Science & TechnologyS


Blackbox

Where's the remotest place on Earth?

Image
© UnknownIn our hyperconnected world, getting away from it all is easier said than done.
So you've hitch-hiked through Central America, stalked rare beasts in Madagascar and trekked your way through northern Chile. You're pretty well travelled, even if you do say so yourself. Before you get ideas about being an intrepid explorer, however, consider this. For all their wide open spaces and seeming wildernesses, none of these places can be described as remote in 2009.

In fact, very little of the world's land can now be thought of as inaccessible, according to a new map of connectedness created by researchers at the European Commission's Joint Research Centre in Ispra, Italy, and the World Bank.

The maps are based on a model which calculated how long it would take to travel to the nearest city of 50,000 or more people by land or water. The model combines information on terrain and access to road, rail and river networks (see the maps). It also considers how factors such as altitude, steepness of terrain and hold-ups like border crossings slow travel.

Telescope

Solar Systems Around Dead Suns?

Image
© NASA/JPL-CaltechArtist concept illustrates a white dwarf surrounded by a disintegrating asteroid.
Using NASA's Spitzer Space Telescope, an international team of astronomers have found that at least 1 in 100 white dwarf stars show evidence of orbiting asteroids and rocky planets, suggesting these objects once hosted solar systems similar to our own.

Team member Dr Jay Farihi of the University of Leicester will present this discovery on April 20th at the European Week of Astronomy and Space Science conference at the University of Hertfordshire.

White dwarf stars are the compact, hot remnants left behind when stars like our Sun reach the end of their lives. Their atmospheres should consist entirely of hydrogen and helium but are sometimes found to be contaminated with heavier elements like calcium and magnesium. The new observations suggest that these Earth-sized stars are often polluted by a gradual rain of closely orbiting dust that emits infrared radiation picked up by Spitzer.

Telescope

Orion hides busy star "nursery": astronomers

London - The constellation Orion hides a busy stellar nursery, crowded with young stars blasting jets of gas in all directions, astronomers reported on Sunday.

A dusty nebula that looks like a fuzzy patch around Orion's "sword" hides a large region bursting with immature stars, they said.

"Regions like this are usually referred to as stellar nurseries, but we have shown that this one is not being well run: it is chaotic and seriously overcrowded," Chris Davis of the Joint Astronomy Center in Hawaii said in a statement.
orion
A close-up view of a spectacular jet popping out of a busy region of star formation in Orion

Meteor

Asteroids won't raise killer waves - but mind the splash?

Image
© Stocktrek Images / Getty
The odds of encountering a tsunami kicked up by an asteroid strike have just plummeted. Best to hope, though, that you're not underneath the almighty splash such an impact could create.

Small impactors hit us far more frequently than larger ones: a 200-metre asteroid hits Earth about every 10,000 years on average, while 10-kilometre objects like the one that probably killed off the dinosaurs strike every 100 million years. Much of the worry over asteroids has centred on the more likely event of a smaller one splashing down in the ocean and triggering a powerful tsunami.

Now simulations to be presented at an asteroid hazard conference in Granada, Spain, this month suggest that small asteroids do not after all pose a major tsunami threat.


Comment: Asteroids that do not strike in the ocean pose a different kind of threat.


Comment: For an in-depth study read: Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls.


Blackbox

Spirit Suffers Memory Gaps and Unexplained Resets

Image
© UnknownSpirit experienced a series of anomalous events beginning on Sol 1872 (April 9, 2009).
Spirit failed to wake up for three planned events. The rover eventually woke up from an expiring alarm clock timer 27 hours later. Then, an unexpected reset of the rover occurred on Sol 1874 (April 11, 2009). A second reset occurred on Sol 1875 (April 12, 2009).

It was also discovered that the rover did not record any data in flash memory on sols 1874 and 1876 (April 11 and April 13, 2009).

Sols 1877 and 1878 (April 14 and April 15, 2009) have been normal without any errors or anomalies. At this time, there is no explanation for these anomalies. The rover is power positive with the batteries fully charging each day. All temperatures are well within allowable limits.

Telescope

Venus Disappears During Meteor Shower

A Venus-Moon conjunction.
© UnknownA Venus-Moon conjunction.
Picture this: It's 4:30 in the morning. You're up and out before the sun. Steam rises from your coffee cup, floating up to the sky where a silent meteor streaks through a crowd of stars. A few minutes later it happens again, and again. A meteor shower is underway.

One of the streaks leads to the eastern horizon. There, just above the tree line, Venus and the crescent Moon hover side by side, so close together they almost seem to touch. Suddenly, Venus wavers, winks, and disappears.

All of this is about to happen--for real. On Wednesday morning, April 22nd, Earth will pass through a stream of comet dust, giving rise to the annual Lyrid meteor shower. At the same time, the crescent Moon and Venus will converge for a close encounter in the eastern sky. Viewed from some parts of the world, the Moon will pass directly in front of Venus, causing Venus to vanish.

Sun

Brown Dwarfs May Be Common In Our Galaxy

Failed stars may be more common than anyone thought. If so, it would change our idea of how stars form.

In 2007, a star near the centre of our galaxy appeared to brighten because another object had focused the star's light onto Earth. From the way the object bent the light, Andrew Gould of Ohio State University in Columbus and colleagues have now found that it is a brown dwarf - a "failed star" with too little mass to sustain the nuclear reactions that power stars.

Current estimates of how common brown dwarfs are suggest this finding is improbable - so either Gould struck lucky or brown dwarfs are more abundant than previously thought.

Pharoah

Newgrange: Ireland's ancient answer to the pyramids

Image
© Sinead Downing photoNewgrange, Ireland: Neolithic spiritual site
For the ancient people of Ireland (and continuing until recent times, when Celtic Druidry was still practiced there by some), the separation between the living and a world beyond was not nearly as well defined as it is for us moderns. They sought every possible way to connect with the world beyond the physical world they toiled in, and with their ancestors and an eternal spirit. Ireland is, because of this, littered with Neolithic structures known as passage tombs, but likely incorporating both rituals of death, and rituals of rebirth. (Ireland has always been a land of spiritual seeking, up to and including the High Crosses developed in the early Christian era.)

Newgrange, the largest so-called passage tomb known, is one such magnificent structure, created about 5000 years ago. It exhibits the tomb qualities most often mentioned, but also the ritual and astronomical qualities that were also important to life in the Neolithic universe.

Info

What Voyager's golden record tells ET about Earth

Image
© National Astronomy and Ionosphere CenterWhat would extraterrestrials make of this Voyager image?
Douglas Vakoch, director of interstellar message composition at the SETI Institute in Mountain View, California, says any future messages sent to ET should reflect the human race as it really is - warts and all.

"One of the standard assumptions [about composing messages] is we should talk about what we all have in common; we should avoid controversy," he says. "My concern is that if we do that, our messages may be pretty brief and pretty boring."

Bulb

Mirror Neurons Fire Better at Close Range

Reaching out
A newly discovered type of brain cell may help us prep for social interactions.

The cells are a special type of "mirror neurons," which are thought to aid understanding of the actions and intentions of others. Mirror neurons fire both when you do something, like grab a bottle of wine, and when you watch another person do the same thing. Instead of carrying out a step-by-step reasoning process to figure out why a friend is grabbing a bottle of wine, we instantly understand what's going on inside his head because it's going on in our heads too.

Now, researchers have discovered some mirror neurons don't just care about what another individual is doing, they also care about how far away they're doing it, and, more importantly, whether there's potential for interaction.

"This was very surprising for us," said Antonino Casile of the University of Tübingen in Germany, co-author of the research, published in Science Thursday. "The current view about mirror neurons is that they might underlie action understanding. But the distance at which an action is performed plays no role in understanding what the others are doing."