NASA’S SPITZER TELESCOPE WITNESSES ASTEROID SMASHUP
From the FMS Global News Desk of Jeanne Hambleton NASA Released 28 August 2014
NASA’s Spitzer Space Telescope has spotted an eruption of dust around a young star, possibly the result of a smashup between large asteroids. This type of collision can eventually lead to the formation of planets.
Scientists had been regularly tracking the star, called NGC 2547-ID8, when it surged with a huge amount of fresh dust between August 2012 and January 2013.
“We think two big asteroids crashed into each other, creating a huge cloud of grains the size of very fine sand, which are now smashing themselves into smithereens and slowly leaking away from the star,” said lead author and graduate student Huan Meng of the University of Arizona, Tucson.
While dusty aftermaths of suspected asteroid collisions have been observed by Spitzer before, this is the first time scientists have collected data before and after a planetary system smashup. The viewing offers a glimpse into the violent process of making rocky planets like ours.
Rocky planets begin life as dusty material circling around young stars. The material clumps together to form asteroids that ram into each other. Although the asteroids often are destroyed, some grow over time and transform into proto-planets.
After about 100 million years, the objects mature into full-grown, terrestrial planets. Our moon is thought to have formed from a giant impact between proto-Earth and a Mars-size object.
In the new study, Spitzer set its heat-seeking infrared eyes on the dusty star NGC 2547-ID8, which is about 35 million years old and lies 1,200 light-years away in the Vela constellation. Previous observations had already recorded variations in the amount of dust around the star, hinting at possible ongoing asteroid collisions.
In hope of witnessing an even larger impact, which is a key step in the birth of a terrestrial planet, the astronomers turned to Spitzer to observe the star regularly. Beginning in May 2012, the telescope began watching the star, sometimes daily.
A dramatic change in the star came during a time when Spitzer had to point away from NGC 2547-ID8 because our sun was in the way. When Spitzer started observing the star again five months later, the team was shocked by the data they received.
“We not only witnessed what appears to be the wreckage of a huge smashup, but have been able to track how it is changing — the signal is fading as the cloud destroys itself by grinding its grains down so they escape from the star,” said Kate Su of the University of Arizona and co-author on the study.
“Spitzer is the best telescope for monitoring stars regularly and precisely for small changes in infrared light over months and even years.”
A very thick cloud of dusty debris now orbits the star in the zone where rocky planets form. As the scientists observe the star system, the infrared signal from this cloud varies based on what is visible from Earth.
For example, when the elongated cloud is facing us, more of its surface area is exposed and the signal is greater. When the head or the tail of the cloud is in view, less infrared light is observed. By studying the infrared oscillations, the team is gathering first-of-its-kind data on the detailed process and outcome of collisions that create rocky planets like Earth.
“We are watching rocky planet formation happen right in front of us,” said George Rieke, a University of Arizona co-author of the new study. “This is a unique chance to study this process in near real-time.”
The team is continuing to keep an eye on the star with Spitzer. They will see how long the elevated dust levels persist, which will help them calculate how often such events happen around this and other stars, and they might see another smashup while Spitzer looks on.
The results of this study are posted online Thursday in the journal Science.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.
This artist’s concept shows the immediate aftermath of a large asteroid impact around NGC 2547-ID8, a 35-million-year-old sun-like star. NASA’s Spitzer Space Telescope witnessed a giant surge in dust around the star, likely the result of two asteroids colliding. Image Credit: NASA/JPL-Caltech
Building Planets Through Collisions
Planets, including those like our own Earth, form from epic collisions between asteroids and even bigger bodies, called proto-planets. Sometimes the colliding bodies are ground to dust, and sometimes they stick together to ultimately form larger, mature planets.
This artist’s conception shows one such smash-up, the evidence for which was collected by NASA’s Spitzer Space Telescope. Spitzer’s infrared vision detected a huge eruption around the star NGC 2547-ID8 between August 2012 and 2013. Scientists think the dust was kicked up by a massive collision between two large asteroids. They say the smashup took place in the star’s “terrestrial zone,” the region around stars where rocky planets like Earth take shape.
NGC 2547-ID8 is a sun-like star located about 1,200 light-years from Earth in the constellation Vela. It is about 35 million years old, the same age our young sun was when its rocky planets were finally assembled via massive collisions — including the giant impact on proto-Earth that led to the formation of the moon. The recent impact witnessed by Spitzer may be a sign of similar terrestrial planet building. Near-real-time studies like these help astronomers understand how the chaotic process works.
SPARKS FLY AS NASA PUSHES THE LIMITS OF 3-D PRINTING TECHNOLOGY
From FMS Global News Desk of Jeanne Hambleton NASA August 28, 2014
NASA has successfully tested the most complex rocket engine parts ever designed by the agency and printed with additive manufacturing, or 3-D printing, on a test stand at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
NASA engineers pushed the limits of technology by designing a rocket engine injector –a highly complex part that sends propellant into the engine — with design features that took advantage of 3-D printing. To make the parts, the design was entered into the 3-D printer’s computer. The printer then built each part by layering metal powder and fusing it together with a laser, a process known as selective laser melting.
The additive manufacturing process allowed rocket designers to create an injector with 40 individual spray elements, all printed as a single component rather than manufactured individually. The part was similar in size to injectors that power small rocket engines and similar in design to injectors for large engines, such as the RS-25 engine that will power NASA’s Space Launch System (SLS) rocket, the heavy-lift, exploration class rocket under development to take humans beyond Earth orbit and to Mars.
“We wanted to go a step beyond just testing an injector and demonstrate how 3-D printing could revolutionize rocket designs for increased system performance,” said Chris Singer, director of Marshall’s Engineering Directorate. “The parts performed exceptionally well during the tests.”
Using traditional manufacturing methods, 163 individual parts would be made and then assembled. But with 3-D printing technology, only two parts were required, saving time and money and allowing engineers to build parts that enhance rocket engine performance and are less prone to failure.
Two rocket injectors were tested for five seconds each, producing 20,000 pounds of thrust. Designers created complex geometric flow patterns that allowed oxygen and hydrogen to swirl together before combusting at 1,400 pounds per square inch and temperatures up to 6,000 degrees Fahrenheit. NASA engineers used this opportunity to work with two separate companies — Solid Concepts in Valencia, California, and Directed Manufacturing in Austin, Texas. Each company printed one injector.
“One of our goals is to collaborate with a variety of companies and establish standards for this new manufacturing process,” explained Marshall propulsion engineer Jason Turpin. “We are working with industry to learn how to take advantage of additive manufacturing in every stage of space hardware construction from design to operations in space. We are applying everything we learn about making rocket engine components to the Space Launch System and other space hardware.”
Additive manufacturing not only helped engineers build and test a rocket injector with a unique design, but it also enabled them to test faster and smarter. Using Marshall’s in-house capability to design and produce small 3-D printed parts quickly, the propulsion and materials laboratories can work together to apply quick modifications to the test stand or the rocket component.
“Having an in-house additive manufacturing capability allows us to look at test data, modify parts or the test stand based on the data, implement changes quickly and get back to testing,” said Nicholas Case, a propulsion engineer leading the testing. “This speeds up the whole design, development and testing process and allows us to try innovative designs with less risk and cost to projects.”
Marshall engineers have tested increasingly complex injectors, rocket nozzles and other components with the goal of reducing the manufacturing complexity and the time and cost of building and assembling future engines. Additive manufacturing is a key technology for enhancing rocket designs and enabling missions into deep space.
3-D Printed Rocket Injector Roars to Life: The most complex 3-D printed rocket injector ever built by NASA roars to life on the test stand at NASA’s Marshall Space Flight Center in Huntsville,Alabama.
Engineers just completed hot-fire testing with two 3-D printed rocket injectors. Certain features of the rocket components were designed to increase rocket engine performance. The injector mixed liquid oxygen and gaseous hydrogen together, which combusted at temperatures over 6,000 degrees Fahrenheit, producing more than 20,000 pounds of thrust.
Image Credit: NASA photo/David Olive
WALKING FISH REVEAL HOW OUR ANCESTORS EVOLVED ONTO LAND
From the FMS Global News Desk of Jeanne Hambleton Embargoed: 27-Aug-2014 Citations Nature Source : McGill University
About 400 million years ago a group of fish began exploring land and evolved into tetrapods – today’s amphibians, reptiles, birds, and mammals.
But just how these ancient fish used their fishy bodies and fins in a terrestrial environment and what evolutionary processes were at play remain scientific mysteries.
Researchers at McGill University published in the journal Nature, turned to a living fish, called Polypterus, to help show what might have happened when fish first attempted to walk out of the water.
Polypterus is an African fish that can breathe air, ‘walk’ on land, and looks much like those ancient fishes that evolved into tetrapods. The team of researchers raised juvenile Polypterus on land for nearly a year, with an aim to revealing how these ‘terrestrialized’ fish looked and moved differently.
“Stressful environmental conditions can often reveal otherwise cryptic anatomical and behavioural variation, a form of developmental plasticity”, says Emily Standen, a former McGill post-doctoral student who led the project, now at the University of Ottawa.
“We wanted to use this mechanism to see what new anatomies and behaviours we could trigger in these fish and see if they match what we know of the fossil record.”
Remarkable anatomical changes
The fish showed significant anatomical and behavioural changes. The terrestrialized fish walked more effectively by placing their fins closer to their bodies, lifted their heads higher, and kept their fins from slipping as much as fish that were raised in water.
“Anatomically, their pectoral skeleton changed to became more elongate with stronger attachments across their chest, possibly to increase support during walking, and a reduced contact with the skull to potentially allow greater head/neck motion,” says Trina Du, a McGill Ph.D. student and study collaborator.
“Because many of the anatomical changes mirror the fossil record, we can hypothesize that the behavioural changes we see also reflect what may have occurred when fossil fish first walked with their fins on land”, says Hans Larsson, Canada Research Chair in Macroevolution at McGill and an Associate Professor at the Redpath Museum.
The terrestrialized Polypterus experiment is unique and provides new ideas for how fossil fishes may have used their fins in a terrestrial environment and what evolutionary processes were at play.
Larsson adds, “This is the first example we know of that demonstrates developmental plasticity may have facilitated a large-scale evolutionary transition, by first accessing new anatomies and behaviours that could later be genetically fixed by natural selection”.
The study was conducted by Emily Standen, University of Ottawa, and Hans Larsson, Trina Du at McGill University.
This study was supported by the Canada Research Chairs Program, Natural Sciences and Engineering Research Council of Canada (NSERC) and Tomlinson Post-doctoral fellowship. McGill University
Image Polypterussenegalus swimming by Antoine Morin
See you soon Jeanne