NASA will smash a spacecraft into an asteroid today in earth’s first ever planetary defence test

NASA will attempt to intentionally crash a spacecraft into an asteroid tonight (September 26) in the first ever test of planetary defence.

That’s right, tonight is the night that all those Hollywood films become reality as the space agency looks to fire a spacecraft at more than 24,000km/h in order to collide with a large falling space rock.

It’ll be the first test of its kind to see if scientists can potentially stop cosmic objects from heading for Earth with disastrous impacts.

They will use the Double Asteroid Redirect Test spacecraft, quite suitably known as DART, to double up as a ‘battering ram’. 

NASA/Johns Hopkins APL/Steve Gribben

Although, don’t be afraid if the test does go wrong. 

NASA reiterated earlier this month that the ‘asteroid posed no threat to Earth’. 

The DART spaceship launched from California last November ahead of a near-year-long journey to complete obliteration.

Its target is a small asteroid called Dimorphos, which orbits a larger one called Didymos. 

Both Didymos and Dimorphos are set to make their closest approach to our planet in years today, passing at a distance of about 10.8 million kilometres from Earth.

If all goes to plan, the impact between the spacecraft and the asteroid will take place tonight (September 26) at 23:14 GMT (09:14 AEST). 

A final manoeuvre from NASA’s end took place earlier today, which has allowed the navigation team to know the position of the asteroid within two kilometres. 

Andrea Danti / Alamy

This means a reduced margin of error for the spacecraft's required trajectory in order to hit a home run on the asteroid. 

Speaking to reporters last week ahead of the mission, Lindley Johnson, a planetary defence officer for NASA, said: "This is an exciting time, not only for the agency, but in space history and in the history of humankind quite frankly."

While the theory certainly seems like something out of Deep Impact, there is scientific reasoning behind the impact.

Johns Hopkins Applied Physics Laboratory Planetary astronomer Andy Rivkin explained: "The point of a kinetic impactor is you ram your spacecraft into the asteroid you're worried about, and then you change its orbit around the sun by doing that."

You can watch the collision live on NASA TV as well as on their YouTube channel. 

You can also check it out through the Rome-based Virtual Telescope Project, which has teamed up with observatories in South Africa and will be focusing on the target asteroid in real-time at the scheduled moment of impact.