Questões de Concurso Público AEB 2014 para Tecnologista Júnior - Desenvolvimento Tecnológico

                        Solar System’s Water is Older Than the Sun

      Next time you’re swimming in the ocean, consider this: part of the water is older than the sun.
      So concludes a team of scientists who ran computer models comparing the ratios of hydrogen isotopes over time. Taking into account new insights that the solar nebula had less ionizing radiation than previously thought, the models show that at least some of the water found in the ocean, as well as in comets, meteorites and on the moon, predate the sun’s birth.
      The only other option, the scientists conclude, is that it formed in the cold, intersteller cloud from which the sun itself originated.
      The discovery, reported in this week’s Science, stems from the insight of lead author Lauren Ilsedore Cleeves, a doctoral student at the University of Michigan, who realized that planet- forming disks around young stars should be shielded from galactic rays by the strong solar winds, dramatically altering the chemistry occurring inside the disks, said Conel Alexander, with the Carnegie Institution of Washington.
      “The findingX makes it quite hard for these regions in the disk to synthesize any new molecules. This was an ‘aha’ moment for us - without any new water creation the only place these ices could have come from was the chemically rich interstellar gas out of which the solar system formed originally,” Cleeves wrote in an email to Discovery News.
      “It’s remarkable that these ices survived the entire process of stellar birth,” she added.
      The finding has implications for the search for life beyond Earth, as water is believed to be necessary for life.
      “If the sun’s formation was typical, interstellar ices - including water - are likely common ingredients present during the formation of all planetary systems, which puts a wonderful outlook on the possibility of other life in the universe,” Cleeves said.
      In addition, it’s not just water that likely survived the solar system’s birth.
      “The same must be true for the organic matter that we know is present in molecular cloud ices. So I think this strengthens the case that we have interstellar organic matter in meteorites and comets too,” Alexander wrote in an email to Discovery News.

                                                                                          Available in: http://news.discovery.com

                        Gravity, review: “heartachingly tender”

            Starring Sandra Bullock and George Clooney as astronauts adrift in
                  space, Alfonso Cuarón’s astonishing thriller is one of the films of
                                           the year, says Robbie Collin

      Watch an astronaut drifting through space for long enough and eventually you notice how much they look like a newborn baby. The oxygen helmet makes their head bigger, rounder and cuter; their hands grasp eagerly at whatever happens to be passing; their limbs are made fat and their movements simple by the spacesuit’s cuddly bulk. They tumble head-over-heels like tripping toddlers or simply bob there in amniotic suspension. Even the lifeline that keeps them tethered to their ship has a pulsing, umbilical aspect.
      Gravity, the new Alfonso Cuarón picture, is a heart- achingly tender film about the miracle of motherhood, and the billion-to-one odds against any of us being here, astronauts or not. It’s also a totally absorbing, often overpowering spectacle - a $100 million 3D action movie in which Sandra Bullock and George Clooney play two Hollywood-handsome spacefarers, fighting for their lives 375 miles above the Earth’s crust.
      A series of captions over the opening titles reminds us that this is a dead zone: no oxygen or air pressure, and nothing to carry sound. “Life in space is impossible,” the final message tells us, as the cinema shakes with Steven Price’s resonant score, and then suddenly falls quiet.
      For Dr. Ryan Stone (Bullock), a mission specialist in orbit for the first time, the lack of noise is welcome. She’s a medical engineer called up by NASA to install new software on to the Hubble Telescope, but also a mother in mourning for her four- year-old daughter, whom she lost in a senseless accident, and the silence enfolds her like a comfort blanket.

                                                            Available in: http://www.telegraph.co.uk