Asteroids vs Earth: Researchers aim to move an asteroid

Professor Alan Fitzsimmons from the Astrophysics Research Centre at Queen’s is playing a role in two space missions that will measure how hard it is to deflect an asteroid. He will be telling people about it in an online public talk on World Asteroid Day, Wednesday 30 June.

Later this year, the NASA Double Asteroid Redirection Test (DART) mission will launch to intercept the Didymos asteroid system. When an asteroid the size of Dimorphos strikes the Earth, it can easily destroy any cities or towns within tens of kilometers.

The DART mission’s target isn’t asteroid Didymos itself, but its smaller moon called Dimorphos. DART will collide with Dimorphos at over 6 kilometers/second in September next year, destroying the spacecraft, but slightly moving the asteroid moon.

Professor Fitzsimmons, who is a member of the DART investigation team, comments: “The team at NASA and Johns Hopkins Applied Physics Laboratory have designed a fantastic mission that should change the orbit of Dimorphos.

“Dimorphos is about 160 m across and is similar to those asteroids mostly likely to cause us concern in the next 100 years. By deflecting it in its path around Didymos, DART will show us it is possible to move a small asteroid that could hit us in years to come.”

Finding out exactly what happened to Dimorphos is the task of the second spacecraft, the European Space Agency Hera Mission. Professor Fitzsimmons is a member of the Science Management Board for the ESA spacecraft.

Hera will launch from Earth in 2024 and arrive at Dimorphos in 2026, staying there for about a year. The spacecraft will precisely measure how massive Dimorphos is and how the small asteroid responded to being hit by DART.

By performing this experiment, scientists will be able to calculate more accurately what needs to be done if a small asteroid is discovered on an impact trajectory with the Earth.

According to Professor Fitzsimmons, DART and Hera will be humanity’s first practice in planetary defense. Both main spacecraft will carry smaller cubesat spacecraft, to help further understand how to move asteroids.

He explains: “We had our first meetings at ESA in 2004 to start designing a mission that would help us protect us from asteroid impacts. Now after two decades we have a truly international project working on a truly global problem.”

World Asteroid Day is held on 30 June every year in recognition of the last major asteroid strike on earth, on that date in 1908.

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