Matthew Ward Agius
Matthew Agius is a science writer for Cosmos Magazine.
NASA’s DART spacecraft is completing its final acts before a scheduled collision with an asteroid on Tuesday 27 September (AEST), with mission controllers releasing images of Jupiter taken during a test of the ship’s onboard camera.
DART (short for Double Asteroid Redirection Test) is a mission that will determine whether the trajectory of an asteroid can be changed using a kinetic impact. The target is a 160-metre-wide asteroid called Dimorphos, which orbits the larger Didymos asteroid every 12 hours.
The mission is part of NASA’s foray into ‘planetary defence’ – investigating solutions for potentially catastrophic events like an earth-bound asteroid impact.
Hello Jupiter
Camera technology is critical to the DART mission’s success, and the spacecraft has now completed a series of milestone instrumentation tests ahead of the collision.
This includes the ship’s onboard camera ‘DRACO’ capturing a series of composite images showing Jupiter and its largest moons Ganymede, Europa, Io and Callisto.
The images show Europa emerging from behind the gas giant on July 1 and August 2. The camera will observe Dimorphos in a similar way when the moonlet visually separates from its parent asteroid Didymos in the lead-up to impact.
Visual separation refers to camera’s perspective of Dimorphos moving either in front or behind the larger asteroid during its 12-hour orbit.
Capturing images of Europa performing the same movement around Jupiter is an important final check of DART’s navigation in the final days before impact. Previously, these camera checks were undertaken by NASA on Earth using ground-based simulations.
CubeSat released ahead of impact
DART has also jettisoned a tiny satellite that will photograph the DART impact from afar.
The LICIACube is an Italian-made CubeSat that has been programmed to photograph Dimorphos’ surface while DART smashes into the moonlet at over 26,000 km/h. After impact, if all goes well, LICIACube will continue to take images of the crater and debris ejected from the blast.
“We are excited to have LICIACube on its way,” says Johns Hopkins Applied Physics Laboratory planetary scientist and DART investigator Andrew Cheng.
“We hope [it] will make a valuable contribution to DART. What it will witness and document will provide us unique and important information that we otherwise wouldn’t get to see.”
In the same way that NASA tested the DRACO camera by photographing Jupiter and its moons, the LICIACube team will calibrate the satellite’s cameras by taking images of astronomically near objects.
The cameras are named after Star Wars characters LUKE (for LICIACube Unit Key Explorer) and LEIA (LICIACube Explorer Imaging for Asteroid).
DART is scheduled to impact the moonlet Dimorphos on 26 September at 11:14pm (UTC)/27 September 9:14am (AEST).