A morte de Rosetta

Source: http://www.nytimes.com/2016/10/01/science/rosetta-spacecraft-to-end-mission-by-sinking-to-its-comet-companion.html?action=click&contentCollection=science&region=rank&module=package&version=highlights&contentPlacement=1&pgtype=sectionfront&_r=0

Vocabulary:

1. spacecraft 
2. part joyous
3. and was blurry because
4. could be matched by a spacecraft.
5. which starred actors from the HBO
6. were shattered by the impact
7. Rosetta’s demise

Text: Rosetta, the first spacecraft (=veículo espacial) to orbit a comet, is dead, setting down in a final embrace with its companion of the past two years.

Radio signals from Rosetta flatlined at 7:19 a.m. Eastern after it did a soft belly-flop onto Comet 67P/Churyumov-Gerasimenko at a speed of two miles per hour, slower than the average walk.

For the last few minutes, people at the European Space Operations Center in Darmstadt, Germany, watched their computer screens mostly in silence, but with some nervous chatter. When the radio signals ceased, they applauded and hugged in a celebration that was part joyous (=alegre), part somber.

“This is it,” said Patrick Martin, the mission manager. “I can announce the full success of this historic descent of Rosetta toward 67P, and I declare the primary mission operations ended for Rosetta.”

Before Rosetta went silent, it collected and sent back one last batch of data and images, including some very close-up shots of the comet’s surface.

The last photograph was taken at a height of 167 feet and was blurry(=borrada) because the camera was designed for viewing from a distance, not close up.

The spacecraft’s 12-year journey — it took a decade to get there — concluded with quite a few firsts, and quite a few fans.

Comets are frozen remnants that hold secrets about the early solar system, and Rosetta was the first spacecraft to do more than just whiz by one. Scientists have learned a lot from Rosetta’s discoveries, adding pieces to the puzzle of how the planets came together and how life arrived on Earth. One of Rosetta’s key findings is that comets are probably not the source of Earth’s water.

Comet 67P, which likely formed outside of Neptune, was one of the few with an orbit that could be matched (=combinar) by a spacecraft. It is only the second Kuiper belt object to be visited by a spacecraft — Pluto was the first, by NASA’s New Horizons mission last year.

Two years of observation revealed a dormant comet coming to life as it neared the sun and heated up, shooting geysers of dust and gas off its surface. Scientists learned that its shape, resembling a rubber duck, most likely occurred when two comets bumped into each other at a low velocity and stuck together.

The European Space Agency created a series of cartoon videos for children. For an older audience it commissioned a short film, “Ambition,” which starred (=estrelado por) actors from the HBO series “Game of Thrones.” Aidan Gillen, who plays Petyr “Littlefinger” Baelish, and Aisling Franciosi, who plays Lyanna Stark, explained the mission’s grand goals with sci-fi storytelling:

The film was released in October 2014, shortly before Rosetta dispatched a small lander, Philae, to the surface of Comet 67P. On Wednesday, the space agency released an epilogue:


After making its closest approach to the sun in August 2015, Comet 67P is now on the outward leg of its orbit. As sunlight grew more faint, Rosetta was less able to generate power from its solar panels.

Mission managers decided on a dive to collect one last batch of data: close-up observations of mysterious pits that appear similar to sinkholes on Earth.

The camera was expected to make out features as a small as one inch wide.

“It will be interesting to get to look into the interior of the pits,” Mohamed Ramy El-Maarry, a postdoctoral researcher at the University of Bern in Switzerland, and a member of the team working with Rosetta’s high-resolution camera, said during a news conference on Thursday.

The instrument that collected and studied dust particles had already been turned off.

During a series of presentations on Thursday, mission scientists described some of their findings, including a variety of “magical landscapes” along with an overall emptiness. They released audio of a “cosmic song,” created by the magnetic fields oscillating in the trail of particles flying off the comet.

Valerie Ciarletti of the Université Paris-Saclay, who helped investigate the comet’s interior with radio waves, said the inside of Comet 67P is about as porous as fresh, powdery snow — 70 percent of the volume is empty space. “It’s very fluffy material,” she said.

Parts of the surface, like the rocky region where Rosetta’s lander Philae wound up, are more dense, with a porosity lower than 50 percent. “It could be something like sand,” Dr. Ciarletti said.

The interior was also homogeneous. There were no big caves or large regions of compressed material.

Thurid Mannel, a scientist at the University of Graz in Austria, described a menagerie of dust particles spanning a wide range of sizes and materials. Many were shattered(=destruidos) by the impact with the device on Rosetta that collected dust particles ejected from the comet. “The dust is very, very fragile,” she said.

The scientists learned much about the comet’s landscape. Dr. El-Maarry described its surface as very dark — reflecting just 3 to 4 percent of the sunlight that hits it. The darkness comes from a dearth of ice at the surface and an abundance of organic molecules.

Some areas are bare rock; others are smooth terrains buried in dust. “You can think of something like a sea of sand being surrounded by cliffs,” Dr. El-Maarry said.

The rocks are cracked with fissures.

“Anywhere we can see that surface and we have good enough resolution, we see fractures everywhere,” Dr. El-Maarry said.

Charlotte Goetz of the Technical University Braunschweig was among the scientists who studied the cloud of charged particles around the comet. When Rosetta first arrived, the interplay of particles from the comet with the solar wind produced oscillations in the magnetic fields that the scientists turned into sound, a “cosmic song.”

Closer in, as more material spewed off the comet, the tune changed. Dr. Goetz on Thursday presented a longer song.

But then, as Rosetta and the comet moved away from the sun, the original song returned.

At the end of Thursday’s presentations, Matt Taylor, the project scientist, thanked the other scientists who he said had “worked their guts out to get to where we are today.”

He said they had mixed feelings: sad about Rosetta’s demise(=morte), and eager to take a deeper look at the reams of data.

“The operations end,” Dr. Taylor said, “but we still have all this science to do, so they’re still happy that we got to this stage.”

IELTS academic and Helium post

Source: http://takeielts.britishcouncil.org/prepare-test/free-sample-tests/reading-sample-test-1-academic/reading-passage-3

Vocabulary:
concerning 
demise 
radioactive decay
feasibility for helium
The dwindling supplies
so artificially deflated

Text: Helium’s future up in the air

A) In recent years we have all been exposed to dire media reports concerning(=em relação) the impending demise(=falecimento) of global coal and oil reserves, but the depletion of another key non-renewable resource continues without receiving much press at all. Helium – an inert, odourless, monatomic element known to lay people as the substance that makes balloons float and voices squeak when inhaled – could be gone from this planet within a generation.

B) Helium itself is not rare; there is actually a plentiful supply of it in the cosmos. In fact, 24 per cent of our galaxy’s elemental mass consists of helium, which makes it the second most abundant element in our universe. Because of its lightness, however, most helium vanished from our own planet many years ago. Consequently, only a miniscule proportion – 0.00052%, to be exact – remains in earth’s atmosphere. Helium is the by-product of millennia of radioactive decay(=decaimento) from the elements thorium and uranium. The helium is mostly trapped in subterranean natural gas bunkers and commercially extracted through a method known as fractional distillation.

C) The loss of helium on Earth would affect society greatly. Defying the perception of it as a novelty substance for parties and gimmicks, the element actually has many vital applications in society. Probably the most well known commercial usage is in airships and blimps (non-flammable helium replaced hydrogen as the lifting gas du jour after the Hindenburg catastrophe in 1932, during which an airship burst into flames and crashed to the ground killing some passengers and crew). But helium is also instrumental in deep-sea diving, where it is blended with nitrogen to mitigate the dangers of inhaling ordinary air under high pressure; as a cleaning agent for rocket engines; and, in its most prevalent use, as a coolant for superconducting magnets in hospital MRI (magnetic resonance imaging) scanners.

D) The possibility of losing helium forever poses the threat of a real crisis because its unique qualities are extraordinarily difficult, if not impossible to duplicate (certainly, no biosynthetic ersatz product is close to approaching the point of feasibility(=viabilidade) for helium, even as similar developments continue apace for oil and coal). Helium is even cheerfully derided as a “loner” element since it does not adhere to other molecules like its cousin, hydrogen. According to Dr. Lee Sobotka, helium is the “most noble of gases, meaning it’s very stable and non-reactive for the most part … it has a closed electronic configuration, a very tightly bound atom. It is this coveting of its own electrons that prevents combination with other elements’. Another important attribute is helium’s unique boiling point, which is lower than that for any other element. The worsening global shortage could render millions of dollars of high-value, life-saving equipment totally useless. The dwindling (=encolhimento) supplies have already resulted in the postponement of research and development projects in physics laboratories and manufacturing plants around the world. There is an enormous supply and demand imbalance partly brought about by the expansion of high-tech manufacturing in Asia.

E) The source of the problem is the Helium Privatisation Act (HPA), an American law passed in 1996 that requires the U.S. National Helium Reserve to liquidate its helium assets by 2015 regardless of the market price. Although intended to settle the original cost of the reserve by a U.S. Congress ignorant of its ramifications, the result of this fire sale is that global helium prices are so artificially deflated(=deflacionadas) that few can be bothered recycling the substance or using it judiciously. Deflated values also mean that natural gas extractors see no reason to capture helium. Much is lost in the process of extraction. As Sobotka notes: "[t]he government had the good vision to store helium, and the question now is: Will the corporations have the vision to capture it when extracting natural gas, and consumers the wisdom to recycle? This takes long-term vision because present market forces are not sufficient to compel prudent practice”. For Nobel-prize laureate Robert Richardson, the U.S. government must be prevailed upon to repeal its privatisation policy as the country supplies over 80 per cent of global helium, mostly from the National Helium Reserve. For Richardson, a twenty- to fifty-fold increase in prices would provide incentives to recycle.

F) A number of steps need to be taken in order to avert a costly predicament in the coming decades. Firstly, all existing supplies of helium ought to be conserved and released only by permit, with medical uses receiving precedence over other commercial or recreational demands. Secondly, conservation should be obligatory and enforced by a regulatory agency. At the moment some users, such as hospitals, tend to recycle diligently while others, such as NASA, squander massive amounts of helium. Lastly, research into alternatives to helium must begin in earnest.