The solar wind has a much bigger impact on Mars than previously thought according to the first results from the ASPERA-3 instrument on Mars Express. Rickard Lundin of the Swedish Institute of Space Research and an international team of co-workers have found that the solar wind — a supersonic plasma of charged particles that flows from the Sun — can penetrate deep into the atmosphere of Mars. One consequence of this is that water and other volatile molecules could escape from the planet (R Lundin et al. 2004 Science 305 1933).
Mars attacked by solar wind PhysicsWeb
Glass breakthrough [Transparent Aluminum!] PhysicsWeb
Scientists in the US have developed a novel technique to make bulk quantities of glass from alumina for the first time. Anatoly Rosenflanz and colleagues at 3M in Minnesota used a “flame-spray” technique to alloy alumina (aluminium oxide) with rare-earth metal oxides to produce strong glass with good optical properties. The method avoids many of the problems encountered in conventional glass forming and could, say the team, be extended to other oxides (A Rosenflanz et al. 2004 Nature 430 761).
Rover reveals magnetic Mars PhysicsWeb
Almost all dust particles in the Martian atmosphere are magnetic, according to new data obtained by NASA’s Mars Exploration Rover Spirit. The craft also examined rocks at the Gusev crater, which were found to contain the strong magnetic mineral magnetite (Fe3O4). The results — obtained by a team of scientists from Denmark, Germany and the US — could help to determine if water was involved in the formation of these minerals (P Bertelsen et al. 2004 Science 305 827).
Carbonates found on Mars PhysicsWeb
Small amounts of carbonate minerals have been discovered on the surface of Mars for the first time. The result could help researchers better understand the history and evolution of the planet as part of their efforts to determine if the conditions for sustaining life ever existed there. Joshua Bandfield and colleagues at Arizona State University discovered that particles on the surface of Mars reflect and absorb infrared radiation in a way that exactly matches that of magnesium-rich carbonates found on Earth (J Bandfield et al. 2003 Sciencexpress to be published).
Poles hint at past climate on Mars PhysicsWeb
Astronomers have found the first direct evidence that the structure of the polar caps on Mars is linked to climate changes driven by fluctuations in the planet’s motion. A team led by Jacques Laskar of the CNRS Institute of Celestial Mechanics in France established the link by inspecting new high-resolution images. The researchers believe that the polar caps could reveal as much about the history of Mars as the terrestrial ice caps have told us about the history of the Earth (J Laskar et al 2002 Nature 419 375).
Photons double up for solar power PhysicsWeb
Solar cells could get an efficiency boost of 30% using a device proposed by physicists in Australia and Germany. Martin Green of the Centre for Third Generation Photovoltaics at the University of New South Wales and colleagues say that ‘down-converters’ could be connected to existing solar cells to double the number of ‘useful’ photons they capture (T Trupke et al 2002 J. Appl. Phys. 92 1668).