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International Asteroid Day: Are we ready when an asteroid hits Earth?



In 1908, a powerful asteroid struck the Podkamennaya Tunguska River in a remote Siberian forest of Russia. The event leveled trees and destroyed forests over 770 square miles, the size of three quarters of the state of Rhode Island. The impact threw people in a city 40 miles off the ground.

Five years ago, an asteroid entered the Earth's atmosphere over Chelyabinsk in Russia. It exploded in the air and released 20 to 30 times more energy than the first atomic bombs. It generated more brightness than the sun, radiated heat, damaged more than 7,000 buildings and injured more than 1,000 people.

The shockwave broke into windows 58 miles away. It went undetected because the asteroid came from the same direction and the same way as the sun.

NASA and other space organizations around the world focus on detecting the threat of near-Earth objects or NEOs. Near-Earth objects are asteroids and comets whose orbits they place within 30 million miles of the Earth.

There are currently no known NEOs that pose a significant threat, NASA announced last week. NASA's NEO program finances and relies on the capture and tracking of US and space observatories and collaborates with other observatories around the world.

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According to Dante Lauretta, principal investigator of NASA's OSIRIS Rex mission, asteroids hit Earth every day. Most of them are so small that they burn in the atmosphere. But small asteroids can still cause damage, especially if they explode in the air over a city like Chelyabinsk. And the smaller they are, the harder they are to recognize the asteroids.

But new technologies and planetary defense plans could change that.

An Asteroid Action Plan

Last week, the US Science and Technology Council released the National Earth Related Objective Prevention Strategy and an action plan outlining the efforts of NASA, the Office of Science, in the next decade Years coordinated and technology policy and FEMA. This plan is based on a strategy that was first drafted by the US government in 2016.
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The plan's goals include improving NEO detection, tracking and identification, Improve predictive modeling, develop NEO distraction and disruption technologies, step up international cooperation to prepare for NEOs, and establish emergency response and action protocols.

The damage an asteroid can cause depends on its size. The one who killed the dinosaurs was 15 kilometers wide. Scientists have mapped 90% of the asteroids one kilometer or more in size and know that they are not a threat, said Detlef Koschny, head of the European Space Agency's near-Earth object team.

But we only detected and mapped less than one percent of NEOs that are less than one kilometer in length. The smaller the asteroid, the greater the likelihood that it hits the earth. According to Koschny, every 10,000 years, 10,000 asteroids meet every 10,000 years and 50-meter asteroids.

Asteroids, which like Chelyabinsk are about 20 meters long, occur on average every 10 to 100 years. "We will definitely see such a thing in our lives again," Koshcny said.

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According to the new report, NASA will search for asteroids that are only 50 meters wide. So far, they have focused on larger, 100-meter-wide and larger, because they can affect entire regions and continents. But also asteroids smaller than 50 meters can cause considerable damage. There are 10 million NEOs larger than 20 meters and 300,000 objects larger than 40 meters which, according to NASA, could pose a risk of collision, but they are hard to spot just days in advance.

The Asteroid Institute is also partnering with Google Cloud and Analytical Graphics Inc. to track asteroid discoveries using a cloud-based platform for the Asteroid Decision Analysis and Mapping Project.

This was intentionally developed because within a few years the Large Synoptic Survey Telescope will go online and enable the discovery of tens of thousands of asteroids in orbits that could bring them closer to Earth, said Ed Lu, Executive Director of the Asteroid Institute and a former NASA astronaut.

"There will be a lot more data and observations on asteroids," Lu said. "We are getting ready for this flood of data and, together with our partners, we are working to understand how well we can determine if an asteroid will hit Earth, and more observations will mean less uncertainty." [196592002]

Asteroid Missions

In 2005, Congress mandated NASA to detect at least 90% of NEOs that are at least 140 meters tall by 2020. Since then, the total number of cataloged NEOs has risen by five. Current capabilities however, estimates indicate that by 2033 we will find less than half of these objects. For this reason, the new plan focuses on improving NEO detection and promoting those skills.

At present, several missions are planned that are currently aimed at investigating and distracting asteroids.

NASA's OSIRIS-REx spacecraft will fly through space for two years to approach an asteroid called Bennu, a large, roundish space rock that has made it onto the NASA's list of potentially dangerous asteroids. That said, Bennu is one of the most dangerous space rock we know because one day he might collide with Earth. It started in September 2016 and will reach Bennu later this year to investigate the composition of the asteroid.
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On Wednesday, the Japanese space probe Hayabusa2 reached the diamond-shaped asteroid Ryugu, three years after launching its mission.

The spaceship is 12.4 miles from the asteroid, from where it will launch a projectile into the rock to excavate subsurface samples. Later, Hayabusa2 will sit on the asteroid and collect the samples. It will leave Ryugu in December 2019 and eventually return to Earth by the end of 2020.

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NASA's Asteroid Redirect mission was developed to develop a robotic spacecraft that has one more Collecting and orbiting tons of heavy boulders from the surface of a NEO – proving that we can change the orbit of a NEO on a less threatening path. But the mission was canceled at the end of 2017.

The new plan proposes to develop diversionary and disruptive missions, such as gravity tractors, kinetic impactors (such as DART) and even a nuclear explosive device that could break asteroids of a certain size into smaller pieces that would dissolve.

This may sound like the preparation for the Last Judgment from "Deep Impact" or "Armageddon," but the asteroids they are destined for probably would not cause the demise of humanity.

What if an asteroid hits Earth? ?

Currently, NASA estimates that we need ten years in advance to prepare for an asteroid in collision with Earth. The more asteroids we catalog, the greater our chance to pursue them and mitigate the risk in such a large timeframe.

And should we take ten years, sophisticated plans must be in place and communicated globally.

"If there has to be an evacuation, where are you evacuating?" said Debbie Lewis, a specialist in asteroid risk management and communications. "Instead of a tent village, I would hope they could put together something more comprehensive." Ten years into the announcement, emergency planning communities can begin to do something. "

In the US, at NASA The Planetary Defense Coordination Office's mission is to enable rapid and accurate communication about potentially dangerous objects. The new US Action Plan envisages efforts by NASA and FEMA to streamline the risk of an approaching asteroid to the public, to establish evacuation in potential impact areas, and other emergency scenarios when we are only a few days or months in advance.
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Two telescopes continuously scan the night sky for objects that are bright enough for what Large objects work well, but smaller objects can not be detected until they are as close as the moon, Koschny said.

"If you only have two of these telescopes on the planet and each telescope needs three weeks to cover the entire sky, you really need to be lucky that a small asteroid crosses your field of vision when you are looking in the right direction ", he said. "That's why we're currently developing extremely large telescopes that can scan all over the sky within 48 hours."

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We also need smaller NEOs on be able to find their final access, days or weeks in advance, and be able to implement civil defense – be it an evacuation or a haven, said Mark Boslough, professor of earth and planet sciences at the University of New Mexico and chair of the Asteroid Day expert panel.

In the Fall Events like Chelyabinsk, where small asteroids blow up, are about raising awareness of what is not to be done.

"We need to make sure people understand when there's a big, unannounced puff of air Go to the windows or look outside in the bright lightning in the sky," said Boslough.

[19659026] Amanda Barnett, Junko Ogura and Sheena McKenzie have contributed to this report.


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