There is enough water frozen at Mars' south pole to cover the entire planet to a depth of about 11 metres, new data collected by the Mars Express orbiter suggests.
The new estimate comes from measurements made by a radar instrument that can see through layers of ice to the bottom of the polar cap, about 3.7 kilometres down.
Science & Technology
Never before has so much news been within reach of li'l ol' you, tucked away there behind your keyboard. In an instant, you can be connected with news organizations the world over, soaking up the latest about the French presidential elections, or the price of tea in China. So how come you know so little of what's going on out there in the big, bad world?
Don't get huffy about it. You know what I'm talking about.
Don't get huffy about it. You know what I'm talking about.
If the plan to replace incandescent light bulbs takes hold, the phaseout could save enough energy to eliminate the need to build 80 of the 150 or so coal-fired power plants now planned nationwide, it is estimated.
Physicists in France are the first to watch single photons appear spontaneously, live a brief life, and then vanish into thin air. The experiment is the best realization so far of "quantum non-demolition" (QND) measurements on single photons, whereby the presence of a photon is determined without destroying it. As well as providing an elegant demonstration of quantum mechanics, the researchers also believe that the technique could be exploited in quantum information systems.
Detecting a photon usually involves absorbing the photon - and ultimately destroying it - in a photodetector. However, it is sometimes possible to make a measurement in a much gentler manner, leaving the system in more or less the same state as was measured. Such QND measurements have become commonplace for large systems like atoms - which can be probed gently using photons. But photons are much more delicate than atoms, which makes QND very difficult.
Detecting a photon usually involves absorbing the photon - and ultimately destroying it - in a photodetector. However, it is sometimes possible to make a measurement in a much gentler manner, leaving the system in more or less the same state as was measured. Such QND measurements have become commonplace for large systems like atoms - which can be probed gently using photons. But photons are much more delicate than atoms, which makes QND very difficult.
A rogue ball of ice as big as Pennsylvania smashes into an Alaska-sized dwarf planet, spewing debris across the solar system and furnishing the planet with two new moons. Although it could be a disaster scene from a sci-fi movie, the event actually took place in the outer realms of our solar system a few billion years ago. "It's just a spectacular story," says planetary scientist Michael Brown of the California Institute of Technology in Pasadena, whose team has discovered the fragments of the cosmic catastrophe. What's more, the find sheds new light on the early history of our solar system.
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| ©NASA/ESA/HST |
| Computer model of 2003 EL61 and its two moons. |
The comet that killed the dinosaurs opened the evolutionary door for one of Earth's most diverse groups of creatures: mammals. David Archibald, Ph.D., a professor of evolutionary biology at San Diego State, has made this transition from dinosaurs to mammals his expertise.
Archibald studies early mammalian fossils and is trying to constrain the origins of the phylum to which humans belong. His research has taken him around the world in search of the remains of terrestrial creatures.
Archibald studies early mammalian fossils and is trying to constrain the origins of the phylum to which humans belong. His research has taken him around the world in search of the remains of terrestrial creatures.
For the first time, scientists of the BaBar experiment at the Department of Energy's Stanford Linear Accelerator Center (SLAC) have observed the transition of one type of particle, the neutral D-meson, into its antimatter particle. Mesons, of which there are about 140 types, are made up of fundamental particles called quarks, which can be produced when particles collide at high energy.
The new observation will be used as a test of the Standard Model, the current theory that best describes all the universe's luminous matter and its associated forces.
The new observation will be used as a test of the Standard Model, the current theory that best describes all the universe's luminous matter and its associated forces.
A scholar looking into the factual basis of a popular but widely criticized documentary that claims to have located the tomb of Jesus said Tuesday that a crucial piece of evidence filmmakers used to support their claim is a mistake.
Stephen Pfann, a textual scholar and paleographer at the University of the Holy Land in Jerusalem, said he has released a paper claiming the makers of "The Lost Tomb of Jesus" were mistaken when they identified an ancient ossuary from the cave as belonging to the New Testament's Mary Magdalene.
The film's director, Simcha Jacobovici, responded that other researchers agreed with the documentary's conclusions.
Stephen Pfann, a textual scholar and paleographer at the University of the Holy Land in Jerusalem, said he has released a paper claiming the makers of "The Lost Tomb of Jesus" were mistaken when they identified an ancient ossuary from the cave as belonging to the New Testament's Mary Magdalene.
The film's director, Simcha Jacobovici, responded that other researchers agreed with the documentary's conclusions.
LOS ANGELES - Scientists believe heat from radioactive decay inside a tiny, icy Saturn moon shortly after it formed billions of years ago may explain why geysers are erupting from the surface today. The Cassini spacecraft last year beamed back dazzling images of Yellowstone-like geysers spewing from a warm section on Enceladus, raising the possibility that the moon, which has an overall surface temperature of about minus-330 degrees, may have an internal environment suitable for primitive life.
A single, specific memory has been wiped from the brains of rats, leaving other recollections intact.
