Science & TechnologyS


Camera

Spacecraft to image unseen side of Mercury

Rachel Courtland
New Scientist
Thu, 02 Oct 2008 22:25 UTC
NASA's Messenger spacecraft will zip past the surface of Mercury on Monday, allowing it to glimpse a third of the planet that has not yet been seen close up.
Mercury's huge Caloris impact basin
© NASA/JHU APL/CIWBuff-coloured volcanic plains in Mercury's huge Caloris impact basin are shown in this mosaic of images taken during Messenger's first flyby on 14 January. As much as 95% of Mercury's surface will be mapped after Messenger's second flyby on 6 October, allowing researchers to estimate for the first time what fraction of the surface is covered by volcanic lava flows.

The flyby will take the car-sized probe within 200 kilometres of the surface, at a speed of more than 24,000 km per hour.

This is the probe's second close look at the scarred, rocky planet. During a flyby on 14 January, Messenger captured detailed images of a previously unseen 20% of the planet's surface.

Monday's flyby will produce more than 1200 images - the first of which will be transmitted back to Earth on Tuesday - to cover an additional 30% of the surface.
Read More...
Info

Neanderthals feasted on seals and dolphins

Ewen Callaway
New Scientist
Thu, 02 Oct 2008 22:17 UTC
They may not have used clubs, but Neanderthals hunted seals too. Anthropologists have discovered ancient seal bones showing signs of butchery, as well as some dolphin remains, in two caves in Gibraltar.
Thoracic vertebra of juvenile common dolphin
© Clive Finlayson, Gibraltar MuseumThoracic vertebra of juvenile common dolphin from Vanguard cave

The discovery bolsters the image of Neanderthals as intelligent and adaptable hunters, rather than knuckle-dragging brutes, says Clive Finlayson of the Gibraltar Museum.

Finlayson was part of an international team of anthropologists who discovered and analysed the marine mammal bones.

"Neanderthals could not have been that stupid and dumb," he says. "These people probably had a pretty good knowledge of the seasons and when to go hunting."

Finlayson and his colleague Yolanda Fernández-Jalvo, of Madrid's National Museum of Natural Sciences, discovered the bones in two cliff-base caves overlooking the Atlantic Ocean: Gorham's cave and Vanguard cave.

The sites, dating to around 40,000 years ago, also contain signs of hearths, tool-making and the remains of molluscs, boars and bears.
Read More...
Telescope

Infrared Echoes Give NASA's Spitzer a Supernova Flashback

Francis Reddy / Rob Gutro
NASA
Wed, 01 Oct 2008 21:11 UTC
Image
© NASA/JPL-Caltech/STScI/CXC/SAOCassiopeia A is among the best-studied supernova remnants. This image blends data from NASA's Spitzer (red), Hubble (yellow), and Chandra (green and blue) observatories.

Hot spots near the shattered remains of an exploded star are echoing the blast's first moments, say scientists using data from NASA's Spitzer Space Telescope.

Eli Dwek of NASA's Goddard Space Flight Center in Greenbelt, Md., and Richard Arendt of the University of Maryland, Baltimore County, say these echoes are powered by radiation from the supernova shock wave that blew the star apart some 11,000 years ago. "We're seeing the supernova's first flash," Dwek says.

Other Spitzer researchers discovered hot spots near the Cassiopeia A supernova remnant and recognized their importance as light echoes of the original blast. Dwek and Arendt used Spitzer data to probe this hot dust and pin down the cause of the echoes more precisely.
Read More...
Star

More Star Births Than Astronomers Have Calculated


Science Daily
Thu, 02 Oct 2008 16:26 UTC
The "birth rate" for stars is certainly not easy to determine. Distances in the universe are far too great for astronomers to be able to count all the newly formed celestial bodies with the aid of a telescope. So it is fortunate that the emerging stars give themselves away by a characteristic signal known as "H-alpha" emissions. The larger the number of stars being formed in a particular region of the firmament, the more H-alpha rays are emitted from that region.

"H-alpha emissions only occur in the vicinity of very heavy stars," explains Jan Pflamm-Altenburg of the Argelander Institute of Astronomy at Bonn University. It has long been accepted that heavy and light stars are always born in a certain ratio to each other. One "H-alpha baby" is thought to be accompanied by 230 lighter stars with a mass too low for them to emit H-alpha rays.
Read More...
Calculator

New Mathematical Model Can Measure Political Party Power


Science Daily
Thu, 02 Oct 2008 16:22 UTC
A new algorithm developed by a computer scientist at the University of Southampton can be used to predict political power balances.

In a paper entitled "Manipulating the Quota in Weighted Voting Games" published in the proceedings of the Association for the Advancement of Artificial Intelligence , Dr Edith Elkind at the University's School of Electronics and Computer Science (ECS) describes how a mathematical model developed to describe voting in a parliament, can facilitate decision making among groups of computerised agents.

'Agents tend to form coalitions in much the same way as political parties,' she said. 'So I thought it would be interesting to look at what would happen to the balance of power if you change the number of votes needed to make a decision.'

In her paper, Dr Elkind, who is part of ECS' Intelligence, Agents, Multimedia Group, illustrates that the power of a political party is very much dependent on whether bills are passed by a simple majority (50% of all votes) or a qualified majority (two thirds of all votes).
Read More...
Telescope

First Detection Of Magnetic Field In Distant Galaxy Surprises Astronomers


Science Daily
Thu, 02 Oct 2008 16:16 UTC
Using a powerful radio telescope to peer into the early universe, a team of California astronomers has obtained the first direct measurement of a nascent galaxy's magnetic field as it appeared 6.5 billion years ago.
steerable radio telescope
© NRAO/AUIThe astronomers used the world's largest fully steerable radio telescope, which stands 485 feet tall -- taller than the Statue of Liberty.

Astronomers believe the magnetic fields within our own Milky Way and other nearby galaxies - which control the rate of star formation and the dynamics of interstellar gas--arose from a slow "dynamo effect." In this process, slowly rotating galaxies are thought to have generated magnetic fields that grew very gradually as they evolved over 5 billion to 10 billion years to their current levels.

But in the October 2 issue of Nature, the astronomers report that the magnetic field they measured in this distant "protogalaxy" is at least 10 times greater than the average value in the Milky Way.
Read More...
Satellite

Galileo satellite knocked offline

Jonathan Amos and Paul Rincon
BBC News
Wed, 01 Oct 2008 04:59 UTC
Giove-B Galileo demonstrator satellite
© BBC NewsThe Giove-B demonstrator was launched earlier this year
A test spacecraft for Europe's future satellite-navigation system has been rocked by a surge of space radiation.

The incident forced the Giove-B satellite to adopt a "safe mode" for two weeks in which only essential power systems were kept running.

European Space Agency (Esa) engineers have brought the satellite back up and are now studying what happened.
Read More...
Cloud Lightning

Cloud Radar: Predicting The Weather More Accurately


Science Daily
Wed, 01 Oct 2008 16:23 UTC
The weather. It's the one topic of conversation that unites Britain - umbrella or sun cream? Now scientists at the Science and Technology Facilities Council have developed a system that measures the individual layers of cloud above us which will make answering the all-important weather questions much easier in future.
Cloud radar
© Science and Technology Facilities CouncilCloud radar deployed at Field Station.

The Cloud Radar will not only allow forecasters to predict the weather more precisely, the information gathered will also enable aircraft pilots to judge more accurately whether it is safe to take off and land in diverse weather conditions, offering a powerful safety capability for civil airports and military air bases.

Developed over 10 years by researchers and engineers at the STFC Rutherford Appleton Laboratory, in collaboration with the Met Office, the Cloud Radar can take a complete and accurate profile of cloud or fog up to 5 miles overhead. Operating at 94 GHz, 50 times higher in frequency than most mobile phones, the radar measures the cloud base height, its thickness, density and internal structure as well as providing similar information on cloud layers at higher altitudes.
Read More...
Telescope

Mars: Ancient And Ongoing Processes That Shape Planet Surface


Science Daily
Wed, 01 Oct 2008 03:47 UTC
The unprecedented image quality of the High Resolution Imaging Science Experiment (HiRISE) carried by NASA's Mars Reconnaissance Orbiter is helping scientists make leaps forward in understanding both the ongoing and ancient processes that shaped the surface of Mars.

Mars 3D view of a few scallops
© NASA/JPL/University of Arizona3D view of a few scallops. The ridges are asymmetrical with a steeper, shorter, scarp-facing-slope and form steps on the scallop floor (HiRISE image PSP_001938_2265 overlaid on a HiRISE DEM).
Professor Alfred McEwen, HiRISE's Principal Investigator, highlighted some of the most recent results at the European Planetary Science Congress in Münster on September 24th.

A study of the nature and distribution of ancient megabreccia, led by McEwen at the University of Arizona, suggests that this bedrock was formed during the late heavy bombardment period. Megabreccia consists of angular, randomly-orientated blocks that formed suddenly in energetic events such as meteorite impacts. It is thought to contain fragments of the oldest and deepest bedrock exposed on the surface of Mars.

"We think that the megabreccia was formed during a period of heightened meteorite activity about 3.9 billion years ago. This is around the time life appears to have begun on Earth, but we have very little record of that era in our terrestrial geology because ancient rocks are heavily metamorphosed. Mars preserves a much better record of the heavy bombardment and, unlike the dry lunar surface, it shows the environmental effects in a water-rich crust," said McEwen.
Read More...
Meteor

Mass Extinctions And The Evolution Of Dinosaurs


Science Daily
Wed, 01 Oct 2008 03:27 UTC
Dinosaurs survived two mass extinctions and 50 million years before taking over the world and dominating ecosystems, according to new research published this week.

Tyrannosaurus Rex, chasing two Parasaurolophuses
© iStockphoto/Allan TooleyIllustration of a Tarbosaurus, a cousin of Tyrannosaurus Rex, chasing two Parasaurolophuses.
Reporting in Biology Letters, Steve Brusatte, Professor Michael Benton, and colleagues at the University of Bristol show that dinosaurs did not proliferate immediately after they originated, but that their rise was a slow and complicated event, and driven by two mass extinctions.

"The sheer size of dinosaurs like Tyrannosaurus makes us think there was something special about these animals that preordained them for success right from the beginning," Brusatte said. "However, our research shows that the rise of dinosaurs was a prolonged and complicated process. It isn't clear from the data that they would go on to dominate the world until at least 30 million years after they originated."

Importantly, the new research also shows that dinosaurs evolved into all their classic lifestyles - big predators, long-necked herbivores, etc. - long before they became abundant or diversified into the many different species we know today.
Read More...