Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.
BBC: The early detection of invasive diseases is important in protecting crops, but crop surveillance is expensive. Now Stephen Parnell of the University of Salford, UK, and his colleagues have developed a model to determine the minimum amount of surveillance needed to detect invasive diseases before they reach epidemic levels. The model is based on current surveillance efforts and their ability to detect diseases and at what level of incidence. By defining the maximum level of incidence a disease should be allowed to reach before it is detected, the model can tell what level of surveillance is needed.
Nature: According to measurements taken from Earth, Pluto's atmosphere has been getting denser since 1988. But measurements taken by New Horizons as it flew by the dwarf planet in July show the opposite. A group of researchers led by Eliot Young of the Southwest Research Institute in Boulder, Colorado, say that on 29 June, just a few weeks before New Horizons's arrival, Pluto's atmospheric pressure was 0.022 Pa. New Horizons measured a pressure of just 0.005 Pa. The discrepancy could be due to the indirect measurement method used by the researchers, who based their finding on the fading of a star's light as Pluto passed in front of it. Furthermore, the Earth-based calculation determines the pressure at an altitude of 50–75 km, whereas New Horizons calculated the pressure at Pluto's surface. It does so by measuring the deflection of radio waves sent from Earth as they pass through Pluto's atmosphere. To try to reconcile the two different measurements, the researchers plan to compare them with existing and new models of Pluto's atmosphere.
New Scientist: According to a new report from the United Nations University and INTERPOL, in 2012 only 35% of Europe's electronic waste was properly disposed of. Of the remainder, 1.3 million tons were stolen, including functional computer components and precious metals worth some €1.7 billion ($1.9 billion). Another 4.7 million tons were improperly disposed of or illegally traded. Improper disposal of electronics poses a threat to the environment and to public health because of the variety of toxic materials—such as lead, cadmium, and mercury—they contain.
Ars Technica: Some exoplanetary systems consist of planets orbiting stars that have distant binary companions. According to new simulations of such systems, if a planet's orbital precession around its star falls into resonance with the orbital period of the binary, the resulting gravitational forces could lead to drastic changes in the planet's orbit. In particular, the planet's orbit could become highly elliptical or be forced into a different plane from that of the other planets in the system. In extreme cases, the planet could be ejected from the system or forced to collide with another planet or with one of the stars.