- Watch NASA Build the Next Mars Rover
- Chemists Inch Closer to Stable Superheavy Atoms
- Wolf Nannies Shorten Sex Lives of Male Pups
Posted: 22 Oct 2010 11:59 AM PDT
By Olivia Solon, Wired UK
Space enthusiasts can now watch a Mars rover being built at the NASA Jet Propulsion Laboratory thanks to a well-positioned webcam.
Curiosity is a large rover with six wheels about the size of a car, weighing in at more than 900 kilos. It is about twice as long and five times as heavy as NASA's previous rovers Spirit and Opportunity, launched in 2003. It is scheduled head to Mars at the tail end of 2011 and will land on the red planet in August 2012. There it will analyze dozens of samples drilled from rocks or scooped from the ground as it explores a great range than any previous Mars rover.
In addition to an on-board geology lab, Curiosity will have a rock-vaporizing laser called ChemCam, which will be able to remove thin layers of material from Martian rocks or soil targets up to nine meters away. It will have a spectrometer to identify the types of atoms excited by the beam and a telescope to capture detailed images of the area illuminated by the beam.
The Curiosity rover's main mission will be to search areas of Mars for past or present conditions favorable for life, and conditions capable of preserving a record of life. It will carry the most advanced payload of scientific gear ever used on Mars' surface, and for the next year you can watch it being assembled.
The "Curiosity Cam," which is located in the viewing gallery above the clean-room floor where the rover is being assembled, launched this week.
Technicians work from around 8am to 11pm Pacific time, Monday to Friday, meaning that those in the UK can catch a glimpse of the action between 4:00 p.m. and 7:00 a.m. They wear head-to-toe white smocks, aka "bunny suits," complete with boots, facemasks and gloves to help prevent any contaminants from hitching a ride on the rover to Mars.
The camera shows a portion of the room that is normally active, but the rover, components and technicians may move out of view.
To watch the webcam, visit the Curiosity Cam Ustream feed. The plan for today (Friday) is to put the wheels in place. Viewers also have the opportunity to take part in scheduled live chats with members of the team, for example at 18.00 GMT (10.00 am Pacific time) you can chat with René Fradet, the flight systems manager for NASA's Mars Science Laboratory.
People can also follow a link to sign up to have their name included on a microchip that will be sent to Mars with Curiosity.
Posted: 22 Oct 2010 11:08 AM PDT
Chemists searching for the island of stability now have a better map. Thanks to the discovery of six new variations of the superheavy elements on the bottom rung of the periodic table, scientists are closer to creating elements that are expected to last long enough for in-depth study.
Researchers at Lawrence Berkeley National Laboratory in California saw the isotopes of rutherfordium, seaborgium, hassium, darmstadtium, and copernicium by watching the decay of the yet-to-be-named element 114, a synthetic element first produced about a decade ago. Each isotope of an element differs in the number of neutrons in its nucleus, a variable that can affect radioactivity and other properties.
The nuclear chemists created a sample of element 114 by bombarding a plutonium target with a beam of calcium ions. As the handful of atoms began to decay — a process that takes less than a 10th of a second — the team saw six previously undiscovered isotopes of other heavy elements, the researchers report in an upcoming issue of Physical Review Letters.
Heavy radioactive elements tend to decay quickly, most commonly by emitting an alpha particle — two protons and two neutrons, the nucleus of a helium atom. Researchers saw element 114 spit out alpha particles in a chain, creating isotopes of elements 112, 110, 108, 106, and 104 — with 169, 167, 165, 163 and 161 neutrons respectively.
Some of the isotopes are living longer, or have a longer half-life, than previously observed superheavy elements. One isotope of element 114 lasts 2.7 seconds before decaying — an "eternity," says Heino Nitsche, a nuclear chemist at Lawrence Berkeley.
Scientists believe that certain combinations of protons and neutrons in a superheavy element's nucleus would place it in an "island of stability" where radioactive decay would be substantially slower than in the superheavy elements discovered so far. The new isotopes may help guide theorists to a better understanding of just where that island lies.
"The half-lives are picking up in a fashion that's pretty encouraging," says chemist Paul Karol at Carnegie Mellon University. "If they actually find something and they live long enough, it means they can do some chemistry on it, which brings it back to the world we can actually see."
The isotopes don't behave quite as expected — some decay more readily, some less willingly, than the leading theoretical model predicts. The discrepancies mean something isn't quite right with the theory that predicts how atoms behave as they are synthesized heavier and heavier.
"The theories don't describe the nucleus. This will give a fundamental improvement of understanding of the nucleus," says Nitsche.
Image: Flickr/Wolfram Burner
Posted: 22 Oct 2010 06:18 AM PDT
It takes a lupine village to raise a red wolf, but nannied pups don't grow up to be the sex machines scientists expect.
Non-breeding wolves that help raise pups ultimately shorten the sex lives of the male pups when they grow up, according to findings published this week in the journal Proceedings of the Royal Society B. Conversely, she-wolves with nannies enjoy a longer reproductive life.
"The negative impact to males was certainly not what we expected to find," said Amanda Sparkman, an evolutionary biologist at Trent University in Ontario who led the study.
The work could help conservationists maintain reintroduced populations of Canis rufus rufus, as the red wolf is known, which first became extinct in the wild about 30 years ago. But Sparkman says it could add another tool to chip away at the genetics behind mammals that contribute to raising juveniles that aren't their own.
"In the context of cooperative breeding, there's some fascinating evolutionary biology going on there," Sparkman said. "More work could help us understand the key problem of why these wolves are cooperative breeders, along with about 3 percent of mammals and 3 percent of birds."
Red wolf packs roamed most of eastern North America 1 to 2 million years ago, when modern genetics tell us they split off from their coyote relatives. Yet fueled by fear of the man-eating wolves of yore and the threat to livestock, colonists hunted and poisoned the carnivore to extinction in the wild by 1980.
"[Conservationists] took the last few individuals into a captive breeding program, however, and it has been one of the most successful to date," Sparkman said. As a result of those efforts, wolves are back from the dead, though listed as critically endangered under the Endangered Species Act.
Sparkman went a step further than conservationists and leaned on 23 years of red wolf data, including a full pedigree of 463 radio-collared canines, to tease out the findings.
"This is really exemplary data, a kind people just don't have on reproduction and survival of a large carnivore," she said.
Wild red wolves live anywhere from four to seven years, with old-timers lasting as long as 13 years. Most pups stick around their pack for a year or two, sometimes nannying their younger siblings each spring before heading out on their own to find a mate and start their own pack.
Using pedigrees and other data from captured and radio-collared wolves, Sparkman discovered nannied pups survived more often and stuck around their packs about a year longer than non-nannied wolves. What's more, nannied females grew up smaller but enjoyed reproductive lifespans nearly double that of non-nannied she-wolves. Males cared for by pack members outside of their parents grew bigger than other pups, yet their sex lives were almost halved.
"This may tie in to other studies about metabolism," Sparkman said, noting faster aging could be a cost for being bigger. "So, smaller females may live and breed longer because their metabolic cost is less."
In the end, Sparkman suspects some evolutionary twist is at work in the wolves rather than learned behavior, seeing as the creatures were wiped out, reintroduced and still practice cooperative breeding.
"I'd say there is definitely a genetic basis overall, but what is actually producing it?" she said. "That's the real question."
Images: U.S. Fish and Wildlife Service Red Wolf Recovery Project/Greg Koch
|You are subscribed to email updates from Johnus Morphopalus's Facebook notes |
To stop receiving these emails, you may unsubscribe now.
|Email delivery powered by Google|
|Google Inc., 20 West Kinzie, Chicago IL USA 60610|