Science & Technology World

Social network giant Facebook has blocked a website from accessing people's profiles in order to delete their online presence. The site, Web 2.0 Suicide Machine, offers to remove users from Facebook, Twitter, LinkedIn and Myspace. It does not delete their accounts but changes the passwords and removes "friend" connections. Seppukoo.com, which offers a similar service, was issued with a "cease and desist" letter by Facebook in 2009. Netherlands-based moddr, behind Web 2.0 Suicide Machine, says it believes that "everyone should have the right to disconnect". However Facebook says that by collecting login credentials, the site violates its Statement of Rights and Responsibilities (SRR). "Facebook provides the ability for people who no longer want to use the site to either deactivate their account or delete it completely," the company said. "We're currently investigating and considering whether to take further action." Web 2.0 Suicide Machine claims that it only stores the name, profile picture and "last words" of its clients, who can choose to watch their friend/follower connections disappear in real time as their profiles unlink from others. "Seamless connectivity and rich social experience offered by web 2.0 companies are the very antithesis of human freedom," says a statement on its website. " Seamless connectivity and rich social experience offered by web 2.0 companies are the very antithesis of human freedom. " Web 2.0 Suicide Machine The machine operates on an adjusted Linux server which runs open source software Apache 2. Seppukoo.com, which offers to remove people from Facebook, received a letter from the social network site's lawyers in December 2009. Once they have deleted their friends Seppukoo clients can choose an image instead of their profile picture to remain as a "memorial" . The site is run by a group called Les Liens Invisibles, and describes itself as an artistic project. The name Seppukoo is taken from a Japanese ritual form of suicide known as Seppuku. In November 2009 the group orchestrated the " virtual suicide" of a group of fictitious Facebook profiles set up in the names of deceased well- known figures including Kurt Cobain, Jim Morrison and Virginia Woolf.

Nasa's Kepler Space Telescope has detected its first five exoplanets, or planets beyond our Solar System. The observatory, which was launched last year to find other Earths, made the discoveries in its first few weeks of science operations. Although the new worlds are all bigger than our Neptune, the US space agency says the haul shows the telescope is working well and is very sensitive. The exoplanets have been given the names Kepler 4 b, 5 b, 6 b, 7 b and 8 b. They were announced at an American Astronomical Society meeting in Washington DC. The planets range in size from an object that has a radius four times that of Earth, to worlds much bigger than even our Jupiter. And they all circle very close to their parent stars, following orbits that range from about 3.2 to 4.9 days. This proximity and the fact that the host stars are themselves much hotter than our Sun means Kepler's new exoplanets experience an intense roasting. Intriguing density Estimated temperatures go from about 1 ,200 C to 1 ,650 C (2 ,200 F to 3 ,000 F). "The planets we found are all hotter than molten lava; they all simply glow with their temperatures," said Bill Borucki, Kepler's lead scientist from Nasa's Ames Research Center in Moffett Field, California. THE KEPLER SPACE TELESCOPE Will study more than 100 ,000 suns Continuously for 4 to 6+ years Tuned to see Earth-size planets Will target the habitable zone Will also see Mars to Jupiter sizes "In fact the upper two are hotter than molten iron and looking at them might be like looking at a blast furnace. They are very bright in their own right and certainly no place to look for life." Kepler 7 b will intrigue many scientists. It is one of the lowest-density exoplanets (about 0.17 grams per cubic centimetre) yet discovered. "The average density of this planet with its core is about the same as Styrofoam," explained Dr Borucki. "So it's an amazingly light planet, something I'm sure theoreticians will be delighted to look at in terms of trying to understand [its] structure." Kepler blasted into space atop a Delta II rocket from Cape Canaveral Air Force Station on 6 March, 2009. It is equipped with the largest camera ever launched into space. The telescope's mission is to continuously and simultaneously observe more than 100 ,000 stars. It senses the presence of planets by looking for a tiny "shadowing" effect when one of them passes in front of its parent star. 'Water worlds' Kepler's detectors, built by UK firm e2 v, have extraordinary sensitivity. Nasa says that if the observatory were to look down at a small town on Earth at night from space, it would be able to detect the dimming of a porch light as somebody passed in front of it. The space agency hopes this sensitivity will lead it to planets that are not only Earth-size but which orbit their stars at distances more favourable to life, where liquid water might potentially reside on their surfaces. The mission's scientists told the AAS meeting that Kepler had measured hundreds of possible planet signatures but that these needed further investigation to establish their true nature. To confirm the existence of the most ideal Earth- like planets would take a few years, they warned. In the meantime, all detections will help scientists improve their statistics on the distributions of planet size and orbital period. The follow-up observations needed to confirm the new exoplanets' existence used a suite of ground-based facilities including the Keck I telescope in Hawaii.

New images of Mars suggest the Red Planet had large lakes on its surface as recently as three billion years ago. The evidence comes from Nasa's Mars Reconnaissance Orbiter (MRO) which spied a series of depressions linked by what look like drainage channels. Scientists tell the journal Geology that the features bear the hallmarks of being produced by liquid water. But they appear to have formed much later in Mars' history than many thought possible, the researchers add. The team, from Imperial and University Colleges London, studied pictures of several flat-floored depressions located above Ares Vallis, a giant gorge running some 2 ,000 km across Mars' equator. The hollows are about 20 km in diameter. Scientists had previously ascribed their formation to the slumping of the ground as ice in the soil was lost to Mars' thin atmosphere almost four billion years ago in the process of sublimation (in which the ice turns directly from a solid into a vapour). But the detail in the MRO pictures has allowed the Imperial-UCL team to trace a series of channels that connect the depressions. The group says these channels could only be formed by running water, and not by ice turning directly into gas. The scientists' ageing of the region, which on bodies like Mars is done by counting craters, suggests the features formed during the so- called Hesperian Epoch on the Red Planet. "The exciting thing is that this occurred at a time when Mars is thought to have been cold and dry and [liquid] water wasn't stable at the surface," Dr Sanjeev Gupta from Imperial College London told BBC News. The researchers propose that Mars may have experienced bouts of short-lived warming during this epoch that were caused perhaps by volcanic activity, meteorite impacts, or even shifts in the planet's orbit. This could have provided both the warmth to melt ice in the soil and the pressure needed in the atmosphere to maintain liquid water on the surface. "We don't really understand what caused this transient episode," Dr Gupta explained. "We have different hypotheses. Maybe local conditions generated an atmosphere creating a minor greenhouse effect that allowed these lakes to exist. We don't know how long they existed for, but it's exciting nonetheless that we see [evidence of] liquid water." The conditions would have made it possible for the depressions to fill with meltwater and even overflow, cutting channels as the liquid ran from a higher basin to a lower one. "This provides another environment - another place to go and look for microbial life," said Dr Gupta. "This would be fossil life. This is somewhere we hadn't perhaps considered as a place to go."