The first video of the Moon orbiting the Earth
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.
(via @DavidGrann)
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kottke.org posts about astronomy
A canyon of fire on the Sun
NASA’s Solar Dynamics Observatory is getting some really amazing shots of the Sun, including this 200,000 mile-long solar eruption that left a huge canyon on the surface of the Sun:
Different wavelengths help capture different aspect of events in the corona. The red images shown in the movie help highlight plasma at temperatures of 90,000° F and are good for observing filaments as they form and erupt. The yellow images, showing temperatures at 1,000,000° F, are useful for observing material coursing along the sun’s magnetic field lines, seen in the movie as an arcade of loops across the area of the eruption. The browner images at the beginning of the movie show material at temperatures of 1,800,000° F, and it is here where the canyon of fire imagery is most obvious.
The level of detail shown is incredible. (via @DavidGrann)
The new hotness: using gravity waves to map the universe
Light (aka electromagnetic radiation) is responsible for most of what we know about the universe. By measuring photons of various frequencies in different ways — “the careful collection of ancient light” — we’ve painted a picture of our endless living space. But light isn’t perfect. It can bend, scatter, and be blocked. Changes in gravity are more difficult to detect, but new instruments may allow scientists to construct a different map of the universe and its beginnings.
LIGO works by shooting laser beams down two perpendicular arms and measuring the difference in length between them-a strategy known as laser interferometry. If a sufficiently large gravitational wave comes by, it will change the relative length of the arms, pushing and pulling them back and forth. In essence, LIGO is a celestial earpiece, a giant microphone that listens for the faint symphony of the hidden cosmos.
Like many exotic physical phenomena, gravitational waves originated as theoretical concepts, the products of equations, not sensory experience. Albert Einstein was the first to realize that his general theory of relativity predicted the existence of gravitational waves. He understood that some objects are so massive and so fast moving that they wrench the fabric of spacetime itself, sending tiny swells across it.
How tiny? So tiny that Einstein thought they would never be observed. But in 1974 two astronomers, Russell Hulse and Joseph Taylor, inferred their existence with an ingenious experiment, a close study of an astronomical object called a binary pulsar [see “Gravitational Waves from an Orbiting Pulsar,” by J. M. Weisberg et al.; Scientific American, October 1981]. Pulsars are the spinning, flashing cores of long-exploded stars. They spin and flash with astonishing regularity, a quality that endears them to astronomers, who use them as cosmic clocks. In a binary pulsar system, a pulsar and another object (in this case, an ultradense neutron star) orbit each other. Hulse and Taylor realized that if Einstein had relativity right, the spiraling pair would produce gravitational waves that would drain orbital energy from the system, tightening the orbit and speeding it up. The two astronomers plotted out the pulsar’s probable path and then watched it for years to see if the tightening orbit showed up in the data. The tightening not only showed up, it matched Hulse and Taylor’s predictions perfectly, falling so cleanly on the graph and vindicating Einstein so utterly that in 1993 the two were awarded the Nobel Prize in Physics.
The moon rocket asteroid
An amateur astronomer discovered asteroid J002E3 orbiting the Earth in 2002. By observing how the object was moving and measuring its spectrum, it was determined that the asteroid was man-made and probably the third stage of Apollo 12’s Saturn V rocket.
In early September 2002, spectral and photometric observations of J002E3 were made at IRTF and Mt. Biglow in an effort to determine whether the object was an asteroid or a human-made. Early observations yielded a possible spin-rate and orientation. Additional spectral observations were completed in May 2003 at the Air Force Maui Optical Supercomputing (AMOS) site. Through the modeling of common spacecraft materials, the observations of J002E3 show a strong correlation of absorption features to a combination of human-made materials including white paint, black paint, and aluminum. Absorption features in the near IR show a strong correlation with paint containing a titanium-oxide semiconductor. Using the material model and the orbital information, it was concluded that J002E3 is a human-made object from an Apollo rocket upperstage, most likely Apollo 12.
Here’s a cool animation showing how the Earth’s gravity temporarily captured J002E3.
The Night Light
Paul Bogard recently published a book on darkness called The End of Night. Nicola Twilley and Geoff Manaugh interviewed Bogard about the book, the night sky, astronomy, security, cities, and prisons, among other things. The interview is interesting throughout but one of my favorite things is this illustration of 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-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.
I can also recommend reading David Owen’s 2007 NYer piece on light pollution.
The Sun telescope
Turning the Sun into a giant radio telescope through gravitational lensing will take some work, but it is possible.
An Italian space scientist, Claudio Maccone, believes that gravitational lensing could be used for something even more extraordinary: searching for radio signals from alien civilizations. Maccone wants to use the sun as a gravitational lens to make an extraordinarily sensitive radio telescope. He did not invent the idea, which he calls FOCAL, but he has studied it more deeply than anyone else. A radio telescope at a gravitational focal point of the sun would be incredibly sensitive. (Unlike an optical lens, a gravitational lens actually has many focal points that lie along a straight line, called a focal line; imagine a line running through an observer, the center of the lens, and the target.) For one particular frequency that has been proposed as a channel for interstellar communication, a telescope would amplify the signal by a factor of 1.3 quadrillion.
Hollywood Star Charts
New prints in the Dorothy shop: these really cool Hollywood Star Charts, available in Golden Age and Modern Day editions.
The Modern Day version of our Hollywood Star Chart features constellations named after some of the most culturally significant films to have appeared on the silver screen since 1960 - present day. The stars that make up the clusters are the Hollywood stars that appeared in them.
The chart is based on the night sky over New York on June 16th 1960 — the date of the first showing of Hitchcock’s ‘Psycho’ at the DeMille Theater. With its new approach to storytelling, characterisation and violence it is seen as a key movie in the start of the post-classical era of Hollywood.
The 108 films featured include those chosen for preservation in the US National Film Registry due to their cultural, historical, or aesthetic significance; Academy Award winners; and a few personal favourites. Films include Easy Rider, Bonnie and Clyde, The Exorcist, The Godfather, Chinatown, Star Wars, Pulp Fiction and Avatar.
You may remember Dorothy from their movie name maps.
Watch the skies
Coudal Partners travelled to rural Nevada to capture this 6 hour and 21 minute real time film of the night sky.
Click through to YouTube to watch it in the original 4K resolution, which is much better than even 1080p. They produced the video in conjunction with the Night Sky edition of their Field Notes notebooks.
Meme star chart
From XKCD, a chart of the memes that various star systems are just hearing from the Earth’s light-speed communications.
This is the meme version of Contact’s opening credits scene, which is one of my favorites:
It’s a bird, it’s a plane, no, it’s a bolide!
Since 861 AD, almost 35,000 meteorites were recorded hitting the Earth but only 1,045 were actually seen falling. This animated infographic is a good way to visualize the data. Bolides is the perfect domain name. (via @DavidGrann)
Video portrait of the Sun
In complete defiance of its parents, NASA’s Solar Dynamics Observatory has stared directly at the Sun for the past three years. Here’s a video of those three years made from still images taken by the SDO.
During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits the Earth at 6,876 miles per hour and the Earth orbits the sun at 67,062 miles per hour.
The video notes say the animation uses two images per day…it would be nice to see the same animation with a higher frame rate. (via ★interesting)
Trippin’ to Mars
Great article by Burkhard Bilger about NASA’s Curiosity mission to Mars.
The search for life on Mars is now in its sixth decade. Forty spacecraft have been sent there, and not one has found a single fossil or living thing. The closer we look, the more hostile the planet seems: parched and frozen in every season, its atmosphere inert and murderously thin, its surface scoured by solar winds. By the time Earth took its first breath three billion years ago, geologists now believe, Mars had been suffocating for a billion years. The air had thinned and rivers evaporated; dust storms swept up and ice caps seized what was left of the water. The Great Desiccation Event, as it’s sometimes called, is even more of a mystery than the Great Oxygenation on Earth. We know only this: one planet lived and the other died. One turned green, the other red.
Perfect read if you’ve been curious about what Curiosity is up to on Mars but needed something a bit more narrative than the mission home page or Wikipedia page to guide you. Also features the phrase “a self-eating watermelon of despair”, so there’s that. Oh, and here’s the Seven Minutes of Terror video referred to in the story.
How well did Galileo observe Jupiter’s moons?
In the pages of Sidereus Nuncius, Galileo described the four large moons of Jupiter in a series of 64 sketches which looked a lot like ASCII art in the text:
Using an online tool for computing the positions of Jupiter’s moons, Ernie Wright compared Galileo’s sketches to the moons’ actual motions.
Click through for an animated GIF of all the comparisons. Not bad for the telescopic state of the art in 1610. For a taste of how celestial objects actually appeared when viewed through Galileo’s telescope, check out this video starting around 7:30. (thx, john)
Earth-sized planet found only 4.3 light years away
A European team of exoplanet hunters has discovered a planet about the size of Earth orbiting Alpha Centauri B, which is in a group of stars closest to the solar system, a mere 4.3 light years away. Lee Billings explains the significance.
At a distance of just over 4.3 light years, the stars of Alpha Centauri are only a cosmic stone’s throw away. To reach Alpha Centauri B b, as this new world is called, would require a journey of some 25 trillion miles. For comparison, the next-nearest known exoplanet is a gas giant orbiting the orange star Epsilon Eridani, more than twice as far away. But don’t pack your bags quite yet. With a probable surface temperature well above a thousand degrees Fahrenheit, Alpha Centauri B b is no Goldilocks world. Still, its presence is promising: Planets tend to come in packs, and some theorists had believed no planets at all could form in multi-star systems like Alpha Centauri, which are more common than singleton suns throughout our galaxy. It seems increasingly likely that small planets exist around most if not all stars, near and far alike, and that Alpha Centauri B may possess additional worlds further out in clement, habitable orbits, tantalizingly within reach.
The Boomerang Meteor
While driving a couple weeks ago, I happened to catch a meteor shooting across the sky:
Saw one of the coolest things ever tonight: a meteor burning up in the lower atmosphere. Super bright, exploded at the end like a firework.
It turned out that “one of the coolest things ever” wasn’t hyperbole. You see, earlier that day over the UK, a meteor streaked across the sky for about 50 seconds:
And then the one I saw happened about two-and-a-half hours later. Spurred by this unlikely coincidence, mathematician Esko Lyytinen of the colorfully named Finnish Fireball Working Group of the Ursa Astronomical Association did some calculations and determined that the two events were actually the same meteor.
He believes a large body grazed the upper atmosphere, dipping to an altitude of 33 miles (53 km) over Ireland before escaping back to space. Because it arrived moving at only about 8 miles (13 km) per second, barely above Earth’s escape velocity, it lingered for more than a minute as it crossed the sky. (This explains why some witnesses mistook it for reentering spacecraft debris.)
Lyytinen says the brief atmospheric passage took its toll. As the meteoroid broke apart, its velocity dropped to just 5.7 miles (9.2 km) per second, too slow to make an escape back to space. Instead, it became a temporary satellite of Earth, looping completely around the globe before reentering the atmosphere — this time for good. “It looks now that the fireball witnessed 155 minutes later in U.S. and Canada, may have been one fragment of the British fireball, most probably the biggest one,” Lyytinen explains.
These earth-grazers are not common but they do happen from time to time. But a visible Earth grazing meteor that enters the atmosphere twice? Unprecedented. So cool! (thx, alex)
The View From Earth of Different Planets Replacing the Moon
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)
Landing on Mars next week: the Curiosity rover
The rest of you can have your Olympics, but the early August event I’m most looking forward to is the arrival on Mars of the Curiosity rover. But NASA has had some problems in the past delivering payloads to Mars, so this is going to be somewhat of a nail-biter. If you haven’t seen it, Curiosity’s Seven Minutes of Terror is well worth watching to see the logistical challenge of getting the rover down to the surface.
Curiosity will hopefully land on the surface on Aug 6 at about 1:30 am ET.
How to measure the size of the Universe
From The Royal Observatory, Greenwich, a short video explanation of how scientists measure the size of the Universe.
This is science for the layperson done right…PBS or the Discovery Channel would have inflated this into a 30-minute show. (via ★interesting)
Time lapse video of the transit of Venus
Venus passed in front of the Sun yesterday for the last time until 2117. The transit took almost seven hours but this NASA video shows it in under a minute.
The coolest video of yesterday’s annular solar eclipse
Cory Poole made this video of the annular solar ecplise yesterday using 700 photographs from a telescope with “a very narrow bandpass allowing you to see the chromosphere and not the much brighter photosphere below it.”
Cory says: “The filter only allows light that is created when hydrogen atoms go from the 2nd excited state to the 1st excited state.” Very cool.
Let’s destroy Mercury and build a Dyson sphere
George Dvorsky argues that if we wanted to, humanity could get a Dyson sphere up and running in a few decades.
The Dyson sphere, also referred to as a Dyson shell, is the brainchild of the physicist and astronomer Freeman Dyson. In 1959 he put out a two page paper titled, “Search for Artificial Stellar Sources of Infrared Radiation” in which he described a way for an advanced civilization to utilize all of the energy radiated by their sun. This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization.
Needless to say, the amount of energy that could be extracted in this way is mind-boggling. According to Anders Sandberg, an expert on exploratory engineering, a Dyson sphere in our solar system with a radius of one AU would have a surface area of at least 2.72x1017 km2, which is around 600 million times the surface area of the Earth. The sun has an energy output of around 4x1026 W, of which most would be available to do useful work.
The downside: we’d have to part with Mercury to do it.
And yes, you read that right: we’re going to have to mine materials from Mercury. Actually, we’ll likely have to take the whole planet apart. The Dyson sphere will require a horrendous amount of material-so much so, in fact, that, should we want to completely envelope the sun, we are going to have to disassemble not just Mercury, but Venus, some of the outer planets, and any nearby asteroids as well.
At Forbes, Alex Knapp explains why Dvorsky’s scheme and timeline might not work.
I emailed Astronomer Phil Plait about this project, who told me in no uncertain terms that the project doesn’t make sense.
“Dismantling Mercury, just to start, will take 2 x 10^30 Joules, or an amount of energy 100 billion times the US annual energy consumption,” he said. “[Dvorsky] kinda glosses over that point. And how long until his solar collectors gather that much energy back, and we’re in the black?”
My God, it’s full of galaxies
The VISTA telescope in Chile recently took a photo of the sky that contains over 200,000 galaxies. For reference, the Hubble Ultra-Deep Field image shows only about 10,000 galaxies (but sees further back in time, I think).
I’ve spent years studying all this, and it still sometimes gets to me: just how flipping BIG the Universe is! And this picture is still just a tiny piece of it: it’s 1.2 x 1.5 degrees in size, which means it’s only 0.004% of the sky! And it’s not even complete: more observations of this region are planned, allowing astronomers to see even deeper yet.
Here’s a full view of the image that looks sorta unimpressive:
You can download the original 17,000 x 11,000 pixel image here (250 Mb, yo) for the full effect. As a preview, this is several levels of zoom in…just a tiny part of the full image.
Comet time lapse
A short time lapse of Comet Lovejoy appearing in the pre-dawn sky over the Andes. Wait for the last sequence…it’s the best one.
Lovejoy was only discovered in Nov 2011 by an amateur astronomer. (via ★interesting)
Solar eclipse…by Saturn
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!
Moon cave!
Indian lunar orbiter Chandrayaan-1 has discovered a large cave on the Moon. Aside from the hey, cool, there’s a cave on the Moon factor, the other big feature of the cave is its constant and temperate temperature.
Temperatures on the moon swing wildly, from a maximum of 262 degrees Fahrenheit to a minimum of -292. The cave holds steady at a (relatively) comfortable -4, since the moon’s weather can’t penetrate its 40-foot-thick wall. It could also protect astronauts from “hazardous radiations, micro-meteoritic impacts,” and dust storms, according to paper published by the journal Current Science.
(via @juliandibbell)
How much is a planet worth?
Over at Boing Boing, Lee Billings has an interview with Greg Laughlin, an astrophysicist who recently came up with an equation for estimating the value of planets, a sort of Drake equation for cosmic economics.
This equation’s initial purpose, he wrote, was to put meaningful prices on the terrestrial exoplanets that Kepler was bound to discover. But he soon found it could be used equally well to place any planet-even our own-in a context that was simultaneously cosmic and commercial. In essence, you feed Laughlin’s equation some key parameters — a planet’s mass, its estimated temperature, and the age, type, and apparent brightness of its star — and out pops a number that should, Laughlin says, equate to cold, hard cash.
At the time, the exoplanet Gliese 581 c was thought to be the most Earth-like world known beyond our solar system. The equation said it was worth a measly $160. Mars fared better, priced at $14,000. And Earth? Our planet’s value emerged as nearly 5 quadrillion dollars. That’s about 100 times Earth’s yearly GDP, and perhaps, Laughlin thought, not a bad ballpark estimate for the total economic value of our world and the technological civilization it supports.
Auditioning replacements for the Moon
This video shows what various planets (Jupiter, Mars, etc.) would look like in the night sky if they orbited the Earth at the same distance as the Moon.
See also Imagining Earth with Saturn’s rings and Helvetica! In! Space!
The new Zodiac
Early this week, I started seeing a little traffic to a post I wrote way back in March of 1999 called The new Zodiac.
An interesting calendrical tidbit: the Zodiac that everyone is familiar with today is actually based upon the movement of the sun through the constellations of 2500 years ago. Today, due to shifts in the earth’s rotation and orbit, the sun moves through 13 constellations, not just 12.
The thirteen constellation is called Ophiuchus. As I’m writing, Ophiuchus is the #1 trending topic on Twitter right now and there are dozens of news articles on the topic in outlets like Time, Huffington Post, and The Washington Post. Patient Zero of this most recent round of new Zodiac reporting is this January 9 Minneapolis Star-Tribune article in which the updated Zodiac is listed as:
Capricorn: Jan 20 - Feb 16
Aquarius: Feb 16 - Mar 11
Pisces: Mar 11 - Apr 18
Aries: Apr 18 - May 13
Taurus: May 13 - Jun 21
Gemini: Jun 21 - Jul 20
Cancer: Jul 20 - Aug 10
Leo: Aug 10 - Sept 16
Virgo: Sept 16 - Oct 30
Libra: Oct 30 - Nov 23
Scorpio: Nov 23 - Nov 29
Ophiuchus: Nov 29 - Dec 17
Sagittarius: Dec 17 - Jan 20
Wikipedia has a slightly different calendar for 2011:
Aries: Apr 19 - May 14
Taurus: May 14 - Jun 21
Gemini: Jun 21 - Jul 21
Cancer: Jul 21 - Aug 11
Leo: Aug 11 - Sept 17
Virgo: Sept 17 - Oct 31
Libra: Oct 31 - Nov 21
Scorpio: Nov 21 - Nov 30
Ophiuchus: Nov 30 - Dec 18
Sagittarius: Dec 18 - Jan 21
Capricorn: Jan 21 - Feb 17
Aquarius: Feb 17 - Mar 12
Pisces: Mar 12 - Apr 19
Which calendar to believe? Who knows, but one thing is for sure: astrology remains a steaming pile of horseshit.
Death spiral and the other top astronomy photos of the year
Bad Astronomy lists its top fourteen astronomy photos of the year, including this nearly unbelievable spiral pattern caused by a binary star.
The object, called AFGL 3068, is a binary star, two stars in an 800-year orbit around one another. One of them is a red giant, a star near the end of its life. It’s blowing off massive amounts of dark dust, which is enveloping the pair and hiding them from view. But the system’s spin is spraying the material out like a water sprinkler head, causing this giant and delicate spiral pattern on the sky. And by giant, I mean giant: the entire structure is about 3 trillion kilometers (about 2 trillion miles) across.
Big orange ball
What is this, do you think? Electron microscope photo of pollen? Infrared tennis ball? Mars? The inside of a baseball?
It’s actually a photo of the Sun taken at the H-alpha wavelength by an amateur astronomer.
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