Category Astronomy/Space

This HiRISE image cutout shows Recurring Slope Lineae in Tivat crater on Mars in enhanced color. The narrow, dark flows descend downhill (towards the upper left). Analysis shows that the flows all end at approximately the same slope, which is similar to the angle of repose for sand. Credit: NASA/JPL/University of Arizona/USGS

Planet appears to have water-restricted environment. Dark features previously proposed as evidence for significant liquid water flowing on Mars have now been identified as granular flows, where sand and dust move rather than liquid water, according to a new article published in Nature Geoscience by the U.S. Geological Survey. These new findings indicate that present-day Mars may not have a significant volume of liquid water...

Space dust collisions as a planetary escape mechanism. arxiv.org/abs/1711.01895

Life on our planet might have originated from biological particles brought to Earth in streams of space dust, a study suggests. Fast-moving flows of interplanetary dust that continually bombard our planet’s atmosphere could deliver tiny organisms from far-off worlds, or send Earth-based organisms to other planets, according to the research. The dust streams could collide with biological particles in Earth’s atmosphere with enough energy to knock them into space, a scientist has suggested.

Such an event could enable bacteria and other forms of life to make their way from one planet in the solar system to another and perhaps beyond...

This is an image of near-infrared-light-driven hydrogen evolution from water photo-driven by triruthenium photosensitizer. Credit: Kyushu University

Scientists have synthesized a compound with 3 ruthenium atoms connected by an organic molecule that absorbs near-infrared light to produce hydrogen from water. The absorbed light stimulates electrons to ‘jump’ into orbitals that do not exist in other, similar compounds. This is the first successful use of infrared light to reduce water into hydrogen, which can be used for energy conversion and storage, and other industrial purposes in a future sustainable energy society.

Solar cells must absorb light of particular wavelengths, depending on how much energy the cell needs to drive the reaction...

The super-Earth exoplanet 55 Cancri e, depicted with its star in this artist’s concept, likely has an atmosphere thicker than Earth’s but with ingredients that could be similar to those of Earth’s atmosphere. Credit: NASA/JPL-Caltech

Twice as big as Earth, the super-Earth 55 Cancri e was thought to have lava flows on its surface. The planet is so close to its star, the same side of the planet always faces the star, such that the planet has permanent day and night sides. Based on a 2016 study using data from NASA’s Spitzer Space Telescope, scientists speculated that lava would flow freely in lakes on the starlit side and become hardened on the face of perpetual darkness...