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European Spacecraft Pulls Alongside Comet “After 10 years and a journey of four billion miles, the European Space Agency’s Rosetta spacecraft arrived at its destination on Wednesday for the first extended, close examination of a comet. A six-minute thruster firing at 5 a.m. Eastern time, the last in a series of 10 over the past few months, slowed Rosetta to the pace of a person walking, about two miles per hour relative to the speed of its target, Comet 67P/Churyumov-Gerasimenko.”

Find out more from the nytimes.

ASTRONOMERS CAPTURE BEST VIEW EVER OF DISINTEGRATING COMET

Astronomers have captured the sharpest, most detailed observations of a comet breaking apart 67 million miles from Earth, using NASA’s Hubble Space Telescope. The discovery is published online today in Astrophysical Journal Letters [http://apjl.aas.org].

In a series of images taken over three days in January 2016, Hubble showed 25 fragments consisting of a mixture of ice and dust that are drifting away from the comet at a pace equivalent to the walking speed of an adult, said David Jewitt, a professor in the UCLA departments of Earth, Planetary and Space Sciences; and Physics and Astronomy, who led the research team.

The images suggest that the roughly 4.5-billion-year-old comet, named 332P/Ikeya-Murakami, or Comet 332P, may be spinning so fast that material is ejected from its surface. The resulting debris is now scattered along a 3,000-mile-long trail, larger than the width of the continental United States.

These observations provide insight into the volatile behavior of comets as they approach the Sun and begin to vaporize, unleashing powerful forces.

“We know that comets sometimes disintegrate, but we don’t know much about why or how,” Jewitt said. “The trouble is that it happens quickly and without warning, so we don’t have much chance to get useful data. With Hubble’s fantastic resolution, not only do we see really tiny, faint bits of the comet, but we can watch them change from day to day. That has allowed us to make the best measurements ever obtained on such an object.”

The three-day observations show that the comet shards brighten and dim as icy patches on their surfaces rotate into and out of sunlight. Their shapes change, too, as they break apart. The icy relics comprise about four percent of the parent comet and range in size from roughly 65 feet wide to 200 feet wide. They are separating at only a few miles per hour as they orbit the Sun at more than 50,000 miles per hour.

The Hubble images show that the parent comet changes brightness frequently, completing a rotation every two to four hours. A visitor to the comet would see the Sun rise and set in as little as an hour, Jewitt said.

The comet is much smaller than astronomers thought, measuring only 1,600 feet across, about the length of five football fields.

Comet 332P was discovered in November 2010, after it surged in brightness and was spotted by two Japanese amateur astronomers.

Based on the Hubble data, the research team suggests that sunlight heated the surface of the comet, causing it to expel jets of dust and gas. Because the nucleus is so small, these jets act like rocket engines, spinning up the comet’s rotation, Jewitt said. The faster spin rate loosened chunks of material, which are drifting off into space. The research team calculated that the comet probably shed material over a period of months, between October and December 2015.

Jewitt suggests that some of the ejected pieces have themselves fallen to bits in a kind of cascading fragmentation. “We think these little guys have a short lifetime,” he said.

Hubble’s sharp vision also spied a chunk of material close to the comet, which may be the first salvo of another outburst. The remnant from still another flare-up, which may have occurred in 2012, is also visible. The fragment may be as large as Comet 332P, suggesting the comet split in two. But the remnant wasn’t spotted until Dec. 31, 2015, by a telescope in Hawaii.

That discovery prompted Jewitt and colleagues to request Hubble Space Telescope time to study the comet in detail.

“In the past, astronomers thought that comets die when they are warmed by sunlight, causing their ices to simply vaporize away,” Jewitt said. “But it’s starting to look like fragmentation may be more important. In comet 332P we may be seeing a comet fragmenting itself into oblivion.”

The researchers estimate that comet 332P contains enough mass for 25 more outbursts. “If the comet has an episode every six years, the equivalent of one orbit around the Sun, then it will be gone in 150 years,” Jewitt said. “It’s just the blink of an eye, astronomically speaking. The trip to the inner solar system has doomed it.”

The icy visitor hails from the Kuiper belt, a vast swarm of objects at the outskirts of our solar system. As the comet traveled across the system, it was deflected by the planets, like a ball bouncing around in a pinball machine, until Jupiter’s gravity set its current orbit, Jewitt said.

The first Space Launch System hardware from NASA’s Michoud Assembly Facility in New Orleans just arrived at NASA’s Marshall Space Flight Center in Huntsville, Alabama. We take a minute to introduce you to the crew of NASA’s barge Pegasus. The crew made an 18-day journey on the barge leaving New Orleans on April 28 and arriving at Marshall on May 15. The barge delivered a structural test version of the core stage engine section of SLS, NASA’s new heavy-lift rocket. Pegasus will deliver four test articles of the rocket’s core stage to Marshall for tests that will simulate the forces experienced during launch. Pegasus will later ferry the flight-ready core stage to NASA’s Stennis Space Center near Bay St. Louis, Mississippi, for testing and then to NASA’s Kennedy Space Center in Florida for integration of the SLS flight vehicle in the Vehicle Assembly Building.

Hubble Hones In on a Hypergiants Home : The super star cluster Westerlund 1, only 15,000 light-years away in our Milky Way neighborhood, hosts one of the largest stars ever discovered.

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People forget that “within the habitable zone” means habitable for us and ‘life as we know it.’

Being that we are completely unfamiliar with life and science outside of what we’ve encountered, it is entirely possible for 'life as we don’t yet know it’ to exist outside of what we personally consider a habitable zone.

*Those razor-like shadows, they’re so black they look photoshopped

NASA Tests 3-D Printed Engine Components

3-D printing isn’t just for toys and plastic models of your head. Witness a hot fire of NASA’s newest design for rocket engine injectors, 3-D printed to up performance in a way that traditional manufacturing of the parts couldn’t attain.

The agency, which tested the experimental injectors last month at Marshall Space Flight Center in Huntsville, Ala., used a type of 3-D printing called direct laser melting. To make the parts, a machine fires a laser at metal powder under the direction of a computer design program. This deposits layers of the metal one on top of the other until the part is complete.

NASA says the technique is letting engineers build the injector out of just two parts instead of the 163 formerly needed using traditional manufacturing methods.

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