The Dust Library
So what can this unusual library tell us? First, there is the simple parts list. The most common component was organic material, present in 40 of the 63 particles – exactly what is unclear, but it could be anything from pollen to sloughed-off bits of researcher. Quartz, found in 34 particles, came next, followed by carbonates (17 particles) and gypsum (14). “The minerals blow in,” says Coe. “They come from all over the world.” Other ingredients included air pollutants and fertiliser chemicals.
headline of the day
Scientist: Sky confirms “shining moon” behind Frankenstein
What Happened When We Moved Out Here
It’s a little out of the way. We love our new home but the location is relatively remote. Not Montana prairie far, and not Desolation of Mordor far, but you have to drive for almost fifteen minutes to get a gallon of gas or milk. We’re twenty-five minutes from the Interstate, so for the first time in decades I cannot sit on my porch and hear the hum of highway traffic. Are these the metrics that define civilization? Do you choose isolation or insulation?
Imagine “a ball of Gruyere colliding into a ball of cheddar”
Point:
The Earth and moon have two Trojan points, one leading ahead of the moon, known as the L-4 point of the system, and one trailing behind, its L-5 point.
The researchers computed that this second moon could have stayed at a Trojan point for tens of millions of years. Eventually, however, this Trojan moon’s orbit would have destabilized once our moon’s orbit expanded far enough away from Earth.
The resulting collision would have been relatively slow at 4,500 to 6,700 miles per hour (7,200 to 10,800 kph), leading its matter to splatter itself across our moon as a thick extra layer of solid crust tens of miles thick instead of forming a crater.
Counterpoint:
A number of explanations have been proposed for the far side’s highlands, including one suggesting that gravitational forces were the culprits rather than an impact from Francis Nimmo at the University of California, Santa Cruz, and his colleagues. Nimmo said that for now there is not enough data to say which of the proposals offers the best explanation for this lunar contrast. “As further spacecraft data and, hopefully, lunar samples are obtained, which of these two hypotheses is more nearly correct will become clear,” Nimmo said in a statement.
What I Just Heard
from outside, in the dark: a very small child saying, insistently, “Thank you! Thank you! Thank you….”
quote out of context
Astronomers will celebrate a remarkable event on 11 July. It will be exactly one year since the planet Neptune was discovered.
Great Big Saturnine Storm
At its most intense, the storm generated more than 10 lightning flashes per second. Even with millisecond resolution, the spacecraft’s radio and plasma wave instrument had difficulty separating individual signals during the most intense period. Scientists created a sound file from data obtained . . . at a slightly lower intensity period.
If you listen vary carefully to the audio file, you can hear Sun Ra.
from the comments
I am falling in love with these heat- and drought-resistant little tepary beans, just as I fell in love with the Sonoran desert. They are so damn tasty pretty much as they are. And they are high in protein and fiber and release sugar very very slowly.
And Tohono O’odham (Papago) legend has it that the Milky Way is made of tepary beans scattered across the sky.
I’m a believer.
“It’s still a good day”
is what my friend Steve said.
He was looking for the first day of summer and for when the full moon was going to happen next week, and he discovered that today is a good day to castrate animals, according to The Old Farmer’s Almanac Astrological Timetable.
kids today
A 22-year-old Australian university student has solved a problem which has puzzled astrophysicists for decades, discovering part of the so-called “missing mass” of the universe during her summer break.
When I was twenty-two, I cleared fifty people off a dance floor.
Precession of the Equinoxes
The thing that caused everyone to freak out because their astrological signs had changed is one of the more fascinating stories in the history of intellectual evolution. That thing is called precession of the equinoxes, and precession is one of those phenomena that is simultaneously invisible and obvious, observable and hidden.
Let’s start with the technicalities and move to the history of it.
In astronomy, axial precession is a gravity-induced, slow and continuous change in the orientation of an astronomical body’s rotational axis. In particular, it refers to the gradual shift in the orientation of Earth’s axis of rotation, which, like a wobbling top, traces out a pair of cones joined at their apices in a cycle of approximately 26,000 years. The term “precession” typically refers only to this largest secular motion; other changes in the alignment of Earth’s axis — nutation and polar motion — are much smaller in magnitude.
So, precession is essentially the planetary equivalent of the wobble in a top as it spins.
If you carve the horizon into twelve roughly equivalent sections, each year, at the equinoxes, the sun will appear to rise in one and set in its opposite. Because of the wobble in the axis of the earth, the section of the sky the sun appears to rise and set in will shift very slowly over a period of roughly 2,160 years. This is the basis of astrology, as various civilizations applied meaning to the constellations they saw in each section. More interestingly, I think, our tracking of it appears to be the basis of astronomy.
To begin to notice that tracking takes time. To fully understand the cycle, and be able to project it forwards and backwards, to mark the passage of time in the relative movement of the stars, would take hundreds, if not thousands, of years — observation, measurement, notation. Once a culture had an awareness of that pattern, no matter on what scale, it could begin to find a place for itself, and make a story out of it, and because we are human, of course, that is what we did.
If you are interested in this subject, and are comfortable with an approach equal parts academic and poetic, you might enjoy Giorgio de Santillana and Hertha von Dechen’s Hamlet’s Mill. It shows glimpses of precession’s possible influence throughout the history of art, an astronomical code for our place in the universe embedded in language.
the Antikythera mechanism
The second century B.C. astronomical calculator found in a shipwreck off the Greek island of Antikythera was even more sophisticated than thought.
Earlier research showed the device also accounted for a subtle weirdness in the motion of the moon. Because the moon’s orbit around the Earth is an ellipse, not a perfect circle, the moon seems to speed up and slow down over the course of a month. In 2006, Tony Freeth of Cardiff University and colleagues showed that a clever configuration of two overlapping gears, with the top gear laid off-center from the bottom gear, could give the moon’s marker its irregular speed.
Because of the Earth’s elliptical orbit around the sun, the sun makes a similarly variable trip across the sky, speeding up and slowing down over the course of the year. But the effect is much more subtle than for the moon.
You are listening to Los Angeles
Okay. My 24/7 soundtrack. Ambient music and live LAPD police radio.
(Thank you, Mr. Ledgerwood.)
Nostalgia de la luz (Nostalgia for the Light)
ALMA (Atacama Large Millimeter/submillimeter Array) y los desaparecidos: the looking-glass reflection of alien abduction narratives.
I wish the telescopes didn’t just look into the sky but could also see through the earth so that we could find them.
Via @pruned.
Tyche, the new ninth planet
John Matese and Daniel Whitmire, astrophysicists from the University of Louisiana at Lafayette, think data gathered from NASA’s Wise telescope will reveal a ninth planet orbiting in the Oort cloud, captured from another solar system by the sun’s gravity.
Whether it would become the new ninth planet would be decided by the International Astronomical Union (IAU). The main argument against is that Tyche probably formed around another star and was later captured by the Sun’s gravitational field. The IAU may choose to create a whole new category for Tyche, Professor Matese said.
Tyche will almost certainly be made up mostly of hydrogen and helium and will probably have an atmosphere much like Jupiter’s, with colourful spots and bands and clouds, Professor Whitmire said. “You’d also expect it to have moons. All the outer planets have them,” he added.
quote out of context
Brad Carter, senior lecturer of physics at the University of southern Queensland in Australia, said the explosion could take place before the end of the year – or indeed at any point over the next million years.
a lot starrier
The night sky may be a lot starrier than we thought. A study suggests the universe could have triple the number of stars scientists previously calculated. For those of you counting at home, the new estimate is 300,000,000,000,000,000,000,000. That’s 300 sextillion.
Also, sextillion.
A Non-scientist’s Conjecture about Anomalous Decay Rates
I’m sure one of our scientist readers can put this to rest quickly, but here’s the deal. I made a post back in August about this article that was circulating then, concerning observed changes in radioactive decay rates that were definitely not supposed to ever change:
When probing the deepest reaches of the Cosmos or magnifying our understanding of the quantum world, a whole host of mysteries present themselves. This is to be expected when pushing our knowledge of the Universe to the limit.
But what if a well-known — and apparently constant — characteristic of matter starts behaving mysteriously?
This is exactly what has been noticed in recent years; the decay rates of radioactive elements are changing. This is especially mysterious as we are talking about elements with “constant” decay rates — these values aren’t supposed to change. School textbooks teach us this from an early age.
This is the conclusion that researchers from Stanford and Purdue University have arrived at, but the only explanation they have is even weirder than the phenomenon itself: The sun might be emitting a previously unknown particle that is meddling with the decay rates of matter. Or, at the very least, we are seeing some new physics.
Last night I was wondering if the particle explanation might not be right: perhaps what is being measured is the first direct evidence of gravitational waves. We have been trying to detect them in various ways for some time now, but with no success. My thought is that perhaps the decay rates are remaining constant–and spacetime is being stretched by a gravitational wave in a way that we aren’t aware of because our perception remains constant (as it would within time dilation effects–in this case applied to a whole region of space). But–I don’t really have the math to work on or fully understand such things, and I may be just talking like a person who believes he has invented a perpetual motion machine.
Starling Murmurations over the Roman Synagogue Last Sabbath
… to the music of The Photographer (Philip Glass):
Gliese 581g, perhaps
Steven Vogt, co-discoverer of the disputed extrasolar planet Gliese 581g, continues to defend the discovery.
“I stand by our data and analysis,” Vogt, an astronomer at the University of California, Santa Cruz, said in an e-mail interview with SPACE.com. “I feel confident that we have accurately and honestly reported our uncertainties and done a thorough and responsible job extracting what information this data set has to offer. I feel confident that anyone independently analyzing this data set will come to the same conclusions.”
“In 15 years of exoplanet hunting, with over hundreds of planets detected by our team, we have yet to publish a single false claim, retraction or erratum,” Vogt said. “We are doing our level best to keep it that way.”
Should I unpack my boxes and cancel the movers?
Remember Gliese 581g? It might not exist.
Astronomer Francesco Pepe of the Geneva Observatory in Switzerland, who spoke Oct. 11 at an International Astronomical Union symposium on planetary systems, reported a new analysis using only HARPS data, but adding an extra 60 data points to the observations published in 2008. He and his colleagues could find no trace of the planet.
An Airplane in Front of the Moon, Chris Thomas
potentially habitable planet found
The paper reports the discovery of two new planets around the nearby red dwarf star Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system other than our own solar system. Like our solar system, the planets around Gliese 581 have nearly circular orbits.
The most interesting of the two new planets is Gliese 581g, with a mass three to four times that of the Earth and an orbital period of just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and that it has enough gravity to hold on to an atmosphere, according to Vogt.
Gliese 581, located 20 light years away from Earth in the constellation Libra, has a somewhat checkered history of habitable-planet claims. Two previously detected planets in the system lie at the edges of the habitable zone, one on the hot side (planet c) and one on the cold side (planet d). While some astronomers still think planet d may be habitable if it has a thick atmosphere with a strong greenhouse effect to warm it up, others are skeptical. The newly discovered planet g, however, lies right in the middle of the habitable zone.
(via marginal revolution)
High Resolution Mars Photographs
A shit load of high-resolution images of Mars.
Wired provides the details:
A new batch of sharp Martian close-ups from NASA’s HiRISE camera were released on Sept. 1. HiRISE (High Resolution Imaging Science Experiment) has been circling Mars on the Mars Reconnaissance Orbiter for four years now, taking dramatic photos of the red planet with a telephoto lens to make any paparazzi jealous. The camera can focus on objects the size of a beach ball from more than 180 miles away.
The 236 new images, taken between July 8 and July 31, cover the planet practically from pole to pole. They zoom in on terrain ranging from volcanic cones to cratered planes, from wind-swept dunes to crusts of ice. The images even capture evidence of ongoing geological processes on Mars today, like fresh craters that may have formed between January and June of this year.
Odd Crater on Mars
Orcus Patera, discovered in 1965 by the Mariner 4 spacecraft, is located near Mars’ equator, between the volcanoes Elysium Mons and Olympus Mons. At 236 miles long, it would stretch from New York to Boston on Earth. Its rim rises over a mile above the surrounding plains, and its floor lies 1,300 to 1,900 feet below its surroundings.
But in spite of lying between two volcanoes and its designation as a patera — the name for deep, complex or irregularly shaped volcanic craters — scientists aren’t at all sure that Orcus Patera has a volcanic origin story.
I love how exaggerated the features on Mars can be compared to Earth because of the relative differences in gravity.
