Category Astronomy/Space

An image of a simulated galaxy cluster showing evidence for a boundary, or “edge” from a 2015 paper in the Astrophysical Journal by Surhud More, Benedikt Diemer and Andre Kravtsov.

University of Pennsylvania research could shed light on the distribution of one of the most mysterious substances in the universe. In the 1970s, scientists noticed something strange about the motion of galaxies. All the matter at the edge of spiral galaxies was rotating just as fast as material in the inner part of the galaxy. But according to the laws of gravity, objects on the outskirts should be moving slower. The explanation: dark matter, which affects everything from how objects move within a galaxy to how galaxies and galaxy clusters clump together in the first place...

Hypothetically, matter can have negative mass in the same sense that an electric charge can be either negative or positive. With negative mass, if you push something, it accelerates toward you. Forbes said, “It looks like the rubidium hits an invisible wall.” (stock image). Credit: © ktsdesign / Fotolia

Experimental technique can help probe phenomena in astrophysics and cosmology. Washington State University physicists have created a fluid with negative mass, which is exactly what it sounds like. Push it, and unlike every physical object in the world we know, it doesn’t accelerate in the direction it was pushed. It accelerates backwards...

Chaotic advection accelerates interfacial transport under hydrothermally relevant conditions Credit: Proceedings of the National Academy of Sciences

A Texas A&M University team has uncovered a physical mechanism that may help answer one of the major questions concerning the origin of life, “How did the building blocks form?” Scientists have long known that the building blocks of life – amino acids, nucleobases and sugars – were present in the early ocean, but they were very low in concentration. In order for life to emerge, these building blocks needed to be combined and enriched into long-chain macromolecules.

“In the early ocean, those building blocks were present in the environment,” Ugaz said. “They were there, but they were so dilute; there is a question about how they combined...

Unprocessed images of Saturn’s moon Atlas was taken on April 12, 2017, by NASA’s Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute

These raw, unprocessed images of Saturn’s moon, Atlas, were taken on April 12, 2017, by NASA’s Cassini spacecraft. The flyby had a close-approach distance of about 7,000 miles (11,000 kilometers). These images are the closest ever taken of Atlas and will help to characterize its shape and geology. Atlas (19 miles, or 30 kilometers across) orbits Saturn just outside the A ring—the outermost of the planet’s bright, main rings.

https://www.nasa.gov/feature/jpl/cassini-sees-flying-saucer-moon-atlas-up-close