Category Astronomy/Space

A representation of two competing black hole models: lamp-post and extended. The black dot is the black hole, blue is its accretion disk, and red is the corona.
Credit: Fumiya Imazato, Hiroshima University

X-ray polarimetry resolves shape of matter around Cygnus X-1 black hole. In an international collaboration between Japan and Sweden, scientists clarified how gravity affects the shape of matter near the black hole in binary system Cygnus X-1. Their findings, which were published in Nature Astronomy this month, may help scientists further understand the physics of strong gravity and the evolution of black holes and galaxies.

Near the center of the constellation of Cygnus is a star orbiting the first black hole discovered in the universe...

Artist impression of the “reverse shock” echoing back though the jets of the gamma-ray burst (GRB 161219B).
Credit: NRAO/AUI/NSF, S. Dagnello

ALMA creates its first-ever movie of cosmic explosion. In the blink of an eye, a massive star more than 2 billion light-years away lost a million-year-long fight against gravity and collapsed, triggering a supernova and forming a black hole at its center. This newborn black hole belched a fleeting yet astonishingly intense flash of gamma rays known as a gamma-ray burst (GRB) toward Earth, where it was detected by NASA’s Neil Gehrels Swift Observatory on 19 December 2016.

While the gamma rays from the burst disappeared from view a scant seven seconds later, longer wavelengths of light from the explosion – including X-ray, visible light, and radio – con...

ESA’s Mars Express has used radar signals bounced through underground layers of ice to find evidence of a pond of water buried below the south polar cap. Credit: Context map: NASA/Viking; THEMIS background: NASA/JPL-Caltech/Arizona State University; MARSIS data: ESA/NASA/JPL/ASI/Univ. Rome; R. Orosei et al 2018

Radar data collected by ESA’s Mars Express point to a pond of liquid water buried under layers of ice and dust in the south polar region of Mars. Evidence for the Red Planet’s watery past is prevalent across its surface in the form of vast dried-out river valley networks and gigantic outflow channels clearly imaged by orbiting spacecraft...

A portion of the Medusae Fossae Formation on Mars showing the effect of billions of years of erosion. The image was acquired by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter.
Credit: NASA/JPL/University of Arizona

The dust that coats much of the surface of Mars originates largely from a single thousand-kilometer-long geological formation near the Red Planet’s equator, scientists have found. A study published in the journal Nature Communications found a chemical match between dust in the Martian atmosphere and the surface feature, called the Medusae Fossae Formation...