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Planetary Defense Exercise Uses Apophis as Hazardous Asteroid Stand-In
NASA ^ | May 31, 2022

Posted on 06/01/2022 9:48:39 PM PDT by BenLurkin

Over 100 participants from 18 countries – including NASA scientists and the agency’s NEOWISE mission – took part in the international exercise.

Watching the skies for large asteroids that could pose a hazard to the Earth is a global endeavor. So, to test their operational readiness, the international planetary defense community will sometimes use a real asteroid’s close approach as a mock encounter with a “new” potentially hazardous asteroid. The lessons learned could limit, or even prevent, global devastation should the scenario play out for real in the future.

To that end, more than 100 astronomers from around the world participated in an exercise last year in which a large, known, and potentially hazardous asteroid was essentially removed from the planetary defense-monitoring database to see whether it could be properly detected anew. Not only was the object “discovered” during the exercise, its chances of hitting Earth were continually reassessed as it was tracked, and the possibility of impact was ruled out.

Coordinated by the International Asteroid Warning Network (IAWN) and NASA’s Planetary Defense Coordination Office (PDCO), the exercise confirmed that, from initial detection to follow-up characterization, the international planetary defense community can act swiftly to identify and assess the hazard posed by a new near-Earth asteroid discovery. The results of the exercise are detailed in a study published in the Planetary Science Journal on Tuesday, May 31.

The exercise focused on the real asteroid Apophis. For a short while after its discovery in 2004, Apophis was assessed to have a significant chance of impacting Earth in 2029 or later. But based on tracking measurements taken during several close approaches since the asteroid’s discovery, astronomers have refined Apophis’ orbit and now know that it poses no impact hazard whatsoever for 100 years or more. Scientific observations of Apophis’ most recent close approach, which occurred between December 2020 and March 2021, were used by the planetary defense community for this exercise.

“This real-world scientific input stress-tested the entire planetary defense response chain, from initial detection to orbit determination to measuring the asteroid’s physical characteristics and even determining if, and where, it might hit Earth,” said Vishnu Reddy, associate professor at the University of Arizona’s Lunar and Planetary Laboratory in Tucson, who led the campaign.

Tracking a ‘New’ Target

Astronomers knew Apophis would approach Earth in early December 2020. But to make the exercise more realistic, the Minor Planet Center (MPC) – the internationally recognized clearinghouse for the position measurements of small celestial bodies – pretended that it was an unknown asteroid by preventing the new observations of Apophis from being connected with previous observations of it. When the asteroid approached, astronomical surveys had no prior record of Apophis.

On Dec. 4, 2020, as the asteroid started to brighten, the NASA-funded Catalina Sky Survey in Arizona made the first detection and reported the object’s astrometry (its position in the sky) to the Minor Planet Center. Because there was no prior record of Apophis for the purpose of this exercise, the asteroid was logged as a brand-new detection. Other detections followed from the Hawaii-based, NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) and Panoramic Survey Telescope and Rapid Response System (Pan-STARRS).

As Apophis drifted into the field of view of NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission, the MPC linked its observations with those made by ground-based survey telescopes to show the asteroid’s motion through the sky. On Dec. 23, the MPC announced the discovery of a “new” near-Earth asteroid. Exercise participants quickly gathered additional measurements to assess its orbit and whether it could impact Earth.

"Even though we knew that, in reality, Apophis was not impacting Earth in 2029, starting from square one – with only a few days of astrometric data from survey telescopes – there were large uncertainties in the object’s orbit that theoretically allowed an impact that year,” said Davide Farnocchia, a navigation engineer at NASA’s Jet Propulsion Laboratory in Southern California, who led the orbital determination calculations for JPL’s Center for Near Earth Object Studies (CNEOS).

During the asteroid’s March 2021 close approach, JPL astronomers used NASA’s 230-foot (70-meter) Goldstone Solar System Radar in California to image and precisely measure the asteroid’s velocity and distance. These observations, combined with measurements from other observatories, enabled astronomers to refine Apophis’ orbit and rule out a 2029 impact for the purpose of the exercise. (Beyond the exercise, they also were able to rule out any chance of impact for 100 years or more.)


Orbiting far above Earth’s atmosphere, NEOWISE provided infrared observations of Apophis that would be not have been possible from the ground because moisture in the Earth’s atmosphere absorbs light at these wavelengths.

“The independent infrared data collected from space greatly benefited the results from this exercise,” said Akash Satpathy, an undergraduate student who led a second paper with NEOWISE Principal Investigator Amy Mainzer at the University of Arizona, describing the results with inclusion of their data in the exercise. “NEOWISE was able to confirm Apophis’ rediscovery while also rapidly gathering valuable information that could be used in planetary defense assessments, such as its size, shape, and even clues as to its composition and surface properties.”

By better understanding the asteroid’s size, participating scientists at NASA’s Ames Research Center in Silicon Valley, California, could also estimate the impact energy that an asteroid like Apophis would deliver. And the participants simulated a swath of realistic impact locations on Earth’s surface that, in a real situation, would help disaster agencies with possible evacuation efforts.

“Seeing the planetary defense community come together during the latest close approach of Apophis was impressive,” said Michael Kelley, a program scientist with PDCO, within NASA’s Planetary Science Division at NASA Headquarters in Washington, who provided guidance to the exercise participants. “Even during a pandemic, when many of the exercise participants were forced to work remotely, we were able to detect, track, and learn more about a potential hazard with great efficiency. The exercise was a resounding success.”

Additional key planetary defense exercise working group leads included Jessie Dotson at NASA Ames, Nicholas Erasmus at the South African Astronomical Observatory, David Polishook at the Weizmann Institute in Israel, Joseph Masiero at Caltech-IPAC in Pasadena, and Lance Benner at JPL, a division of Caltech.

NEOWISE’s successor, the next-generation NEO Surveyor, is scheduled to launch no earlier than 2026 and will greatly expand the knowledge NEOWISE has amassed about the near-Earth asteroids that populate our solar system.

More information about CNEOS, asteroids, and near-Earth objects can be found at:

TOPICS: Astronomy; Science
KEYWORDS: apophis; asteroid; asteroids; astronomy; catastrophism; comet; comets; hazardousasteroid; impact; planetarydefense; science

1 posted on 06/01/2022 9:48:39 PM PDT by BenLurkin
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To: BenLurkin

Oh no!
You know what that means!!!

If covid pandemic exercise was a precursor for covid attack.
And monkeypox exercise was a precursor for monkeypox attack.

Then this means there is going to be an asteroid attack.

2 posted on 06/01/2022 9:58:34 PM PDT by DannyTN
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To: BenLurkin

(planetary defense)

I’m counting on Bruce Willis and Steve Buscemi.

Is that wrong?

3 posted on 06/01/2022 10:01:11 PM PDT by SaveFerris (The Lord, The Christ and The Messiah: Jesus Christ of Nazareth - http://www.BiblicalJesusChrist.Com/)
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To: DannyTN

We pissed off a group of aliens who came in peace,

Now they are going to sit back and throw rocks at us

4 posted on 06/01/2022 10:45:29 PM PDT by algore
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To: BenLurkin

The real hazard with Earth-grazers is they just need a calibrated nudge to become Earth-impacters at a specific location.

Of course giving a nudge to an asteroid or comet requires access to space, and there’s probably gonna be a big war over that very thing. Ultimately there can be only one country or treaty organization which controls access to space.

As for why, for one thing because mining and killing satellites and space stations is way too easy. Nudging dangerous space rocks to make them weapons is going to become easier and easier as well. The only sure security against space sabotage/attack is hegemony over space and a policy of destroy-during-boost applied to unauthorized launches.

For another thing, imagine if we the US wanted to send 50 ambassadors, one from each state, to the UN and every major country. They would rightly say, send us ONE or forget it. Now extrapolate to exo-politics, if we live so long as to see it in action.

5 posted on 06/02/2022 12:28:30 AM PDT by JustaTech (A mind is a terrible thing)
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To: BenLurkin

Apophis? Seriously? They chose the name Apophis as a possible threat to the Earth? What’s next... Anubis? .. Hathor?

6 posted on 06/02/2022 1:40:39 AM PDT by Ronaldus Magnus III (Do, or do not, there is no try. )
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To: SaveFerris

Yes. Because Colonel Jack O’Neill is far more qualified to defeat Apophys.

Two days in a row I got a Jack O’Neill reference in.

Stayed tuned tomorrow as I go for the hat trick.

7 posted on 06/02/2022 2:47:21 AM PDT by HYPOCRACY (This is the dystopian future we've been waiting for!)
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To: Ronaldus Magnus III

All taken out by SG1

8 posted on 06/02/2022 2:48:24 AM PDT by HYPOCRACY (This is the dystopian future we've been waiting for!)
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To: BenLurkin
So how many Ha'taks will Apophis be deploying for this exercise?

I'm sure he's not pleased that his OPSEC was blown for this exercise.

9 posted on 06/02/2022 2:50:39 AM PDT by markomalley (Directive 10-289 is in force)
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To: BenLurkin

A global effort to detect then assess.......I think they should focus on prevention.

10 posted on 06/02/2022 2:57:25 AM PDT by Hot Tabasco (I'm Jimmy Crack Corn and I don't care)
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Ping me when ya do!

11 posted on 06/02/2022 3:35:16 AM PDT by SaveFerris (The Lord, The Christ and The Messiah: Jesus Christ of Nazareth - http://www.BiblicalJesusChrist.Com/)
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To: markomalley
I'm sure he's not pleased that his OPSEC was blown for this exercise.

It won't be, um... Replicated, anytime soon probably.

12 posted on 06/02/2022 3:45:05 AM PDT by Sirius Lee (They intend to murder us. Prep if you want to live and live like you are prepping for eternal life)
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To: BenLurkin

Don’t Look Up!”

13 posted on 06/02/2022 4:08:12 AM PDT by Tallguy
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To: BenLurkin

Spotted, identified and watched all the way to impact. Nice. That’s really helpful.

14 posted on 06/02/2022 4:34:48 AM PDT by PIF (They came for me and mine ... now its your turn)
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To: BenLurkin

I’m going with this ends up a fail - Rev 8:8-9

15 posted on 06/02/2022 5:25:35 AM PDT by gbaker
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To: gbaker


1. Richard Firestone Younger Dryas Event
2. Bronze Age collapse
3. Tunguska comet impact
4. Gunnar Heinsohn Plague of Justinian
5. Dennis Cox Dragonstorm Project
6. - Search for academic papers on asteroid impact.

This issue kills global warming and becomes the science driver for the next century. Make some noise.

16 posted on 06/02/2022 8:41:52 AM PDT by Yollopoliuhqui
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To: SuperLuminal; BenLurkin; 75thOVI; Abathar; agrace; aimhigh; Alice in Wonderland; AnalogReigns; ...
Thanks BenLurkin.

17 posted on 06/16/2022 7:06:32 AM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: SunkenCiv; BenLurkin

I can see it won’t be a dull summer with you guys around.



18 posted on 06/16/2022 8:22:55 AM PDT by Monkey Face (~~ Animals would never allow the dumbest of the lot to be the leader of their pack. ~~ Facebook)
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To: Monkey Face


19 posted on 06/16/2022 9:02:18 AM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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