![]() "That's the recoil force, an extra force that's pushing against the asteroid," says Cheng, adding that this extra force was actually a lot bigger than the push that the spacecraft delivered by hitting the asteroid and embedding itself inside. The orbiting Hubble Space Telescope was on the wrong side of Earth when the collision happened, so it couldn't watch the event, but it gazed at the asteroid soon after and watched the debris cloud change over time. "That's something really exciting to see," says Jian-Yang Li, with the Planetary Science Institute, who says that eventually, a comet-like tail formed and got longer and longer. It looked remarkably like tails that occasionally are seen on other asteroids, he says. It had never been clear what created those so-called 'active' asteroids, although some astronomers suspected impacts played a role. ![]() "DART is the first experiment that actually demonstrated that impact can indeed generate a tail," he says. The tail streaming off of Dimorphos can still be detected by telescopes. ![]() "We are still observing," says Cristina Thomas with Northern Arizona University, who says observations should wrap up this month. Next year, the European Space Agency will send out a mission called Hera that should take close-up images of the asteroid, revealing the size of any crater left behind. It should also be able to determine the asteroid's mass. While astronomers say no large space rocks are currently known to threaten Earth, many small-but-still-dangerous asteroids have not yet been tracked, and planetary defenders say it's good to be prepared, just in case.Īll of this should help astronomers understand even more about how to push asteroids around. ![]() Why are asteroids and comets such weird shapes? "It makes me feel a lot better to see that it worked, and that it worked so well.- What happened when the dinosaur-killing asteroid slammed into Earth? "We've shown now that we have a method to move an asteroid," says Graykowski. What are the largest impact craters on Earth?įollowing the collision, powerful observatories have been watching the asteroid from Earth and, in the case of the James Webb Space Telescope (JWST) and the Hubble Space Telescope, from space. By looking for when the combined sunlight reflected from the asteroid pair dipped, indicating that Dimorphos had passed into the larger Didymos' shadow, scientists calculated that Dimorphos' orbital period was more than a half hour shorter than before the impact. Follow-up observations from radar instruments also directly measured the same orbit, confirming that it had gone from 11 hours and 55 minutes to 11 hours and 23 minutes. "For the first time ever, humanity has changed the orbit of a planetary body, of a planetary object - first time ever." "Let's all just kind of take a moment to soak this in," Lori Glaze, head of NASA's Planetary Science Division, said during the news conference. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |