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NASA will send probe to impact an asteroid

publicado a la‎(s)‎ 3 jul. 2020 7:06 por Plataforma Sites Dgac   [ actualizado el 9 oct. 2020 11:28 ]
For decades, astronomers around the world have been scrutinizing the cosmos with some unease. Although it does not appear to occur regularly, there can be instances in which asteroids could impact the Earth with devastating effects.
An artist's conception of NASA's DART Mission.

Another artist's image from NASA's DART Mission just before the probe crashes against Didymos asteroid's smaller body.
Scientists believe it was such an incident that caused the extinction of the dinosaurs 65 million years ago and more recent of such events have occurred, as the Tunguska explosion in the Russian steppe on June 30, 1908, which left a lot of destruction locally, but thankfully they have not gone beyond that. 

Hollywood has also been responsible for installing the theme in the collective imagination with films such as Armageddon and Deep Impact, both released in 1998. 

Science protects the planet 

But beyond the fiction of the cinema, scientists scan the neighborhoods of our Solar System in search for potentially dangerous asteroids heading our way, also devising plans and projects to implement in case of an imminent threat. 

One such initiative is the Double Asteroid Redirection Test (DART), a mission that the US space agency, NASA, will execute in 2021.

Specifically, DART is conceived as a test of planetary defense technologies to prevent the Earth from being hit by a dangerous asteroid. 

The scientists in charge envision DART as the first demonstration of the “kinetic impact” technique for changing the motion of an asteroid in space. 

To test this technique through the DART probe, the heads of the Applied Physics Laboratory, NASA's Solar System Exploration Program and NASA's Office for the Coordination of Planetary Defense chose the binary asteroid Didymos, which is nearby to the Earth. 

The main body Didymos is 780 meters wide, but its secondary body, or small moon, is about 160 meters in size, which is closer to the size of asteroids that could pose a threat to the planet.

According to the mission plan, the DART probe will achieve the deflection with a kinetic impact by crashing into the small moon at a speed of approximately 6.6 kilometers per second with the help of an onboard camera and a sophisticated autonomous navigation program. 

An international team of astronomers coordinated by researcher Cristina Thomas, from the University of Arizona, in the United States, has been observing the asteroid Didymos since 2015.

The most recent studies were carried out from Cerro Paranal, in Northern Chile, where scientists used the Very Large Telescope of the European Southern Observatory (ESO). 

From fiction to reality

Experts expect the collision to change the speed of the small moon in its orbit around the main body by a fraction of one percent, but that would change the orbital period of the secondary body by several minutes, enough to be observed and measured using telescopes.

“Even though we are performing ground-based observations, we don’t know much about Didymos B in terms of composition and structure,” said about the asteroid Angela Stickle, DART’s Impact Simulation Working Group Lead from APL.

“We need to anticipate a wide range of possibilities and predict their outcomes, so that after DART slams into Didymos B we’ll know what our measurements are telling us,” she added.

The window for the launch of the DART probe will begin in late July, 2021. The device will reach space aboard a SpaceX Falcon 9 rocket that will take off from the United States Air Force Base in Vandenberg, California.

Once in space, the DART probe will deploy a set of solar panels that will power its electric propulsion system. According to NASA, by using an electric propulsion system, DART could benefit from great flexibility in the mission schedule and at the same time it would be able to demonstrate in practice the new generation of ion thruster technology, which could be used in future NASA missions.

After a year-long journey through space after its launch, the probe will intercept Didymos' secondary body in late September, 2022, when the asteroid is going to be about 11 million kilometers from Earth.

That will allow observations to be made from telescopes and planetary radars to measure the change in the speed and trajectory of the small moon after the DART’s impact. 

Sources: NASA and BBC Mundo en Español.
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