A new image from the NASA/ESA Hubble Space Telescope shows two tails of dust ejected from the 160-m-wide asteroid moonlet Dimorphos, which orbits a larger, 780-m-wide asteroid Didymos.
At the top right of the image, there are arrows indicating the direction of impact by NASA’s DART spacecraft. The direction of impact arrow points in the 10 o’clock direction. The ‘to Sun’ arrow points in the 8 o’clock direction. At the bottom right are compass arrows indicating the orientation of the image on the sky. The north arrow points in the directly straight up. The east arrow points to the left in the 9 o’clock direction. Image credit: NASA / ESA / STScI / Jian-Yang Li, PSI / Joseph DePasquale.
On September 26, 2022, NASA’s Double Asteroid Redirection Test (DART) spacecraft intentionally crashed into Dimorphos for the first planetary defense test.
Current data show that the impact shortened Dimorphos’ original 11 hour and 55 minute orbit around Didymos by about 32 minutes.
Repeated Hubble observations over the last several weeks have allowed astronomers to present a more complete picture of how the system’s debris cloud has evolved over time.
The observations show that the ejected material 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 Didymos-Dimorphos system.
Imagery indicates the second tail formed between October 2 and October 8.
In the Hubble image, DART impacted Dimorphos 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 we’re currently working to understand,” DART researchers said.
“The northern tail is newly developed. In the coming months, we will be taking a closer look at the data from Hubble to determine how the second tail developed.”
“There are a number of possible scenarios we will investigate.”
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This article is based on text provided by the National Aeronautics and Space Administration.
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