind.”
“It’s basically a dead planet,” she added. “We give it another 200 years, tops.”
The alien researchers stated that the dramatically warming atmosphere of RP-26 contains alarming amounts of carbon dioxide and methane, as well as an ozone layer that-for reasons they cannot begin to fathom-has been allowed to develop a gaping hole. They also noted the presence of melting polar icecaps, floods, and enough pollutants to poison “every last drop of the planet’s fresh water, if you can even call it that.”
You finally really did it. You maniacs! You blew it up! God damn you! God damn you all to hell!
A pair of scientists looked at the rate at which the complexity of life increases and then extrapolated back to a point of zero complexity, aka the origin of life. The answer they came up with is 9.7 ± 2.5 billion years ago. Which is much older than the Earth. This idea has some provocative implications:
Sharov and Gordon say their interpretation also explains the Fermi paradox, which raises the question that if the universe is filled with intelligent life, why can’t we see evidence of it.
However, if life takes 10 billion years to evolve to the level of complexity associated with humans, then we may be among the first, if not the first, intelligent civilisation in our galaxy. And this is the reason why when we gaze into space, we do not yet see signs of other intelligent species.
There’s nothing like a composite photo of the Perseids meteor shower to hammer home the realization that the Earth is hurtling through space like the Millennium Falcon making the Kessel Run. Photo by David Kingham.
Where have I seen this before, a massive long-lasting Arctic storm that looks a lot like a hurricane? Oh right, The Day After Tomorrow.
The storm had an unusually low central pressure area. Paul A. Newman, chief scientist for Atmospheric Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Md., estimates that there have only been about eight storms of similar strength during the month of August in the last 34 years of satellite records. “It’s an uncommon event, especially because it’s occurring in the summer. Polar lows are more usual in the winter,” Newman said.
Arctic storms such as this one can have a large impact on the sea ice, causing it to melt rapidly through many mechanisms, such as tearing off large swaths of ice and pushing them to warmer sites, churning the ice and making it slushier, or lifting warmer waters from the depths of the Arctic Ocean.
I love The Day After Tomorrow. I know it’s a cheeseball disaster movie (which is pretty much why I love it) but it’s also looking more than a little prescient. Well, as prescient as a cheeseball disaster movie can be anyway. In the Washington Post the other day, prominent climatologist James Hansen wrote that human-driven climate change is responsible for an increase in extreme weather.
My projections about increasing global temperature have been proved true. But I failed to fully explore how quickly that average rise would drive an increase in extreme weather.
In a new analysis of the past six decades of global temperatures, which will be published Monday, my colleagues and I have revealed a stunning increase in the frequency of extremely hot summers, with deeply troubling ramifications for not only our future but also for our present.
This is not a climate model or a prediction but actual observations of weather events and temperatures that have happened. Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change.
In many ways, the phrase “global warming” is grossly misleading. “Oh,” we think, “it’s gonna be a couple degrees warmer in NYC in 20 years than it is now.” But the Earth’s climate is a chaotic non-linear system, which means that a sudden shift of a degree or two — and when you’re talking about something as big as the Earth, a degree over several decades is sudden — pushes things out of balance here and there in unpredictable ways. So it’s not just that it’s getting hotter, it’s that you’ve got droughts in places where you didn’t have them before, severe floods in other places, unusually hot summers, and even places that are cooler than normal, all of which disrupts the animal and plant life that won’t be able to acclimate to the new reality fast enough.
But pretty Arctic cyclone though, right?
What if Mars orbited the Earth at the same distance as the Moon…what would that look like? How about Neptune? Or Jupiter? Like this:
See also what the Earth would look like with Saturn’s rings. (via @stevenstrogatz)
Well, now, this is gorgeous. Stamen Design overlaid watercolor textures on OpenStreetMap map tiles to show you what it would look like if your favorite watercolorist designed Google Maps.
It’s fun to scroll and scroll. (via @tomcoates)
And since we all could stand to look at more pretty things, watch this video of what different landscapes would look like if Earth had Saturn’s rings. (via @ianmurren)
Space always seems so far away and much of it actually is. But space is actually quite close to where we are all sitting right now. The Kármán line, the commonly accepted boundary between the Earth’s atmosphere and space, is only 62 miles above sea level.
The line was named after Theodore von Kármán, (1881-1963) a Hungarian-American engineer and physicist who was active primarily in the fields of aeronautics and astronautics. He first calculated that around this altitude the Earth’s atmosphere becomes too thin for aeronautical purposes (because any vehicle at this altitude would have to travel faster than orbital velocity in order to derive sufficient aerodynamic lift from the atmosphere to support itself). Also, there is an abrupt increase in atmospheric temperature and interaction with solar radiation.
A distance of 62 miles can covered by a car on the interstate in less than an hour. Stable Earth orbits are achievable at only 100 miles above the Earth, with the ISS and Space Shuttles usually orbiting at a height of ~200 miles. To show how small a distance that really is, I made the following image…the orange line in the upper left represents 200 miles away from the surface.
The Cassini spacecraft caught this remarkable photo of Saturn eclipsing the Sun in 2006.
Click through for the big image and the massive image. If you look close can see the Earth in the image, for reals!