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  • richardmitnick 2:36 pm on April 22, 2019 Permalink | Reply
    Tags: , , , , , NASA NEOCam, ,   

    From PBS NOVA: “How This NASA Telescope is Defending the Earth From Asteroids” 

    From PBS NOVA

    April 19, 2019
    Katherine J. Wu

    1
    An artist’s conception of the Wide-field Infrared Survey Explorer, or WISE spacecraft, in its orbit around Earth, which has now been repurposed into NEOWISE. NEOWISE has been scouring the skies for near-Earth objects for the past five years. Image Credit: NASA/JPL-Caltech

    With rogue asteroids and comets on the move, space can sometimes be a bit of a warzone.

    Serious impacts with Earth are few and far between. But these collisions can be catastrophic (just ask a few disgruntled dinosaurs circa 66 million years ago)—and Earthlings are often caught unaware.

    That’s why a team of NASA astronomers has spent the past five years scouring the skies for near-Earth objects (NEOs)—asteroids and comets that orbit the Sun in our vicinity—in the hopes of potentially staving off impending doom.

    “If we find an object only a few days from impact, it greatly limits our choices,” NASA astronomer Amy Mainzer said in a statement. “We’ve focused on finding NEOs when they are further away from Earth, providing the maximum amount of time and opening up a wider range of mitigation possibilities.”

    The endeavor is a part of NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission, an Earth-orbiting satellite equipped with cameras and an infrared-sensitive telescope. And the spacecraft, which isn’t limited to tracking the trajectories of asteroids, has kept itself busy: In the past half decade, it has recorded more than 95 billion measurements of asteroids, comets, stars, and galaxies, with data collection ongoing.

    These measurements have revealed more than 1,000 wayfaring asteroids near our planet in the past half decade. None of these NEOs currently pose any threat to us here on Earth. But according to NASA estimates, about 20,000 near-Earth objects have flitted in and out of our neighborhood in recent decades—almost 900 of which were more than 3,200 feet across. And it was only six years ago that a meteor just 66 feet in diameter injured over 1,500 people when it exploded over the Russian region of Chelyabinsk.

    Detecting rocky interlopers, however, is no easy task. Because NEOs are often so small and far away, they’re frustratingly hard to spot under even the best of circumstances. What’s more, under visible light, these objects can look as dark as coal or printer toner, making them hard to pick out against the black backdrop of space.

    But the NEOWISE telescope has found a clever workaround—one that essentially involves it donning a set of cosmic night vision goggles. Heated by the warmth of the Sun, rocky bodies near Earth emit an infrared glow. By working in infrared, the telescope can pick up on any objects that are comin’ in hot, providing Mainzer’s team with images that reveal properties like a NEO’s size, mass, and composition. These measurements could someday help engineers calculate the amount of energy needed for a spacecraft to “nudge” (or detonate) a looming asteroid off an Earthbound path.

    The NEOWISE spacecraft, which was initially launched for a separate mission in 2009, will eventually reach the end of its tenure when its changing orbit prevents it from acquiring high-quality data. But a plan is already in the works to succeed it with another telescope called NEOCam—a new and improved addition to the NEO suite that will purposefully be designed to peer into space for asteroids.

    NASA NEOCam depiction

    If funded, NEOCam will “do a much more comprehensive job of mapping asteroid locations and measuring their sizes,” Mainzer said in the statement.

    NEOCam’s fate hasn’t yet been decided. For now, its predecessor remains on the frontlines of defense, and will still be actively collecting data. So for any asteroids, comets, or meteors headed our way, the message is clear: Earth has plans to take the heat—and it starts with taking note of it.

    See the full article here .

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    NOVA is the highest rated science series on television and the most watched documentary series on public television. It is also one of television’s most acclaimed series, having won every major television award, most of them many times over.

     
  • richardmitnick 9:38 am on December 3, 2018 Permalink | Reply
    Tags: , , , , , , , NASA NEOCam   

    From Science Alert: “Astronaut Warns This Neglected NASA Telescope Is Our Best Chance to Avoid Death by Asteroid” 

    ScienceAlert

    From Science Alert

    3 DEC 2018
    DAVE MOSHER

    A former NASA astronaut says the agency he used to work for has a duty to protect civilians from killer asteroids, but that it isn’t meeting that obligation.

    The threat of asteroid strikes might seem as abstract as outer space itself. But the risk, while infrequent, is real – and potentially more deadly than the threat posed by some of the most powerful nuclear weapons ever detonated.

    Risk of death from above

    In 1908, a space rock estimated to be several hundred feet in diameter screamed into Earth’s atmosphere at many thousands of miles per hour, causing the foreign body to explode over the remote Tunguska region of Russia with the force of a thermonuclear weapon.

    The resulting blast flattened trees over an area nearly twice the size of New York City.

    More recently, in 2013, a roughly 70-foot-wide meteorite shot over Chelyabinsk, Russia.

    The concussive fireball smashed windows for miles around and sent more than 1,000 people in multiple cities to hospitals, several dozen of them with serious injuries.

    We know they’re out there

    NASA is poignantly aware of such risks – and so are lawmakers.

    In 2005 Congress made one of the agency’s seven core goals to track down 90 percent of asteroids 460 feet (140 meters) and larger, which could lead to a worse-than-Tunguska-level event. The deadline for this legally mandated goal is 2020.

    So far, however, telescopes on Earth and in space have found less than one third of these near-Earth objects (NEOs) and NASA will almost certainly fail to hit its deadline.

    Practically, this means tens of thousands of NEOs big enough to wipe out a city have yet to be found, according to a June 2018 report published by the White House.

    The same report concludes that even with current and planned capabilities, less than half of such space rocks will be located by 2033.

    We have the technology to confront the problem

    Russell “Rusty” Schweickart, an aerospace engineer retired astronaut who flew on the Apollo 9 mission, says there is a solution in waiting for this problem: NASA can launch the Near-Earth Object Camera (NEOCam), which is a small infrared observatory, into space.

    NASA NEOCAM

    “It’s a critical discovery telescope to protect life on Earth, and it’s ready to go,” Schweickart told Business Insider at The Economist Space Summit on November 1.

    NEOCam’s designers have pitched the mission to NASA multiple times. The mission has received several million dollars here and there to continue its development in response to those proposals, but the agency has denied full funding in every instance on account of it not being the best purely science-focused mission.

    “For God’s sake, fund it as a mainline program. Don’t put it in yet another competition with science,” Schweickart said. “This is a public safety program.”

    How NEOCam would hunt for ‘city killer’ asteroids

    Telescopes that are looking in the right place at the right time can detect a dot of that light sneaking across the blackness of space. This allows scientists to calculate an NEO’s mass, speed, orbit, and the odds that it will eventually smack into Earth.

    Small NEOs, though, aren’t very bright. This means a telescope has to be big, see a lot of the sky, and use very advanced hardware to pick them up. These monstrous telescopes take a very long time to build and calibrate and are budget-crushingly expensive.

    Take the Large Synoptic Survey Telescope (LSST), for example, which is one of Earth’s best current hopes of finding killer asteroids.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    The project broke ground in 2015 and is expected to cost about half a billion dollars to build.

    Based on its current construction schedule, it won’t be fully operational until late 2021, at the soonest, or able to fulfill the 90 percent detection goal set by Congress until the mid-2030s.

    LSST, like all ground-based observatories, also comes with two major limitations.

    The first: “You can’t see asteroids near the Sun. You’re blinded by the sky,” Mark Sykes, director of the Planetary Science Institute and a scientist on the NEOCam team, previously told Business Insider.

    “Right now we have to wait until those pop out in front of us.”

    Sykes said the second snag is that ground-based telescopes mainly rely on visible light for detection. “If [an asteroid] has a dark surface, it’s going to be very hard to see,” he said.

    NEOCam addresses these two problems by being in space, where Sykes says “you’re not blinded by the sky.”

    The telescope would also use an advanced, high-resolution infrared camera. Infrared is a longer wavelength of light that’s invisible to our eyes, but if a source is strong enough – say, a roaring fire – we can feel invisible light as warmth on our skin.

    Asteroids warmed by the Sun, radioactive elements, or both will emit infrared light, even when they’re too small or dark for ground-based telescopes to see. Which means NEOCam could spot them merely by their heat signatures.

    This approach is already proven to work.

    The prime example is NASA’s eight-year-old Wide-field Infrared Survey Explorer (WISE) telescope, which has found roughly 275 NEOs, including 50 potentially hazardous asteroids, or PHOs (so named because they come within 4.6 million miles of Earth at some point in their orbits).

    NASA Wise Telescope

    1
    (NASA/JPL-Caltech)

    However, it’s a less powerful telescope, has a smaller field of view, an older camera that requires cryogenic cooling that eventually runs out (NEOCam’s doesn’t need it), and wasn’t designed just to hunt asteroids.

    The telescope, now called NEOWISE, may end operations in December 2018.

    NEOCam is Earth’s best immediate hope for quick detection of asteroids

    According to a recent study in The Astronomical Journal, neither NEOCam nor LSST alone would ever achieve Congress’ 90 percent detection mandate – only by working together, the research found, could the observatories achieve that goal over a decade.

    But NEOCam offers significant upgrades to the situation under LSST.

    In its latest pitch to NASA, the NEOCam team proposed to launch in 2021 and find two-thirds of missing objects in the larger-than-460-feet (140 meters) category within four years, or about a decade ahead of LSST’s schedule.

    Less than 70 percent of all NEOs that are 460 feet (140 meters) or larger have not been found, according to a report published by the White House’s National Science and Technology Council (NSTC) in December 2016.

    This amounts to about 25,000 nearby asteroids and roughly 2,300 potentially hazardous ones.

    The NTSC report suggests that an orbiting telescope like NEOCam could also help root out asteroids that would strike with a force somewhere between a Tunguska-type event (occurring about once every 100-200 years) and a Chelyabinsk-type event (occurring about once every 10 years), of which less than 1 percent have been located.

    So if launching a more-capable replacement for NEOWISE is a top priority, why might NASA not fully fund NEOCam for a 2024 launch?

    ‘NASA has a responsibility to do it’

    The team behind NEOCam has pitched the mission to NASA three times – in 2006, 2010, and 2015 – and three times NASA has punted on fully funding the telescope.

    The last instance it was denied, sources told Business Insider the proposal had no major technical weaknesses. Instead, it was a case of trying to jam a square peg into a round bureaucratic hole.

    The NASA competition it was a part of, called Discovery, values scientific firsts – not ensuring humanity’s safety – and thus did not grant NEOCam nearly US$450 million to develop its spacecraft and a rocket with which to launch it.

    NASA instead picked two new space missions to explore the Solar System: Lucy, a probe that will visit swarms of ancient asteroids lurking near Jupiter, and Psyche, which will orbit the all-metal core of a dead planet.

    For Schweickart’s part, he doesn’t care about the distinction.

    “NASA has a responsibility to do it, and it’s not happening,” he said. “It needs to be put into the NASA budget both by NASA and by the Congress.”

    NEOCam did get US$35 million in the 2018 government funding bill to keep itself going, but proponents say this is not enough to get the telescope to a launch pad.

    “In the meantime, NEOCam is in a zombie state and all the while Earth waits inevitably in the crosshairs,” Richard Binzel, a planetary scientist and expert on the hazards posed by asteroids at Massachusetts Institute of Technology, told Business Insider in an email.

    Binzel is one of three scientists who wrote a recent op-ed in Space News in support of fully funding the project, even though they’re not on the project’s team.

    Binzel and others argue NEOCam could get launched by raising the House of Representatives’ proposed budget for NASA planetary defence by another US$40 million (up from a US$160 million to US$200 million) and by sharing a rocket ride with a spacecraft called IMAP, which the agency plans to launch in 2024.

    By working in coordination with ground-based telescopes, NEOCam could achieve nearly 70 percent detection in four years, and the agency’s target of 90 percent detection in less than 10 years.

    Finding such money is not easy though. Binzel said the infrequency of asteroid strikes makes it politically uncostly to instead fund other initiatives year after year.

    “But the consequences of being wrong are irresponsible, especially when the capability to gain the necessary knowledge is easily within our grasp,” he said.

    “We should simply act like responsible adults and ‘just do it.’ What are we waiting for?”

    It’s now up to President Trump and Congress

    Schweickart acknowledged that NASA’s budgeting and culture has, for decades, been focused on pushing top-tier scientific exploration and that deviating from this norm – Congressional mandate or not – isn’t easy.

    “You’re going upstream. You’re fighting a pretty strong headwind within NASA,” he said, adding that pulling money from science budgets to fund anything is extremely unpopular. “But government agencies are not at liberty to ask for increases in their budget.”

    Schweickart and fellow retired astronaut Ed Lu tried years ago to end-run around the problem by co-founding the B612 Foundation, which is a nonprofit dedicated to developing NEO-detecting capabilities.

    But the group tabled its longest-running (and most expensive) idea, the Sentinel space telescope, in part to improve NEOCam’s chances of getting funded. On Oct. 29, the organisation even publicized its strong support for lawmakers fully funding its rival.

    The public also appears to be on-board with NASA making asteroid detection projects like NEOCam happen.

    In a June poll by Pew Research Center, nearly two-thirds of 2,500 American adults surveyed said that asteroid monitoring should be a top priority for NASA. (Only monitoring climate change was higher.)

    It remains to be seen what the Trump administration will decide to do with NEOCam in the next NASA budget, and if Congress authorizes that funding.

    “That’s a February discussion,” Stephen Jurczyk, NASA’s associate administrator, told Business Insider at the Economist Space Summit.

    “All of that’s all embargoed until the president releases his budget to Congress.”

    Jurczyk acknowledged the tension between NASA’s duty to locate dangerous asteroids along with internal changes required to make that work happen.

    “It is to some extent a cultural issue, where we kind of have this mentality of pure science and pure competition,” he said.

    “I think we’re starting to evolve to a more diverse and more balanced approach between pure science and other things that we need to do.”

    The question is whether those changes will happen before the next Tunguska-type asteroid arrives at Earth. Given enough warning, we might fly out to such a space rock and prevent a calamity or, if there isn’t enough time for that, try to move people out of harm’s way.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
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