Ongoing flow activity was highlighted a few years ago on Mars by high-resolution cameras. Various flow types have been identified (new channels, dark lineae, bright deposits…) but there is still no consensus about possible formation mechanisms: dry avalanche? liquid water? carbon dioxide ice? A study conducted at the Institut d’Astrophysique Spatiale reveals for the first time the composition of winter ice forming in association with flows. Results suggest the coexistence of several current formation mechanisms.
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The stratospheric balloon carrying the PILOT instrument was launched from Timmins in Canada at 9 pm (local time) on Sunday, September 20th. The gondola, weighting more than a ton, the heaviest the CNES took in the last 25 years, was lifted by a stratospheric balloon of 800.000 m3 and reached the altitude of 39.500 m after 3 hours of ascent. After a last transfer of helium carried out just before take-off, the detectors reached nominally their operating temperature of 320 mK when the balloon reached its flight ceiling, and the scientific observations could then start.
The CLASP instrument (Chromospheric Lyman Alpha Spectropolarimeter) was successfully launched by a sounding rocket on September 3, 2015 at 17H UT from White Sands Missile Range in New Mexico. The suborbital flight was nominal. The instrument went nominally through its observing program and the data quality is superb.
To reconcile the standard cosmological model with the X-ray measured number of galaxy clusters, a team of French scientists has shown that the cluster masses should be increased by 70% compared to current estimates. These results follow the conclusions obtained by the Planck mission in 2013 from observations of galaxy clusters in the microwave domain. This huge difference is intriguing: either our understanding of the physics of galaxy clusters needs to be revised, or the standard cosmological model is incomplete.
IAS is participating to the national open lab day "Fête de la Science" in the week of the 5th of October. After visits by students from several schools, the laboratory will be open for the general public on Sunday the 11th of October, from 2 to 6PM.
Here is the programme of activities and talks (in French) during this afternoon:
The interplanetary dust particles commonly called IDPs are micrometric extraterrestrial grains (typical size of ten microns). They are collected by NASA’s stratospheric aircrafts (at an altitude of ~ 25 km). Their origin asteroidal and/or cometary has always been a subject of investigation.
In recent years we have conducted a systematic analysis of IDPs using infrared micro-spectroscopy through a collaboration with the SMIS beamline at the SOLEIL synchrotron.
This work reveals, in one hand, the connection between asteroids/comets and extraterrestrial material collected for laboratory studies, and gives in another hand, valuable information on the relationship between organic matter and mineral phases probably due to physical and chemical processes in the primitive nebula.
A multidisciplinary team involving researchers from the IAS, the CIMAP, the IPNO, the GANIL, and Rio de Janeiro's PUC Catholic University has characterized in the laboratory the effects of heavy cosmic rays on the structure and sputtering of water ice in interstellar and planetary environments. These experiments are used to study phase changes induced by swift heavy ions, similar to the Galactic cosmic rays. They complement and extend the knowledge already obtained at lower energies. In addition to the ice phase change, these studies reveal the importance of water ice molecules released in the gas phase by swift heavy Galactic ions, or sputtering of interstellar ices present in dense and cold interstellar clouds.
After 7 long months, Philae has awoken from hibernation. Its first signs of life reached Earth on Saturday evening (June, 13th) then again the following night. The hope to see Philae awake again and communicating has just come true.
Many new and enigmatic high redshift galaxies that are intensively forming stars have been discovered using ESA’s Planck and Herschel satellites . These galaxies occur in clumps – and could be the long-sought formation phase of galaxy clusters. Some appear very bright, and have been found to be gravitationally lensed galaxies. These rapidly star-forming galaxies could help solve a central problem in cosmology: how did the large scale structure of galaxies form?
A partial solar eclipse will be visible from Orsay, between 9:21am to 11:30am. At maximum at 10:28, about 80% of the Sun will be eclipsed.
Many researchers from IAS will be present in schools. An observation will be possible at IAS with special eclipse sunglasses, with comments from astrophysicists Frédéric Baudin and Clara Froment.