Category Astronomy/Space

This artist’s rendering shows the hot, molten Moon emerging from a synestia, a giant spinning donut of vaporized rock that formed when planet-sized objects collided. The synestia is in the process of condensing to form the Earth. This new model for the Moon’s origin answers outstanding questions about how the Moon’s composition compares to that of Earth. Credit: Image by Sarah Stewart/UC Davis based on NASA rendering.

A new explanation for the Moon’s origin has it forming inside the Earth when our planet was a seething, spinning cloud of vaporized rock, called a synestia. The new model led by researchers at the University of California, Davis and Harvard University resolves several problems in lunar formation...

Figure 1: The Milky Way galaxy, perturbed by the tidal interaction with a dwarf galaxy, as predicted by N-body simulations. The locations of the observed stars above and below the disk, which are used to test the perturbation scenario, are indicated.

An international team of astronomers led by the Max Planck Institute for Astronomy (MPIA) has made a surprising discovery about the birthplace of groups of stars located in the halo of our Milky Way galaxy. These halo stars are grouped together in giant structures that orbit the center of our galaxy, above and below the flat disk of the Milky Way. Researchers thought they may have formed from debris left behind by smaller galaxies that invaded the Milky Way in the past.

But astronomers now have compelling evidence showing that some of these ha...

Image of the Whirlpool galaxy, or M51. X-ray light seen by NASA’s Chandra X-ray Observatory is shown in purple, and optical light from NASA’s Hubble Space Telescope is red, green and blue. The ultraluminous X-ray source, or ULX, in the new Caltech-led study is indicated. Credit: NASA/CXC/Caltech/M.Brightman et al.; Optical: NASA/STScI

Astronomers find new clues in galactic mystery of ultraluminous sources of X-rays. In the 1980s, researchers began discovering extremely bright sources of X-rays in the outer portions of galaxies, away from the supermassive black holes that dominate their centers. At first, researchers thought these cosmic objects, called ultraluminous X-ray sources, or ULXs, were hefty black holes with more than ten times the mass of the sun...

An artist’s impression of a flare from Proxima Centauri, modeled after the loops of glowing hot gas seen in the largest solar flares. An artist’s impression of the exoplanet Proxima b is shown in the foreground. Proxima b orbits its star 20 times closer than the Earth orbits the Sun. A flare 10 times larger than a major solar flare would blast Proxima b with 4,000 times more radiation than the Earth gets from our Sun’s flares. Credit: Roberto Molar Candanosa / Carnegie Institution for Science, NASA/SDO, NASA/JPL.

Flare illuminates lack of a dust ring; puts habitability of Proxima b in question. Astronomers have detected a massive stellar flare – an energetic explosion of radiation – from the closest star to our own Sun, Proxima Centauri, which occurred last March...