Astronomy 106: the cosmic origins of life
University of Rochester, Fall semester 2015

Photo/artwork credits:

"Alien" plant, Kepler satellite,
planet and moon: Kepler/Ames
Research Center/NASA

Trilobite: Wikimedia Commons.

Black smoker: NOAA.

"Hammerhead" ribozyme (space-
filled molecular model): Hudel
Luecke, University of California, Irvine.

Australopithecus skull: Wikimedia

Archive of features of current interest 

How the class fared: final grade, exam, homework and participation statistics. (15 December 2015)
Exam #3 takes place today, in your choice of 75-minute spans that lie completely between 11 AM and 6 PM. Click on the flying saucer at left to read the instructions, and then to take the test. (10 December 2015)
Crop-yield increases, which we have achieved and counted upon since the Neolithic Revolution, have not been as large lately: the rate of increase has declined by 2.5% per decade because of global warming. That is to say, yields keep increasing, but not as fast, meaning that the population will reach the maximum that Earth can feed sooner than it otherwise might. (7 December 2015)
"Come back, Nukes! Most is forgiven!" A few climate scientists recommend strongly that we consider using our abundant nuclear energy sources, as we seek to keep atmospheric CO2 below 450 ppm. (5 December 2015)
Practice Exam #3 will be available from now through 7PM Wednesday, 9 December, right before the review session. Click on the flying saucer at left to read the instructions, and take the practice test. (3 December 2015)
About 2-4 times more than expected of the largest exoplanet candidates produced by Kepler are turning out to be low-mass stars rather than brown dwarfs or genuine planets. This affects what we think about the most massive exoplanets, and about just how barren the brown-dwarf desert is, but doesn't affect the census of smaller planets, including Jupiters, Neptunes, super-Earths and Earthlike planets. (3 December 2015)
From ribozyme to ribosome: deconstruction of ribosome structure shows how the first several steps of RNA World might have taken place. (1 December 2015)
Another in a long series of claims that humans arrived in southern South America long before the better-known "Clovis" megafauna-hunters got to North America. Like its predecessors, the claim is disputed, mostly on the basis of concerns about the age accuracy, and the lack of contemporary human remains. (30 November 2015)
An Associated Press meta-exam on climate change, in which candidates's statements were taken from interviews and the debates, anonymized, and fact-checked by experts: really, Red folks, that's all you got? You want Christie, Rubio, Fiorina, Trump, Carson or Cruz making decisions on environmental policy? (24 November 2015)
Lamar Smith (R, TX) vs. experimental facts and the scientific-journal peer-review system: no matter how impractical and dangerous, some people insist that they can have their own, wishful set of facts, unsupported by experiment. They want the real facts stamped out. I guess that's why they chose Mr. Smith to represent them. (24 November 2015)
This is interesting, check it out: a calculator that tells you the effects of an asteroid impact, given the asteroid's size, density and velocity. See how large an asteroid can land in LA and knock buildings down in New York. Courtesy of Jay Melosh and friends. (24 November 2015)
The harsh conditions during the P-T global warming and mass extinction apparently led to natural selection of polyploidy in conifers. (24 November 2015)
OMG!! Infant planets photographed for the first time!! except it's not the first time. As we have seen in class, a picture of the largest of these planets was published in 2012, and the wake these planets leave in the disk from which they formed was observed in 2011 and 2007, from which their existence was first demonstrated; also they're still using the graphics from a press release about a different infant planet discovery in 2005. It's really good work, but just in case you were wondering why it wasn't featured in the NY Times... (18 November 2015)
Another Denisovan molar, this one an amazing 110,000 years old, yields both mitochondrial and nuclear gene sequences. (16 November 2015)
Uh-oh, there may be a lot of methane sequestered in Arctic pack ice. (15 November 2015)
Observations of liquid ethane-methane monsoons on Titan: no wonder those rocks look like river rocks. (12 November 2015)
More evidence that Earth's water came more from asteroids (and meteorites) than from comets (and IDPs). (12 November 2015)
Another of this year's $3M Breakthrough Prizes went (in toto!) to evolutionary geneticist Svante Pääbo, who was already on tap to be one of the stars of the last third of our course. (9 November 2015)
Our own Professors Kevin McFarland (left) and Steve Manly (right), together with postdocs Phil Rodrigues and Dan Ruterbories and grad student Melanie Day, shared -- with some 1500 other colleagues -- this year's Breakthrough Prize in Fundamental Physics, for their pioneering work on the properties of neutrinos. At $3M this prize outweighs both the Shaw ($2M) and Nobel ($1M) prizes. (9 November 2015)
Exam #2 takes place today, in your choice of 75-minute spans that lie completely between 11 AM and 6 PM. Click on the trilobite at left to read the instructions, and then to take the test. (10 November 2015)
Practice Exam #2 will be available from now through 5PM Monday, 9 November, a couple of hours before the review session. Click on the trilobite at left to read the instructions, and take the practice test. (25 September 2015)
Reanalysis of the atmospheric CO2-driven Eocene global 5 C temperature spike (50 Mya) has shown that the peak CO2 concentration was only half what was previously thought: 680 parts per million. For reference, the concentration now is 400 ppm and will reach 800 ppm by 2100 at current rates. (3 October 2015)
Today NASA's Cassini satellite passes through the plumes ejected by Enceladus's south-pole geysers. (28 October 2015)
Mitochondrial DNA sequencing from recently discovered, ancient gravesites near the Bering Strait provides strong support for one of the leading, traditional ideas of how the Americas were populated: namely, through the Yukon-Alberta gap between ice sheets as the last ice age abated, rather than down the west coast. (28 October 2015)
Well, 2015 continues the hundred-year trend and becomes the warmest of the last 1600 years; lakes and rivers form on the Greenland ice sheet as its melting becomes catastrophic; and the cradle of civilization, the Persian Gulf region, projects to be uninhabitable by 2100. But Jim Inhofe, the tea-party senator from Oklahoma, still plans to picket the next major climate-science conference to tell the scientists that they're Wrong because winter still happens. (26 October 2015)
A very rich new archaeological find sheds light on the Mycenaeans, the earliest high civilization of Europe. (26 October 2015)
Please give our TAs some feedback on how they're doing, by filling out the Physics and Astronomy TA/TI Survey (20 October 2015)
This month we mark the 20th anniversary of the discovery of exoplanets. The anniversary of the publication of the discovery paper, at the end of November, will be celebrated at the Extreme Solar Systems conference. (20 October 2015)
See how many planets you can pack into a habitable zone, in Super Planet Crash! Explore gravity and design your own planetary systems with Orbits and Gravity Kit! Detect exoplanets from radial-velocity data, in Systemic Live! All courtesy of our friends at the University of Texas and the Space Telescope Science Institute, Drs. Joel Green, Randi Ludwig, and Stefano Meschiari. (15 October 2015)
New timing for arrival of Homo sapiens in East Asia, based on new fossil finds in Fuyan Cave: 80000-120000 years ago, quite a while before they arrived in Europe.  (14 October 2015)
A new statistic to help in your next fantasy draft for habitable exoplanets: the Habitability Score, which accounts for where in the habitable zone a planet lies, and the eccentricity of its orbit, as well as its albedo and such. (8 October 2015)
It's Nobel Prize week! Drop in on the instructors and ask them about the significance of natural sources of medications, of cellular self-repair of DNA, and of neutrino oscillations. (7 October 2015)
Keeping our robots and satellites aseptic: if you're looking for evidence of life, you have to make sure you don't bring life with you. (5 October 2015)
The following item is a good reminder of the importance of the Near-Earth Object Camera (NEOCam), now approved by NASA for Phase 2 development. (1 October 2015)
As long suspected, it now appears that large-scale volcanism and lava flows followed the asteroid impact, 65 Myr ago, that led to the demise of the dinosaurs. (1 October 2015)
Exam #1 takes place today, in your choice of 75-minute windows, starting any time after 11 AM and ending by 6 PM. Click on the hot Jupiter at left to read the instructions, and then to take the test. (1 October 2015)
Ryan's Review Session notes. (30 September 2015)
We have known for a while that Mars has lots of water ice under its surface, and lots of evidence for erosion caused by liquid flow on its surface. Now NASA's Mars Reconnaissance Observer has found the liquid water (in "recurring slope lineae"). Is Mars habitable after all? (28 September 2015)
Practice Exam #1 will be available from noon Friday, 25 September, through the beginning of the review session at 7PM Wednesday, 30 September. Click on the hot Jupiter at left to read the instructions, and take the practice test. (25 September 2015)
A binary-orbit simulation which shows how the orbital motion translates into changes in the spectrum. Play with it and it will help you understand how radial-velocity exoplanet detection works. (24 September 2015)
No evidence from any of the Milky Way's neighboring galaxies that advanced civilizations are harnessing a significant fraction of those galaxies' energy -- or, if they are, they are being commendably efficient in their use of energy on a galactic scale. (17 September 2015)
Now it looks like Saturn's second major moon, Enceladus, has a global liquid-water ocean under its smooth icy surface -- a distinction previously only held by Jupiter's second moon Europa. (17 September 2015)
The best detection so far in images of the orbital motion of an exoplanet: a year and a half's worth of the 21.6 year orbital period of beta Pictoris b, tracked by the Gemini Planet Imager. (16 September 2015)
"Evolution caught red-handed:" if mutating flu viruses and Roundup-resistant weeds weren't enough for you, now there's evidence of the transposition of an entire gene between two different places in the fruit-fly genome, about two million years ago. (14 September 2015)
First evidence for molecular oxygen in the oceans -- and therefore of aerobic forms of life therein -- pushed back another few hundred million years, to 3.2 Gya. (11 September 2015)
A new species of our genus, Homo, claimed on the basis of recently-found, rather complete skeletons that seem to be 2.5-2.8 million years old. Welcome, Homo naledi. (10 September 2015)
New Horizons On to 2014 MU69! A tiny but not-uninteresting Kuiper-belt object turns out to lie within New Horizon's limited maneuvering range. It'll get there for New Year's, 2019.(28 August 2015)
Laysan rails Here's why you should take seriously the idea that the sixth mass extinction in our planet's history is already under way. (2 August 2015)
Sherpas Though the Neanderthals and Denisovans contributed less than 5% of modern DNA, this small amount was crucial in survival and adaptation. (29 June 2015)
Primordial_Goo A few rocks are being thrown at RNA World as a theory for the origin of primitive life, but the rock-throwers haven't any better ideas. (24 June 2015)

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