Obama promete ida a Marte até 2030

Source: https://www.scientificamerican.com/article/blue-planet-red-planet-politics-obama-s-giant-leap-for-legacy/

Text:
for any full-throttle interest
in the realm beyond Earth.

to withstand an influx

reiterated interest in Earth’

international affairs
stepping out globally


Blue Planet/Red Planet Politics: Obama's Giant Leap for Legacy

In the waning days of his administration, the president has been paying unusual attention to space, recently highlighting his accomplishments and further goals for exploration of the solar system

Space has been back on the radar lately for the White House—an uncharacteristic situation in an administration that has not been known for any full-throttle(=if a person or a machine is at full throttle, they are doing something as well and with as much energy as they can) interest in the realm beyond Earth.
In an October 11 CNN opinion piece, Pres. Barack Obama underscored his belief that the U.S. will take the giant leap to Mars. “We have set a clear goal vital to the next chapter of America’s story in space,” Obama wrote, “sending humans to Mars by the 2030s and returning them safely to Earth, with the ultimate ambition to one day remain there for an extended time.”

The plan was not new—Obama first announced his intention to explore the Red Planet in 2010, and NASA has been pursuing the necessary technology ever since. But the opinion piece suggests the president is thinking about his legacy in space—particularly at a time when private companies such as Elon Musk’s SpaceX are pursuing Mars exploration plans of their own.

The CNN editorial popped up the same day as a White House space update, “Making Human Settlement of Space a Reality,” came out from John Holdren, director of the Office of Science and Technology Policy, along with NASA Administrator Charles Bolden. It announced two new NASA initiatives that build on the president’s vision to enable humans to sustainably live and work in space. One has several select companies developing habitation systems able to sustain and transport astronauts on long-duration, deep-space missions such as a trip to Mars. The other new plan would begin to allow companies to add their own modules and other capabilities to the International Space Station.

Then there was Obama’s guest editing of Wired magazine’s November issue, in which he said his favorite movie last year was The Martian. He added that he is “predisposed” to admire any movie where Americans dare the odds and motivate the world. “But what really grabbed me about the film is that it shows how humans—through our ingenuity, our commitment to fact and reason, and ultimately our faith in each other—can science the heck out of just about any problem,” Obama wrote in an introduction to the issue.

And on October 13 Obama signed an executive order—“Coordinating Efforts to Prepare the Nation for Space Weather Events”—to make sure power grids, satellites and other vital national interests are equipped to withstand (=resistir) an influx of charged particles sent our way by periodic flare-ups on the sun.
All of this was prelude to Obama’s own voyage that same day to Carnegie Mellon University for The White House Frontiers Conference. Among the science and technology themes on the agenda were interplanetary space exploration and the thriving U.S. space industry. Up for discussion: How will American investments in science and technology help us settle “the final frontier”—space?

Forget-Me-Not
The president’s reiterated(=repetiu) interest in Earth’s planetary neighbor is marvelous rocket rumble to the ears of Chris Carberry, CEO of Explore Mars, a humans-on-Mars advocacy group. He sees Obama’s initiative as a way to assure the public that Red Planet exploration is firmly in NASA’s sights—there is a caveat, however. “The next administration and Congress will need to make a lot of important decisions,” Carberry says, “with regards to mission architecture options, precursor missions and budget in the next couple of years,” if landing humans on Mars is to become reality anytime soon.

Obama and Mars are not strangers. In 2010 he called on NASA to head for the Red Planet, have astronauts orbit that world by the mid-2030s and return them safely to Earth. “And a landing on Mars will follow. And I expect to be around to see it,” he said in a 2010 speech at the Kennedy Space Center. So why the announcement now? “It is a reminder that six years ago he set NASA on the journey to Mars…and that they are still going. He hasn’t changed his mind,” says John Logsdon, professor emeritus of political science and international affairs(=assuntos) at George Washington University. “As his administration draws to a close, it is his summing up of what he believes his record has been.”

Yet whether Mars will truly be part of the president’s space legacy remains to be seen, says Marcia Smith, founder and editor of SpacePolicyOnline.com. “I think Obama’s civil space legacy will be his embrace of commercial partnerships, not humans to Mars,” she says. Ultimately Obama’s legacy depends in large part on what the next administration does, Smith says. If it continues the Mars exploration program he set up, Obama will likely receive kudos, whether or not it is deserved, she says. NASA’s big and yet-to-fly booster, the Space Launch System and the Orion piloted spacecraft—key elements of NASA’s journey to Mars—exist today because of Congress, not the president. “But he did extend the International Space Station to 2024,” she says, “providing more years to study human reaction to spaceflight.” On the other hand, if the next president cancels the drive for Mars—the way Obama canceled “The Vision for Space Exploration,” which targeted further human exploration of the moon, as blueprinted in 2004 by Pres. George W. Bush—“it will be just another footnote in history.”

Uncertainties
Although the overall Obama space scorecard is checkered, the area of commercial partnerships is where his administration shines, Smith says. During the past eight years NASA has pursued unprecedented private partnerships that should have commercial companies flying NASA astronauts to and from the space station in the near future. The ultimate fate of this program and the broad range of other public-private partnerships initiated under the administration is still unfolding, but it is clear that “a new paradigm” has emerged during Obama’s years in the Oval Office. Whether it is sustained by the next president “will be interesting to watch,” she concludes.

Space policy expert Logsdon senses “uncertainties” surrounding the next administration’s handling of the nation’s space agenda. “Whether to put the moon back in is the biggest one,” says Logsdon, pointing to the Bush administration’s canceled plans. Such a goal is something that European Space Agency Director General Johann-Dietrich Wörner has been campaigning for what has been tagged as an international “moon village.” “My biggest disappointment with Obama,” Logsdon continues, “is lack of international leadership, not reaching out as the U.S. president to the international community and saying ‘let’s do this together”—stepping out globally beyond low Earth orbit.

Another transition issue, according to Logsdon, is whether the next U.S. chief executive makes explicit an invitation to other countries to join America in planning exploration in general, and whether China is included in that goal. Doing so could make the difference in ultimately reaching the Red Planet or not. In the past 40 years the U.S. space program has received less than 1 percent of the federal spending budget, Logsdon says. “And I see nothing that will change that on the horizon.”
Bottom line to all this boosterism: If NASA truly wants to make it to Mars, it will probably need to enlist international technology, expertise and funding.

Materia preta no universo

Source: https://www.scientificamerican.com/article/new-techniques-could-target-more-exotic-dark-matter/

Vocabulary:

1. physicists
2. that comprises most of the cosmos
3. results came out
4. must further test future

Text:
New Techniques Could Target More Exotic Dark Matter
After decades of experiments have failed to find evidence for physicists’ favored dark matter candidate particles, scientists plan searches for alternatives

Where is the dark matter? Scientists who have hunted for decades for the stuff that comprises(=compreende) most of the cosmos’ mass are starting to worry that they are looking in the wrong places. After the latest null results came out this summer from the most sensitive search yet for the particles thought to make up dark matter, a limited theoretical range of masses and other characteristics remains viable for the particles. Now physicists have proposed two new methods to trawl this slim remaining territory, which has been out of reach to experiments so far.

Most of the universe’s mass is dark matter, around 80% of it. Although we cannot see or touch it, scientists know its gravity distorts images of distant objects and holds galaxies together. Since the 1980s, experiments buried deep in mountains and mines have waited patiently to see if a dark matter particle will pass through. Europe’s Large Hadron Collider (LHC) slams other particles together hoping to create some dark matter in the process. But so far, the elusive substance has failed to turn up at either the LHC or the Large Underground Xenon (LUX) experiment in South Dakota.

Researchers are now facing growing hints that existing experiments may be targeting the wrong kinds of particles, and finding dark matter will require new techniques.
Dark matter searches to date have mostly searched for “weakly interacting massive particles” (WIMPs), theoretical particles that would weigh between 1 giga-electron volt (GeV) and 1 tera-electron volt (TeV), or between one and 1,000 times the mass of a proton. Many physicists have long viewed them as the most promising dark matter candidates, because theory implies that WIMPs should contribute about as much mass to the universe as the amount of dark matter astronomers have measured, but the particles have so far failed to appear. These experiments tend to search for rare instances of WIMPs impacting atoms in some detecting material; in the case of LUX, the material is liquid xenon, but others have used solid germanium or other substances.

“The WIMP paradigm is under siege” after so many failures to find them have limited the number of places they could still be hiding, says Kathryn Zurek of the Lawrence Berkeley National Laboratory in Berkeley, California. Zurek led two recent studies proposing new ways of searching for dark matter in the form of particles that would be lighter than WIMPs, such as so-called asymmetric dark matter. Such particles might interact with the normal particles we know of via some yet-undiscovered dark force. “The idea is that you can have this hidden sector where dark matter is really light … and can have individual particle interactions with [regular] particles,” Zurek says. “It’s not a paradigm people had been really thinking about until less than a decade ago.”

In place of traditional dark matter detector materials, Zurek’s team’s first method uses superconducting aluminum, a substance whose electrons are free to move without any resistance. Within the superconductor electrons bind themselves with partner electrons in so-called “Cooper pairs.” Energy from an incoming dark matter particle could break up one of these pairs and send vibrations through the superconductor, which hypersensitive heat detectors called transition edge sensors (TESs) would read out. The researchers published this method last January in Physical Review Letters.

The second method, published last month in Physical Review Letters, uses superfluid helium, a zero-viscosity liquid of ultra-cold helium atoms that can move around each other without any resistance. An incoming dark matter particle could interact with a helium nucleus, causing a chain reaction that sends a set of phonons, quantum sound waves, to TESs. Both methods require a much slighter knock from dark matter into the detecting material to generate a signal than existing experiments, and can therefore spot particles as light as 1 keV, a millionth the mass of a proton. Traditional experiments are sensitive only to particles as light as 10 MeV, ten thousand times heavier than a keV.

The current generation of dark matter experiments are getting upgrades; LUX is becoming the LUX-ZEPLIN (ZonEd Proportional scintillation in LIquid Noble gases) or LZ experiment, XENON100 in Italy is becoming XENON1T and the Super Cryogenic Dark Matter Search (SuperCDMS)  in Minnesota will move to a new Canadian site. But even the improved versions can only probe down to around 10 MeV at best. If they cannot find anything, scientists will likely look to proposals like Zurek’s to probe even lighter masses of potential particles. Yet such experiments will require research and development into what superconducting aluminum or superfluid helium detectors will actually look like, and where they should build such a detector. “These experiments will be technically challenging but not very expensive,” Zurek says.

“[This research] is the direction the field is moving partly because we haven't found the standard WIMPs,” says Dan Bauer, a scientist at the Fermi National Accelerator Laboratory in Illinois and the SuperCDMS spokesperson. Although scientists are still holding out hope that higher mass WIMPs will appear, “we realized that we’ve always been looking under particular lampposts. There's a lot of territory available for lighter mass dark matter particles.”

And as experimentalists build detectors that can spot lighter particles, theoretical physicists are likely to come up with more ideas for types of dark matter candidate particles that could be found there. “Theorists are very creative,” says Bob Jacobsen, a University of California, Berkeley, physicist who works on LUX and LZ. “If there's a [mass] region that hasn't been explored, the theorists will say can they do something that's mathematically consistent. If they publish it, it's our job to rule it out.”

Superconductor and superfluid detector proof-of-concepts will ultimately require physicists to divide their time between current searches and research and development, says Chris Tully, a Princeton University physicist. “You have to build these technologies in parallel with running experiments” he says. He hopes to begin seeing mockups in five to 10 years’ time, depending on funding (though Zurek herself thought it would be closer to 10 years). Whereas the experiment Tully works on, the Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield (PTOLEMY) , and  SuperCDMS  have TESs already developed, scientists must further(=promover) test future detectors to ensure they can pick out dark matter particles from contaminating radiation that causes a similar signal in the detector. Current experiments are located deep underground or in mountains to shield against cosmic rays, high-energy particles from space that produce signals that can obscure dark matter.

Superfluid or superconductor experiments would instead need shielding from stray electromagnetic waves, such as those from cell phones, Zurek says. Bauer says that SuperCDMS’ Sudbury Neutrino Observatory Laboratory is building such shielding now. Ultimately, “It's amazing how little we know,” says Jacobsen. “We're looking for the first clue in the crime scene. If you don't have the first clue, you don't know where to look.”