Six months of warning is not enough to stop an asteroid from hitting Earth, we need 5 to 10 years!

NASA has simulated a scenario in which an asteroid is approaching the Earth and will hit it in six months.

Experts don't think there's enough time to stop it. We need at least five years to deflect the asteroid.

To have that long of a warning time? NASA needs a new space telescope that can spot asteroids.

Last month, experts at NASA and other space agencies around the world were faced with a disturbing hypothetical scenario: a mysterious asteroid had just been spotted 35 million miles away and was heading toward Earth. The space rock is expected to hit Earth within six months.

The scenario is fictional and is part of a week-long exercise that simulates an impending asteroid to help U.S. and international experts practice how to respond to such a situation.

The simulation taught the research team a hard lesson:If an Earth-impacting asteroid is found with so little warning, there is nothing anyone can do to stop it from hitting Earth. Experts believe that current technology cannot stop an asteroid from hitting the Earth, considering that it has only six months to do so. No spacecraft could destroy an asteroid or push it out of its orbit so that it would leave the ground and fly onto the rocks in that long a period of time.

Paul Chodas, a manager at NASA's Near Earth Object Research Center, helped lead the most recent simulation, as well as five similar simulations before it. The exercise dooms participants to failure, he said.

"This is what we call a short-term warning scenario," he said. "By design, it's very challenging."

In reality, scientists would need years - not months - of warning if a fictional asteroid like this were to fly toward Earth. At least five years, according to Droidas. Others, like MIT astronomer Richard Binzel, say we'd need at least a decade.

Binzel told Insider.com, "If faced with a real asteroid threat, time is the most valuable commodity you could hope to get."

But scientists have yet to identify most of the dangerous space rocks that pass near Earth, making it highly unlikely that we'll get a five- or 10-year warning period. in 2005, Congress tried to address the problem by requiring NASA to discover and track 90 percent of all near-Earth objects above 140 meters (460 feet). At that scale, an asteroid could destroy a city the size of New York. But so far, NASA has found only 40 percent of them.

Binzel said:This means that, as of now, we're left to luck to protect ourselves from a major asteroid impact." "But luck is not the plan."

To defend a planet, "know your enemy."

In NASA's recent simulation, the scientists involved didn't know how big the hypothetical asteroid would be until a week ago.

"We don't know if the object is 35 meters or 500 meters in diameter. That's very important." Sarah Sonnett, a researcher at the Planetary Science Institute, also participated in the experiment.

A 35-meter-long asteroid could explode in the atmosphere and send shock waves to nearby areas. A 500-meter-long asteroid could destroy a city and affect an area the size of France.

So a key part of stopping an asteroid from hitting the Earth is to learn as much as possible about the rock. This includes its size, its path around the sun, and its composition. With this information, scientists can evaluate strategies to dismantle the rock or destroy its path.

"It takes time to learn about your enemy," Binzel said.

Ideally, Sonnett said, scientists would be able to study a dangerous asteroid as it passes Earth several times in its orbit around the sun, and then that orbit brings it close enough to Earth to collide with it. Observing a passing asteroid multiple times can take years or even decades.

Step 2:Destroy or deflect the asteroid

NASA has three main tools in its planetary defense arsenal. The first method is to detonate an explosive device near an incoming asteroid, blowing it into smaller, less dangerous pieces. The second method is to fire a laser that heats and vaporizes the space rock enough to alter its orbit. The third method is to launch a spacecraft to hit the asteroid and deflect it from its orbit.

NASA is about to test the last strategy. The "Double Asteroid Redirect Test" will launch a probe to the asteroid Dimorphos in the fall of 2022 and hit it with a purpose.

But any of the three options would take several years, Jodas said.

He says: "It's generally a long, multi-year process from proposing to actually having a launch vehicle, not to mention you have to cruise to the destination and deflect the asteroid."

After that, it takes one to two years for the asteroid's orbit around the sun to change enough to carry it away from Earth. That's why the timeline is important:The sooner scientists discover the dangerous space rock, the lower the deflection mission must go.

But of course, all these methods are useless if no one knows the asteroid is coming.

"I think the best investment is knowledge. The best investment is knowing what's out there in the market," Binzel says.

That means completing a catalog of near-Earth objects that could damage Earth.

NASA is developing a space telescope to track asteroids

NASA is planning a mission to track asteroids that are too faint to be observed by Earth-based telescopes. the NEO survey mission (NEO stands for Near Earth Object) will launch an infrared telescope into Earth orbit in 2026.

She said:If we start looking for these objects now and tracking them, understanding their orbits, knowing where they're going, and then determining their size, then we should be in good shape."

If the telescope launches and works as planned, it will complete NASA's congressional mandate to find 90 percent of the most dangerous NEOs.

But NEO surveyors have been on the "edge of NASA mission hell" for five years, in Binzel's words. It has not gone through the early stages of development because of insufficient funding.

Sonnett prayed that the NEO mission would perform well in the upcoming review. At the end of this month, NASA will assess whether the mission is ready to move on to the next phase. If so, the team can begin building prototypes and developing hardware and software. If not, the telescope's launch could be further delayed.

"Because we now have the ability to detect and know what's out there, I think scientifically we have a moral responsibility to get that information," Binzel said. "It would be unconscionable for us to be shocked by what we might see as an asteroid impact."

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