Category Astronomy/Space

The layer cake of sedimentary rock near Big Bend, Texas, shows the alternating layers of shale and limestone characteristic of the rock laid down at the bottom of a shallow ocean during the late Cretaceous period. The rock holds the 87 million-year-old signature of a ‘resonance transition’ in the orbits of Mars and Earth, definitive geologic evidence that the orbits of the planets in our solar system behave differently than prevailing theory, which held that the planets orbit like clockwork in a quasiperiodic manner. Credit: Bradley Sageman, Northwestern University

© ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA). Left, an image of comet Chury showing outgassing of water vapor, which entrains dust (© ESA/Rosetta/NAVCAM). Right, the neck region, between the comet’s two lobes. Various types of relief can be seen, including the dunes, at bottom left (circled in red), in the sandy region.

The gamma-ray excess (shown in yellow-white) at the heart of M31 hints at unexpected goings-on in the galaxy’s central region. Scientists think the signal could be produced by a variety of processes, including a population of pulsars or even dark matter. Credit: NASA/DOE/Fermi LAT Collaboration and Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF

An infographic describing three theories on how the Earth got its iron signature.Designed by Laura Martin/The University of Texas at Austin Jackson School of Geosciences. Images 1 and 2 from NASA/JPL-Caltech, Image 3 from X-Science, Earth from NASA/JPL.