Science & Technology


Starfish are capable of ejecting foreign objects from their bodies to quickly heal themselves

© University of Southern Denmark
A starfish squeezes a foreign body through its arm tip.
Starfish have strange talents. Two biology students from University of Southern Denmark have revealed that starfish are able to squeeze foreign bodies along the length of their body cavities and out through their arm tips. This newly discovered talent gives insight into how certain animals are able to quickly heal themselves.

The two biology students, Frederik Ekholm Gaardsted Christensen and Trine Bottos Olsen have discovered a starfish behaviour that has never previously been described in the scientific literature. As part of their studies they were asked to tag some starfish (Asterias rubens), so that researchers could reidentify and study the starfish. The tags were injected into the starfish, as a veterinarian tags a dog or cat.

"But every time we put a tag into a starfish, they rid themselves of the tag within a few days. It came out directly through the skin; the starfish simply pushed it out through the skin at the end of one arm and then went on as if nothing had happened", the two students explain.

Fireball 4

Asteroid Icarus to make closest approach to Earth on Tuesday

© NASA JPL Small-Body Database Browser/Osamu Ajiki/Ron Baalke/Ade Ashford
Earth-crossing asteroid 1566 Icarus (1949 MA) will miss our planet by a safe five million miles, or 21 lunar distances, at 4:39 pm BST on 16th June 2015 — the closest it will approach Earth until 2090.
Asteroid Icarus, which stretches more than half a mile long, will pass within "close-range" to the earth on Tuesday.

The asteroid will make its closest approach to Earth on Tuesday, passing within five million miles.

Though the asteroid will be in close proximity, it will be too dim to be seen through everyday backyard telescopes.

For those hoping to catch a glimpse of the space rock, Slooh will run a live broadcast from the Canary Islands starting at 5 p.m. EDT.


Biodiversity limits outbreaks of disease among humans and wildlife

© University of South Florida
A team of University of South Florida biologists and colleagues found broad evidence that supports the controversial 'dilution effect hypothesis,' which suggests that biodiversity limits outbreaks of disease among humans and wildlife. The research may be critical to understanding how and why disease outbreaks occur.
With infectious diseases increasing worldwide, the need to understand how and why disease outbreaks occur is becoming increasingly important. Looking for answers, a team of University of South Florida (USF) biologists and colleagues found broad evidence that supports the controversial 'dilution effect hypothesis,' which suggests that biodiversity limits outbreaks of disease among humans and wildlife.

The paper describing their research appears in a recent issue of the Proceedings of the National Academy of Sciences.

'The dilution effect hypothesis is important because it warns that human-mediated biodiversity losses can exacerbate disease outbreaks, yet it has been contentiously debated,' said study lead author Dr. David Civitello, postdoctoral researcher in the Department of Integrative Biology at USF.


Scientists emerge from 8 months of simulated life on Mars

© Image from
Six scientists, who took part in the NASA-funded HI-SEAS Mars simulation project by living in secluded space modules on a Hawaii volcano for eight months, have finally emerged from their isolation.

Saturday was the first time since the project started that they stepped outside without space suits.

"When we first walked out the door, it was scary not to have a suit on," crew member Jocelyn Dunn, 27, told the media. "We've been pretending for so long."

Comment: An interesting look into how people can live in a close community.


Philae comet probe wakes up, reports after 7 months without contact - ESA

© AFP Photo / ESA
Rosetta's lander Philae.
The lander Philae, dropped onto the surface of Comet 67P by the Rosetta spacecraft, has reawakened and reported back, the European Space Agency says. Philae has been out of contact for the past 7 months.

First contact with Philae lasted 85 seconds. It turns out the lander had woken up earlier, but this is the first time since November it has managed to "speak" to Earth.

"We have also received historical data - so far, however, the lander had not been able to contact us earlier," the ESA blog states.

"Philae is doing very well: it has an operating temperature of -35ºC and has 24 Watts available," Philae Project Manager Dr. Stephan Ulamec says in the blog. "The lander is ready for operations."


Japan plans sending a moon probe to Mars by 2022

© Public Domain
Fresh off successfully retrieving samples from an asteroid in 2011, Japan's space agency, JAXA, has just unveiled an even loftier goal: to land a probe on one of Mars' two moons. It would be a major milestone in prolonged spaceflight, and may even help us understand what became of the ancient, Martian oceans.

Our sister planet with perhaps the greatest potential for extraterrestrial life in the solar system, the Martian surface is already littered with signs of our extra-planetary reach. In 2008, the Phoenix lander went dark after being overwhelmed by a dust storm, and is just one of several defunct robots abandoned on the Martian surface.

In addition to these expired machines, the red planet still hosts seven workable spacecraft. Five float in orbit, while the Opportunity and Curiosity rovers still roam the desert examining rocks and sand and soil.


Impact of testosterone on amygdala depends on motivation rather than on the emotion itself

The activity of the emotion centres in the brain -- the amygdalae -- is influenced by motivation rather than by the emotions themselves. This can be concluded from research carried out at Radboud University into the hormone testosterone. Testosterone increases amygdala activity in a person who is approaching a socially threatening situation and decreases the activity when such a situation is avoided.

It was already known that the amygdala response to images of angry faces was stronger in a person who had received testosterone. This new study shows that this only happens when people approach angry faces and not when they avoid them.

Comment: The amygdala is a part of the reward circuit in the brain that records emotional memories. It acts as an "inner sentry" - and protects from repeating painful experiences by ascribing to outside stimuli a sense of "pleasure" or "pain". It is a very fast and subconsciously acting system that bypasses the much slower input from the rational brain. If humans enter a social situation and want to bond, they have to silence their amygdala to turn off the sentry. Also testosterone increases dopamine levels in the reward circuitry.

Given that the effect of testosterone can be modified by motivation, the above study seems to indicate that there are further factors involved in this feedback loop, which currently are not very clear.


Trail-blazing ants show hints of metacognition when seeking food

© FLPA/Rex
I think, therefore I ant sure.
Do they know they don't know? Ants seem to examine their knowledge, a little like humans do when unsure of which route to take.

Tomer Czaczkes and Jürgen Heinze from the University of Regensburg in Germany let black garden ants find food on a T-shaped maze, with the food always in one arm. Then they switched the food to the other arm, creating uncertainty for the ants.

Ants that headed in the wrong direction were less likely to leave a trail for the other ants to follow.

"It makes, sense," says Czaczkes. "You don't want to give your sisters wrong information."

He says this might show that ants can question their own knowledge, a basic facet of higher metacognition - awareness of one's own thoughts - although it doesn't prove this.

If true, these ants would be just the second reported case of an insect showing such advanced cognitive behaviour.

Browsing through our memories and reflecting on their quality and strength, to double check what we know and then make the best decision, is an everyday task for us.

But it has been confirmed only for relatively advanced species, such as mammals and a few birds. Recent research has shown that bees, when faced with a particularly difficult task, simply opt out of doing it - a behaviour that may be interpreted as a form of metacognition.

Now, it seems that ants might be capable of a similar mental feat, despite their tiny and simple brain.

Snowflake Cold

At near absolute zero, molecules may start to exhibit 'exotic states of matter'

© Jose-Luis Olivares/MIT
MIT researchers have successfully cooled a gas of sodium potassium (NaK) molecules to a temperature of 500 nanokelvin. In this artist's illustration, the NaK molecule is represented with frozen spheres of ice merged together: the smaller sphere on the left represents a sodium atom, and the larger sphere on the right is a potassium atom.
The air around us is a chaotic superhighway of molecules whizzing through space and constantly colliding with each other at speeds of hundreds of miles per hour. Such erratic molecular behavior is normal at ambient temperatures.

But scientists have long suspected that if temperatures were to plunge to near absolute zero, molecules would come to a screeching halt, ceasing their individual chaotic motion and behaving as one collective body. This more orderly molecular behavior would begin to form very strange, exotic states of matter—states that have never been observed in the physical world.

Now experimental physicists at MIT have successfully cooled molecules in a gas of sodium potassium (NaK) to a temperature of 500 nanokelvins—just a hair above absolute zero, and over a million times colder than interstellar space. The researchers found that the ultracold molecules were relatively long-lived and stable, resisting reactive collisions with other molecules. The molecules also exhibited very strong dipole moments—strong imbalances in electric charge within molecules that mediate magnet-like forces between molecules over large distances.

Martin Zwierlein, professor of physics at MIT and a principal investigator in MIT's Research Laboratory of Electronics, says that while molecules are normally full of energy, vibrating and rotating and moving through space at a frenetic pace, the group's ultracold molecules have been effectively stilled—cooled to average speeds of centimeters per second and prepared in their absolute lowest vibrational and rotational states.

"We are very close to the temperature at which quantum mechanics plays a big role in the motion of molecules," Zwierlein says. "So these molecules would no longer run around like billiard balls, but move as quantum mechanical matter waves. And with ultracold molecules, you can get a huge variety of different states of matter, like superfluid crystals, which are crystalline, yet feel no friction, which is totally bizarre. This has not been observed so far, but predicted. We might not be far from seeing these effects, so we're all excited."

Zwierlein, along with graduate student Jee Woo Park and postdoc Sebastian Will—all of whom are members of the MIT-Harvard Center of Ultracold Atoms—have published their results in the journal Physical Review Letters.


Jupiter's Great Red spot is shrinking temporarily?

© Damian Peach
Graphical comparison showing how Jupiter’s Great Red Spot has shrunk in the past 125 years using photographs taken in 1890. See below for details on how it was done.
Maybe it's too soon for a pity party, but the profound changes in the size and prominence of Jupiter's Great Red Spot (GRS) in the past 100 years has me worried. After Saturn's rings, Jupiter's big bloody eye is one of astronomy's most iconic sights.

This titanic hurricane-like storm has charmed earthlings since Giovanni Cassini first spotted it in the mid-1600s. Will our grandchildren turn their telescopes to Jove only to see a pale pink oval like so many others rolling around the planet's South Tropical Zone?