OrbitalHub

NASA dixit:

“An international team of astronomers has developed a 3D model of a giant cloud ejected by the massive binary system Eta Carinae during its 19th century outburst. Eta Carinae lies about 7,500 light-years away in the southern constellation of Carina and is one of the most massive binary systems astronomers can study in detail. The smaller star is about 30 times the mass of the sun and may be as much as a million times more luminous. The primary star contains about 90 solar masses and emits 5 million times the sun’s energy output. Both stars are fated to end their lives in spectacular supernova explosions.

Between 1838 and 1845, Eta Carinae underwent a period of unusual variability during which it briefly outshone Canopus, normally the second-brightest star. As a part of this event, which astronomers call the Great Eruption, a gaseous shell containing at least 10 and perhaps as much as 40 times the sun’s mass was shot into space. This material forms a twin-lobed dust-filled cloud known as the Homunculus Nebula, which is now about a light-year long and continues to expand at more than 1.3 million mph (2.1 million km/h).

Using the European Southern Observatory’s Very Large Telescope and its X-Shooter spectrograph, the team imaged near-infrared, visible and ultraviolet wavelengths along 92 separate swaths across the nebula, making the most complete spectral map to date. The researchers have used the spatial and velocity information provided by this data to create the first high-resolution 3D model of the Homunculus Nebula.

The shape model was developed using only a single emission line of near-infrared light emitted by molecular hydrogen gas. The characteristic 2.12-micron light shifts in wavelength slightly depending on the speed and direction of the expanding gas, allowing the team to probe even dust-obscured portions of the Homunculus that face away from Earth.”

Credit: NASA Goddard

NASA dixit:

“This supercomputer simulation shows one of the most violent events in the universe: a pair of neutron stars colliding, merging and forming a black hole. A neutron star is the compressed core left behind when a star born with between eight and 30 times the sun’s mass explodes as a supernova. Neutron stars pack about 1.5 times the mass of the sun — equivalent to about half a million Earths — into a ball just 12 miles (20 km) across.

As the simulation begins, we view an unequally matched pair of neutron stars weighing 1.4 and 1.7 solar masses. They are separated by only about 11 miles, slightly less distance than their own diameters. Redder colors show regions of progressively lower density.

As the stars spiral toward each other, intense tides begin to deform them, possibly cracking their crusts. Neutron stars possess incredible density, but their surfaces are comparatively thin, with densities about a million times greater than gold. Their interiors crush matter to a much greater degree densities rise by 100 million times in their centers. To begin to imagine such mind-boggling densities, consider that a cubic centimeter of neutron star matter outweighs Mount Everest.

By 7 milliseconds, tidal forces overwhelm and shatter the lesser star. Its superdense contents erupt into the system and curl a spiral arm of incredibly hot material. At 13 milliseconds, the more massive star has accumulated too much mass to support it against gravity and collapses, and a new black hole is born. The black hole’s event horizon — its point of no return — is shown by the gray sphere. While most of the matter from both neutron stars will fall into the black hole, some of the less dense, faster moving matter manages to orbit around it, quickly forming a large and rapidly rotating torus. This torus extends for about 124 miles (200 km) and contains the equivalent of 1/5th the mass of our sun. The entire simulation covers only 20 milliseconds.

Scientists think neutron star mergers like this produce short gamma-ray bursts (GRBs). Short GRBs last less than two seconds yet unleash as much energy as all the stars in our galaxy produce over one year.

The rapidly fading afterglow of these explosions presents a challenge to astronomers. A key element in understanding GRBs is getting instruments on large ground-based telescopes to capture afterglows as soon as possible after the burst. The rapid notification and accurate positions provided by NASA’s Swift mission creates a vibrant synergy with ground-based observatories that has led to dramatically improved understanding of GRBs, especially for short bursts.”

Credit: NASA Goddard

ESA dixit:

“Rosetta will come to within about 10 km of the nucleus to deploy Philae, which will take several hours to reach the surface. Because of the comet’s extremely low gravity, landing gear will absorb the small forces of landing while ice screws in the probe’s feet and a harpoon system will lock the probe to the surface. At the same time a thruster on top of the lander will push it down to counteract the impulse of the harpoon imparted in the opposite direction. Once it is anchored to the comet, the lander will begin its primary science mission, based on its 64-hour initial battery lifetime. The animation then shows five of Philae’s 10 instruments in action: CIVA, ROLIS, SD2, MUPUS and APXS. Rosetta’s Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI.”

Credit: ESA

ESA dixit:

“This short animation explains the relative sizes of the Rosetta spacecraft and comet 67P/Churyumov–Gerasimenko. Rosetta is 32 m from tip to tip of the solar wings. Assuming the comet measures about 4 km across, that’s 125 times the width of Rosetta. Unlike typical artist’s impressions, this image is scaled to convey the vast difference in size between Rosetta and the comet, even when the spacecraft is in a close 10 km orbit, as depicted here. Rosetta arrives at the comet at an altitude of 100 km in the first week of August, and will move progressively closer over the following two months, with the intention to orbit at an altitude of just 10 km, depending on the comet’s activity. For Philae’s deployment in November, Rosetta will come to within a few kilometres of the surface. The comet depicted in this animation is an artist’s impression.”

Credit: ESA

ESA dixit:

“Liftoff of an Ariane 5 launcher from Europe’s spaceport in French Guiana with ESA’s last Automated Transfer vehicle to the Space Station. The fifth and final mission of ESA’s Automated Transfer Vehicle got off to a flying start with its launch from Europe’s Spaceport in Kourou, French Guiana, heading for the International Space Station. Georges Lemaître is the fifth ATV built and launched by ESA as part of Europe’s contribution to cover the operational costs for using the Space Station. Named after the Belgian scientist who formulated the Big Bang Theory, ATV Georges Lemaître lifted off at 23:47 GMT on 29 July (01:47 CEST 30 July, 20:47 local time 29 July) on an Ariane 5 ES rocket. The vehicle will deliver 6561 kg of freight, including 2628 kg of dry cargo and 3933 kg of water, propellants and gases.”

Credit: ESA / CNES / Arianespace

NASA dixit:

“The historic 1964 Ranger 7 mission was the first true success in the United States’ early quest to explore the moon.
The JPL-built spacecraft launched July 28. Three days later, it made a targeted impact on the moon, sending back more than 4,300 photos along the way.”

Credit: NASA