DART’s impact shortened Dimorphus’s orbit around Didymos by 32 minutes
LICIACube Explorer image just after the DART
impact. Dimorphus is the blob near the top.
After two weeks of analyzing the orbit of Dimorphus around its parent asteroid Didymos, astronomers have determined that the impact of DART on Dimorphus shortened its orbit by 32 minutes.
Prior to DART’s impact, it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. Since DART’s intentional collision with Dimorphos on Sept. 26, astronomers have been using telescopes on Earth to measure how much that time has changed. Now, the investigation team has confirmed the spacecraft’s impact altered Dimorphos’ orbit around Didymos by 32 minutes, shortening the 11 hour and 55-minute orbit to 11 hours and 23 minutes. This measurement has a margin of uncertainty of approximately plus or minus 2 minutes.
Before its encounter, NASA had defined a minimum successful orbit period change of Dimorphos as change of 73 seconds or more. This early data show DART surpassed this minimum benchmark by more than 25 times.
It also appears the ejecta from the impact — much greater than expected — helped propel Dimorphus, a result that I think was also not expected.
Researchers are now shifting to studying the debris and asteroid itself, to better understand what happened as well as the nature of Dimorphus itself. This will also include a European probe dubbed Hera that will launch in 2024 an dvisit both asteroids in 2026.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
LICIACube Explorer image just after the DART
impact. Dimorphus is the blob near the top.
After two weeks of analyzing the orbit of Dimorphus around its parent asteroid Didymos, astronomers have determined that the impact of DART on Dimorphus shortened its orbit by 32 minutes.
Prior to DART’s impact, it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. Since DART’s intentional collision with Dimorphos on Sept. 26, astronomers have been using telescopes on Earth to measure how much that time has changed. Now, the investigation team has confirmed the spacecraft’s impact altered Dimorphos’ orbit around Didymos by 32 minutes, shortening the 11 hour and 55-minute orbit to 11 hours and 23 minutes. This measurement has a margin of uncertainty of approximately plus or minus 2 minutes.
Before its encounter, NASA had defined a minimum successful orbit period change of Dimorphos as change of 73 seconds or more. This early data show DART surpassed this minimum benchmark by more than 25 times.
It also appears the ejecta from the impact — much greater than expected — helped propel Dimorphus, a result that I think was also not expected.
Researchers are now shifting to studying the debris and asteroid itself, to better understand what happened as well as the nature of Dimorphus itself. This will also include a European probe dubbed Hera that will launch in 2024 an dvisit both asteroids in 2026.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Henceforth, I will refer to Didymos as “Fluffy”.
Um, that means I going to have to refer to Dimorphos, Didymos II, as ‘Fluffy Abused’.
Even better news for asteroid mining?
From rubble-pile to rocket pile. Acts a bit like non-Newtonian goo, wave bounces back to the wound and is ejected out the disturbed area.
Concussion propulsion.
My asteroid-derived resources, not yours.
Here first.
Don’t get in my way.
Step back. Way back.
The soon to be new-normal.
Worked for 1800’s America.
Will work again.
“What the dinosaurs saw: the Chicxulub impact”
https://youtu.be/vq3nWnTkFbk
4:36
Did the DART impact also alter the orbit of the system of the 2 asteroids around the sun at all and would it be detectable over a long period of time?
If the answer is yes, would have hitting the larger of the 2 binary asteroids (Didymous) have the same or less sun orbital change impact? I understand that Dimorphous was chosen for the impact because is was much easier to observe its orbit change around Didymous.
Mark: More time and observations are required to see what, if any, happened to the entire solar orbit of the two asteroids. Also, Dimorphus was picked because this was a test which carried some tiny risk (really infinitesimal) , and the mission designers wanted to minimize that as much as possible. Hitting the tiny asteroid moon accomplished that. Moreover, being smaller they had a better shot at actually changing its orbit.
Most commenters seem overjoyed that the orbital change achieved was orders of magnitude greater than the expected, but I’ll offer a contrarian viewpoint: I think the reason for the high transfer of momentum was the rubble-pile nature of the target, and a more solid body might have responded considerably less.
What this implies to me is that the mechanics of asteroid impacts are extraordinarily complex, and will require a detailed understanding of the internal makeup of each individual target asteroid. Thus, deflecting an asteroid that we discover “late” could be very problematic. I think we need whole bunch more DART experiments!
Ray Van Dune,
I agree. The asteroids that are made up of stones, rocks, and boulders may be the easiest to push around. The ones that are more solid may take more effort. More testing is needed for these solid asteroids, otherwise the planning would be difficult.
PSW Science: Meeting Number 2464
October 10, 2022
“The Double Asteroid Redirection Test”
Andrew Cheng, Andrew Rivkin
https://youtu.be/1vEQ26WQG4c?t=655
I am hearing it would take 30 years of lead time if it had us in the cross-hairs. True?
Nukes to the rescue
https://www.engadget.com/2007-08-08-nasa-draws-up-plans-for-nuke-packing-asteroid-interceptor.html
By my calculations, the reduced orbital period means that Dimorphus’s orbit is now 3% closer to Didymos than it was before. Of course this assumes circular orbits, which they aren’t. My solution is only good for circular orbits in a vacuum.
https://www.youtube.com/watch?v=Id0Ppz4OBKE (Big Bang Theory: spherical chickens joke)
The joke is a classic, right?
Sheldon- Why did the chicken cross the mobius strip?
https://youtu.be/j9u42WSaF04
0:06
I can’t help but wonder why it took so long for us to do a test like this. We had the technology to do it decades ago, but somehow it waited until less expensive commercial rockets were available. Coincidence?
Probably.