Category Astronomy/Space

University of Houston optometrist Nimesh Patel has quantified the changing eye structure of returning International Space Station astronauts.

Findings examine pre- and post-flight space station astronauts. Astronauts who spend time aboard the International Space Station return to Earth with changes to the structure of their eyes which could impact their vision. NASA has studied the phenomenon, known as space flight-associated neuro-ocular syndrome (SANS), for several years, and now a University of Houston optometrist has quantified some of the changes using optical coherence tomography imaging, reporting his findings in JAMA Ophthalmology...

Stars indicate quasars and bright (faint) galaxies at the same epoch are shown as circles (dots). The galaxy overdensity with respect to the average density is shown by the contour. The pair members are associated with high density regions of galaxies. Credit: NAOJ

Astronomers have identified nearly 200 ‘protoclusters,’ the progenitors of galaxy clusters, in the early Universe, about 12 billion years ago, about 10X more than previously known. They also found that quasars don’t tend to reside in protoclusters; but if there is one quasar in a protocluster, there is likely a second nearby. This result raises doubts about the relation between protoclusters and quasars.

In the Universe, galaxies are not distributed uniformly...

Upper right: This is a Hubble Space Telescope image of galaxy NGC 1277. Background: The galaxy lives near the center of the Perseus cluster of over 1,000 galaxies, located 240 million light-years away from Earth. Credit: NASA, ESA, M. Beasley (Instituto de Astrofísica de Canarias), and P. Kehusmaa

Astronomers have put NASA’s Hubble Space Telescope on an Indiana Jones-type quest to uncover an ancient “relic galaxy” in our own cosmic backyard. The very rare and odd assemblage of stars has remained essentially unchanged for the past 10 billion years. This wayward stellar island provides valuable new insights into the origin and evolution of galaxies billions of years ago...

A precession driven flow is supposed to power magnetic field self-excitation in a planned liquid metal dynamo experiment at HZDR. Credit: HZDR

Precession sufficient to generate a magnetic field. Flows of molten metal can generate magnetic fields. This dynamo effect creates cosmic magnetic fields, like those found on planets, moons and even asteroids. Over the coming years, a globally unique experiment, in which a steel drum containing several tons of liquid sodium rotates around two axes, is intended to demonstrate this effect. It will be carried out in the new DRESDYN facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), an independent German research laboratory.

Similarly to how a bicycle dynamo converts motion into electricity, moving conductive fluids can generate magnetic field...