Science & TechnologyS


Info

Earliest Animal Footprints Ever Found Show Animals Walking 30 Million Years Earlier Than Previously Thought

The fossilized trail of an aquatic creature suggests that animals walked using legs at least 30 million years earlier than had been thought. The tracks -- two parallel rows of small dots, each about 2 millimeters in diameter -- date back some 570 million years, to the Ediacaran period.
Trackway of one of the earliest animals
© Kevin Fitzsimons, Ohio State UniversityTrackway of one of the earliest animals, a multi-legged creature that walked over the bed of an ancient sea once covering Nevada. The animal left behind a pair of parallel impressions - small, round dots in the silt that later became rock.

The Ediacaran preceded the Cambrian period, the time when most major groups of animals first evolved.

Scientists once thought that it was primarily microbes and simple multicellular animals that existed prior to the Cambrian, but that notion is changing, explained Loren Babcock, professor of earth sciences at Ohio State University.

"We keep talking about the possibility of more complex animals in the Ediacaran -- soft corals, some arthropods, and flatworms -- but the evidence has not been totally convincing," he said. "But if you find evidence, like we did, of an animal with legs -- an animal walking around -- then that makes the possibility much more likely."

Saturn

Saturn's Radio Broadcasters Mapped In 3D For First Time

Observations from NASA's Cassini spacecraft have been used to build, for the first time, a 3D picture of the sources of intense radio emissions in Saturn's magnetic field, known as the Saturn Kilometric Radiation (SKR).
Saturn
© EuroplanetProjection of radio sources onto plane perpendicular to line between Cassini and the centre of Saturn.

The SKR radio emissions are generated by high-energy electrons spiralling around magnetic field lines threaded through Saturn's auroras. Previous Cassini observations have shown that the SKR is closely correlated with the intensity of Saturn's UV aurora and the pressure of the solar wind.

The measurements were made using Cassini's Radio and Plasma Wave Science (RPWS) experiment. The results will be presented by Dr Baptist Cecconi, of LESIA, Observatoire de Paris, at the European Planetary Science Congress on the 23rd of September.

Star

Sun Is Not A Perfect Sphere, NASA Spacecraft Finds

Scientists using NASA's RHESSI spacecraft have measured the roundness of the sun with unprecedented precision. They find that it is not a perfect sphere. During years of high solar activity the sun develops a thin "cantaloupe skin" that significantly increases its apparent oblateness: the sun's equatorial radius becomes slightly larger than its polar radius.
© Gary Palmer"Cantaloupe ridges" on the sun. The glowing white magnetic network is what gives the sun its extra oblateness during times of high solar activity. Amateur astronomer Gary Palmer took the picture in July 2005 using a violet calcium-K filter.

Their results appear the Oct. 2nd edition of Science Express.

"The sun is the biggest and therefore smoothest object in the solar system, perfect at the 0.001% level because of its extremely strong gravity," says study co-author Hugh Hudson of UC Berkeley. "Measuring its exact shape is no easy task."

The team accomplished the task by analyzing data from the Reuven Ramaty High-Energy Solar Spectroscopic Imager, RHESSI for short, an x-ray/gamma-ray space telescope launched in 2002 on a mission to study solar flares. Although RHESSI was never intended to measure the roundness of the sun, it has turned out ideal for the purpose. RHESSI observes the solar disk through a narrow slit and spins at 15 rpm. The spacecraft's rapid rotation and high data sampling rate (necessary to catch fast solar flares) make it possible for investigators to trace the shape of the sun with systematic errors much less than any previous study. Their technique is particularly sensitive to small differences in polar vs. equatorial radius or "oblateness."

Sun

Sun Warms and Cools the Earth

In an op-ed in a Polish weekly I commented recently on a remarkable decrease of global temperature in 2008, and over the past decade. Not surprisingly the op-ed evoked a strong reaction from Polish co-workers of IPCC, denying the existence of cooling. Surprising, however, was that the criticism dwelled upon a "global climatic conspiracy", and "colossal international plot". I did not use these words nor even hinted at such an idea. The idea was probably apparent from the data and facts I presented, showing weaknesses of the man-made global warming hypothesis. Without irrational political or ideological factors, it is really difficult to understand why so many people believe in human causation of the Modern Warm Period, which was never plausibly proved by scientific evidence. Some of these factors I will discuss here.

Bomb

Flashback Friend or Foe? Crows Never Forget a Face, It Seems

Image
© Keith Brust; Jeff WallsI KNOW YOU - John M. Marzluff, a wildlife biologist tested crows’ ability to distinguish between faces.
Crows and their relatives - among them ravens, magpies and jays - are renowned for their intelligence and for their ability to flourish in human-dominated landscapes. That ability may have to do with cross-species social skills. In the Seattle area, where rapid suburban growth has attracted a thriving crow population, researchers have found that the birds can recognize individual human faces.

The researchers used a simple hat and masks to test the animals' abilities.

Comment: Interesting that the power structures of society have nearly destroyed an analogous ability within the human population to recognize pychopathic predators and share that knowledge, particularly in women.


Cow Skull

Big fossil found in hurricane Ike-ravaged home's front yard

A homeowner whose beachfront property in Texas was destroyed during Hurricane Ike has found a football-size fossil tooth in the debris.

Dorothy Sisk asked her colleague, Lamar University paleontologist Jim Westgate, to accompany her to her Bolivar Peninsula home after Ike hit. Together they found something unusual in the remains of Sisk's front yard: a six-pound fossil tooth.

Telescope

Dark matter makes galaxy's stars live long and prosper

Stars at the centre of the Milky Way could gobble up enough dark matter to extend their lifetimes by a billion or more years, a new study suggests. If such stars are found, they could help reveal what the mysterious dark matter is actually made of.
Sun-like stars on tight orbits around the centre of the Milky Way
© E L Wright/UCLA/COBE/DIRBE/NASASun-like stars on tight orbits around the centre of the Milky Way may gobble up enough dark matter to appear redder and brighter than they would otherwise.

Although it constitutes roughly 90% of the Milky Way's mass, dark matter is thought to be too diffuse in most parts of the galaxy to have a large effect on stars. But close to the colossal black hole at the galactic centre, the material might be sufficiently dense that stars can capture it at high rates.

To investigate dark matter's effect on such stars, Pat Scott of Stockholm University in Sweden and colleagues modelled the evolution of stars as they gravitationally accumulated weakly interacting massive particles, or WIMPs - a popular group of dark matter candidates.

Telescope

What happened to the Kuiper Belt's smallest objects?

The hunt continues for the outer solar system's tiniest residents. A two-year search to find small objects there has turned up nothing, bolstering theories that 'all hell broke loose' in the solar system just a few hundred million years after it formed.

Astronomers have found more than 1000 objects in the Kuiper Belt, a ring of icy bodies beyond Neptune. There are fewer large Kuiper Belt Objects than smaller ones, but the exact size distribution is unknown because only a handful of KBOs smaller than 70 kilometres across have been found - they simply reflect too little sunlight to be observed.

Meteor

Meteorites From Inner Solar System Match Up To Earth's Platinum Standard

Some of the world's rarest and most precious metals, including platinum and iridium, could owe their presence in the Earth's crust to iron and stony-iron meteorites, fragments of a large number of asteroids that underwent significant geological processing in the early Solar System.
asteroid impact with early Earth
© ESAArtist's impression of asteroid impact with early Earth that led to lunar formation.

Dr Gerhard Schmidt from the University of Mainz, Germany, has calculated that about 160 metallic asteroids of about 20 kilometres in diameter would be sufficient to provide the concentrations of these metals, known as Highly Siderophile Elements (HSE), found in the Earth's crust. Dr Schmidt will be presenting his findings at the European Planetary Science Congress in Münster on Monday 22nd September.

Dr Schmidt said, "A key issue for understanding the origin of planets is the knowledge of the abundances of HSE in the crust and mantle of the Earth, Mars and the Moon. We have found remarkably uniform abundance distributions of HSE in our samples of the Earth's upper crust. A comparison of these HSE values with meteorites strongly suggests that they have a cosmochemical source."

Star

Spotless Sun: Blankest Year of the Space Age

Astronomers who count sunspots have announced that 2008 is now the "blankest year" of the Space Age.