Thursday, August 04, 2005

Astronomers detect '10th planet', etc

Here are excerpts from science news articles, in assumed order of interest, with my brief comments in square brackets:
Astronomers detect '10th planet', BBC, 30 July, 2005, Dr David Whitehouse. Astronomers in the United States have announced the discovery of the "10th planet" to orbit our Sun. The largest object found in our Solar System since Neptune in 1846, it was first seen in 2003 ... Designated 2003 UB313, it is about 3,000km across - a world of rock and ice and somewhat larger than Pluto. Scientists say it is three times as far away as Pluto, in an orbit at an angle to the orbits of the main planets. Astronomers think that at some point in its history, Neptune probably flung the small world into its highly inclined 44-degree orbit. ... It is currently 97 Earth-Sun distances away - more than twice Pluto's average distance from the Sun. ... Its discoverers are Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory in Hawaii, and David Rabinowitz of Yale University. ... David Rabinowitz [said]... "It has been a remarkable day and a remarkable year. 2003 UB313 is probably larger than Pluto. It is fainter than Pluto, but three times farther away. "Brought to the same distance from the Sun as Pluto, it would be brighter. So today, the world knows that Pluto is not unique. There are other Plutos, just farther out in the Solar System where they are a little harder to find." It was picked up using the Samuel Oschin Telescope at Palomar Observatory and the 8m Gemini North telescope on Mauna Kea. ... Chad Trujillo [said] ... "I feel extremely lucky to be part of a discovery as exciting as this. It's not every day that you find something Pluto-sized or larger!" "The spectra ... shows that the surface of 2003 UB313 is very similar to that of Pluto." .. The discovery of 2003 UB313 comes just after the announcement of the finding of 2003 EL61, which appears to be a little smaller than Pluto. The discoveries will once again ignite the debate about the qualifications of an object to be called a planet, an issue the International Astronomical Union is wrestling with ... Modern techniques have revealed several far-off objects that approach Pluto's size, such as Quaoar (detected in 2002) and Sedna (found in 2004); and the promise of Brown and his colleagues is that more will soon be detected. Some researchers suspect there could even be Mars-sized objects lurking in this region of the Solar System known as the Kuiper belt. ... Planet casts new light on solar system, Daily Telegraph, Robert Matthews, 3 August 2005 ... According to Professor Mark Bailey, the director of the Armagh Observatory, Northern Ireland, the discovery is likely to cast new light on the formation of the sun's family of planets about 4,500 million years ago. "It may be that the sun was once part of a cluster of stars, and these scattered the bodies making up the early solar system into the strange orbits we see today," he said. [A great achievement! But if astronomers cannot be sure that there are not "Mars-sized objects lurking in this region of" our "Solar System", then what hope have they got of detecting Earth-sized planets in far more distant exoplanetary systems? The last comment by Prof. Mark Bailey about our Solar System's "strange orbits we see today," indicates that it and Earth may be unique. See also: 'New planet' found in solar system, ABC, July 30, 2005; Scientists Claim Discovery of 10th Planet, ABCNEWS/Associated Press, Alicia Chang, July 31, 2005;
Astronomers claim discovery of solar system's 10th planet, CNN, July 31, 2005.]
Scientists Deem Saturn Moon Titan Dry Scientists Find No Signs of Hydrocarbon Oceans on Titan, Saturn's Planet-Sized Moon By Alicia Chang ABCNEWS/The Associated Press Aug. 3, 2005 - Scientists peering through a ground-based telescope say the surface of Saturn's planet-sized moon Titan appears dry and not awash in oceans of liquid hydrocarbons as is commonly believed. ... telescopes and orbiting spacecraft have yet to turn up evidence of a global ocean of methane on Titan. In the latest study, scientists using the Keck II telescope in Hawaii failed to see any reflections of sunlight that would indicate a body of liquid on the frozen moon during several viewings in 2003 and 2004, said lead researcher Robert West of the Jet Propulsion Laboratory in Pasadena. Results appear in Thursday's issue of the journal Nature. ... Scientists believe Titan's smoggy atmosphere may be similar to that of the primordial Earth and studying it could provide clues to how life began. ..." [Another problem for the Oparin-Haldane primordial soup origin of life hypothesis?]
How Lowly Bacteria Froze Earth Solid, Livescience, Robert Roy Britt, 1 August 2005. Earth has been through many cold spells since its birth 4.5 billion years ago. Scientists say some drastic episodes froze the planet all the way to the equator. Yet these "snowball Earth" scenarios expose a gaping lack of understanding: What caused them? Lowly bacteria, according to a new study. In the first and worst snowball episode, 2.3 billion years ago, bacteria suddenly developed the ability to break down water and release oxygen. The influx of oxygen destroyed methane in the atmosphere, which had acted as a blanket to keep the planet warm. ... The idea is presented in the latest issue of the Proceedings of the National Academy of Sciences by researchers at Caltech. In modelling the scenario, the scientists say Earth's exact position from the Sun is the only thing that saved the planet from a permanent deep-freeze. ... Before the first snowball event, the Sun was only 85 percent as bright as now. But the planet was temperate, much like today. Scientists believe that's because the atmosphere was loaded with methane, a greenhouse gas. ... Then along came cyanobacteria, which evolved into the first organisms to use water in photosynthesis, releasing oxygen as a byproduct. Scientists had thought the shift might have occured perhaps as far back as 3.8 billion years ago. But the Caltech scientists searched ancient rocks for clues and found no evidence for the change prior to 2.3 billion years ago. Here's what they think happened: A regular old Ice Age set in, and glaciers advanced to middle-latitudes as they would many times in geologic history. When the glaciers retreated back toward the poles, they scoured the land and released abundant nutrients into the oceans. There were no plants or animals back then. The cyanobacteria, with their newly developed ability to make oxygen, fed off the fresh flow of nutrients, the thinking goes, and their numbers exploded. And things, well, they snowballed from there. ... "Their greater range should have allowed the cyanobacteria to come to dominate life on Earth quickly and start releasing large amounts of oxygen," said study team member Robert Kopp, a Caltech graduate student. ... Global temperatures plummeted to minus 58 Fahrenheit (-50 C). Ice at the equator was a mile thick. Most organisms died. Biology clung to hydrothermal vents or survived underground, Kopp and his colleagues say. Even today, life has shown itself to be incredibly resilient, eating rocks, swimming in boiling water and enduring thousands of years in the deep freeze. Then evolution pulled another trick, the scientists figure. Some of the organisms that did survive adapted to breathe oxygen, now that there was a lot of it. It was this ability to use oxygen that allowed life to evolve to more complex forms, the scientists say. ... That leaves the question of how we got out of that frozen mess the bacteria got us into. Eventually, the scientists say, the changed biology and chemistry caused carbon dioxide to build up enough to generate another greenhouse period. Temperatures climbed to perhaps 122 Fahrenheit (50 C) around the globe, evidence indicates. "It was a close call to a planetary destruction," says Kopp's supervising professor, Joe Kirschvink. "If Earth had been a bit further from the Sun, the temperature at the poles could have dropped enough to freeze the carbon dioxide into dry ice, robbing us of this greenhouse escape from snowball Earth."[Another fine-tuned parameter for life on Earth! I have added this to my "Problems of Evolution" book outline, PE "Earth's fitness for life ... Distance from Sun ... Just right to escape `snowball Earth'"]
S Korea unveils first dog clone, BBC, 3 August 2005. Scientists in South Korea have produced the first dog clones, they report in Nature magazine this week. One of the puppies died soon after birth but the other, an Afghan hound named Snuppy, is still doing well after 16 weeks, the researchers say. ... "The dog has characteristics similar to human beings," lead researcher Woo Suk Hwang of Seoul National University, South Korea, told the BBC. "Some of their diseases are almost the same as human diseases. "So [dog clones] could be very valuable in finding technologies useful for curing human diseases. This is our main research call." ... Snuppy, whose name stands for Seoul National University puppy, was made from a cell taken from the ear of a three-year-old male Afghan hound. ... and placed ... into an empty egg cell. This egg was then stimulated to start dividing and develop into an embryo. Once growing, it was transferred to Snuppy's surrogate mother, a yellow labrador. ... Although many other animals have been successfully cloned, dogs are notoriously difficult: the South Korean team only obtained three pregnancies from more than 1,000 embryo transfers into 123 recipients. Of these, one miscarried and one died soon after birth; only Snuppy remains. ... Some people are concerned about the ethical implications of this research. "Canine cloning runs contrary to the Kennel Club's objective 'To promote in every way the general improvement of dogs'," Phil Buckley, spokesman for the Kennel Club [said]. "Cloning cannot be used to make improvements because the technique simply produces genetic replicas of existing dogs. "Also, will these cloned dogs end up being used in the laboratory? That opens a whole new can of worms." ... Dr Freda Scott-Park, President Elect of the British Veterinary Association, is concerned about the likely reaction of dog lovers. "This report demonstrates just how fast the world of genetic manipulation is moving and no one should underestimate the far-reaching consequences of this work," she said. "Sadly however, the media interest is likely to attract pet owners keen to re-create their much loved pets. ... cloning animals raises many ethical and moral issues that have still to be properly debated within the profession." However, another member of the cloning team, Dr Gerald Schatten from the University of Pittsburgh School of Medicine, US, said they are not in the business of cloning pets. "The overall objective of this programme is to learn about the root causes of diseases," he told the BBC. "We believe it is possible, if you can responsibly develop the ability to derive stem cells from cloned dog embryos, that our very best friends may turn out to be the first beneficiaries of stem cell medicine. "And as we treat naturally occurring diseases in dogs, we'll learn about whether it is effective in our pets and we'll also learn whether it's safe and effective for our loved ones." ... [That out of "more than 1,000 embryo transfers ... only Snuppy remains", shows the enormous expense, ethical repugnance and therefore practical uselessnes in the real world, such cloning is. See also: Scientists announce world's first cloned dog, ABC, August 4, 2005; Cloning's gone to the dogs, The Australian, Leigh Dayton, August 04, 2005.]

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