RESUMO
We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'.
RESUMO
In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.
RESUMO
As unrelated complications, peripheral nerve injury and heterotopic ossification (HO) are frequently observed in brain injured patients. Our case presentation is a 24-year-old man who sustained a brain injury in a motor vehicle accident. At two months postinjury he remained at a Rancho Level II and had HO identified in eight joints. Over the next several months, his cognition improved and he demonstrated active movement at the left wrist, but no movement at the right wrist. Plain radiographs and bone scan were consistent with myositis ossification posterior to the right mid-humerus and no fracture was identified. Electromyography revealed a right radial nerve injury below the branch to the triceps. Nine months postinjury, the patient had 4-/5 strength in right wrist extension. A thorough evaluation of all possible etiologies for a given impairment may lead to altered treatment and/or prognosis.
