WANTED: Rocky planet outside of our solar system. Must not be too hot or too cold, but just the right temperature to support life.
It sounds like a simple enough wish list, but finding a planet that fulfils all of these criteria has kept astronomers busy for decades. Until recently, it meant finding a planet in the "Goldilocks zone" - orbiting its star at just the right distance to keep surface water liquid rather than being boiled off or frozen solid.
Now, though, it's becoming increasingly clear that the question of what makes a planet habitable is not as simple as finding it in just the right spot. Many other factors, including a planet's mass, atmosphere, composition and the way it orbits its nearest star, can all influence whether it can sustain liquid water, an essential ingredient for life as we know it. As astronomers explore newly discovered planets and create computer simulations of virtual worlds, they are discovering that water, and life, might exist on all manner of weird worlds where conditions are very different from those on Earth. And that means there could be vastly more habitable planets out there than we thought possible. "It's like science fiction, only better," says Raymond Pierrehumbert, a climate scientist at the University of Chicago, who studies planets inside and outside of our solar system.
Science & Technology
© T Gregory Guzik
A balloon-borne experiment flying over Antarctica measured a surprisingly high number of energetic electrons streaming in from space.
A balloon-borne experiment flying over Antarctica measured a surprisingly high number of energetic electrons streaming in from space.
High-energy electrons are found throughout space and are accelerated when stars explode in supernovae. But a balloon-borne detector flying over Antarctica called the Advanced Thin Ionization Calorimeter (ATIC) has detected 70 more high-energy electrons than the normal background level attributed to supernova blasts.
John Wefel of Louisiana State University in Baton Rouge, who led the collaboration, says there are two possible explanations.
The electrons could come from a nearby astrophysical object, such as a pulsar, that lies within 3000 light years from Earth. But the team has spent four years trying to fit the signal to such an object and has yet to find a good match.
Tufts of frozen woolly mammoth hair have yielded a rough draft of its genome. It's the most successful attempt to sequence the DNA of an extinct ancient animal to date, and although we won't see resurrected mammoths grazing the tundra anytime soon, it could give us a peek into the reasons for their extinction.
Sequencing extinct organisms is tricky since DNA strands quickly degrade after death into short fragments that are difficult to piece back together. In porous tissue like bone, these fragments can also become flooded by DNA from bacteria and fungi growing on the decomposing body, making it hard to pick out the genetic material of interest.
To solve this, Stephan Schuster from Pennsylvania State University and colleagues sequenced DNA from the hair of two frozen woolly mammoths, which died in Siberia roughly 20,000 and 60,000 years ago respectively.
Sequencing extinct organisms is tricky since DNA strands quickly degrade after death into short fragments that are difficult to piece back together. In porous tissue like bone, these fragments can also become flooded by DNA from bacteria and fungi growing on the decomposing body, making it hard to pick out the genetic material of interest.
© Peter Brooker/Rex Features
Mammoth hair protects DNA from the ravages of nature.
Mammoth hair protects DNA from the ravages of nature.
To solve this, Stephan Schuster from Pennsylvania State University and colleagues sequenced DNA from the hair of two frozen woolly mammoths, which died in Siberia roughly 20,000 and 60,000 years ago respectively.
When a researcher noticed that bass notes from his MP3 player were making drops of liquid bounce, it began the development of a new technique to levitate droplets, thus keeping them from contamination by surfaces.
In theory, scientists could learn a lot about our health by testing tiny amounts of bodily fluids - a drop of blood, a tear, a bead of sweat. But something this small is easily contaminated by other liquids or surfaces. So what are scientists doing? They're making liquids bounce, dance, and float lightly through the air. Researchers from Belgium's University of Liege published their findings November 18th in the New Journal of Physics.
In theory, scientists could learn a lot about our health by testing tiny amounts of bodily fluids - a drop of blood, a tear, a bead of sweat. But something this small is easily contaminated by other liquids or surfaces. So what are scientists doing? They're making liquids bounce, dance, and float lightly through the air. Researchers from Belgium's University of Liege published their findings November 18th in the New Journal of Physics.
© James Brickwood
Lost heritage: staff at work on the restoration.
Lost heritage: staff at work on the restoration.
The sandstone carvings, in bushland near Grotto Point at Clontarf, are unusual because they are thought to date from the years immediately before or during white settlement.
After more than a century as a local attraction, the carved images of a kangaroo, a sun fish and flying boomerangs were infested with lichen and partly covered with bracken and dirt.
Australian and New Zealand researchers have used ancient DNA from penguin fossils to make a startling discovery that may change the way we view species extinctions.
A team from the University of Adelaide, the University of Otago, and Canterbury Museum in New Zealand has identified a previously unknown penguin species while conducting research on New Zealand's endangered yellow-eyed penguin, one the world's rarest penguin species and the subject of an extensive conservation effort.
The Waitaha penguin became extinct after Polynesian settlement but before 1500 AD, creating an opportunity for the yellow-eyed penguin to subsequently colonise the New Zealand mainland from its base in the sub-Antarctic islands.
"Our findings demonstrate that yellow-eyed penguins on mainland New Zealand are not a declining remnant of a previous abundant population, but came from the sub-Antarctic relatively recently and replaced the extinct Waitaha Penguin," said team member Dr Jeremy Austin, deputy director of the Australian Centre for Ancient DNA.
"Previous analysis of fossil records and anecdotal evidence suggested that the yellow-eyed penguin was more abundant and widespread in the past, but it now appears they have only been around for 500 years," he said.
A team from the University of Adelaide, the University of Otago, and Canterbury Museum in New Zealand has identified a previously unknown penguin species while conducting research on New Zealand's endangered yellow-eyed penguin, one the world's rarest penguin species and the subject of an extensive conservation effort.
© Canterbury Museum
Mounted specimen of Yellow-eyed Penguin.
Mounted specimen of Yellow-eyed Penguin.
The Waitaha penguin became extinct after Polynesian settlement but before 1500 AD, creating an opportunity for the yellow-eyed penguin to subsequently colonise the New Zealand mainland from its base in the sub-Antarctic islands.
"Our findings demonstrate that yellow-eyed penguins on mainland New Zealand are not a declining remnant of a previous abundant population, but came from the sub-Antarctic relatively recently and replaced the extinct Waitaha Penguin," said team member Dr Jeremy Austin, deputy director of the Australian Centre for Ancient DNA.
"Previous analysis of fossil records and anecdotal evidence suggested that the yellow-eyed penguin was more abundant and widespread in the past, but it now appears they have only been around for 500 years," he said.
A team of astronomers from Penn State and Nicolaus Copernicus University in Poland has discovered a new planet that is closely orbiting a red-giant star, HD 102272, which is much older than our own Sun. The planet has a mass that is nearly six times that of Jupiter, the largest planet in our solar system.
The team includes Alexander Wolszczan, the discoverer of the first planets ever found outside our solar system, who is an Evan Pugh Professor of Astronomy and Astrophysics and the director of the Center for Exoplanets and Habitable Worlds at Penn State; and Andrzej Niedzielski, who leads his collaborators in Poland. The team suspects that a second planet may be orbiting HD 102272, as well.
The findings, which will be published in a future issue of The Astrophysical Journal, shed light on the ways in which aging stars can influence nearby planets.
The team includes Alexander Wolszczan, the discoverer of the first planets ever found outside our solar system, who is an Evan Pugh Professor of Astronomy and Astrophysics and the director of the Center for Exoplanets and Habitable Worlds at Penn State; and Andrzej Niedzielski, who leads his collaborators in Poland. The team suspects that a second planet may be orbiting HD 102272, as well.
© Thomas Sebring
The Hobby-Eberly Telescope, one of the largest and most powerful telescopes in the world, photographed at dusk.
The Hobby-Eberly Telescope, one of the largest and most powerful telescopes in the world, photographed at dusk.
The findings, which will be published in a future issue of The Astrophysical Journal, shed light on the ways in which aging stars can influence nearby planets.
Bolivian farmer Primo Rivera had long wondered about the dents in a rocky hill near his home. Paleontologists solved the mystery this month: they are fossilized dinosaur footprints -- the oldest in Bolivia.
"I used to come to look at the prints when I was a kid ... but I didn't know what had made them," said Rivera, 35, who lives in the southern province of Chuquisaca.
The fossilized footsteps that intrigued Rivera for two decades are thought to be about 140 million years old, much older than other dinosaur prints found in the Andean country.
"I used to come to look at the prints when I was a kid ... but I didn't know what had made them," said Rivera, 35, who lives in the southern province of Chuquisaca.
The fossilized footsteps that intrigued Rivera for two decades are thought to be about 140 million years old, much older than other dinosaur prints found in the Andean country.
Closely related animal species share most of their genes and look almost identical. However, minor morphological differences allow us to tell them apart. What is the genetic basis for these differences? Often, the explanation is provided by minor changes in spatial and temporal activity of transcription factors - "regulator" genes which are conserved throughout the animal kingdom.
However, every group of animals also possesses a small proportion of genes which are, in contrary, extremely variable among closely related species or even unique. For example, a gene may be present in one species or animal group, but not in any other. Such genes are referred to as "novel," "orphan" or "taxonomically restricted". Their function and origin are often obscure. What are these genes needed for?
© iStockphoto/Klaas Lingbeek- van Kranen
Jellyfish. Every group of animals possesses a small proportion of genes which are extremely variable among closely related species or even unique.
Jellyfish. Every group of animals possesses a small proportion of genes which are extremely variable among closely related species or even unique.
However, every group of animals also possesses a small proportion of genes which are, in contrary, extremely variable among closely related species or even unique. For example, a gene may be present in one species or animal group, but not in any other. Such genes are referred to as "novel," "orphan" or "taxonomically restricted". Their function and origin are often obscure. What are these genes needed for?
© MIT Lincoln Laboratory
Pan-STARRS 1 prototype, part of the Panoramic Survey Telescope and Rapid Response System, Haleakala mountain, Maui
Pan-STARRS 1 prototype, part of the Panoramic Survey Telescope and Rapid Response System, Haleakala mountain, Maui
Silicon chips developed at MIT Lincoln Laboratory are at the heart of a new survey telescope that will soon provide a more than fivefold improvement in scientists' ability to detect asteroids and comets that could someday pose a threat to the planet.
The prototype telescope installed on Haleakala mountain, Maui, will begin operation this December. It will feature the world's largest and most advanced digital camera, using the Lincoln Laboratory silicon chips. This telescope is the first of four that will be housed together in one dome. The system, called Pan-STARRS (for Panoramic Survey Telescope and Rapid Response System), is being developed at the University of Hawaii's Institute for Astronomy.
