Posted by: Paul A. Forsyth | October 30, 2014

Photo of the Month

Comet-C2013A1-SidingSpring-NearMars-Hubble-20141019

Comet Siding Spring near Mars.

Composite NASA Hubble Space Telescope image of the positions of planet Mars and comet Siding Spring during the comet’s close pass by the planet (with a distance at closest approach of about 87,000 miles), approx. 2:28 p.m. EDT, October 19, 2014.

From NASA’s press release:

NASA used its extensive fleet of science assets, particularly those orbiting and roving Mars, to image and study this once-in-a-lifetime comet flyby. In preparation for the comet flyby, NASA maneuvered its Mars Odyssey orbiter, Mars Reconnaissance Orbiter (MRO), and the newest member of the Mars fleet, Mars Atmosphere and Volatile EvolutioN (MAVEN), in order to reduce the risk of impact with high-velocity dust particles coming off the comet.

(Just another reminder that Mars — and the orbital space around Mars — is at present
populated solely by robots.)

Image Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA. Source: Wikimedia Commons.

Posted by: Patrick Allen Foster | October 29, 2014

Assorted Links

1. So, Ebola is spreading through multiple West African countries, and there’s a critical shortage of trained medical personnel in the areas where the epidemic is worst; but, please, by all means, Slate, let’s worry about whether there are too many missionary doctors manning the front lines.

2. Tyler Cowen: “How far does the radius of trust extend?”

3. Pankaj Mishra on Modi’s Idea of India. (H/T: 3 Quarks Daily.)

4. Keith Humphreys on organ donation and opt-in vs. opt-out models: “when European health professionals show up to harvest organs from a newly dead individual, that person’s family often says “no way”, nudges be damned. The state could legally take the person’s organs by force of course, but unsurprisingly it does not. In contrast, in the US opt-in model, both families and the state respect the deceased donor’s wishes because they know they were the result of a proactive decision rather than a bureaucratically-designed nudge. More simply, an active choice has legitimacy that a nudged choice does not.” See also this Wonkblog post and this post by Megan McArdle.

5. You had one job, rhino. One job: at the start of the month, there were only seven northern white rhinos left in the world, including two breeding males. Now, one of the remaining males has died.

From the Guardian:

Suni, a 34-year-old northern white, and the first of his species to be born in captivity, was found dead on Friday by rangers at the Ol Pejeta Conservancy near Nairobi. While there are thousands of southern white rhinos in the plains of sub-Saharan Africa, decades of rampant poaching has meant the northern white rhino is close to extinction.

Suni was one of the last two breeding males in the world as no northern white rhinos are believed to have survived in the wild. Though the conservancy said Suni was not poached, the cause of his death is currently unclear.

Suni was born at the Dvur Kralove Zoo in Czech Republic in 1980. He was one of the four northern white rhinos brought from that zoo to the Ol Pejeta Conservancy in 2009 to take part in a breeding programme.

Annoyingly, Suni died without having impregnated any of the remaining breeding-age females. Dammit.

On a positive note: there are some 20,000 southern white rhinos still living. The remaining northern white rhinos may be cross-bred with their southern cousins.

Posted by: Patrick Allen Foster | October 28, 2014

Tuesday Art Blogging

Rembrandt Harmensz. van Rijn - Jeremia treurend over de verwoesting van Jeruzalem - Google Art Project

Rembrandt, Jeremiah Lamenting the Destruction of Jerusalem, 1630.

Currently owned by the Rijksmuseum, Amsterdam.

Image Source: Wikimedia Commons.

Posted by: Patrick Allen Foster | October 27, 2014

On College Admissions, Briefly

Blogger Thoreau:

I recall reading that the use of standardized tests for college admissions started with a noble goal in mind, to expand the net of higher education beyond people from the sort of social class that went to the “good” preparatory high schools, by identifying raw talent in places that would have otherwise gone unexamined. Of course, the tests became high stakes, and eventually became correlated with measures of advantage.

Thoreau asks if it is possible to design a test that does not fall into this familiar trap. As Admiral Nimitz said, the world wonders…

Speaking of admissions, essays, and kids with advantages, This American Life had a program back in September on the subject. I especially liked this segment, where Ira Glass is interviewing Clark (admissions director at Ga Tech) (emphasis added):

Ira Glass: Are there trends in what kids are writing about– where you feel like you see little fads and you get sick of them?

Rick Clark: Oh, well the age-old one that– I mean, again, pretty much anybody that you would interview who’s been in college admission for any period of time would be– you know, we just call it now the mission trip essay. And great to go on a mission trip, great to have a cultural experience. But inevitably, the way it reads is so predictable.

You know, we flew down to somewhere in Central America. And we got off the plane. It was really hot. And we got on the bus, and 20 miles outside of the village, our bus broke down. But we got picked up by like a chicken truck and taken into town. And then, over the course of my time there, I went expecting to help others. But it was, in fact, me who was changed.

And even just when you first start reading that essay, you’re like, oh, here it comes again.

Posted by: Patrick Allen Foster | October 25, 2014

Random Art Blogging

Millais leaves

John Everett Millais, Autumn Leaves, 1856.

Source: Wikimedia Commons.

NPR: “Researchers have successfully decoded the genes of a 45,000-year-old man from Siberia. The results offer clues about early human life outside of Africa as well as how humans interacted with Neanderthals and other groups around at the time.”

Ars Technica (emphasis added):

Based on Y chromosome and mitochondrial genome, the Ust’-Ishim DNA appears to reside at the base of a broad group of populations that exist in current Eurasia. The rest of the genome indicates that it lacks many of the individual DNA changes that have appeared in current populations. All of which suggests that the population it belongs to is ancestral to Europeans and Asians.

But if you look at overall relatedness, the genome is slightly closer to current Asian populations than it is to Europeans. The authors note that other data has led researchers to hypothesize that Europeans have had an influx of DNA from a population that did not participate in the initial migration out of Africa—perhaps a second wave out of Africa.

Another source of DNA present in non-African populations that was not involved in that initial migration comes from archaic humans, the Neanderthals and Denisovans. The Ust’-Ishim skeleton has no indications of any Denisovan DNA, which furthers indications that this DNA might have been picked up somewhere along the southern coast of Asia.

Neanderthal DNA is present, and in roughly the same percentage that’s found in current human populations: about 2.3 percent. If you assume that interbreeding was common during the years of our coexistence with Neanderthals, then you might have expected that number to be higher, so this argues against it.

While the same fraction of Neanderthal DNA is present, there is a key difference: the stretches of Neanderthal DNA are quite a bit longer. You’d actually expect that, since recombination with the modern human genome will gradually break up the Neanderthal sequences over time. The authors of the paper use this process as a clock and date the time of our interbreeding with Neanderthals to about 50 to 60,000 years ago. That’s on the high end of previous estimates and places the interbreeding at a time where modern humans had just left Africa and were sharing the Mid-East with Neanderthals.

See also this New York Times story.

(For my previous blogging on this topic, see here.)

Posted by: Paul A. Forsyth | October 22, 2014

Hubble Finds New Targets for New Horizons Past Pluto

Hubble Survey Finds Two Kuiper Belt Objects to Support New Horizons Mission
Source: Hubblesite.org

Time-lapse Hubble images of two new Kuiper Belt objects that are potential targets for the New Horizons spacecraft after it finishes its Pluto mission. They desperately need new names.

The NASA unmanned spacecraft New Horizons has been traveling towards Pluto since 2006. New Horizons should be making its flyby of Pluto and its moons in July 2015, becoming the first spacecraft to visit Pluto and providing the first detailed images of the dwarf planet.

After its Pluto encounter, New Horizons will continue on its journey away from the heart of the Solar System. Mission planners have always intended that New Horizons, if possible, should visit some other object beyond Pluto. The problem: at the time of launch, astronomers had not identified any potential targets within range. The Kuiper Belt contains thousands (perhaps millions) of small bodies of rock and ice — including some dwarf planets — but New Horizons can only be steered toward objects within a small cone of space extending out from Pluto.

Last week, NASA announced that Hubble has identified three new Kuiper Belt objects within that cone — three new post-Pluto potential targets for New Horizons. Two of those objects are shown above. All three are quite small, probably with diameters in the range of 20-50 km. (For comparison: the asteroid Eros, the site of a base in the novel Ender’s Game, has a mean diameter of about 16 km. The Moon’s diameter is about 3,460 km, and Pluto’s diameter is [we think] 2,368 ± 20 km. See also this list.)

From what NASA and the Hubble folks tell us so far, it sounds like the most likely post-Pluto target for New Horizons — potential target 1 or PT1 — is KBO 1110113Y (the object on the left above). From Emily Lakdawalla:

What do we know about PT1 so far? Its orbit is circular and close to the plane of the ecliptic, so it is a Cold Classical Kuiper belt object, meaning that it has had a very different history from Pluto. Pluto is a member of a population of objects in the Kuiper belt whose orbits were changed as Neptune migrated outward, scattering them. Pluto now has an inclined and elliptical orbit that is locked in a resonance with Neptune, such that Pluto orbits the Sun twice for every three times Neptune does. In contrast, Cold Classical objects were probably never tossed around in this way. So PT1 could be very pristine, a cold, never-heated relic of solar system formation. On the other hand, it’s very small, estimated to be 30 to 45 kilometers in diameter, and scientists think that most objects of that size are not primordial, but are actually fragments from collisions of larger objects, which would make it less pristine.

If KBO 1110113Y is chosen, then New Horizons should make a fly-by of the KBO around January 2019. Before that happens, I strongly suggest that the Hubble folks pick a new name for the object; “KBO 1110113Y” does not exactly roll off the tongue. Something mythological would seem appropriate, but I’m not sure what mythological names are still available.

EightTNOs

Astronomers haven’t even bothered to give a proper name to 2007 OR10 yet, and that’s after seven years.

Image Credit: (1) NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team. Source: HubbleSite. (2) Artistic representations of the eight largest Trans-Neptunian Objects. Image by Lexicon. Used under a CC BY-SA 3.0 license. Source: Wikimedia Commons.

Posted by: Patrick Allen Foster | October 21, 2014

Tuesday Art Blogging

Waterhouse-Diogenes

John William Waterhouse, Diogenes and the Young Women, 1882.

Source: Wikimedia Commons.

Posted by: Patrick Allen Foster | October 17, 2014

Friday Diversion

Here’s a website to determine how conservative or liberal your first name is. “Crowdpac calculates this score based on the average of all campaign contributions made by people with this name since 1980.”

H/T: Ann Althouse.

Posted by: Patrick Allen Foster | October 15, 2014

Random Art Blogging, Cynic Edition

Jean-Léon Gérôme - Diogenes - Walters 37131

Jean-Léon Gérôme, Diogenes, 1860.

Currently housed at the Walters Art Museum, Baltimore, Maryland.

Source: Wikimedia Commons.

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