Philae sleeps, but Rosetta's not done yet

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Its battery dead, the European lander is lost in a crater somewhere on a huge comet. But the orbiter that brought it there still has plenty of science left to do.



As of Saturday morning, the Philae lander is in a digital coma somewhere on the surface of comet 67P/Churyumov-Gerasimenko. But even if the history-making little robot never wakes again, the Rosetta mission and the orbiter of the same name still have a long journey ahead of them.

The plan was for Philae to land at a targeted site on the comet, firing harpoons into the surface of the icy rock to keep itself locked in place for a long trip around the sun. The strong grip was particularly important since a comet this size has only a tiny fraction of the gravity of a place like Earth, leaving little Philae at risk of floating off into space.

But when showtime came, there were problems with Philae's downward thrusters and with firing the harpoons. The European Space Agency reports that the lander bounced off the surface of the comet twice and eventually landed somewhere else without much access to the sunlight its solar panels need to keep it functioning.

Friday evening, Philae used its remaining energy to upload all its data before going into hibernation mode. There was a time slot early this morning during which, the ESA had reported, communication with the lander was possible, but that time has now come and gone.

Still, Rosetta remains.

Even if Philae stays lost in a comet crater for the next year, the orbiter that traveled almost half a billion miles to get to this point will continue to orbit the comet and its lost lander.

Right now, Rosetta has been pulling out to a 30 kilometer orbit of the comet. It will come closer again early next month to get more details on the comet -- some of its flybys will be as close as 8 kilometers to the comet. There's a whole lot of potential science and data about comets, planets and our solar system packed in that process, building up to the trio's closest encounter with the sun, next August.

Before that point there may also be better opportunities to rouse Philae.

https://www.youtube.com/watch?v=crbnOY8WeB8#t=15

NASA's new map may help save Earth from 'killer' asteroids

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(Click image to download)

A new map has been devised by NASA, which shows frequency of small asteroid impacts from 1994 to 2013 and it has provided clues on larger ones that could pose a danger to Earth. NASA's Near Earth Object (NEO) Program reveals that small asteroids frequently enter and disintegrate in the Earth's atmosphere with random distribution around the globe.

Released to the scientific community, the map visualizes data gathered by U.S. government sensors from 1994 to 2013. It indicated that Earth's atmosphere was impacted by small asteroids, resulting in a bolide (or fireball), on 556 separate occasions in a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are usually harmless. The notable exception was the Chelyabinsk event which was the largest asteroid to hit Earth in this period.

The new data could help scientists better refine estimates of the distribution of the sizes of NEOs including larger ones that could pose a danger to Earth. Finding and characterizing hazardous asteroids to protect Earth has been high priority for NASA. It is one of the reasons NASA has increased by a factor of 10 investments in asteroid detection, characterization and mitigation activities over the last five years.

Source : dnaindia

10 Wonders Of The Universe

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What's the biggest thing in the universe? Find out here, along with 9 other incredible astronomical wonders.

http://www.youtube.com/watch?v=yUbQnHvXYEI

3D-printed engine parts future of space launches: NASA

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A team of NASA researchers has found that 3D manufactured copper parts could withstand the heat and pressure required of combustion engines used in space launches.

The US space agency and California-based rocket and missile propulsion manufacturer Aerojet Rocketdyne (AR) conducted 19 hot-fire tests on four injector and thrust chamber assembly configurations at NASA's Glenn Research Centre.

"The successful hot fire test of engine components provides confidence in the additive manufacturing process and paves the way for full-scale development," said Tyler Hickman, lead engineer for the test at Glenn.

3D printing approach is changing the speed, cost and flexibility of designing and building future machines for space and earth applications.

The work is a major milestone in the development and certification of different materials used in the manufacturing process.

Copper alloys offer unique challenges to the additive manufacturing processes.

"Additively manufactured metal propulsion components are truly a paradigm shift for the aerospace industry," added Paul Senick, Glenn project manager.

This will improve efficiency and bring down the cost of space launches and other earth applications, he concluded.

Source : business standard

A Universe of Blue Dots? --"Water Common During the Formation of All Planetary Systems"

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The new SciFi blockbuster, Interstellar, shows astonauts from post apocalyptic earth, destroyed by what appears to be a modern dust-bowl, catapulted into the unknown of outer space in the hopes of finding a new home for the human race, only to discover an extraterrestrial tidal wave on a distant exo planet. How realistic is the premise of an alien water planet? New findings suggest it's based on solid science.
"This is an important step forward in our quest to find out if life exists on other planets," said Tim Harries, from the University of Exeter's Physics and Astronomy department, who was part of the research team. "We know that water is vital for the evolution of life on Earth, but it was possible that the Earth's water originated in the specific conditions of the early solar system, and that those circumstances might occur infrequently elsewhere. By identifying the ancient heritage of Earth's water, we can see that the way in which our solar system was formed will not be unique, and that exoplanets will form in environments with abundant water. Consequently, it raises the possibility that some exoplanets could house the right conditions, and water resources, for life to evolve."
The implication of these findings is that some of the solar system's water must have been inherited from the Sun's birth environment, and thus predate the Sun itself. If our solar system's formation was typical, this implies that water is a common ingredient during the formation of all planetary systems.

To date, the Kepler satellite has detected nearly 1,000 confirmed extrasolar planets. The widespread availability of water during the planet-formation process puts a promising outlook on the prevalence of life throughout the galaxy.

A pioneering new study has shown that water found on Earth predates the formation of the Sun – raising hopes that life could exist on exoplanets, the planets orbiting other stars in our galaxy. The ground-breaking research set out to discover the origin of the water that was deposited on the Earth as it formed.

It found that a significant fraction of water found on Earth, and across our solar system, predates the formation of the Sun. By showing that water is 'inherited' from the environment when a star is born, the international team of scientists believe other exoplanetary systems also had access to an abundance of water during their own formation.

As water is a key component for the development of life on Earth, the study has important implications for the potential for life elsewhere in the galaxy.

Scientists have previously been able to understand the conditions present when stars are formed by looking at the composition of comets and asteroids, which show which gases, dust and, most importantly, ices were circling the star at its birth.

The team of international scientists were able to use 'heavy water' ices – those with an excess of water made with the element deuterium rather than hydrogen – to determine whether the water ices formed before, or during, the solar system's formation.

European Space Agency releases first picture from comet surface

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The European Space Agency has released the first picture taken by the Philae landing probe from the surface of a comet after determining that the craft had stabilized following a tension-filled landing.

The photo released Thursday shows a rocky surface with one of the lander's three feet. Philae became the first spacecraft to land on a comet when it touched down Wednesday on the comet, 67P/Churyumov-Gerasimenko.  Harpoons meant to anchor the lander to the surface failed to work properly, causing Philae to bounce twice.

Scientists are still analyzing what effect the two bounces had on the spacecraft and plan to release further details at a news briefing at 8 a.m. EST.

Gerhard Schwehm, a scientist on the Rosetta mission, told The Associated Press on Thursday that it may still be possible to fire the harpoons but in any case the lander is "very healthy." However, Lander project manager Stephan Ulamec told the BBC that he was wary of making another attempt to fire the harpoons on the grounds that Philae could be thrown back into space.

The BBC reported that ESA scientists are still trying to determine the craft's precise location on the comet, while engineers say it may have bounced hundreds of feet off the surface on its first landing attempt.

A key question is whether Philae's drill can be used to extract samples from beneath the surface without pushing the lander into space. Gravity on the comet is 1/100,000th that of Earth, meaning the washing machine-sized lander weighs just 0.04 ounces there.

Philae and Rosetta will use 21 instruments to analyze the comet over the coming months. Scientists hope the $1.62 billion will help them better understand comets and other celestial objects, as well as possibly answer questions about the origins of life on Earth.

Source : fox news

The Rosetta comet landing has made history

http://i.telegraph.co.uk/multimedia/archive/02758/Rosetta_2758749b.jpg

After 10 years of hard work and one nerve-wracking night, the Rosetta mission has made history by landing on the surface of a comet.

The lander Philae was confirmed to touch down on the surface of the comet more than 300 million miles away at 11:03 a.m. Eastern. Now, scientists expect it to send a panoramic image home and begin analyzing the comet for scientists back on Earth.

Philae is already transmitting scientific data back home, but we're still waiting to see whether the probe is in a stable position. Until we know it's anchored tight, it could roll onto its back and never get back up.

Tensions were high in the European Space Agency's German mission control center, especially as the landing window approached. Because the comet that Philae landed on is so far from Earth, there's a communications delay of 28 minutes. So as the minutes ticked by, the Rosetta team knew that Philae had already either landed or failed — and there was nothing they could do but wait for the data to reach them. Those following the video online were nearly as desperate for news, and Twitter became a sounding chamber of anticipation and excitement.

But a few minutes after 11 a.m., the stern, cautious expressions of the mission control team melted into smiles. And just like that, the world swiveled from anxiety to elation: Philae was on the surface of the comet and ready to do some science.

The comet contains the materials that originally formed our solar system, frozen in time. By digging them out, we can learn more about the origins of our planet. The Rosetta spacecraft has made invaluable observations about the comet's attributes, and it will continue to do so as it follows it around the sun for the next year. But Philae will be able to look more closely at the comet's physical and molecular composition.

"It's a look at the basic building blocks of our solar system, the ancient materials from which life emerged," said Kathrin Altwegg of the University of Bern in Switzerland, one of the Rosetta project's lead researchers. "It's like doing archaeology, but instead of going back 1,000 years, we can go back 4.6 billion."

It's no easy thing to land on a comet's surface: These chunks of rock and ice are constantly spinning, and Comet 67P/Churyumov-Gerasimenko, which was discovered in 1969, orbits the sun at a speed of about 85,000 mph. It's irregularly shaped — like a toddler's play-dough impression of a duck, or something — and its surface is uneven and pitted. And in a universe of unimaginable proportion, Rosetta's target is just 2.5 miles in diameter — smaller than Northwest Washington's Columbia Heights neighborhood.

So Rosetta has taken an onerous journey to get in sync with the comet's orbit, which would allow it to drop down a lander. In 2004, the spacecraft began what would be three looping orbits around the sun, altering its trajectory as it skimmed Mars, just 150 miles from the surface, and enduring 24 minutes in the planet’s shadow to align with Churyumov-Gerasimenko. The cumulative distance traveled by the craft – with all its looping and gravity assists – is a stunning 4 billion miles. “When the Rosetta signal reappeared after the passage behind Mars, shortly after the end of the ‘shadow’ period, there was a collective sigh of relief,” ESA said.

At one point in 2011, the spacecraft even had to hibernate for nearly three years. It flew so far from the sun — nearly 500 million miles — that its solar panels couldn't leech enough energy to keep the spacecraft operational. But in January of this year, Rosetta woke up, and quickly approached its target.

The last leg of this landing has not been without its bumps. Even as the mission approached its most critical moment, controllers at the European Space Agency on Tuesday night reported a problem with the thruster on the lander that could make for a rough landing. The gravity of the problem — and the extent to which it threatened the mission — remained unknown. “We’ll need some luck not to land on a boulder or a steep slope,” blogged Stephan Ulamec, lander manager for the project.

Source : washington post