Science & TechnologyS


Magnify

Archaeologists hunt for Cleopatra's tomb

Alexandria, Egypt - High on a hill overlooking the Mediterranean Sea, buried deep under the crumbling limestone of a temple to the goddess Isis, archaeologists believe the body of Queen Cleopatra may lie.

The tomb of the Egyptian queen has never been found but archaeologists are discovering more evidence that Cleopatra's priests carried her body to the temple after her suicide, where it could lie with her lover Marc Antony.

"This could be the most important discovery of the 21st century," Zahi Hawass, Egypt's chief archaeologist, told reporters on a tour of the temple on Sunday. "This is the perfect place for them to be hidden."

Meteor

The International Space Station and Meteor Cross Paths

Image
© Stan Nelson
On April 2nd, ham radio operator Stan Nelson of Roswell, New Mexico, was listening to the radar's signals when the International Space Station and a meteor passed through the beam in quick succession.

The slowly descending tone at the beginning of the soundtrack is the radar's doppler-shifted reflection from the ISS. It sounds like the whistle of a train racing past a stationary bystander. Indeed, the basic physics of the doppler shift is the same in both cases.

The rapidly descending tone near the end of the soundtrack is the radar's doppler-shifted reflection from a meteor. Because meteors travel through space some two to ten times faster than Earth-orbiting spacecraft, their radar reflections are much more sharply doppler shifted.

Click on the dynamic spectrum to listen.

Sun

Best of the Web: Low sunspot cycle fascinates scientists

Image
© SOHO/MDISpotless sun
Unusual trends - especially astronomical ones - are a great way to cause the public to panic.

But for those worried about a strangely long trend of missing sunspots, scientists have a message: Don't expect the sun to change its spots overnight.

Sunspots are dark areas on the sun's surface caused by intense magnetic activity. They indicate a natural sort of churning caused by the rotation of plasma inside the sun. And they are often associated with things like solar flares, mass ejections and other phenomenon indicating increased solar activity.

Since 2004, the sun has been in a prolonged period of low sunspot activity, which has led some to fear that the phenomenon could lead to global cooling, a new ice age, the death of the sun or even to the end of the world predicted by the Mayan calendar.

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.