I’m Gonna Move You Baby!

In the 1960s singer-songwriter Jaime Brockett did his comedic version of a Leadbelly epic song about the “USS” Titanic and the pugilist Jack Johnson, throwing in a massive pile of hemp rope for effect. “They wouldn’t let Jack Johnson on board -they said this ship don’t haul no coal”.  Because he was black, Jack Johnson was not allowed on the ship according to the song. Then, after getting very “high” from inhaling burning rope (I know, hemp does not have THC so it doesn’t get you high) our captain decided to ram the ice burg instead of trying to avoid it. He announced “I’m gonna move you baby”, rammed the ice burg, and the Titanic went right on down. On hearing the news, Jack Johnson supposedly does the Eagle Rock dance on the docks. For the record, this didn’t happen. Jack Johnson was in New York as the Titanic set sail.

The Titanic could not move that ice burg the way our fictitious captain intended but NASA just moved an asteroid’s satellite by slamming it with a DART. DART (Double Asteroid Redirection Test) is a smashing success and now NASA is in good position to play Earth saver.

Launched on November 23, 2021, DART took nearly a year to reach asteroid Didymos and its satellite Dimorphos. The 1260-pound spacecraft had a partner, the LICIA cube built by the Italian Space Agency. On September 26, 2022, LICIA took images of DART as DART encountered the 530-foot diameter Dimorphos at 14,700 miles per hour. The resulting plume of debris formed a nice tail, trailing Dimorphos and giving it a comet-like appearance.

Back on Earth, the DART team was ecstatic, but it would be about 72 hours before they knew if the mission was successful. To be a success NASA suggested the impact needed to alter Dimorphos’ orbit by a minimum of 73 seconds, enough to alter Didymos’ trajectory.

It was better than hoped, the impact sped up Dimorphos, reducing its orbit time by 32 minutes. The mission succeeded but the ultimate question for this project is to determine how much the trajectory of Didymos has been changed. The data NASA collects from this project will serve as a model and when the time comes, the means to save Earth from a catastrophic asteroid or comet collision.

We know asteroids come in various densities, maybe requiring additional testing data. An example is asteroid Bennu, recently visited by the OSIRIS-REX mission to collect and return asteroid material to Earth for study. Bennu, scientists found, is rocky but very loose. The collection arm sank quite a way into Bennu before thrusters lifted it away. Other asteroids can be more solid and require a different kind of push.

What’s in the Sky?

October 22nd; 7:30 pm: Astronomy Night at Tye Preston Memorial Library in Canyon Lake

October 24th; 30 minutes before sunrise; east: Mercury is just below a waning crescent Moon