A chemical survey of exoplanets with ARIEL

Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

Origins and genetic legacy of prehistoric dogs

Dogs were the first domestic animal, but little is known about their population history and to what extent it was linked to humans. We sequenced 27 ancient dog genomes and found that all dogs share a common ancestry distinct from present-day wolves, with limited gene flow from wolves since domestication but substantial dog-to-wolf gene flow. By 11,000 years ago, at least five major ancestry lineages had diversified, demonstrating a deep genetic history of dogs during the Paleolithic. Coanalysis with human genomes reveals aspects of dog population history that mirror humans, including Levant-related ancestry in Africa and early agricultural Europe. Other aspects differ, including the impacts of steppe pastoralist expansions in West and East Eurasia and a near-complete turnover of Neolithic European dog ancestry

Proximity to overhead power lines and childhood leukaemia: an international pooled analysis

© 2018, Cancer Research UK. Background: Although studies have consistently found an association between childhood leukaemia risk and magnetic fields, the associations between childhood leukaemia and distance to overhead power lines have been inconsistent. We pooled data from multiple studies to assess the association with distance and evaluate whether it is due to magnetic fields or other factors associated with distance from lines. Methods: We present a pooled analysis combining individual-level data (29,049 cases and 68,231 controls) from 11 record-based studies. Results: There was no material association between childhood leukaemia and distance to nearest overhead power line of any voltage. Among children living < 50 m from 200 + kV power lines, the adjusted odds ratio for childhood leukaemia was 1.33 (95% CI: 0.92–1.93). The odds ratio was higher among children diagnosed before age 5 years. There was no association with calculated magnetic fields. Odds ratios remained unchanged with adjustment for potential confounders. Conclusions: In this first comprehensive pooled analysis of childhood leukaemia and distance to power lines, we found a small and imprecise risk for residences < 50 m of 200 + kV lines that was not explained by high magnetic fields. Reasons for the increased risk, found in this and many other studies, remains to be elucidated

This Just In piece on Real ID, the federal government\u27s proposed standardize

This Just In piece on Real ID, the federal government\u27s proposed standardized ID-card system. In January 2007, Maine was the first state to pass a resolution rejected Real ID, and followed up five months later with a law preventing the state from participating. The Department of Homeland Security (DHS) failed to grant Maine an extension until last week. Had DHS not issued an extension, Maine IDs would have been inadmissible as federal identification starting on May 11. Real ID has become an immigration issue more than a security measure. To get the extension, Gov. John Baldacci has to agree to a set of modifications, including that Maine will stop issuing licenses to anyone who cannot prove citizenship or legal-resident status. The Maine Civil Liberties Union is disappointed that Baldacci acquiesced to the DHS demands, saying the proposed modifications are costly and unfair, and will shove immigration issues to the forefront of Maine politics

This Just In piece on Perry O\u27Brien, a 25-year-old army veteran from Peaks Isl

This Just In piece on Perry O\u27Brien, a 25-year-old army veteran from Peaks Island, who served in Afghanistan in 2003. O\u27Brien, who has since been discharged from the army as a conscientious objector, is the testimonial team leader for Iraq Veterans Against the War (IVAW). IVAW will sponsor Winter Soldier 2008, where more than 100 Iraq and Afghanistan veterans will testify that abuses such as those at Abu Ghraib prison are not isolated incidents, but extreme examples of widespread misconduct. Winter Soldier 2008 is scheduled to take place in March at the University of Maryland

This Just In piece featuring a brief interview in question-and-answer format w

This Just In piece featuring a brief interview in question-and-answer format with Maine author Linda Greenlaw. Greenlaw, a fishing-boat captain and author of two non-fiction books on fishing, has written Slipknot, a mystery novel set in the fictional port town of Green Haven, Maine. Greenlaw begins promoting Slipknot across New England this week

This Just In piece on the upcoming Skill Share and Harvest Dinner, organized b

This Just In piece on the upcoming Skill Share and Harvest Dinner, organized by members of the Winter Cache Project. Local-food activists will share the secrets of seasonal eating, including root-cellaring, pickling, and homemade beer and wine. The dinner is being presented October 20, at North Deering Grange Hall in Portland

This Just In piece on AddVerb Productions\u27 recent performance of When Turtles

This Just In piece on AddVerb Productions\u27 recent performance of When Turtles Make Love, which addresses the communication challenges between parents and teenagers when it comes to talking about sex. Monday\u27s performance of the play at Portland High School comes at an opportune time in light of the ongoing birth-control controversy at King Middle School. Portland is a pilot community in Planned Parenthood\u27s national Real Life Real Talk initiative

This just in piece on Country Noel, a Christmas store in the Old Port owned by

This just in piece on Country Noel, a Christmas store in the Old Port owned by Jean Wright and her husband. She explains how the year-round Portland Christmas store is a successful operation and why she enjoys the happy concept