Institut d’Astrophysique Spatiale

First stars formed even later than previously thought

2 September 2016 Astronomy Now

ESA’s Planck satellite has revealed that the first stars in the universe started forming later than previous observations of the Cosmic Microwave Background indicated. This new analysis also shows that these stars were the only sources needed to account for reionising atoms in the cosmos, having completed half of this process when the universe had reached an age of 700 million years.

Gullies on Mars sculpted by dry ice rather than liquid water?

23 December 2015 Astronomy Now

Mars’ gullies may be formed by dry ice processes rather than flowing liquid water, as previously thought. This is the conclusion of a study conducted by two French scientists published in Nature Geoscience. They show that, during Martian late winter and spring, underneath the seasonal CO₂ ice layer heated by the Sun, intense gas fluxes can induce gas-lubricated debris flows which look like water-sculpted gullies on Earth.

Space observatories find missing clue to galaxy cluster formation

2 April 2015 Astronomy Now

Astronomers using the Herschel Space Observatory and Plank satellite, plus University of Arizona observatories, discover likely precursors of the galaxy clusters we see today and reveal glimpses into how galaxies like our Milky Way came to be.

Primordial gravitational waves remain elusive

31 January 2015 Astronomy Now

Despite earlier reports of a possible detection, a joint analysis of data from ESA’s Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial gravitational waves.