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Watch NASA Launch DART, a Mission to Crash Into an Asteroid – The New York Times

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An early morning liftoff kicks off DART, NASA’s first mission to test a spacecraft that could one day save Earth from a deadly space rock.

NASA is about to launch a spacecraft with one simple mission: Smash into an asteroid at 15,000 miles per hour.

The mission, the Double Asteroid Redirection Test, or DART, leaves Earth early on Wednesday to test whether slamming a spacecraft into an asteroid can nudge it into a different trajectory. Results from the test, if successful, will come in handy if NASA and other space agencies ever need to deflect an asteroid to save Earth and avert a catastrophic impact.

The DART spacecraft is scheduled to lift off atop a SpaceX Falcon 9 rocket on Wednesday at 1:20 a.m. Eastern time (or 10:20 p.m. local time) from the Vandenberg Space Force Base in California.

NASA plans to host a livestream of the launch on its YouTube channel starting at 12:30 a.m. on Wednesday.

If bad weather around the Vandenberg launch site prompts a delay, the next opportunity for liftoff would be about 24 hours later.

NASA is crashing DART into an asteroid to test, for the first time, a method of planetary defense that could one day save a city, or maybe the whole planet, from a catastrophic asteroid impact.

DART “is something of a replay of Bruce Willis’s movie, ‘Armageddon,’ although that was totally fictional,” Bill Nelson, NASA’s administrator, said in an interview.

If all goes as planned with DART, NASA will have a confirmed weapon in its planetary defense arsenal. Should a different asteroid ever wind up on a collision course with Earth, the world’s space agencies would have confidence that an asteroid missile like DART would shoo the space rock away.

NASA/Johns Hopkins/APL

After launching to space, the spacecraft will make nearly one full orbit around the sun before it crosses paths with Dimorphos, a football-field-size asteroid that closely orbits a bigger asteroid, called Didymos, every 11 hours and 55 minutes. Astronomers call those two asteroids a binary system, where one is a mini-moon to the other. Together, the two asteroids make one full orbit around the sun every two years.

Dimorphos poses no threat to Earth, and the mission is essentially target practice. DART’s impact will happen in late September or early October next year, when the binary asteroids are at their closest point to Earth, roughly 6.8 million miles away.

Four hours before impact, the DART spacecraft, formally called a kinetic impactor, will autonomously steer itself straight toward Dimorphos for a head-on collision at 15,000 miles per hour. An onboard camera will capture and send back photos to Earth in real time until 20 seconds before impact. A tiny satellite from the Italian Space Agency, deployed 10 days before the impact, will come as close as 34 miles from the asteroid to snap images every six seconds in the moments before and after DART’s impact.

Telescopes on Earth will fix their lenses on the crash site, showing the two asteroids as tiny dots of reflected sunlight. To measure whether DART’s impact changed Dimorphos’s orbit around Didymos, astronomers will track the time between one flicker of light — which indicates that Dimorphos has passed in front of Didymos — and another, which indicates that Dimorphos has orbited behind Didymos.

If Dimorphos’s orbit around Didymos is extended by at least 73 seconds, DART will have successfully performed its mission. But mission managers expect the impact to lengthen the asteroid’s orbit even more, by about 10 and 20 minutes.

Simply striking hazardous space rocks with a nuclear weapon, like in “Armageddon” and other science fiction disaster films, could create a field of more hazardous space rocks, multiplying the dangers posed to Earth, rather than eliminating them.

Still, a nuclear device, if used the right way, is one of a few conceptual tools within NASA’s planetary defense toolbox.

For any small and distant asteroids that could threaten Earth in the next few decades, a mission like DART “has a pretty good probability of getting the job done,” said Brent Barbee, an aerospace engineer at NASA’s Goddard Space Flight Center.

“But if the asteroid is any bigger than that, or if the warning time is any shorter than that, then that’s where you transition from looking at kinetic impactors to nuclear devices,” Mr. Barbee said.

Astronomers and officials from various space agencies have simulated deflecting an asteroid away from Earth with the force of nuclear blasts.

Other asteroid-destroying simulations have shown that nuclear explosives could be used to annihilate some smaller asteroids as close as two months from impact, while posing little risk to Earth.

“There’s a lot of challenging aspects of a nuclear mission besides just the physics of the device itself, and how the device would interact with the asteroid,” Mr. Barbee said.

Treaties that ban the use of nuclear weapons, and the Outer Space Treaty, the cornerstone set of international space laws signed in the 1960s, prohibit the placement or use of nuclear weapons in space

That suggests that any countries’ emergency use of a nuclear-tipped spacecraft to fend off a killer asteroid would amount to a treaty violation. But that legal predicament could be resolved by an emergency meeting of the United Nations Security Council.

Headlines about asteroids making close passes of our planet are routine. But Earth should be safe from hazardous space rocks for the next century, according to NASA.

The agency maintains a database of near-Earth objects that come within about 28 million miles from Earth. The closest object to whiz by Earth in the next few days will be an asteroid between 50 and 100 feet wide, coming within 511,246 miles on Thanksgiving. (That’s about twice the distance to the moon.)

About 27,000 such objects have been tracked by NASA so far, which is just 40 percent of the total amount the agency is tasked with finding under its Near-Earth Object Observations Program.

NASA also maintains the Sentry Risk Table, which is a separate list of asteroids that have a higher chance of impacting Earth (though the chances remain extremely low). One celebrity on that list is Bennu, a gravelly, acorn-shaped asteroid about the size of a skyscraper. It has a 0.057 percent chance of impacting Earth sometime between the years 2178 and 2290.

NASA sent a spacecraft called OSIRIS-REx to Bennu last year to scoop up a suitcase’s worth of rock samples and bring them back to Earth in September 2023.

Of course, space rocks large and small surprise people on Earth all the time, whether by crash-landing on a Canadian woman’s bed or by shattering windows during atmospheric re-entry over a Russian city.

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BEYOND LOCAL: NASA launches spacecraft to test asteroid defense concept – BayToday

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LOS ANGELES (AP) — NASA launched a spacecraft Tuesday night on a mission to smash into an asteroid and test whether it would be possible to knock a speeding space rock off course if one were to threaten Earth.

The DART spacecraft, short for Double Asteroid Redirection Test, lifted off from Vandenberg Space Force Base atop a SpaceX Falcon 9 rocket in a $330 million project with echoes of the Bruce Willis movie “Armageddon.”

If all goes well, the boxy, 1,200-pound (540-kilogram) craft will slam head-on into Dimorphos, an asteroid 525 feet (160 meters) across, at 15,000 mph (24,139 kph) next September.

“This isn’t going to destroy the asteroid. It’s just going to give it a small nudge,” said mission official Nancy Chabot of Johns Hopkins Applied Physics Laboratory, which is managing the project.

Dimorphos orbits a much larger asteroid called Didymos. The pair are no danger to Earth but offer scientists a better way to measure the effectiveness of a collision than a single asteroid flying through space.

Dimorphos completes one orbit of Didymos every 11 hours, 55 minutes. DART’s goal is a crash that will slow Dimorphos down and cause it to fall closer toward the bigger asteroid, shaving 10 minutes off its orbit.

The change in the orbital period will be measured by telescopes on Earth. The minimum change for the mission to be considered a success is 73 seconds.

The DART technique could prove useful for altering the course of an asteroid years or decades before it bears down on Earth with the potential for catastrophe.

A small nudge “would add up to a big change in its future position, and then the asteroid and the Earth wouldn’t be on a collision course,” Chabot said.

Scientists constantly search for asteroids and plot their courses to determine whether they could hit the planet.

“Although there isn’t a currently known asteroid that’s on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there,” said Lindley Johnson, planetary defense officer at NASA. “The key to planetary defense is finding them well before they are an impact threat.”

DART will take 10 months to reach the asteroid pair. The collision will occur about 6.8 million miles (11 million kilometers) from Earth.

Ten days beforehand, DART will release a tiny observation spacecraft supplied by the Italian space agency that will follow it.

DART will stream video until it is destroyed on impact. Three minutes later, the trailing craft will make images of the impact site and material that is ejected.

John Antczak, The Associated Press

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Doing Photon Upconversion A Solid: Crystals That Convert Light To More Useful Wavelengths – Eurasia Review

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Solid-solution organic crystals have been brought into the quest for superior photon upconversion materials, which transform presently wasted long-wavelength light into more useful shorter wavelength light. Scientists from Tokyo Institute of Technology revisited a materials approach previously deemed lackluster—using a molecule originally developed for organic LEDs—achieving outstanding performance and efficiency. Their findings pave the way for many novel photonic technologies, such as better solar cells and photocatalysts for hydrogen and hydrocarbon productions.

Light is a powerful source of energy that can, if leveraged correctly, be used to drive stubborn chemical reactions, generate electricity, and run optoelectronic devices. However, in most applications, not all the wavelengths of light can be used. This is because the energy that each photon carries is inversely proportional to its wavelength, and chemical and physical processes are triggered by light only when the energy provided by individual photons exceeds a certain threshold.

This means that devices like solar cells cannot benefit from all the color contained in sunlight, as it comprises a mixture of photons with both high and low energies. Scientists worldwide are actively exploring materials to realize photon upconversion (PUC), by which photons with lower energies (longer wavelengths) are captured and re-emitted as photons with higher energies (shorter wavelengths). One promising way to realize this is through triplet-triplet annihilation (TTA). This process requires the combination of a sensitizer material and an annihilator material. The sensitizer absorbs low energy photons (long-wavelength light) and transfers its excited energy to the annihilator, which emits higher energy photons (light of shorter wavelength) as a result of TTA (Figure 1).

Finding good solid materials for PUC has proven challenging for a long time. Although liquid samples can achieve relatively high PUC efficiency, working with liquids, especially those comprising organic solvents, is inherently risky and cumbersome in many applications. However, previous trials to create PUC solids generally suffered from poor crystal quality and small crystal domains, which lead to short travelling distances of triplet excited states and thus, low PUC efficiency. Additionally, in most previous solid PUC samples, stability under continuous photoirradiation was not tested and experimental data were often acquired in inert gas atmospheres. Hence, the low efficiency and insufficient materials stability had been of concern for a long time.

Now, in a recent study led by Associate Professor Yoichi Murakami from Tokyo Tech, Japan, a team of researchers found the answer to this challenge. Published in Materials Horizon, their paper (open access) describes how they focused on van der Waals crystals, a classical materials class that has not been considered for the quest of high-efficiency PUC solids. After discovering that 9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (ANNP), a hydrocarbon molecule originally developed for blue organic LEDs, was an excellent annihilator for embodying their concept, they tried mixing it with platinum octaethylporphyrin (PtOEP), a staple sensitizer that absorbs green light.

The team found that aggregation of the sensitizer molecules could be completely avoided by utilizing the crystalline phase of a van der Waals solid solution with a sufficiently low proportion of PtOEP to ANNP (around 1:50000). They proceeded to thoroughly characterize the obtained crystals and found some insight into why using the ANNP annihilator prevented the aggregation of the sensitizer when other existing annihilators had failed to do so in previous studies. Moreover, the solid crystals the team produced were highly stable and exhibited outstanding performance, as Dr. Murakami remarks: “The results of our experiments using simulated sunlight indicate that solar concentration optics such as lenses are no longer needed to efficiently upconvert terrestrial sunlight.”

Overall, this study brings van der Waals crystals back into the game of PUC as an effective way of creating outstanding solid materials using versatile hydrocarbon annihilators. “The proof-of-concept we presented in our paper is a major technical leap forward in the quest for high-performance PUC solids, which will open up diverse photonics technologies in the future,” concludes Dr. Murakami. Let us hope further research in this topic allows us to efficiently transform light into its most useful forms.

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New Russian module docks with International Space Station – CGTN

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A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Russian cargo craft carrying a new docking module successfully hooked up with the International Space Station Friday after a two-day space journey.

The new spherical module, named Prichal (Pier), docked with the orbiting outpost at 6:19 p.m. Moscow time (1519 GMT). It has six docking ports and will allow potential future expansion of the Russian segment of the station.

The module has moored to the docking port of the new Russian Nauka (Science) laboratory module.

On Wednesday, a Soyuz rocket took off from the Russian launch facility in Baikonur, Kazakhstan, carrying the Progress cargo ship with Prichal attached to it. After entering space, the cargo ship with the module went into orbit.

Progress is also delivering 700 kilograms of various cargoes to the space station and is expected to undock from the station on December 22.

The first Soyuz spacecraft is expected to dock at the new module on March 18, 2022, with a crew of three cosmonauts: Oleg Artemyev, Denis Matveev and Sergei Korsakov.

Earlier this week, the Russian crew on the station started training for the module’s arrival, simulating the use of manual controls in case the automatic docking system failed.

The space outpost is currently operated by NASA astronauts Raja Chari, Thomas Marshburn, Kayla Barron, and Mark Vande Hei; Russian cosmonauts Anton Shkaplerov and Pyotr Dubrov; and Matthias Maurer of the European Space Agency.

Source(s): AP

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