Didymos-Dimorphos System on October 11

Two tails of dust ejected from the Didymos-Dimorphos asteroid system are seen in new images from NASA’s Hubble Space Telescope, documenting the lingering aftermath of the NASA’s Double Asteroid Redirection Test (DART) impact.

The DART spacecraft impacted Dimorphos, a small moonlet of Didymos, on Sept. 26 in a planetary defense test to change Dimorphos’ orbit by crashing into it.

Repeated observations from Hubble over the last several weeks have allowed scientists to present a more complete picture of how the system’s debris cloud has evolved over time. The observations show that the ejected material, or “ejecta,” has expanded and faded in brightness as time went on after impact, largely as expected. The twin tail is an unexpected development, although similar behavior is commonly seen in comets and active asteroids. The Hubble observations provide the best-quality image of the double-tail to date.

Following impact, Hubble made 18 observations of the system. Imagery indicates the second tail formed between Oct. 2 and Oct. 8.

In this image, DART impacted the Didymos-Dimorphos system from the 10 o’clock direction.

The relationship between the comet-like tail and other ejecta features seen at various times in images from Hubble and other telescopes is still unclear, and is something the Investigation Team is currently working to understand.

About the colours

The images are separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope. The color results from assigning a blue hue to a monochromatic (grayscale) image.

About the data

This image was created from HST data from proposal: 16674 (J. Li).