The new early warning system of meteor warning of the Earth is more necessary than ever

A rapid warning system for meteorite impacts capable of destroying entire cities is on alert this week as the Earth crosses a vast trail of cosmic debris.

Astronomers focus their attention on the Ara constellation in a south-facing corner of the sky after sunset in the UAE. Calculations show that this will probably give a better view of the contents of the so – called Taurid complex, a trail of matter left by a giant comet that has disintegrated after entering the solar system there are thousands of thousands of people. years.

They are looking for signs of meteors similar to the 100-meter object that plunged into the Earth's atmosphere in June 1908 and exploded in Siberia with the violence of 1,000 atomic bombs from Hiroshima.

Known as the Tunguska event, he razed thousands of square kilometers of forest near the Tunguska River in Siberia. If such an event occurred in a city, the resulting shock wave would be devastating.

When a much smaller meteor exploded over central Russia in February 2013, the explosion amounted to a detonation of 500,000 tons of TNT. Despite a width of only 20 meters, the meteor shook buildings, destroyed windows and made more than 1600 victims, injured by shards of glass, temporary deafness and sunburns due to the intense light of the sun. explosion.

Astronomers hope that this week's observations of the Taurid complex will help to better understand the likelihood of such events.

It is also seen as a test of a network of telescopes designed to detect small but potentially dangerous meteors early enough to alert people who may be affected.

Funded by NASA, the latest Asbestos Land Impact Warning System (ATLAS) currently consists of two telescopes located on the Hawaiian Islands in the central Pacific. Other instruments will be added over the next few years.

Unlike conventional telescopes, ATLAS instruments scan the entire sky every 48 hours and use a computer to spot fast-moving, fuzzy objects heading for the Earth.

This allows them to detect meteors as small as the one that exploded over Russia in 2013 and calculate their trajectory – stating up to a week in advance of where they are. are going to hit.

The network had its first success last month in spotting an incoming meteor just 4 feet wide while it was still 500,000 kilometers from the Earth – even further than the Moon.

Code 2019MO, code-named, exploded on June 22 over the Caribbean near the island of Puerto Rico with the violence of 4,000 tons of TNT. It is thought that all the debris has plunged into the sea, but the weather satellites monitoring the area have witnessed the explosion at altitude.

Although this coincides with the passage of the Earth through the Taurid complex, 2019MO is not part of this meteor shower. On the contrary, astronomers believe that it finds its origin in the asteroid belt, the vast disk of rubbish between the orbits of Mars and Jupiter.

Even so, the event provided a "test track" to the impact alert system being deployed around the world.

Next year, astronomers will begin using a large telescope capable of locating objects the size of Tunguska months or even years before encountering the Earth.

Based in the Andes in central Chile, the Large Synoptic Telescope (LSST) has a mirror 8.4 meters in diameter that will photograph the entire sky every few nights. By comparing images night after night, computers will be able to identify more than 90% of objects that could pose a major threat to the Earth in the next decade or so.

But finding dangerous asteroids is just the beginning. NASA and the European Space Agency (ESA) are currently working on the very first mission of Earth's defense against a cosmic disaster.

Called AIDA mission (Impact and deformation of asteroids), it consists in drawing a 500 kg probe on a small asteroid to see if it is possible to move dangerous objects from the Earth.

According to current plans, NASA will launch in June 2021 a probe in the direction of Didymos, an asteroid the size of a mountain surrounded by a companion 160 meters wide.

Impacting at about 24,000 km / h, the probe will leave the small companion intact, but will slightly alter its orbit. A second probe built by ESA will then travel to Didymos and will send landers to the surface of his mate to examine the effects of the impact.

The data will provide astronomers with insight into the effectiveness of nudging asteroids as a method of avoiding impacts with the Earth.

In an ESA video explaining the mission's astrophysicist – and former Queen's guitarist, Dr. Brian May acknowledged that the mission "will be really very difficult," a giant asteroid there are 66 million d & rsquo; Years (see box).

"Could we prevent an asteroid from hitting the planet Earth? Dinosaurs could not – but we, humans, benefit from the knowledge and science of our side, "said Dr. May.

Robert Matthews is visiting science professor at Aston University in Birmingham, UK.