OrbitalHub

NASA dixit:

“Scientists from NASA Goddard have discovered that not only are Saturn’s rings younger than previously thought, but also that the rings are actually disappearing at a rapid pace through a process called ring rain.”

Video Credit: NASA

NASA dixit:

“This 4K visualization shows the Moon’s phase and libration at hourly intervals throughout 2019, as viewed from both Northern and Southern Hemisphere. Each frame represents one hour. In addition, this visualization shows the moon’s orbit position, sub-Earth and subsolar points, distance from the Earth at true scale, and labels of craters near the terminator.”

Video Credit: NASA Goddard

NASA dixit:

“A planetary science Ph.D. student at University College London’s Mullard Space Science Laboratory in the United Kingdom, has developed a new image-processing technique to mine through the wealth of data about comet tails. The findings offer the first observations of striations forming in the tails, and an unexpected revelation about the Sun’s effect on comet dust.

Understanding how dust behaves in the tail — how it fragments and clumps together — can teach scientists a great deal about similar processes that formed dust into asteroids, moons and even planets all those billions of years ago. With this study, scientists gain new insights to long-held mysteries. The work sheds light on the nature of striated comet tails from the past and provides a crucial lens for studying other comets in the future. But it also opens a new line of questioning: What role did the Sun have in our solar system’s formation and early history?”

Video Credit: NASA Goddard/Genna Duberstein

NASA dixit:

“About a year ago, astronomers excitedly reported the first detection of electromagnetic waves, or light, from a gravitational wave source. Now, a year later, researchers are announcing the existence of a cosmic relative to that historic event. The discovery was made using data from telescopes including NASA’s Chandra X-ray Observatory, Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, the NASA/ESA Hubble Space Telescope, and the Discovery Channel Telescope (DCT).

The object of the new study, called GRB150101B, was first reported as a gamma-ray burst detected by Fermi in January 2015. This detection and follow-up observations at other wavelengths show GRB150101B shares remarkable similarities to the neutron star merger and gravitational wave source discovered by Advanced Laser Interferometer Gravitational Wave Observatory (LIGO) and its European counterpart Virgo in 2017 known as GW170817. The latest study concludes that these two separate objects may, in fact, be related.”

Video Credit: NASA

NASA dixit:

“This visualization uses a digital 3D model of the Moon built from global elevation maps and image mosaics by NASA’s Lunar Reconnaissance Orbiter mission. It was created to accompany a performance of Claude Debussy’s Clair de Lune by the National Symphony Orchestra Pops, led by conductor Emil de Cou, at the Kennedy Center for the Performing Arts in Washington, DC, on June 1 and 2, 2018, as part of a celebration of NASA’s 60th anniversary.

The visuals were composed like a nature documentary, with clean cuts and a mostly stationary virtual camera. The viewer follows the Sun throughout a lunar day, seeing sunrises and then sunsets over prominent features on the Moon. The sprawling ray system surrounding Copernicus crater, for example, is revealed beneath receding shadows at sunrise and later slips back into darkness as night encroaches.”

Video Credit: NASA

NASA dixit:

“Scientists studying what amounts to a computer-simulated “pulsar in a box” are gaining a more detailed understanding of the complex, high-energy environment around spinning neutron stars, also called pulsars. The model traces the paths of charged particles in magnetic and electric fields near the neutron star, revealing behaviors that may help explain how pulsars emit gamma-ray and radio pulses with ultraprecise timing.

A pulsar is the crushed core of a massive star that exploded as a supernova. The core is so compressed that more mass than the Sun’s squeezes into a ball no wider than Manhattan Island in New York City. This process also revvs up its rotation and strengthens its magnetic and electric fields.

Various physical processes ensure that most of the particles around a pulsar are either electrons or their antimatter counterparts, positrons. To trace the behavior and energies of these particles, the researchers used a comparatively new type of pulsar model called a “particle in cell” (PIC) simulation.

The PIC technique lets scientists explore the pulsar from first principles, starting with a spinning, magnetized neutron star. The computer code injects electrons and positrons at the pulsar’s surface and tracks how they interact with the electric and magnetic fields. It’s computationally intensive because the particle motions affect the fields and the fields affect the particles, and everything is moving near the speed of light.

The simulation shows that most of the electrons tend to race outward from the magnetic poles. Some medium-energy electrons scatter wildly, even heading back to the pulsar. The positrons, on the other hand, mostly flow out at lower latitudes, forming a relatively thin structure called the current sheet. In fact, the highest-energy positrons here — less than 0.1 percent of the total — are capable of producing gamma rays similar to those detected by NASA’s Fermi Gamma-ray Space Telescope, which has discovered 216 gamma-ray pulsars.”

Video Credit: NASA Goddard