Back in September, NASA deliberately crashed a spacecraft into an asteroid to test potential planetary defense technology. To mark the publication of his four new scientific papers confirming the method works, NASA has released a shocking video captured by the Hubble Space Telescope.
NASA and other organizations produce catalogs of asteroids that circle the neck of our solar system. This will allow us to get as much warning as possible if an asteroid is discovered on a collision course with the Earth. In such cases, we can potentially launch a defensive attack to keep them away from our home planet and prevent a major or global catastrophe.
The Double Asteroid Redirection Test (DART) was an exercise in just such a strategy. To test whether an asteroid’s orbit can be altered, NASA slammed a probe into a small space rock called Dimorphos, which orbits a larger asteroid known as Didymos. And sure enough, it soon became apparent that the trajectory was much shorter than expected.
A scientific paper discussing this experiment has now been published, confirming that the technique is viable and providing details about what happened. It turns out that Dimorphos’ surface was littered with a lot more boulders and boulders than expected, and the impact created a large cloud of dust that actually pushed the asteroid up a bit.
“Before impact, we expected the impact to shorten Demorphos’ trajectory by about 10 minutes,” said study co-author Tony Farnham. “However, after the collision, we found that the orbital period was further shortened, shortening his normal 12-hour orbit by just over 30 minutes. In other words, the ejected material acted as a jet, turning the Moon back into its original position. It pushed it further out of orbit.”
NASA, ESA, STScI, J. Li (PSI)
The Hubble Space Telescope was also able to capture a time-lapse video of this material being ejected by the collision and how the cloud evolved over the next few hours or days. The video begins 1.3 hours before his impact, with bright spots containing both Didymus and Dimorphus. The second image shows the system two hours after impact, showing a cone of ejected material.
After about 17 hours, the cone begins to transform into a pinwheel shape under the influence of the gravity of the large rock. The debris is then swept backward by the solar wind, forming a comet-like tail. This tail then bizarrely splits in half for several days.
These newly published papers will help inform future missions should this planetary defense plan need to be put into action.
The study was published in a journal Nature [1],[2],[3],[4]Hubble’s video can be seen in the video below.
Timelapse video of the Didymos-Dimorphos system
Source: NASA, University of Maryland
