Courtesy NASAWe like to think of our home planet – Earth – as a pretty unique place. It's the only planet in our solar system capable of sustaining life. We look through telescopes and to see exotic looking planets of various sizes and shapes. But we're the one and only Earth, right?
A new census of planets in the Milky Way galaxy shakes up that thinking. New data collected by NASA's Kepler spacecraft pegs one in six stars in the Milky Way of having planets that are the same size as Earth. That one-sixth fraction translates into an estimate of about 17 billion planets that are the same approximate size as our home.
So we're not as exclusive as might like to think. But the exclusivity meters edges back toward us when you factor in the Goldilocks zone – a distance from the host star that's not too hot nor too cold to sustain life. So far, extended research on the new-found planets has identified only four Earth-sized planets that could possibly reside in a Goldilocks zone. The Kepler project has identified a total of 2,740 potential new planets with more research ongoing.
Courtesy GLOBE at Night(This post is a copy and paste of an email I received for this interesting citizen scientist activity...)
What would it be like without stars at night? What is it we lose? Starry night skies have given us poetry, art, music and the wonder to explore. A bright night sky (aka light pollution) affects energy consumption, health and wildlife too. Spend a few minutes to help scientists by measuring the brightness of your night sky. Join the GLOBE at Night citizen-science campaign. There are 5 GLOBE at Night campaigns in 2013: January 3 - 12, January 31 - February 9, March 3 - 12, March 31 - April 9, and April 29 - May 8. Make a difference and join the GLOBE at Night campaign.
GLOBE at Night is a worldwide, hands-on science and education program to encourage citizen-scientists worldwide to record the brightness of their night sky. During five select sets of dates in 2013, children and adults match the appearance of a constellation (Orion or Leo in the northern hemisphere, and Orion and Crux in the southern hemisphere) with seven star charts of progressively fainter stars. Participants then submit their choice of star chart with their date, time and location. This can be done by computer (after the measurement) or by smart phone or pad (during the measurement). From these data an interactive map of all worldwide observations is created. Over the past 7 years of 10-day campaigns, people in 115 countries have contributed over 83,000 measurements, making GLOBE at Night the most successful, light pollution citizen-science campaign to date. The GLOBE at Night website is easy to use, comprehensive, and holds an abundance of background information. Through GLOBE at Night, students, teachers, parents and community members are amassing a data set from which they can explore the nature of light pollution locally and across the globe.
Listen to a fun skit on GLOBE at Night in a 7-minute audio podcast here.
Courtesy NASA Ames/Chris McKay Scientists working at the bottom of the world have discovered a hardy strain of bacteria living comfortably in a salty lake buried under 20 meters of ice in East Antartica.
The body of water, called Lake Vida, is nearly 3000 years old and might as well be situated on one of Jupiter’s moons. It’s by no means a vacation destination. Sunlight no longer reaches it. The bacteria living in it survive in a pitch-black environment, with sub-freezing temperatures, and in waters that contain seven times the amount of salt found in seawater,
"Lake Vida is a model of what happens when you try to freeze a lake solid, and this is the same fate that any lakes on Mars would have gone through as the planet turned colder from a watery past," says co-leader Peter Doran of the University of Illinois, Chicago. Scientists from NASA, the Desert Research Institute in Reno, and several other institutions make up the expedition team.
The microorganisms belong to a species new to science. They thrive in a briny mix rich in hydrogen, nitrous oxide, and carbon - not exactly your normal chemical stew for gracious living – but somehow the bacteria manage to extract energy from the concoction. The researchers think the high salt content interacting with minerals in lake sediments may be responsible for the unusual chemistry.
The discovery of life in Lake Vida could help in our search for life on other planets or beneath the surfaces of their icy moons.
"This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn's moon Enceladus and Jupiter's moon Europa," said Chris McKay, of NASA’s Ames Research Center, and co-author of the paper published online recently in the Proceedings of the National Academy of Sciences Early Edition.
Other subsurface lakes in Antarctica are also under investigation, Lake Vostok, which I posted about previously, and Lake Ellsworth in West Antarctica. Both lakes are millions of years older, and buried under kilometers of ice rather than just meters. It will be interesting to see if some form of life can manage to survive in those even more extreme conditions.
Courtesy National ArchivesSomeone contact Mulder and Scully. Recently declassified documents show that the US Air Force was actually working on building flying saucers in the 1950s. Known as Project 1794, the four digitized documents available on the National Archives website, indicate the program involved development of a disk-shaped aircraft capable of achieving air speeds between Mach 3 and Mach 4 (2,300-3,000 mph) and a height of 100,000 feet! Propulsion was based on the Coandă effect, created by high-speed rotation of the saucer's outer rim. Jet turbines supplied the power. Avro Canada, a Canadian aircraft manufacturer, was also in on this very secret project. The truth might out there, but we might have to wait until the remainder of the two full boxes of documents is digitized and posted online.
Courtesy Mark RyanI don’t have a clue who or what entity officially proclaimed October as International Dinosaur Month (and there doesn’t seem to be any official site online), but whoever it was, it’s a great idea! This means not only do we get to celebrate Earth Science Week (October 14-20), and National Fossil Day (October 17*) this month but we also get to celebrate everyone’s favorite prehistoric beasts! A quick Internet search brought up a couple teacher sites here, here and here each offering some interesting ideas on how to celebrate the great Mesozoic monsters this month. There's also this International Dinosaur Month site on Pinterest , and another Pinterest site (mine) featuring dinosaur postcards. Or you could go view some dinosaurs at a local or nearby museum. Below, I’ve included a few museum links to dinosaur-related exhibits, and a site that lists dinosaur exhibitions around the world. If you or your classes are celebrating dinosaurs this month or have other suggestions on how to do so, please let us know.
*The Science Museum of Minnesota will celebrate National Fossil Day on Saturday, October 20 this year.
Courtesy Photo and sculpting by Tyler Keillor via ZookeysA fossil found in South Africa over 50 years ago has finally come to light as a new species of heterodontosaurid dinosaur and named Pegomastax africanus, or "thick jaw from Africa". No larger than a house cat, Pegamstax lived about 200 million years ago near the very beginning of the Jurassic period. The bizarre, two-legged herbivore had a beak like a parrot but also large, sharp vampire-like fangs that were backed up by a couple of equally nasty bottom teeth. Although unusual for a plant-eater, the sharp teeth would have been useful in nipping off leaves, twigs, and other tasty plant morsels, or for defending itself against predators or mating rivals. It may have also sported some nasty porcupine-like quills for further protection against predation.
Paleontologist Paul Sereno of the University of Chicago first laid eyes on the fossil while a graduate student at a Harvard University laboratory back in 1983. Other projects, however, diverted his attention from the rare specimen until recently when he finally found time to analyze it and publish his conclusions in the journal Zookeys.
News of the mini-dino “vampire" couldn’t have come at a better time, and all you little rug-rats out there who haven’t decided yet what to be for Halloween should find comfort in the announcement. A prickly Pegomastax costume would make for one scary night creature, and probably guarantee you bagfuls of delicious, (and perhaps, ironically) fang-rotting candy.
The mission of NFD is to “promote public awareness of fossils as well as to foster a greater appreciation of their scientific and educational value.”
This year the official day falls on October 17, but celebrations take place at various locations around the country over several days. Here at the Science Museum of Minnesota, the day will be celebrated on Saturday, October 20, 1pm-4pm throughout the museum. You can see what events are happening in your own area here.
Besides going out and hunting for fossils, one of my favorite NFD activities is the National Fossil Day Art & Photography Contest. As in previous years, the competition is open to anyone across several age groups. This year’s theme is “Careers in Paleontology”. A panel of NFD partners and paleontologists will select the winning entries. I’ve already sent in my submission but you have until October 5th (postmark deadline) to enter your own masterpiece.
National Fossil Day is usually observed in conjunction with Earth Science Week and this year is no different. EWS occurs October 14-20, and this year’s theme is Discovering Careers in the Earth Sciences.
Courtesy NASA / JPL-Caltech / Dr. Philip Bart, LSURecent investigations into microfossils show that Antarctica hasn’t been quite the icebox scientists have imagined it to be over the past 34 million years. Pollen and leaf wax samples from Miocene-aged sediments indicate the continent has experienced some periods of warming since the beginning of the most recent glacial period. The core samples studied came from ocean sediments collected near Antarctica, and particulates found in the samples indicate more rain fell on the ice-covered continent during the Middle Miocene epoch (15.5 – 20 million years ago) than previously thought, enough rain to spur the growth of forests of small, stunted trees.
Paleoclimatologist and organic geochemist Sarah Feakins of the University of Southern California and her colleagues analyzed core samples taken from between 144 and 1,100 meters beneath the ocean floor – levels dating back to the Middle Miocene. Spikes of concentrated amounts of pollens and leaf wax appeared in two periods – one about 16.4 million years ago, and another about 15.7 million years ago. The warm periods were relatively short, each lasting less than 30,000 years.
In a previous study, palynologist Sophie Warny of Louisiana State University had first described the pollen and leaf wax spikes found in the core samples, and she and Feakins eventually teamed up for the recent study. The team determined the particle spikes didn’t arise from the leaf wax and pollen blowing in from elsewhere but rather came from two species of trees that once lined the shores of Antarctica. The two species, podocarp conifer and southern beech wouldn’t have grown very tall – maybe knee-high – and neither spreads their pollen over wide areas. Had the pollens blown in from elsewhere - say South America or New Zealand - there were would have been more species in the mix.
Using a mass spectrometer, Feakins and NASA researchers analyzed the ratio of hydrogen to deuterium atoms in the wax molecules which indicated the temperature at the Antarctica location during the two warm periods was about 7 degrees Celsius during the summer. Today, summer temperatures in the same region are about –4 °C. The average global temperature at the time was about 3 °C higher than it is today. As the overall global temperature changes a relatively greater change in polar temperature isn't unexpected due to a process called polar amplification.
The data from Feakins and Warny’s study, which appeared in Nature Geoscience, adds to growing concerns over the sensitivity of Earth’s climatic and hydrological systems. At the moment, no trees line the shores of Antarctica, but current levels of carbon dioxide (393 parts per million) are not far off those thought to have existed during the Middle Miocene’s warm periods (400-600 parts per million) when forests did exist on the margins of the icy continent. This could indicate that even small changes in carbon dioxide levels can are capable of creating big changes in climate.
Courtesy Illustration by Cheung Chungtat via PLoS ONEThe stomach contents of two carnivorous dinosaur skeletons discovered in China show evidence of both bird and dinosaur remains, raising questions about the carnivores' behaviors in acquiring the meals. The two predators, both species of Sinocalliopteryx (and larger cousins of Compsognathus) came from the Early Cretaceous-aged Jianshangou Beds of the lower Yixian Formation in Liaoning province.
The holotype of Sinocalliopteryx gigas included the skull and skeleton, and also signs of “long filamentous integument”, i.e. feathery fuzz. Inside its gut researchers detected the remains of a dromeosaurid (Sinornithosaurus?). The abdomen of the second, recently discovered specimen contains the remains of not one but two primitive birds of the species Confuciusornis sanctus. It also contains the bones of a possible ornithischian dinosaur.
The researchers, led by paleontologist Lida Xing of the University of Alberta, can’t say for certain how the second Sinocallioptyryx acquired the two birds, but several hypotheses have been made. One is that S. gigas was a stealthy hunter with the prowess of a modern day cat, able to stalk and pounce on the unsuspecting early avians. Another possibility is that Sinocalliopteryx scavenged the Confuciusornis meals. But because the remains of the two primitive birds are in the same proximity in the Sinocallioptyryx gut, and show similar levels of being digested, this latter hypothesis opens the question of what would have been the possibility of two C. sanctus dying (or being killed by something else) in such close proximity to each other. The cat-like behavior seems more likely. It could also be possible that the two primitive birds were fledglings that fell out of their nest, or just weren’t as agile as modern birds are in taking flight to avoid predatory attacks.
The remarkable Sinocalliopteryx fossils have also revealed new information about how the digestive systems of some dinosaurs operated. The dinosaur bone found in S. gigas gut is degraded and heavily corroded by stomach acid. Whatever kind of dinosaur it was, it seems to have been consumed first, followed later by the two Confuciusornis. Similar corrosion isn’t evident in the two confuciusornines specimens suggesting S. gigas was still digesting the ornithischian meal when it caught and ate the two avians in fairly rapid succession. This also points to S. gigas having a high rate of metabolism, unlike most reptiles and more like that of modern birds.
Most modern birds egress (vomit) up bone material and don’t try to digest it, while alligators and some vultures living today are able to break down bone material with strong stomach acid in a foregut. A cold-blooded alligator would need about 13 days of digestion to reach the apparent level of bone corrosion seen in the gut of the S. gigas, while warm-blooded birds would need only about 12 hours.
So what kind of scenario does all this intestinal evidence present? Was Sinocalliopteryx gigas a catlike predator that actively hunted, killed, and consumed its own meals, or was it just an opportunistic scavenger of leftovers and road kill? I tend to favor the stalk and pounce method but further evidence would be necessary to say for certain. In the meantime, you can read all about this recent study online in the open access journal PloS ONE.
Courtesy Mark RyanWhat a difference a year can make. The water levels of the Mississippi River this year are at their lowest on record, yet just last year, in the spring of 2011, extreme flooding of Ol’ Muddy was a source of deep concern for those living along its eroding banks.
NASA’s Earth Observatory page shows the striking difference in the river’s appearance near Memphis using two Landsat satellite images taken a year apart. One photograph shows the river in August of 2011 just after the river returned to its pre-flood levels. But if you compare it to a more recent image, its obvious that water levels have gone the opposite direction from flooding. The site conveniently allows you to combine the two views into a single image with a scroll bar you can manipulate back and forth over to see “then and now” differences (just click on the "View Image Comparison" button below the photos).
The lower levels of 2012 have allowed the US Army Corp of Engineers to patch and reinforce some of the levees built along the river to hold back flood waters, but tons of sediment from last year’s floods have reshaped river traffic corridors, reducing barge holding capacities and adding additional shipping costs.