“The sun emitted a mid-level solar flare, peaking at 3:01 p.m. EDT on Oct. 2, 2014. NASA’s Solar Dynamics Observatory, which watches the sun 24-hours a day, captured images of the flare. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.
This flare is classified as an M7.3 flare. M-class flares are one-tenth as powerful as the most powerful flares, which are designated X-class flares”.
Music: “No Comment Before Sunset” by Lars Leonhard, courtesy of the artist and BineMusic.
“Filled with more than 3,700 pounds of hardware and critical science experiments, the SpaceX Dragon cargo craft left the International Space Station, headed for a deorbit and a parachute-assisted splashdown in the Pacific Ocean west of Baja California. Dragon arrived at the station on Sept. 23 on the fourth resupply mission to the outpost for the U.S. commercial firm. Dragon is the only cargo vehicle servicing the space station that can return cargo and scientific experiments back to Earth intact for researchers to retrieve for post-flight analysis.”
“After four successful missions to the International Space Station, including three official resupply missions for NASA, SpaceX is set to launch its fourth official Commercial Resupply (CRS) mission to the orbiting lab. The SpaceX CRS-4 mission is targeting launch at 06:14 UTC Saturday, September 20 from Launch Complex 40 at the Cape Canaveral Air Force Station, Florida. If all goes as planned, Dragon will arrive at the station on Monday, September 22 for an expected four-week visit. Dragon is scheduled to return to Earth in mid-October for a parachute-assisted splashdown off the coast of southern California. Dragon is the only operational spacecraft capable of returning a significant amount of supplies back to Earth, including experiments.”
“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.”
“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.”
“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.”
Subscribe to blog posts using RSS
