Killer Asteroids Are Hiding in Plain Sight. A New Tool Helps Spot Them.

Killer Asteroids Are Hiding in Plain Sight. A New Tool Helps Spot Them.


Ed Lo wants to save the Earth from the killer asteroid.

Or at least, if a giant space rock gets in our way, Dr. Lou, a former NASA astronaut with a doctorate in applied physics, wants to find it before it hits us – hopefully With years of early warning and an opportunity for humanity. To turn it.

On Tuesday, the B612 Foundation, a nonprofit group led by Dr. Lou, announced the discovery of more than 100 asteroids. (The foundation is named after Antoine de Saint-Exupéry’s children’s book “The Little Prince”; B612 is the protagonist’s domestic asteroid.)

Which in itself is notable. New asteroids are being reported all the time by SkyWatchers around the world. This includes backyard binoculars and robotic survey amateurs who regularly scan the night sky.

Significantly, the B612 did not build new telescopes, nor did it make new observations with existing telescopes. Instead, researchers funded by B612 applied state-of-the-art computational power to year-old images – 412,000 of them in the National Optical-Infrared Astronomy Research Laboratory, or NOIRLab’s Digital Archives – 68 of Universal Light. To get the asteroid out of the billion dots. Imprisoned in pictures.

“It’s a modern way of astronomy.Dr. Lou said.

Research is on the rise. “Planetary Defense” Efforts by NASA and Other Organizations Around the world.

Today, about 25,000 asteroids near Earth are at least 460 feet in diameter, of which only 40 percent have been found. The remaining 60 percent – about 15,000 space rocks, each capable of emitting hundreds of millions of tons of energy equivalent to TNT during a collision with the Earth – has not been identified.

B612 collaborated with Joachim Moines, a graduate student at the University of Washington, and his doctoral adviser, Mario Jurk, a professor of astronomy. He and colleagues at the university’s Institute for Data Intensive Research in Astrophysics and Cosmology developed an algorithm capable of examining astronomical imagery, not just to identify points of light that could be asteroids. You can also find out which points of light are in the pictures. Different nights are actually the same asteroid.

In essence, researchers have developed a method of discovery that has already been seen but not noticed.

Normally, asteroids are discovered when the same part of the sky is photographed multiple times during a night. A gust of light in the night sky has many points of light. Distant stars and galaxies are in that order. But objects that are very close inside the solar system move rapidly, and their positions change at night.

Astronomers call a series of observations of a single moving object overnight a “tracklet”. A tracklet gives an indication of the movement of an object, indicating to astronomers where they can find it another night. They can also find old photos for the same thing.

Many astronomical observations that are not part of a systematic asteroid search inevitably record the asteroid, but at the same time and place, multiple observations are not required to keep tracklets together.

For example, NOIRLab images were taken primarily by Chile’s Victor M. Blanco 4-Meter Telescope as part of a survey of about one-eighth of the night sky to map the distribution of galaxies in the universe.

Extra spots of light were ignored, as they were not what astronomers were reading. “They’re just random data in random images of the sky,” Dr. Lou said.

But for Mr. Moines and Dr. Jork, a point of light that is not a star or galaxy is the starting point of their algorithm, which they called Tracklet-less Heliocentric Orbit Recovery, or THOR.

The motion of an asteroid is determined by the law of gravity. THOR creates a test orbit that corresponds to the observed point of light, assuming a certain distance and speed. It then calculates where the asteroid will be after that and in the previous nights. If there is a point of light in the data, it could be the same asteroid. If the algorithm can combine five or six observations together in a few weeks, it is a promising candidate for asteroid discovery.

In principle, there are an infinite number of possible test orbits to test, but to calculate this would require an impractical eternity. In practice, because asteroids converge around specific orbits, the algorithm only needs to consider a few thousand carefully selected possibilities.

Still, calculating thousands of test orbits for thousands of potential asteroids is a huge task. But the advent of cloud computing – the vast computational power and data storage that is distributed across the Internet – makes it possible. Google has given time to this effort on its Google Cloud Platform.

“This is one of the best applications I’ve seen,” said Scott Penberthi, director of applied artificial intelligence at Google.

So far, scientists have examined data from the NOIRLab archives, about one-eighth of a month in September 2013. THOR extracted 1,354 possible asteroids. Many of them were already in the asteroid catalog of the International Astronomical Union’s Minor Planet Center. Some of these were first observed, but only one night and the tracklet was not sufficient to determine the orbit with confidence.

The Minor Planet Center has so far confirmed 104 objects as new discoveries. The NOIRLab archive contains seven years of data, which shows that tens of thousands of planets are waiting to be discovered.

“I think it’s great.,Matthew Payne, director of the Minor Planet Center, who was not involved in the development of THOR. “I think it’s very interesting and it also allows us to make good use of existing archival data.

The algorithm is currently designed to locate only the main belt satellites, which are in orbit between Mars and Jupiter, not the closest asteroids to Earth, which could collide with our planet. Planets close to Earth are more difficult to identify because they move faster. Different observations of the same asteroid can be separated in time and distance, and the algorithm needs to do more crunching to make the connection.

“It simply came to our notice then. “There’s no reason why this can’t happen. I didn’t really get a chance to try it.”

Not only is THOR capable of discovering new planets in old data but it can also change future observations. Take, for example, Vera C. Rubin ObservatoryFormerly known as the Large Synoptic Survey Telescope, it is currently under construction in Chile.

Funded by the National Science Foundation, the Rubin Observatory is an 8.4-meter telescope that will repeatedly scan the night sky to see what changes over time.

Part of the observatory’s mission is to study the massive structure of the universe and to identify distant bursting stars, also called supernovae. Near the house, it will also see a multitude of smaller bodies from planets orbiting the solar system.

Several years ago, some scientists suggested that the observational patterns of the Rubin telescope could be adjusted to identify more asteroid trachelates and thus more quickly detect more dangerous, undiscovered asteroids. Could do But that change may have slowed other astronomical research.

If the THOR algorithm works well with Rubin data, the telescope will not need to scan the same part of the sky twice a night, allowing it to cover twice as much area instead.

“It could be revolutionary in principle, or at least very important,” said Zeljko Ivzic, director of the telescope and author of a scientific paper that described THOR and tested it against observations.

If the telescope could return to the same spot in the sky every two nights instead of every four, it could benefit other research, including the search for supernovae.

“This will be another effect of the algorithm that has nothing to do with the asteroid,” said Dr. Ivezic. “It’s a beautiful illustration of how the landscape is changing. The ecosystem of science is changing because software can now do things that you could not have imagined 20, 30 years ago.” Yes, you could not even think.

For Dr. Lou, THOR offers a different way of accomplishing the same goals he set a decade ago.

At the time, the B612 was eyeing an exciting and far more expensive project. The non-profit organization Sentinel was going to build, launch and operate its own space telescope.

At the time, Dr. Lowe and other B612 leaders were frustrated by the slow pace of search for dangerous space rocks. In 2005, Congress passed a mandate to NASA to locate and track 90% of orbiters near the Earth, which is 460 feet or more in diameter by 2020. Half of them were found.

It was difficult for B612 to raise $ 450 million from private donors to underwrite Sentinel, especially as NASA was considering its own space telescope to find an asteroid.

When the National Science Foundation approved the construction of the Rubin Observatory, B612 reconsidered its plans. “We can immediately focus and say, ‘Is there a different way to solve this problem that we have to solve?'” Dr. Lowe said.

The Rubin Observatory will conduct its first test observation in about a year and will be operational in about two years. Dr. Ivezic said Rubin’s ten-year observations, along with the search for other asteroids, could eventually meet Congress’ 90 percent goal.

NASA is also stepping up its defense efforts for the planets. Its asteroid telescope, called the NEO Surveyor, is in the preliminary design phase, with the goal of launching it in 2026.

And later this year, its double asteroid redirection test mission will transform a projectile into a smaller asteroid and measure how much it changes the asteroid’s velocity. China’s National Space Agency is working on a similar mission.

For the B612, instead of shaking up the nearly half-billion-dollar telescope project, it could contribute to less expensive research efforts like THOR. Last week, it announced that it had received 1.3 million in gifts for further work on cloud-based computational tools for asteroid science. The foundation also received a grant from Tattoo Handmade Vodka, which will receive up to $ 1 million from other donors.

B612 and Dr. Lou are no longer just trying to save the world. “We’re answering a simple question about what vodka has to do with asteroids.” They said.

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