Hubble Views of Dimorphos Ejecta

These images from NASA’s Hubble Space Telescope, taken 22 minutes, 5 hours, and 8.2 hours after NASA’s Double Asteroid Redirection Test (DART) intentionally impacted Dimorphos, show expanding plumes of ejecta from the asteroid’s body. This event was the world’s first test of the kinetic impact technique using a spacecraft to deflect an asteroid by modifying its orbit.

The Hubble images show ejecta from the impact that appear as rays stretching out from the body of the asteroid. The bolder, fanned-out spike of ejecta to the left of the asteroid is in the general direction from which DART approached. In the Hubble images, astronomers estimate that the brightness of the Didymos system increased by 3 times after impact. They’re also particularly intrigued by how that brightness then held steady, even eight hours after impact.

These observations, when combined with data from NASA’s James Webb Space Telescope, will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, how fast it was ejected, and the distribution of particle sizes in the expanding dust cloud.

Hubble will observe the Didymos-Dimorphos system ten more times over the next three weeks to monitor how the ejecta cloud expands and fades over time.

Hubble observations were conducted in one filter, WFC3/UVIS F350LP, and assigned the color blue.

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).