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kottke.org posts about space

One way the universe might end

My favorite astrophysicist Katie Mack recently reposted a Cosmos article she wrote about a relatively obscure model for the total annihilation of the universe, called “vacuum decay.”

Essentially, what vacuum decay relies on is the fact that we don’t know for sure whether space is in the lowest energy, most stable possible state (a true vacuum) or at an adjacent, slightly higher energy level (a false vacuum). Space could be only metastable, and a random quantum fluctuation or sufficiently high level energy event could push part of the universe from the false vacuum to the true one. This could cause “a bubble of true vacuum that will then expand in all directions at the speed of light. Such a bubble would be lethal.”

It’s compellingly badass, and as Mack notes, frightfully efficient. First, it’s not the slow petering out that is heat death. Also, it wouldn’t just eliminate our current universe, but all possibility of a universe anything like ours. Vacuum decay destroys space like Roman generals salting the earth at Carthage.

The walls of the true vacuum bubble would expand in all directions at the speed of light. You wouldn’t see it coming. The walls can contain a huge amount of energy, so you might be incinerated as the bubble wall ploughed through you. Different vacuum states have different constants of nature, so the basic structure of matter might also be disastrously altered. But it could be even worse: in 1980, theoretical physicists Sidney Coleman and Frank De Luccia calculated for the first time that any bubble of true vacuum would immediately suffer total gravitational collapse.

They say: “This is disheartening. The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in a new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it.

“However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some creatures capable of knowing joy. This possibility has now been eliminated.”


First Man

I don’t know why I’m so skeptical about First Man, the upcoming biopic about Neil Armstrong and the first Moon landing. Oh wait, yes I do: Apollo 11 holds a special place in my heart, as does Armstrong and his role in the historic landing, and I’m very protective of it. It would be so easy and, in my opinion, wrong to load this story up with unnecessary drama when there’s already so much there in the story, even though it might not be naturally cinematic.

On the other hand, the trailer looks great, Ryan Gosling is a terrific actor, director Damien Chazelle’s previous films are really good (Whiplash and La La Land), and the film is based on the authorized and well-received biography by James Hansen. Ok fine, I just talked myself into it!


Law & Order: Martian Victims Unit

I loved this imaginative and clever piece by Geoff Manaugh called How Will Police Solve Murders on Mars? about how a future human settlement on Mars would handle matters of law and order. For one things, crimes might be more difficult to investigate.

Consider the basic science of crime-scene analysis. In the dry, freezer-like air and extreme solar exposure of Mars, DNA will age differently than it does on Earth. Blood from blunt-trauma and stab wounds will produce dramatically new spatter patterns in the planet’s low gravity. Electrostatic charge will give a new kind of evidentiary value to dust found clinging to the exteriors of space suits and nearby surfaces. Even radiocarbon dating will be different on Mars, Darwent reminded me, due to the planet’s atmospheric chemistry, making it difficult to date older crime scenes.

The Martian environment itself is also already so lethal that even a violent murder could be disguised as a natural act. Darwent suggested that a would-be murderer on the Red Planet could use the environment’s ambient lethality to her advantage. A fatal poisoning could be staged to seem as if the victim simply died of exposure to abrasive chemicals, known as perchlorates, in the Martian rocks. A weak seal on a space suit, or an oxygen meter that appears to have failed but was actually tampered with, could really be a clever homicide hiding in plain sight.

At a broader level, what sort of political system develops because of the Martian environment might shape how law enforcement happens.

In the precarious Martian environment, where so much depends on the efficient, seamless operation of life-support systems, sabotage becomes an existential threat. A saboteur might tamper with the oxygen generators or fatally disable a settlement’s most crucial airlock. When human life is so thoroughly entwined with its technical environment, we should not consider these sorts of acts mere petty crimes, he explained to me. In a literal sense, they would be crimes against humanity-even, on a large enough scale, attempted genocide.

“I think the fact that tyranny is easier in space is a foregone conclusion,” he explained to me, precisely because there is nowhere to escape without risking instant death from extreme cold or asphyxiation. In other words, the constant presence of nearly instant environmental lethality will encourage systems of strong social control with little tolerance for error. Orders and procedures will need to be followed exactly as designed, because the consequences of a single misstep could be catastrophic.

A few paragraphs after this, the terrifyingly wonderful phrase “politically motivated depressurization” is used. I don’t think we’re super close to the colonization of Mars, but Manaugh says, better to think about it now before we “unwittingly construct an interplanetary dystopia run by cops who shoot first and ask questions later”.


How We Could Build a Moon Base Today

This video explores how humans could begin to colonize the Moon today, using currently available technology.

We actually do have the technology and current estimates from NASA and the private sector say it could be done for $20-40 billion spread out over about a decade. The price is comparable to the International Space Station or the budget surplus of Germany in 2017.

That’s also only 12-25% of the net worth of Jeff Bezos. I don’t know whether that’s more an illustration of the relative affordability of building a Moon base or of Bezos’ wealth, but either way it’s a little bit crazy that the world’s richest man can easily afford to fund the building of a Moon base and somehow it’s not happening (or even close to happening).


A 20-year time lapse of stars orbiting a massive black hole

The European Southern Observatory’s Very Large Telescope in Chile has been watching the supermassive black hole in the center of our galaxy and the stars that orbit it. Using observations from the past 20 years, the ESO made this time lapse video of the stars orbiting the black hole, which has the mass of four million suns. I’ve watched this video like 20 times today, my mind blown at being able to observe the motion of these massive objects from such a distance.

The VLT was also able to track the motion of one of these stars and confirm for the first time a prediction made by Einstein’s theory of general relativity.

New infrared observations from the exquisitely sensitive GRAVITY, SINFONI and NACO instruments on ESO’s Very Large Telescope (VLT) have now allowed astronomers to follow one of these stars, called S2, as it passed very close to the black hole during May 2018. At the closest point this star was at a distance of less than 20 billion kilometres from the black hole and moving at a speed in excess of 25 million kilometres per hour โ€” almost three percent of the speed of light.

S2 has the mass of about 15 suns. That’s 6.6 ร— 10^31 pounds moving at 3% of the speed of light. Wowowow.


Live TV coverage of the Apollo 11 landing and Moon walk

Apollo 11 TV Coverage

In May 1961, President John F. Kennedy stood before Congress and said:

I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.

A little more than 8 years later, it was done. On July 20, 1969, 49 years ago today, Neil Armstrong and Buzz Aldrin landed on the Moon, took a walk, and returned safely to Earth a few days later. And the whole thing was broadcast live on television screens around the world.

For the 40th anniversary of the landing in 2009, I put together a page where you can watch the original CBS News coverage of Walter Cronkite reporting on the Moon landing and the first Moon walk, synced to the present-day time. Just open this page in your browser and the coverage will start playing at the proper time. Here’s the schedule (all times EDT):

4:10:30 pm: Moon landing broadcast starts
4:17:40 pm: Lunar module lands on the Moon

4:20:15 pm: Break in coverage

10:51:27 pm: Moon walk broadcast starts
10:56:15 pm: First step on Moon
11:51:30 pm: Nixon speaks to the Eagle crew
12:00:30 am: Broadcast end (on July 21)

You can add these yearly recurring events to your calendar: Moon landing & Moon walk.

Here’s what I wrote when I launched the project, which is one of my favorite things I’ve ever done online:

If you’ve never seen this coverage, I urge you to watch at least the landing segment (~10 min.) and the first 10-20 minutes of the Moon walk. I hope that with the old time TV display and poor YouTube quality, you get a small sense of how someone 40 years ago might have experienced it. I’ve watched the whole thing a couple of times while putting this together and I’m struck by two things: 1) how it’s almost more amazing that hundreds of millions of people watched the first Moon walk *live* on TV than it is that they got to the Moon in the first place, and 2) that pretty much the sole purpose of the Apollo 11 Moon walk was to photograph it and broadcast it live back to Earth.

I’ve been listening to the audiobook of Andrew Chaikin’s account of the Apollo program, A Man on the Moon, and the chapter about Apollo 11’s Moon landing was riveting.1 I’ve watched the TV footage & listened to the recordings dozens of times and I was still on the edge of my seat, sweating the landing alongside Armstrong and Aldrin. And sweating they were…at least Armstrong was. Take a look at his heart rate during the landing; it peaked at 150 beats per minute at landing (note: the “1000 ft altitude” is mislabeled, it should be “100 ft”):

Neil Armstrong's heart rate during the Apollo 11 Moon landing

For reference, Armstrong’s resting heart rate was around 60 bpm. There are a couple of other interesting things about this chart. The first is the two minutes of missing data starting around 102:36. They were supposed to be 10 minutes from landing on the Moon and instead their link to Mission Control in Houston kept cutting out. Then there were the intermittent 1201 and 1202 program alarms, which neither the LM crew nor Houston had encountered in any of the training simulations. At the sign of the first alarm at 102:38:26, Armstrong’s heart rate actually appears to drop. And then, as the alarms continue throughout the sequence along with Houston’s assurances that the alarm is nothing to worry about, Armstrong’s heart rate stays steady.

Right around the 2000 feet mark, Armstrong realizes that he needs to maneuver around a crater and some rocks on the surface to reach a flat landing spot and his heart rate steadily rises until it plateaus at the landing. At the time, he thought he’d landed with less than 30 seconds of fuel remaining. That Neil Armstrong was able to keep his cool with unknown alarms going off while avoiding craters and boulders with very little fuel remaining and his heart rate spiking while skimming over the surface OF THE FREAKING MOON doing something no one had ever done before is one of the most totally cold-blooded & badass things anyone has ever done. Damn, I get goosebumps just reading about it!

Update: The landing broadcast just aired and I wanted to explain a little about what you saw (you can relive it here).

The shots of the Moon you see during the landing broadcast are animations…there is obviously no camera on the Moon watching the LM descend to the surface. There was a camera recording the landing from the LM but that footage was not released until later. This is in contrast to the footage you’ll see later on the Moon walk broadcast…that footage was piped in live to TV screens all over the world as it happened.

The radio voices you hear are mostly Mission Control in Houston (specifically Apollo astronaut Charlie Duke, who acted as the spacecraft communicator for this mission) and Buzz Aldrin, whose job during the landing was to keep an eye on the LM’s altitude and speed โ€” you can hear him calling it out, “3 1/2 down, 220 feet, 13 forward.” Armstrong doesn’t say a whole lot…he’s busy flying and furiously searching for a suitable landing site. But it’s Armstrong that says after they land, “Houston, Tranquility Base here. The Eagle has landed.”. Note the change in call sign from “Eagle” to “Tranquility Base”. :)

Two things to listen for on the broadcast: the 1201/1202 program alarms I mentioned above and two quick callouts by Charlie Duke about the remaining fuel towards the end: “60 seconds” and “30 seconds”. Armstrong is taking all this information in through his earpiece โ€” the 1202s, the altitude and speed from Aldrin, and the remaining fuel โ€” and using it to figure out where to land.

The CBS animation shows the fake LM landing on the fake Moon before the actual landing โ€” when Buzz says “contact light” and then “engine stop”. The animation was based on the scheduled landing time and evidently couldn’t be adjusted. The scheduled time was overshot because of the crater and boulders situation mentioned above.

Cronkite was joined on the program by former astronaut Wally Schirra. When Armstrong signaled they’d landed, Schirra can be seen dabbing his eyes and Cronkite looks a little misty as well as he rubs his hands together.

  1. The book is read by Bronson Pinchot, who played Balki Bartokomous on the 80s sitcom Perfect Strangers. He is a fantastic audiobook narrator.โ†ฉ


The chaotic clouds of Jupiter

Jupiter Clouds Swirl

This newly released photo of the chaotic clouds of Jupiter would make a great marbled paper pattern.

NASA’s Juno spacecraft took this color-enhanced image at 10:23 p.m. PDT on May 23, 2018 (1:23 a.m. EDT on May 24), as the spacecraft performed its 13th close flyby of Jupiter. At the time, Juno was about 9,600 miles (15,500 kilometers) from the planet’s cloud tops, above a northern latitude of 56 degrees.

The region seen here is somewhat chaotic and turbulent, given the various swirling cloud formations. In general, the darker cloud material is deeper in Jupiter’s atmosphere, while bright cloud material is high. The bright clouds are most likely ammonia or ammonia and water, mixed with a sprinkling of unknown chemical ingredients.

You can view a “charmingly British” short film about making marbled paper right here.


What the uncharted territories of outer space might look like…

Harkening back to when visual effects teams used colorful liquids & chemicals to simulate space travel for films like 2001, Helios uses those same techniques to visualize “what the uncharted territories of outer space might look like”.

Helios considers what the uncharted territories of outer space might look like. It was created as a passion project in my basement studio using various liquids and chemicals. It is staged as an audiovisual stimulus inspired by the aesthetics of vintage NASA space travel.

Having spent my entire childhood in an area lacking both basic infrastructure and light pollution, I developed an escapist obsession for watching the night sky and contemplating. I would constantly get on people’s nerves asking: “What do the limits of the universe look like? And what’s behind that?”

Here’s a look at the process behind the video, along with some high-resolution screencaps.


Those grainy Moon photos from the 60s? The actual high-res images looked so much better.

In 1966 and 1967, NASA sent five spacecraft to orbit the Moon to take high-resolution photos to aid in finding a good landing spot for the Apollo missions. NASA released some photos to the public and they were extremely grainy and low resolution because they didn’t want the Soviet Union to know the capabilities of US spy satellites. Here’s a comparison to what the public saw at the time versus how the photos actually looked:

Old Moon New Moon

The Lunar Orbiters never returned to Earth with the imagery. Instead, the Orbiter developed the 70mm film (yes film) and then raster scanned the negatives with a 5 micron spot (200 lines/mm resolution) and beamed the data back to Earth using lossless analog compression, which was yet to actually be patented by anyone. Three ground stations on earth, one of which was in Madrid, another in Australia and the other in California recieved the signals and recorded them. The transmissions were recorded on to magnetic tape. The tapes needed Ampex FR-900 drives to read them, a refrigerator sized device that cost $300,000 to buy new in the 1960’s.

The high-res photos were only revealed in 2008, after a volunteer restoration effort undertaken in an abandoned McDonald’s nicknamed McMoon.

They were huge files, even by today’s standards. One of the later images can be as big as 2GB on a modern PC, with photos on top resolution DSLRs only being in the region of 10MB you can see how big these images are. One engineer said you could blow the images up to the size of a billboard without losing any quality. When the initial NASA engineers printed off these images, they had to hang them in a church because they were so big. The below images show some idea of the scale of these images. Each individual image when printed out was 1.58m by 0.4m.

You can view a collection of some of the images here.


Jeff Bezos sees space as the “only” option to spend his money on

Jeff Bezos

Jeff Bezos is super rich, $131 billion kind of rich. Business wise, an admirable drive, some incredible ideas, and a very forward looking mind, playing three dimensional chess some might say. And yet, when considering what he might do with his fortune, he was a bit disappointing.

The only way that I can see to deploy this much financial resource is by converting my Amazon winnings into space travel. That is basically it, […] the most important work that I’m doing.

Blue Origin is expensive enough to be able to use that fortune, I am currently liquidating about $1 billion a year of Amazon stock to fund Blue Origin. And I plan to continue to do that for a long time. Because you’re right, you’re not going to spend it on a second dinner out.

Going to space is a great dream but I’m not sure it’s the only thing worth spending billions on. And I’m not the only one.

Great discoveries have come out of our space dreams and accomplishments, I’m sure many more will. Just look at what Elon Musk has done in a few years. Bezos’ comment was, at the very least, tone deaf. If he’s such a great leader, he should also lead for the greater good now, not just for far away dreams of space.


A high-resolution tour of the Moon from NASA

Using imagery and data that the Lunar Reconnaissance Orbiter spacecraft has collected since 2009, NASA made this video tour of the Moon in 4K resolution. This looked incredible on my iMac screen.

As the visualization moves around the near side, far side, north and south poles, we highlight interesting features, sites, and information gathered on the lunar terrain.

See also The 100-megapixel Moon and A full rotation of the Moon.


“Oh My God!” People’s Reactions to Looking at the Moon Through a Telescope.

Wylie Overstreet and Alex Gorosh took a telescope around the streets of LA and invited people to look at the Moon through it. Watching people’s reactions to seeing such a closeup view of the Moon with their own eyes, perhaps for the first time, is really amazing.

Whoa, that looks like that’s right down the street, man!

I often wonder what the effect is of most Americans not being able to see the night sky on a regular basis. As Sriram Murali says:

The night skies remind us of our place in the Universe. Imagine if we lived under skies full of stars. That reminder we are a tiny part of this cosmos, the awe and a special connection with this remarkable world would make us much better beings โ€” more thoughtful, inquisitive, empathetic, kind and caring. Imagine kids growing up passionate about astronomy looking for answers and how advanced humankind would be, how connected and caring we’d feel with one another, how noble and adventurous we’d be.


Are These Photographs of Moons or Pancakes?

Pancake Moons

Pancake Moons

Pancake Moons

Nadine Schlieper and Robert Pufleb have published a book called Alternative Moons. The book is filled with photographs of pancakes that look like moons.

See also Christopher Jonassen’s photos of frying pans that look like Europa, one of Jupiter’s moons. Oh, and don’t forget about the world’s best pancake recipe.


The Falcon Heavy launch, space advertising for billionaires, and the beauty of science

I’ve slept on it and my mind & soul are still reeling from the SpaceX launch of Falcon Heavy yesterday. I can’t tell you why exactly, but when the two side boosters landed safely back on Earth at nearly the same instant, as in a beautifully choreographed ballet, I nearly burst into tears. Just watching the replay gets me all verklempt:

Of course, the boosters were supposed to land at the same time. They broke away from the main stage at the same time and were controlled by identical computer systems in their descent; it’s a simple matter of high school physics to solve for the time it takes two uniform objects to travel from point A to point B. But as Richard Feynman said about the beauty of a flower, knowing the science makes moments like this more wondrous.

And then right after that, the video showed what appears to be a human driving a car in Earth orbit to the strains of David Bowie’s Life on Mars. What an incredible, ridiculous, ludicrous thing:

SpaceX Carman

There is ample prior art, but I suspect Elon Musk launching a Tesla Roadster into orbit will go down in history as the first notable advertisement in space, a marketing stunt for the ages. However, it seems problematic that billionaires can place billboards in orbit and then shoot them willy nilly into the asteroid belt without much in the way of oversight. As the Roadster recedes from Earth and our memory, will it become just another piece of trash carelessly tossed by humanity into a pristine wilderness, the first of many to come? Or as it ages, will it become an historic artifact, a orbiting testament to the achievement and naivety of early 21st century science, technology, and culture? It’s not difficult to imagine, 40 or 50 years from now, space tourists visiting the Roadster on its occasional flybys of Mars and Earth. I wonder what they’ll think of all this?

Update: The Roadster has been assigned an interplanetary ID by NASA: Tesla Roadster (AKA: Starman, 2018-017A). Using data from a Chilean telescope, astronomers have been able to figure out how fast the car is tumbling in space from the changes in brightness: 1 rotation every ~4.8 minutes (although there’s some disagreement in the comments that it might be twice that). At any rate (har har), here’s a time lapse video of the car taken with the 4.1-m SOAR telescope in Chile:

Astrophotographer Rogelio Bernal Andreo also captured the Roadster moving across the sky in this video:


Watch the Falcon Heavy launch live at 2:20pm ET today

SpaceX is scheduled to launch their massive new rocket for the first time today. You can catch a live stream of the launch here:

When Falcon Heavy lifts off, it will be the most powerful operational rocket in the world by a factor of two. With the ability to lift into orbit nearly 64 metric tons (141,000 lb) โ€” a mass greater than a 737 jetliner loaded with passengers, crew, luggage and fuel โ€” Falcon Heavy can lift more than twice the payload of the next closest operational vehicle, the Delta IV Heavy, at one-third the cost. Falcon Heavy draws upon the proven heritage and reliability of Falcon 9.

As part of the launch, the three engine cores will land back on Earth, as they have been doing for years now with their other rockets. You can watch an animation of how they hope the launch will go:

The payload for this rocket test is SpaceX CEO Elon Musk’s red Tesla Roadster. No, really. If all goes as planned, the Roadster and its passenger (a dummy wearing a SpaceX suit) will be put into an orbit around the Sun somewhere in the vicinity of Mars, driving around the solar system for a billion years. SpaceX isn’t saying exactly where the Roadster might end up, but engineer Max Fagin has a guess about its eventual orbit:

You can read more about the launch from Phil Plait and on PBS NewsHour.

Update: The new time for the launch is 2:20pm ET. The launch window lasts until 4pm ET.


Flyover video of Jupiter’s Europa

NASA engineer Kevin Gill stitched together images from two 1998 observations of Europa by the Galileo spacecraft to create this super smooth flyover video of the icy Jovian moon. The details:

Processed using low resolution color images (IR, Green, Violet) from March 29 1998 overlaying higher resolution unfiltered images taken September 26 1998. Map projected to Mercator, scale is approximately 225.7 meters per pixel, representing a span of about 1,500 kilometers.


A time lapse video where you can actually see the Crab Nebula expanding

The Crab Nebula is the result of a supernova that happened 6,500 light years away from Earth. From our perspective, the supernova happened almost 1000 years ago, in July, 1054. Using a home-built telescope, amateur astronomer Detlef Hartmann took a photos of the Crab Nebula over a ten-year period and assembled them into a time lapse video of the nebula’s expansion. Even after a millennia and across all that distance, the expansion of the nebula is clearly visible. And why not, those gases are moving at a clip of 1400 kilometers per second (more than 3 million miles per hour or 0.5% the speed of light).

As Phil Plait notes, we’re used to seeing things in our solar system move in the skies, but far-away bodies? That’s just weeeeeird.

Sure, the Moon moves in the sky, and the planets around the Sun, but deep sky objects โ€” stars, nebulae, galaxies โ€” are so distant that any physical motion at all is incredibly difficult to detect. They may as well be frozen in time. Being able to see it… that’s astonishing.

Hartmann’s is not the first Crab Nebula animation; I also found animations using images from 2002 & 2012, 1973 & 2001, 1999 & 2012, and 1950 & 2000. Someone with an interest in astronomy and photo/video editing should put all these views together into one 68-year time lapse of the nebula’s expansion.


Photos from the Curiosity rover’s 2000 days on Mars

Mars Curiosity Photos

Mars Curiosity Photos

Mars Curiosity Photos

NASA’s Curiosity rover has been on Mars for more than 2000 days now, and it has sent back over 460,000 images of the planet. Looking at them, it still boggles the mind that we can see the surface of another planet with such clarity, like we’re looking out the window at our front yard. Alan Taylor has collected a bunch of Curiosity’s photos from its mission, many of which look like holiday snapshots from the rover’s trip to the American Southwest.


Lost in Light: How Light Pollution Obscures Our View of the Night Sky

Because of light pollution from urban areas, many people around the world don’t know what the night sky actually looks like. Sriram Murali made a video to illustrate light pollution levels by shooting the familiar constellation of Orion in locations around the US with different amounts of light pollution, from bright San Francisco to a state park in Utah with barely any light at all. In SF, about all you can see are the handful of stars that make up Orion’s belt, arms, and legs. But as the locations get darker, the sky explodes in detail and Orion is lost among the thousands of visible stars (and satellites if you look closely).

This video is a followup to one Murali made of the Milky Way in increasingly dark locations, which is even more dramatic:

But he did the second video with Orion as a reference because many people had no concept of what the Milky Way actually looks like because they’ve never seen it before. Murali explains why he thinks light pollution is a problem:

The night skies remind us of our place in the Universe. Imagine if we lived under skies full of stars. That reminder we are a tiny part of this cosmos, the awe and a special connection with this remarkable world would make us much better beings โ€” more thoughtful, inquisitive, empathetic, kind and caring. Imagine kids growing up passionate about astronomy looking for answers and how advanced humankind would be, how connected and caring we’d feel with one another, how noble and adventurous we’d be.

The measurement scale for sky darkness is called the Bortle scale, as explained by David Owen in his wonderful piece in the New Yorker:

In Galileo’s time, nighttime skies all over the world would have merited the darkest Bortle ranking, Class 1. Today, the sky above New York City is Class 9, at the other extreme of the scale, and American suburban skies are typically Class 5, 6, or 7. The very darkest places in the continental United States today are almost never darker than Class 2, and are increasingly threatened. For someone standing on the North Rim of the Grand Canyon on a moonless night, the brightest feature of the sky is not the Milky Way but the glow of Las Vegas, a hundred and seventy-five miles away. To see skies truly comparable to those which Galileo knew, you would have to travel to such places as the Australian outback and the mountains of Peru.

Nicola Twilley and Geoff Manaugh interviewed Paul Bogard, author of a book on darkness about light pollution and the Bortle scale:

Twilley: It’s astonishing to read the description of a Bortle Class 1, where the Milky Way is actually capable of casting shadows!

Bogard: It is. There’s a statistic that I quote, which is that eight of every ten kids born in the United States today will never experience a sky dark enough to see the Milky Way. The Milky Way becomes visible at 3 or 4 on the Bortle scale. That’s not even down to a 1. One is pretty stringent. I’ve been in some really dark places that might not have qualified as a 1, just because there was a glow of a city way off in the distance, on the horizon. You can’t have any signs of artificial light to qualify as a Bortle Class 1.

A Bortle Class 1 is so dark that it’s bright. That’s the great thing โ€” the darker it gets, if it’s clear, the brighter the night is. That’s something we never see either, because it’s so artificially bright in all the places we live. We never see the natural light of the night sky.

If you’d like to find a place near you with less light pollution, check out The Light Pollution Map. I’m lucky enough to live in a place with a Bortle class of 3 and I’ve visited class 2 locations before…visiting one of the class 1 parks out west is definitely on my bucket list.


The 2017 Hubble Space Telescope Advent Calendar

Hubble Advent 2017

From Alan Taylor at In Focus, the 10th anniversary installment of the Hubble Space Telescope Advent Calendar. One image taken by the Hubble for each day in December leading up to Dec 25th. Here’s Taylor’s caption for the image above:

A Caterpillar in the Carina Nebula. Scattered across the enormous Carina nebula are numerous dense clumps of cosmic gas and dust called Bok globules, including this one, which resembles a huge glowing caterpillar. First described by by astronomer Bart Bok, the globules are relatively small, dark, and cold regions made up of molecular hydrogen, carbon oxides, helium, and dust. The glowing edge of the caterpillar indicates that it is being photoionized by the hottest stars in the surrounding cluster. It has been hypothesized that stars may form inside these dusty cocoons.


Voyager 1 just fired its trajectory thrusters for the first time since 1980

Nasa Voyager

The last time that the four trajectory thrusters on the Voyager 1 probe were fired, Jimmy Carter was still President of the United States. But with the main attitude control thrusters deteriorating from trying to keep the probe oriented correctly, the team thought they could keep the mission going using the trajectory thrusters. So they fired them up.

On Tuesday, Nov. 28, 2017, Voyager engineers fired up the four TCM thrusters for the first time in 37 years and tested their ability to orient the spacecraft using 10-millisecond pulses. The team waited eagerly as the test results traveled through space, taking 19 hours and 35 minutes to reach an antenna in Goldstone, California, that is part of NASA’s Deep Space Network.

Lo and behold, on Wednesday, Nov. 29, they learned the TCM thrusters worked perfectly โ€” and just as well as the attitude control thrusters.

Voyager 1 was launched in 1977, is currently more than 13 billion miles from Earth, and is still functional and doing science. Incredible.


Google Maps in space: spinnable maps of our solar system’s planets & moons

Google Maps Io

Maaaaps! Innnnn! Spaaaaaaaace! Google Maps now features spinnable spherical maps of several planets and moons in our solar system, including Mars, the Moon, Io, Pluto, Enceladus, Titan, and Charon. Super fun. Here’s Google’s blog post about the new maps. (via emily lakdawalla)


The first asteroid from outside our solar system pays us a visit

Asteroid Oumuamua

Back in October, the solar system welcomed a visitor from interstellar space…the first interstellar asteroid ever detected.

Astronomers have confirmed that an object that recently passed by our planet is from outside our Solar System โ€” the first interstellar asteroid that’s ever been observed. And it doesn’t look like any object we’ve ever seen in our cosmic neighborhood before.

Follow-up observations, detailed today in Nature, have found that the asteroid is dark and reddish, similar to the objects in the outer Solar System. It doesn’t have any gas or dust surrounding it, like comets do, and it’s stretched long and skinny, looking a bit like an oddly shaped pen. It’s thought to be about a quarter-mile long, and about 10 times longer than it is wide. That makes it unlike any asteroids seen in our Solar System, none of which are so elongated.

Here’s a video of the asteroid’s path through the solar system:

Um, folks…that looks like a rocket. How do we know this “asteroid” isn’t actually an ancient alien ship that’s become encrusted with rock over millions of years? Or an ancient weapon gone awry? We’ve all seen the first Star Trek movie, right? (I am only a little bit kidding about this.)

Update: Scientists โ€” or at least one scientist who has a billionaire’s ear โ€” think that’s there’s something a little odd about Oumuamua, so they’re going to check it for radio signals. Spoiler: they’re not going to find any, but wouldn’t it be fun if they did!?

Update: They listened and did not find any radio signals coming from Oumuamua.

Update: As of October 2018, here’s what we know about Oumuamua.

A few months later, another collaboration found that ‘Oumuamua wasn’t just being pulled by the sun’s gravity. Instead, it was being slightly accelerated by an unseen force, which they argued could only be attributed to comet “outgassing” acting like a thruster. With this additional information, the case appeared to be closed. “Interstellar asteroid is really a comet,” read the headline of a press release put out by the European Space Agency.


Jimmy Iovine and most bomb record in the solar system

While preparing for a conference talk/conversation I’m doing in Amsterdam this weekend, I was reading about the Golden Record that NASA sent along as a potential greeting from Earth to alien civilizations who might run across the Voyager probes in interstellar space millions of years from now. For the 40th anniversary of the Voyager launches, science writer Timothy Ferris (author of the Pulitzer-nominated Coming of Age in the Milky Way) wrote about the production of the Record for the New Yorker.

In the winter of 1976, Carl was visiting with me and my fiancee at the time, Ann Druyan, and asked whether we’d help him create a plaque or something of the sort for Voyager. We immediately agreed. Soon, he and one of his colleagues at Cornell, Frank Drake, had decided on a record. By the time nasa approved the idea, we had less than six months to put it together, so we had to move fast. Ann began gathering material for a sonic description of Earth’s history. Linda Salzman Sagan, Carl’s wife at the time, went to work recording samples of human voices speaking in many different languages. The space artist Jon Lomberg rounded up photographs, a method having been found to encode them into the record’s grooves. I produced the record, which meant overseeing the technical side of things. We all worked on selecting the music.

Carl Sagan was project director, Ann Druyan the creative director, and Ferris produced the Record. And the sound engineer for the Golden Record? I was surprised to learn: none other than Jimmy Iovine, who was recommended to Ferris by John Lennon.

I sought to recruit John Lennon, of the Beatles, for the project, but tax considerations obliged him to leave the country. Lennon did help us, though, in two ways. First, he recommended that we use his engineer, Jimmy Iovine, who brought energy and expertise to the studio. (Jimmy later became famous as a rock and hip-hop producer and record-company executive.)

Lennon, Springsteen, Tom Petty, Patti Smith, Stevie Nicks, Interscope, Dre, Snoop, Death Row Records, Eminem, Lady Gaga, Beats By Dre, Apple, *and* The Golden Record? Iovine is like the record industry’s Forrest Gump or something. How was this not in The Defiant Ones?


How to make an Extremely Large Telescope

The Giant Magellan Telescope, currently under construction at the University of Arizona’s Mirror Lab, will be one of the first of a new class of telescopes called Extremely Large Telescopes. The process involved in fashioning the telescope’s seven massive mirrors is fascinating. This is one of those articles littered with mind-boggling statements at every turn. Such as:

“We want the telescope to be limited by fundamental physics โ€” the wavelength of light and the diameter of the mirror โ€” not the irregularities on the mirror’s surface,” says optical scientist Buddy Martin, who oversees the lab’s grinding and polishing operations. By “irregularities,” he’s talking about defects bigger than 20 nanometers โ€” about the size of a small virus. But when the mirror comes out of the mold, its imperfections can measure a millimeter or more.

Precision of 20 nanometers on something more than 27 feet in diameter and weighing 17 tons? That’s almost unbelievable. In this video, Dr. Wendy Freedman, former chair of the board of directors for the GMT project, puts it this way:

The surface of this mirror is so smooth that if we took this 27-foot mirror and then spread it out, from coast-to-coast in the United States, east to west coast, the height of the tallest mountain on that mirror would be about 1/2 an inch. That’s how smooth this mirror is.

You need that level of smoothness if you’re going to achieve better vision than the Hubble:

With a resolving power 10 times that of the Hubble Space Telescope, the GMT is designed to capture and focus photons emanating from galaxies and black holes at the fringes of the universe, study the formation of stars and the worlds that orbit them, and search for traces of life in the atmospheres of habitable-zone planets.

The telescope has a price tag of $1 billion and should be operational within the the next five years in Chile.


Gorgeous computer-generated animation of a nebula

Designed by Teun van der Zalm, Nebulae is a computer generated nebula set to atmospheric music by Lee Rosevere. Worth seeking out a large screen for viewing. Several of van der Zalm’s other videos are equally beautiful variations on the same theme.


The 100-megapixel Moon

100 Megapixel Moon

Seรกn Doran used images from the Lunar Reconnaissance Orbiter to create this 100-megapixel image of the Moon (full 10000x10000 pixel image here). Phil Plait explains how Doran made the image:

LRO WAC images have a resolution of about 100 meters per pixel over a swath of about 60 km of lunar surface (using what’s called the pushbroom technique, similar to how a flatbed scanner works). They are usually taken straight down, toward the spacecraft nadir (the opposite of the zenith). To get the correct perspective for the Moon as a globe, Doran took the images, along with altimeter data, and mapped them onto a sphere. That way features near the edge look foreshortened, as they really do when you look at the entire Moon. He also used Apollo images to make sure things lined up. So the image isn’t exactly scientifically rigorous, but it is certainly spectacular.

The image is also available at Gigapan for easier exploration.


The Universe is much bigger than it is old

In a Twitter thread, author Oliver Morton compares the physical scale of the Universe with its age (from the perspective of humans).

If a human life is 70 years long, there has been room for 200 million lives since the big bang, but 200 million humans, end to end, would reach just a bit further than the moon. If you had started walking towards the centre of the galaxy on the day of the big bang (had there been days, you, paths & galaxies), you would have got about 20 parsecs by now: just 0.25% of the way.

Maybe walking pace is the wrong metric. A nerve impulse travels around 70 times faster than a person walks. But even at the speed of thought, the age of the universe is too small for something to have reached the centre of the galaxy.

The situation is even worse when you choose another reference object, like UY Scuti, the largest known star. The red hypergiant is nearly 1.5 billion miles across and, because of its size and position near the center of the galaxy, is probably around 13 billion years old, just a few hundred million years younger than the age of the Universe itself.

Even if you use light as a marker, the size of Universe remains unfathomably immense. Over the course of the Universe’s lifetime, a photon could have travelled 13.8 billion light-years, just 15% of the current estimate of the Universe’s diameter of 93 billion light-years. See also what are the physical limits of humanity?


The Astronomy Photographer of the Year for 2017

Astronomy Photo 2017

Astronomy Photo 2017

Astronomy Photo 2017

Put on by the Royal Observatory Greenwich, The Astronomy Photographer of the Year is the largest competition of its kind in the world. For the 2017 awards, more than 3800 photos were entered from 91 countries. It’s astounding to me that many of these were taken with telescopes you can easily buy online (granted, for thousands of dollars) rather than with the Hubble or some building-sized scope on the top of a mountain in Chile.

The photos above were taken by Andriy Borovkov, Alexandra Hart, and Kamil Nureev.


SpaceX wants to send people to Mars by 2024

Spacex BFR

Elon Musk says SpaceX is on target to send cargo to Mars in 2022 and people in 2024. The way the company will do it is by focusing its resources on a new vehicle, the Interplanetary Transport System (codename: the BFR). That vehicle will be able to travel to Mars, but can also be used to generate revenue for the company through launching satellites, resupplying the ISS, and going to the Moon.

Musk also proposed a variety of new uses for the scaled-down rocket beyond just going to Mars. Supposedly, the ITS can be used to launch satellites, take cargo to the International Space Station, and even do lunar missions to set up a Moon base. SpaceX’s current Falcon 9 fleet is used to do a few of those things already, but Musk says eventually the company will turn to the ITS to do all of its space missions.

“We can build a system that cannibalizes our own products, makes our own products redundant, then all the resources we use for Falcon Heavy and Dragon can be applied to one system,” he said at the conference. Musk says the cost of launching cargo on the ITS will be fairly cheap, too, since the rocket and spaceship will be a fully reusable system โ€” unlike the Falcon 9, which is only 70 to 80 percent reusable.

Musk also astoundingly asserted that the same rocket system could be used for long-distance travel on Earth.

He ended his talk with a pretty incredible promise: using that same interplanetary rocket system for long distance travel on Earth. Musk showed a demonstration of the idea on stage, claiming that it will allow passengers to take “most long distance trips” in just 30 minutes, and go “anywhere on Earth in under an hour” for around the same price of an economy airline ticket.

As they say, “huge if true”. Musk is like the sci-fi Oprah here: You get a electric car! And you get a trip to Mars! And you get a self-driving car! And you get a 30-minute Hyperloop trip from SF to LA! And you get a rocket shuttle from NYC to Mumbai in 43 minutes for $1200! Beeeeeeeeees!!!!