OrbitalHub

NASA dixit:

“Doomed neutron stars whirl toward their demise in this animation. Gravitational waves (pale arcs) bleed away orbital energy, causing the stars to move closer together and merge. As the stars collide, some of the debris blasts away in particle jets moving at nearly the speed of light, producing a brief burst of gamma rays (magenta). In addition to the ultra-fast jets powering the gamma-rays, the merger also generates slower moving debris. An outflow driven by accretion onto the merger remnant emits rapidly fading ultraviolet light (violet). A dense cloud of hot debris stripped from the neutron stars just before the collision produces visible and infrared light (blue-white through red). The UV, optical and near-infrared glow is collectively referred to as a kilonova. Later, once the remnants of the jet directed toward us had expanded into our line of sight, X-rays (blue) were detected. This animation represents phenomena observed up to nine days after GW170817.”

Music credit: “Exploding Skies” from Killer Tracks

Video credit: NASA’s Goddard Space Flight Center/CI Lab

NASA dixit:

“Engineers at NASA’s Stennis Space Center in Mississippi on October 19 completed a hot-fire test of RS-25 rocket engine E2063, a flight engine for NASA’s new Space Launch System (SLS) rocket. Engine E2063 is scheduled to help power SLS on its Exploration Mission-2 (EM-2), the first flight of the new rocket to carry humans.”

Video credit: NASA

ESA dixit:

“This remarkable footage shows the flyby of asteroid 2012 TC4 during the night of 11/12 October 2017. At the time this was recorded, the estimated 10-20 m-diameter asteroid was approaching Earth. It made its closest approach at 07:41 CEST on 12 October, just 43 782 km away – much closer than the Moon and inside the orbit of some satellites.

This was captured by astronomers Peter Schlatter and Dominik Bodenmann working at the ZIMLAT telescope at the Swiss Optical Ground Station and Geodynamics Observatory operated by the Astronomical Institute of the University of Bern (AIUB).”

Video credit: ESA / AIUB

NASA dixit:

“Outside the International Space Station, Expedition 53 Commander Randy Bresnik and Flight Engineer Joe Acaba of NASA conducted a spacewalk on October 20 to continue upgrades to and maintenance of station hardware. It was the third spacewalk in two weeks for Expedition 53 crew members outside the Quest airlock. During the excursion, Bresnik and Acaba replaced a failed camera light on the new Latching End Effector “hand” on the Canadarm2 robotic arm, installed a new high definition camera on the starboard truss of the complex, replaced a fuse on the Dextre Special Dexterous Manipulator attachment for the arm and removed thermal blankets from two spare electrical routing units for future robotic replacement work, if required. It was the fifth spacewalk in Bresnik’s career and the third for Acaba.”

Video credit: NASA

NASA dixit:

“February 21, 2017. NASA’s Cassini spacecraft captured these remarkable views of a propeller feature in Saturn’s A ring. These are the sharpest images taken of a propeller so far, and show an unprecedented level of detail. The propeller is nicknamed “Santos-Dumont,” after the pioneering Brazilian-French aviator. This observation was Cassini’s first targeted flyby of a propeller. The views show the object from vantage points on opposite sides of the rings. The top image looks toward the rings’ sunlit side, while the bottom image shows the unilluminated side, where sunlight filters through the backlit ring.

The two images are reprojected at the same scale (0.13 mile or 207 meters per pixel) in order to facilitate comparison. Cassini scientists have been tracking the orbit of this object for the past decade, tracing the effect that the ring has upon it. Now, as Cassini has moved in close to the ring as part of its ring-grazing orbits, it was able to obtain this extreme close-up view of the propeller, enabling researchers to examine its effects on the ring. These views, and others like them, will inform models and studies in new ways going forward.

Like a frosted window, Saturn’s rings look different depending on whether they are seen fully sunlit or backlit. On the lit side, the rings look darker where there is less material to reflect sunlight. On the unlit side, some regions look darker because there is less material, but other regions look dark because there is so much material that the ring becomes opaque. Observing the same propeller on both the lit and unlit sides allows scientists to gather richer information about how the moonlet affects the ring. For example, in the unlit-side view, the broad, dark band through the middle of the propeller seems to be a combination of both empty and opaque regions. The propeller’s central moonlet would only be a couple of pixels across in these images, and may not actually be resolved here. The lit-side image shows that a bright, narrow band of material connects the moonlet directly to the larger ring, in agreement with dynamical models. That same thin band of material may also be obscuring the moonlet from view. Lengthwise along the propeller is a gap in the ring that the moonlet has pried open. The gap appears dark on both the lit and unlit sides. Flanking the gap near the moonlet are regions of enhanced density, which appear bright on the lit side and more mottled on the unlit side.

One benefit of the high resolution of these images is that, for the first time, wavy edges are clearly visible in the gap. These waves are also expected from dynamical models, and they emphasize that the gap must be sharp-edged. Furthermore, the distance between the wave crests tells scientists the width of the gap (1.2 miles or 2 kilometers), which in turn reveals the mass of the central moonlet. From these measurements, Cassini imaging scientists deduce that the moonlet’s mass is comparable to that of a snowball about 0.6 mile (1 kilometer) wide.”

Image credit: NASA/JPL-Caltech/Space Science Institute

NASA dixit:

“February 14, 2017. Daphnis, one of Saturn’s ring-embedded moons, is featured in this view, kicking up waves as it orbits within the Keeler gap. The mosaic combines several images to show more waves in the gap edges. Daphnis is a small moon at 5 miles (8 kilometers) across, but its gravity is powerful enough to disrupt the tiny particles of the A ring that form the Keeler gap’s edge. As the moon moves through the Keeler gap, wave-like features are created in both the horizontal and vertical plane.

Images like this provide scientists with a close-up view of the complicated interactions between a moon and the rings, as well as the interactions between the ring particles themselves, in the wake of the moon’s passage. Three wave crests of diminishing sizes trail Daphnis here. In each subsequent crest, the shape of the wave evolves, as the ring particles within the crests collide with one another.

Close examination of Daphnis’ immediate vicinity also reveals a faint, thin strand of ring material that almost appears to have been directly ripped out of the A ring by Daphnis. The images in this mosaic were taken in visible light, using the Cassini spacecraft narrow-angle camera at a distance of approximately 17,000 miles (28,000 kilometers) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 71 degrees. Image scale is 551 feet (168 meters) per pixel.”

Image credit: NASA/JPL-Caltech/Space Science Institute