Scientific discoveries this week: 3/18/13

Berkeley, California
Researchers from UC Berkeley have developed a new experiment that simulates conditions in deep space. The experiment revealed that the complex building blocks of life may have been created on icy interplanetary dust and then carried to earth by a comet or meteor. They showed that conditions in space can create complex dipeptides, or linked pairs of amino acids, the building blocks of life. It opens the possibility that these molecules were brought to earth by a comet or meteorite, catalyzing the formation of proteins, enzymes, and complex molecules such as sugars that are necessary for life. Scientists in the past discovered amino acids in numerous meteorites but they have not found the complex molecular structures necessary to start life on Earth. In a vacuum chamber at 10 Kelvin, the team simulated an icy snowball in space with carbon dioxide, ammonia and hydrocarbons such as methane, ethane, and propane. When the snowball was zapped with high-energy electrons (to simulate cosmic rays) the chemicals reacted and formed dipeptides. After analyzing the organic residues, they found complex molecules—a total of nine different amino acids and two dipeptides—highly capable of catalyzing biological evolution on earth.

Pasadena, California
Researchers from Caltech found strong evidence that salty water from the liquid ocean beneath Europa, Jupiter’s icy moon, actually makes its way to the surface. The findings suggest that there is a chemical exchange between the ocean and surface, making the ocean a richer chemical environment. Learning more about Europa’s surface could lead to learning more about its oceans. The evidence also suggests that energy is flowing into the oceans via the exchange between the surface and the ocean, which is important for the possibility of life there. Since the Galileo spacecraft showed that Europa was covered with an icy shell, scientists have debated the composition of its surface. Using available technology on ground based telescopes, the researchers identified a spectroscopic feature on Europa’s surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could only originate from the ocean under the ice. According to the researchers, “Magnesium should not be on the surface of Europa unless it’s coming from the ocean, so that means ocean water gets onto the surface, and stuff on the surface presumably gets into the ocean water.” Europa is frozen in relation to Jupiter meaning that the same hemisphere is always leading in its orbit. The leading hemisphere has a yellowish appearance, while the trailing hemisphere seems to be streaked with a red material. Europa’s ocean is thought to be 100 kilometers deep and cover the entire globe. Scientists have debated about the spectroscopic data from the red side. Another of Jupiter’s moons, Io, spews volcanic sulfur from its atmosphere and some of that sulfur ends up hurtling towards the trailing hemisphere of Europa due to Jupiter’s strong magnetic field. The researchers improved the data pertaining to Europa using the Keck II telescope on Mauna Kea, which is outfitted with adaptive optics to adjust for the blurring effect of Earth’s atmosphere. They mapped the distribution of pure water ice versus anything else on the moon and found that even Europa’s leading hemisphere contains significant amount of non-water ice. At low latitudes on the trailing hemisphere (the area with the greatest concentration of non-water ice) they found a dip in the spectrum that had never been detected before. When the researchers tested various materials to find what could have created this dip they found that the only chemical that made such a dip was magnesium sulfate. These findings indicate that there must be magnesium from the surface bonding with the sulfur from Io. Magnesium is not the only unexpected element on the surface of Europa. The icy moon is surrounded by an atmosphere of atomic sodium and potassium, originating from the surface. The researchers believe that sodium and potassium chlorides are actually the dominant salts on the surface of Europa, but they are not detectable because they have no clear spectral features. The researchers also hypothesize that the ocean is chlorine-rich and that the sodium and potassium must be present as chlorides therefore resembling the salty ocean of the Earth. The research team also emphasized that Europa is a premier target in the search for life beyond Earth.

Boston, Massachusetts
A recent study shows that attention-deficit hyperactivity disorder (ADHD) often does not go away and that children with ADHD are more likely to have other psychiatric disorders as adults. They also appear more likely to commit suicide and to be incarcerated as adults. The study is the first of its kind to follow a large population-based study of children with ADHD into adulthood. ADHD is the most common neuro-developmental disorder of childhood affecting about seven percent of all children. The study followed all children in Rochester, New York who were born between 1976 and 1982 and whose families allowed access to their medical records. That amounted to 5,718 children including 367 diagnosed with ADHD. At a follow-up on the group, the researchers found that 29 percent of children with ADHD still had ADHD as adults, 57 percent of children with ADHD had at least one psychiatric disorder as adults compared with 35 percent of those who did not have childhood ADHD. Seven of the 367 children with ADHD had died by the time of the study, with three of the deaths from suicide and of the 4,946 other children 37 had died with five by suicide. The doctors involved in the study think the findings may underestimate the bad outcomes of childhood ADHD. Most of those studied were white and middle class, with good educations and access to health care. According to a doctor involved, “outcomes could be worse in socioeconomically challenged populations.” The study’s researchers recommend a more chronic disease approach to ADHD and a system of care designed for the long haul.

Toronto, Canada
A team of astronomers from the university of Toronto has made the most detailed examination yet of the atmosphere of a Jupiter-like planet beyond our solar system. The team used the high-resolution imaging spectrograph called OSIRIS on the Keck II telescope to analyze the distant planet. They uncovered the chemical fingerprints of specific molecules revealing a cloudy atmosphere containing carbon monoxide and water vapor. There are currently two leading models on how systems of planets form, called core accretion and gravitational instability. Planetary properties such as the composition of a planet’s atmosphere can indicate whether a system formed according to one model or another. The findings are the sharpest spectrum ever obtained of an extrasolar planet and they also reveal that the carbon to oxygen ratio is consistent with the core accretion scenario, the model thought to explain the formation of our own solar system. The planet, designated HR 8799c, is one of four gas giants known to orbit a star 130 light-years from Earth. According to the core accretion model, the star HR 8799 was originally surrounded by nothing but a huge disk of gas and dust. As the gas cooled, ice formed and depleted the disk of oxygen atoms. Ice and dust then collected into planetary cores which attracted surrounding gas to form large atmospheres. The gas was depleted of oxygen, and this is reflected in the planet’s atmosphere today as an enhanced carbon to oxygen ratio. According to the model, large gas giant planets form at great distances from the central star, and smaller rocky planets are closer in. These rocky planets, not too far, nor too close to the star are prime candidates for supporting life.

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