Science & TechnologyS


Fireball 5

Effects of ancient meteor impacts still visible on Earth today

Chesapeake Bay Crater
© USGSThe Chesapeake Bay Crater impact site was formed more than 35 million years ago by a comet or asteroid 5 to 8 miles (8 to 13 kilometers) in diameter.
More than 35 million years ago, a 15-story wall of water triggered by an asteroid strike washed over Virginia from its coast, then located at Richmond, to the foot of the inland Blue Ridge Mountains - an impact that would affect millions of people should it occur today. Yet despite its age, the effects of this ancient asteroid strike, as well as other epic space rock impact scars, can still be felt today, scientists say.

The Virginia impact site, called the Chesapeake Bay Crater, is the largest known impact site in the United States and the sixth largest in the world, said Gerald Johnson, professor emeritus of geology at the College of William and Mary in Virginia. Despite its size, clues about the crater weren't found until 1983, when a layer of fused glass beads indicating an impact were recovered as part of a core sample. The site itself wasn't found until nearly a decade later.

The comet or asteroid that caused the impact, and likely measured 5 to 8 miles (8 to 13 kilometers) in diameter, hurtled through the air toward the area that is now Washington, D.C., when it fell. The impact crated a massive wave 1,500 feet (457 meters) high, researchers said.

Though the impactor left a crater about 52 miles across and 1.2 miles deep (84 km across and 1.9 km deep), the object itself vaporized, Johnson explained.

"I'm just sad we can't have a piece of it," Johnson said in a statement.

Moon

'Rotating moon' filmed by NASA - video


Nasa video footage shows what the moon would look like as it rotates. The images are impossible to witness from Earth, because the moon is 'tidally locked' to it, meaning only one of its faces ever points toward the planet. These timelapse pictures were captured using Nasa's Lunar Reconnaissance Orbiter, which circles the moon at an altitude of 50km

Comet 2

NASA's Deep Impact 'comet-chaser' spacecraft unexpectedly falls silent

Image
A spacecraft that gave scientists their first peek into a comet's icy interior will explore no more, NASA said Friday.

The space agency declared an end to the Deep Impact spacecraft after it unexpectedly fell silent. Engineers tried for a month to regain contact, but lost hope.

Mission scientist Jessica Sunshine of the University of Maryland said she was "saddened at the loss of an old friend."

Deep Impact put on a celestial fireworks display July 4, 2005, when it fired a projectile into comet Tempel 1. The high-speed impact carved a crater and hurled a plume of debris into space, giving scientists their first glimpse of the comet's frozen primordial ingredients.

Afterward, Deep Impact journeyed toward comet Hartley 2, flying through a blizzard of ice particles and escaping unharmed. It later flew by the distant comet Garradd and also observed stars in search of Earth-size planets outside the solar system.

Before Deep Impact lost contact last month, it was studying another comet named Ison that could shine as bright as the moon when it makes a close swing by Earth in November.

Info

Formation of unusual ring of radiation around Earth explained?

Radiation Ring
© Yuri Shprits, Adam Kellerman, Dmitri Subbotin/UCLARing-formation between belts: Model showing third radiation ring (red). Recent observations by NASA's Van Allen Probes mission showed an event in which three radiation zones were observed at extremely high energies, including an unusual medium narrow ring (red) that existed for approximately four weeks. The modeling results, displayed in this illustration, revealed that for particles at these high energies, different physical processes are responsible for the acceleration and loss of electrons in the radiation belts, which explains the formation of the unusual long-lived ring between the belts. The discovery will help protect satellites form the harmful radiation in space, UCLA scientists report.
Since the discovery of the Van Allen radiation belts in 1958, space scientists have believed these belts encircling Earth consist of two doughnut-shaped rings of highly charged particles -- an inner ring of high-energy electrons and energetic positive ions and an outer ring of high-energy electrons.

In February of this year, a team of scientists reported the surprising discovery of a previously unknown third radiation ring -- a narrow one that briefly appeared between the inner and outer rings in September 2012 and persisted for a month.

In new research, UCLA space scientists have successfully modeled and explained the unprecedented behavior of this third ring, showing that the extremely energetic particles that made up this ring, known as ultra-relativistic electrons, are driven by very different physics than typically observed Van Allen radiation belt particles. The region the belts occupy -- ranging from about 1,000 to 50,000 kilometers above Earth's surface -- is filled with electrons so energetic they move close to the speed of light.

Magic Wand

'Cascade of events' caused sudden explosion of animal life

The explosion of animal life on Earth around 520 million years ago was the result of a combination of interlinked factors rather than a single underlying cause, according to a new study.

Dozens of individual theories have been put forward over the past few decades for this rapid diversification of animal species in the early Cambrian period of geological time.

But a paper by Professor Paul Smith of Oxford University and Professor David Harper of Durham University suggests a more holistic approach is required to discover the reasons behind what has become known as the Cambrian Explosion.

Theories for the Cambrian Explosion fall into three main categories - geological, geochemical and biological - and most have been claimed as standalone processes that were the main cause of the explosion.

Whatever the cause, this major evolutionary event led to a wide range of biological innovation, including the origin of modern ecosystems, a rapid increase in animal diversity, the origin of skeletons and the first appearance of specialist modes of life such as burrowing and swimming.

Telescope

Everything you need to know about Comet ISON in 2013

ISON
© Alfons DiepvensISON on Sept. 17, 2013
Comet C/2012 S1 (ISON) has been the most talked-about comet of 2013. When discovered in late 2012, it was said to have the potential to become a striking object visible to the eye alone around the time of its perihelion - or closest point to the sun - on November 28, 2013. People started saying Comet ISON and comet of the century in the same sentence. In June and July 2013, Comet ISON was behind the sun as seen from Earth, but when it was recovered in early August, it wasn't as bright as hoped. What will happen with Comet ISON in the remaining months of 2013? Comets are notoriously unpredictable, but it's safe to say that many are waiting to see if Comet ISON will sizzle ... or fizzle.

Sun

Sun's super-fast plasma 'conveyor belt' surprises scientists

Sun's Meridional Circulation
© NASA SDO/HMIThe sun's meridional circulation is shown in this artist's conception based on research at Stanford's Hansen Experimental Physics Laboratory.
The sun's insides churn much more quickly than previously thought, a new study shows, a finding expected to improve predictions of solar storms that hurl charged particles at Earth.

The flow of plasma - superheated, electrically charged gas - within the sun is more complex than scientists had believed, the study found. Further, this flow extends only half as deep as predicted, to roughly 62,000 miles (100,000 kilometres) beneath the solar surface.

"Our previously held beliefs about the solar cycle are not totally accurate, and ... we may need to make accommodations," lead author Junwei Zhao, a senior research scientist at the Hansen Experimental Physics Laboratory at Stanford University, said in a statement.

Bug

'Alien bugs' discovered in atmosphere

Nitzschia
© Milton Wainwright et al.This image shows a diatom frustule, possibly a Nitzschia species, captured on a stud from a height of 25 km in the stratosphere. Image
British scientists believe they have found small bugs from outer space in the Earth's atmosphere.

Tiny organisms were discovered by University of Sheffield experts on a research balloon they had sent 27 kilometres into the atmosphere during last month's Perseids meteor shower. The microscopic bugs were detected when the balloon landed back on the ground in Wakefield, West Yorkshire in England.

But the scientists insist the samples could not have been carried from the Earth's surface into the stratosphere - the second layer of our atmosphere, which stretches up to 50 kilometres from the ground. Strict tests were taken to avoid any contamination, they said.

Professor Milton Wainwright, who led the team, said: 'Most people will assume that these biological particles must have just drifted up to the stratosphere from Earth, but it is generally accepted that a particle of the size found cannot be lifted from Earth to heights of, for example, 27 kilometres.

'The only known exception is by a violent volcanic eruption, none of which occurred within three years of the sampling trip.' He went on: 'We can only conclude that the biological entities originated from space.

'Our conclusion then is that life is continually arriving to Earth from space, life is not restricted to this planet and it almost certainly did not originate here.' The findings are to be published in the Journal of Cosmology.

'If life does continue to arrive from space then we have to completely change our view of biology and evolution,' Prof Wainwright added. 'New textbooks will have to be written.'

He said further 'crucial' tests on the samples are planned and researchers will carry out further experiments during a meteor shower in October.

Comet 2

Comet ISON still on track for fall spectacle

Comet ISON
© NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science TeamThis is a contrast-enhanced image produced from the Hubble images of Comet C/2012 S1 (ISON) to reveal the subtle structure in the inner coma of the comet. In this computer-processed view, the Hubble image has been divided by a computer model coma that decreases in brightness proportionally to the distance from the nucleus, as expected for a comet that is producing dust uniformly over its surface. ISON's coma shows enhanced dust particle release on the sunward-facing side of the comet's nucleus, the small, solid body at the core of the comet. This information is invaluable for determining the comet's shape, evolution, and spin of the solid nucleus.
Remember when we, and everyone else in the media circuit, reported about how Comet ISON was fizzling out? Well, forget about it, because a very reliable source tells redOrbit that the comet is still on track to potentially provide a spectacular show in the night sky.

Comet ISON has been closely watched by several astronomers over the past year with great anticipation, but also with a little hesitation. It is a tricky balance, because comets have been notorious for disappointment in the past, particularly when media grabs hold of the subject and helps hype up events like this.

In August, Comet ISON emerged from behind the sun and was first picked up by amateur astronomer Bruce Gary. Reports said that according to Gary's observations, this comet was headed for disappointment, rather than the fall spectacle that news sources hyped it up to be. Since then, not a lot of new information has emerged about the comet from the media outlets, so redOrbit reached out to Karl Battams, an astrophysicist and computational scientist at the US Naval Research Laboratory, to get an update about Comet ISON.

Question

Do animals cry?

Image
Despondent baby elephant weeps for hours after mom gives birth, then attacks him at game preserve in China.
Certain animals may weep out of sorrow, similar to human baby cries, say animal behavior experts.

Many may have wondered if this was true after news reports last week described a newborn elephant calf at Shendiaoshan Wild Animal Nature Reserve in eastern China. The calf reportedly cried inconsolably for five hours after being stomped on by his mother that then rejected the little elephant. The calf, named Zhuang-zhuang, has since been "adopted" by a keeper and is doing well, according to the news site Metro.

"Some mammals may cry due to loss of contact comfort," animal behaviorist Marc Bekoff explained to Discovery News. (Bekoff wrote about the topic, himself, in this blog.)

"It could be a hard-wired response to not feeling touch," added Bekoff, former professor of ecology and evolutionary biology at the University of Colorado, Boulder, who, with primatologist Jane Goodall, co-founded the organization Ethologists for the Ethical Treatment of Animals: Citizens for Responsible Animal Behavior Studies.mmary

Comment: Comment: Baby elephant in China can't stop crying after being stomped by mom