Category Astronomy/Space

View of comet 67P taken by Rosetta.
Credit: European Space Agency

Scientists have found that molecular oxygen around comet 67P is not produced on its surface, as some suggested, but may be from its body. The European Space Agency’s Rosetta spacecraft escorted comet 67P/Churyumov-Gerasimenko on its journey round the sun from August 2014 – September 2016, dropping a probe and eventually crashing onto its surface.

When the comet is close enough to the sun the ice on its surface ‘sublimes’ – transforms from solid to gas – forming a gas atmosphere called a coma. Analysis of the coma by instruments on Rosetta revealed that it contained not only water, CO and CO2, as anticipated, but also molecular oxygen.

Molecular oxygen is O2, and on Earth it is essential for life, where it is produced by photo...

This spectacular image from the SPHERE instrument on ESO’s Very Large Telescope is the first clear image of a planet caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star.
Credit: ESO/A. Müller et al.

SPHERE, a planet-hunting instrument on ESO’s Very Large Telescope, has captured the first confirmed image of a planet caught in the act of forming in the dusty disc surrounding a young star. The young planet is carving a path through the primordial disc of gas and dust around the very young star PDS 70. The data suggest that the planet’s atmosphere is cloudy.

The SPHERE instrument enabled...

The central portion of Osuga Valles, which has a total length of 164 km. In some places, it is 20 km wide and plunges to a depth of 900 m. Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

The valley networks of Mars bear a strong resemblance to those found in arid landscapes on Earth. Researchers have been able to demonstrate this using the branching angles of river valley confluences. Based on these observations, they infer that Mars once had a primeval climate in which sporadic heavy precipitation eroded valleys. The surface of Mars bears imprints of structures that resemble fluvial steam networks on Earth.

Scientists therefore assume that there must have been once enough water on the red planet to feed water streams that incised their path into the soil...

The artist’s concept depicts Kepler-186f. Image credit: NASA Ames/JPL-Caltech/T. Pyle

Researchers suggest that two Earth-like exoplanets (Kepler-3186f and 62f) have very stable axial tilts, much like the Earth, making it likely that each has regular seasons and a stable climate. A new study from the Georgia Institute of Technology provides new clues indicating that an exoplanet 500 light-years away is much like Earth.

Kepler-186f is the first identified Earth-sized planet outside the solar system orbiting a star in the habitable zone. This means it’s the proper distance from its host star for liquid water to pool on the surface. The Georgia Tech study used simulations to analyze and identify the exoplanet’s spin axis dynamics...