#pdc2023 — Public Fediverse posts

The last installment of this year's hypothetical asteroid impact scenario from #PDC2023 in April was finally released: https://cneos.jpl.nasa.gov/pd/cs/pdc23/epoch4.html.

Again:

This is a test.

In this scenario, deflection did not succeed so that impact effects can be considered.

This is only a test.

We have the technology.

Also, contrary to this opinion piece, the impact hazard is not an 'existential risk'.

I would like to see the rest of the #PDC2023 hypothetical impact scenario, though.

https://theglobeandmail.com/opinion/article-somewhere-a-large-asteroid-is-on-course-to-eventually-hit-earth-will/

(Also: the term "existential risk" is currently being co-opted by a variety of scammers who pretend that "AI" is an existential risk and sometimes mention the impact hazard & other real risks as a cover. Scientists should be careful.)

For everyone who attended #PDC2023 in April:

The next installment in this year's hypothetical impact scenario has been released: https://cneos.jpl.nasa.gov/pd/cs/pdc23/epoch3.html.

For everyone else:

This is only a test.

Let no one mistake pre-scripted scenarios as training tools for anything real.

A bit of an odd request for asteroid folks:

If any of you have contact information for Qi Chen at the CNSA Deep Space Exploration Laboratory, could you email it to me?

I have been unable to find any email address on the English-language internet.

#PDC2023

For other #PDC2023 attendees:

I may have missed it: Was there a timeline for when the rest of the hypothetical impact scenario was going to be released?

The second half is still listed as "coming soon" - https://cneos.jpl.nasa.gov/pd/cs/pdc23/epoch3.html .

And for everyone else:

This is only a test.

#PDC2023
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RT @IAU_Outreach
Keeping track of the @UNOOSA #IAAPDC2023? Worried about Near Earth Objects? ☄️

Learn more here: http://ow.ly/MTIN50NCVxj

#Astronomy #NEOs #Asteroids #LookUp

Image Credit: NASA/JPL-Caltech
Blue pts = all known NEAs between 1/1/1999 - 1/31/2018
https://twitter.com/IAU_Outreach/status/1644282005914284032

.@pgbrown described the #2022WJ1 impact and breakup from last November to #PDC2023 today: https://az659834.vo.msecnd.net/eventsairwesteuprod/production-atpi-public/08ebca3439744d63b5e4a193c144fcff
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RT @pgbrown
Bright fireball over Southern Ontario last night at 3:26 am caused by impact of asteroid 2022WJ1. This sub-meter-sized asteroid (one of the smallest NEAs ever detected) produced a spectacular fireball, though it was cloudy in many…
https://twitter.com/pgbrown/status/1594024499862982658

If you have been wondering what happens when you hit a rock pile with a particle beam.
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RT @meganimpact
Alex Vazsonyi’s poster on modeling ejecta produced by Ion Beam Deflection at asteroids (also viewable from https://atpi.eventsair.com/QuickEventWebsitePortal/23a01---8th-planetary-defense-conference/programme-website/Agenda) #pdc2023
https://twitter.com/meganimpact/status/1643929337803186177

Legend tells of a NASA acronym dictionary, in which there are many overloaded entries.
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RT @astrosnapper
We often have a name/hashtag collision between the Planetary Defense Conference #pdc2023 and the darts competition but now we have DART https://nctr.pmel.noaa.gov/Dart/ for tsunami detection vs #DARTMission for planetary defense as well...
https://twitter.com/astrosnapper/status/1643997955987492865

#PDC2023 will be continuing though tomorrow, but this will end my live-posting about the meeting.

Thanks go to the organizers for setting up usable remote participation.

Impact effects session at #PDC2023 ends with discussion of evacuation and sheltering recommendations for impactors of various sizes.

Compared to hurricane evacuations, but with very much more warning.

Integrated in to more general disaster plans.

Denis Vida (@meteordoc) provides a case study of reconstructing the orbit, mass, and strength of a meter-scale impactor.

Emphasizes need for high-resolution images. Energy release from the bolide as a function of time is not sufficient to say what exactly happened.

#PDC2023

Timothy Titus discusses "cascading hazards" from asteroid impacts; after the immediate impact effects but localized rather than e.g. global impact winters from large impacts.

Example: Erosion and landslides due to vegetation loss from airburst or fireball.

#PDC2023

#PDC2023 today will focus on the effects of asteroid impacts and Earth-based disaster response.

The #PDC2023 hypothetical asteroid impact LARP continues with deflection mission designs for nuclear blast deflection; forced by the improbable scenario.

Concept design is called "Mitigation Using a Fission Nuclear device" / MUFN / "muffin".

Something for @NuclearAnthro there.

This from the 2019 Planetary Defense Conference remains true at the 2023 Planetary Defense Conference.

#PDC2023
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RT @michael_w_busch
Reviewing #PDC2019 #PlanetaryDefense tweets, I am reminded of Sagan & Ostro 1994 - "Long-Range Consequences of Interplanetary Collisions": https://www.jstor.org/stable/43312710?seq=1#page_scan_tab_contents.

Specifically: No, we should not have asteroid deflection spacecraft constantly on standby.…
https://twitter.com/michael_w_busch/status/1122930157847818242

Sabina Raducan relates model results that the #DARTMission impactor would have completely disrupted a <60 m or smaller asteroid.

Unless I missed it; the mass of the impactor for the CNSA kinetic impact demonstration has not yet been released?

#PDC2023

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RT @michael_w_busch
For target selection, Qi Chen emphasizes first criterion that deflection _ must not _ cause any risk to Earth.

Second criterion is size 20-90 m, which may …
https://twitter.com/michael_w_busch/status/1643166334698631169

#DARTMission modeling team presents their results of simulating the impact onto Dimorphos to #PDC2023.

Ongoing question of what counts as a "crater" and what counts as global reshaping of the asteroid.

Public communication panel at #PDC2023 on describing the impact hazard with analogy to other natural disasters.

Note social media platforms undermining verification & enabling impersonation and the proliferation of automated plagiarism & disinformation tools as current problems.

Dan Scheeres reviews how Apophis' spin state may change in the 2029 flyby for #PDC2023.

Uses work we did with Yu Takahashi on spin state changes of Toutatis as an analogy; but Apophis is a far more extreme case.

See also Brozovic et al. about #TeamRadar options in 2029.

#TeamRadar
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RT @astrosnapper
Maxime Devogele of @NAICobservatory looking at (52768) 1998 OR2 a large (2km) #NEO. Top-shaped NEO like Bennu but also crater visible in radar obs. 100 lightcurves from 22 observatories. Size independent albedo from polarimetry obs - 22% albedo #pdc2023
https://twitter.com/astrosnapper/status/1643554992240963584

.@annevirkki describes @AreciboRadar observations of nearly 200 asteroids post hurricane Maria; focusing on their radar scattering properties and going beyond single polarization ratio measurements to full radar scattering phase function measurements.

#PDC2023 #TeamRadar

David Dunham reviews asteroid occultation observations for #PDC2023, focusing on recent observations of mission targets for @DESTINY_JAXA, @haya2_jaxa, and @OSIRISREx.

Commentary:

When predicting potential asteroid impacts many centuries in the future, we cannot plot risk corridor uncertainty region maps on Earth's surface as can be done on several-decade timescales.

Changes in Earth's rotation make that impossible.

#PDC2023

Fuentes-Muñoz: For long-term limits of trajectory prediction, the asteroids' positions along their orbits are generally unconstrained. Search for time intervals where MOID drops low enough for an impact to be possible, but can only be low-probability 'virtual' impacts.

#PDC2023

Oscar Fuentes-Muñoz discusses long-term limits of trajectory prediction for kilometer-scale asteroids.

1950 DA with the potential impact in 2880 that we cannot quite yet rule out remains the primary case.

Notes it has another set of potential impacts in late 5000s.

#PDC2023

Today at #PDC2023, including - among many other things - options for future planetary radar facilities following the loss of @AreciboRadar.

#TeamRadar
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RT @UNOOSA
#IAAPDC2023 continues with Day 3⃣!

How do we characterize near-Earth objects☄️?
What global activities are contributing to this effort🔭?

Follow the panels live to find out!
👉https://media.un.org/en/asset/k1b/k1bffqyw9r
https://twitter.com/UNOOSA/status/1643523632524673025

For #PDC2023, Luca Conversi reviews NEOMIR space-based asteroid monitor proposal from ESA.

Would work down to 30º from the Sun, providing a month of notice for any future Chelyabinsk-like impactor from that way.

Complement to NEO Surveyor complete count of larger rock piles.

The first #PDC2023 poster session is today.

For everyone not in-person in Vienna, copies of the posters are available at https://atpi.eventsair.com/QuickEventWebsitePortal/23a01---8th-planetary-defense-conference/programme-website/Agenda .

And I recommend both all of the #TeamRadar posters and Roth et al., "ALMA Observations of the DART Mission" to your attention.

#PDC2023
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RT @UNOOSA
📖New publication is out!

Explore the brochure to learn more about near-Earth objects☄️, the risks they pose & the role of #UNOOSA in promoting global cooperation🤝 for planetary defence.

👉http://bit.ly/3K7zYXG

#IAAPDC2023
https://twitter.com/UNOOSA/status/1643225816753483776

#PDC2023 opens today with reviews of impact hazard work in different parts of the world.

Great to hear more about what @astrokiwi and company have been working on in New Zealand!
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RT @UNOOSA
Welcome to Day 2⃣ of #IAAPDC2023!

In the morning session, we explore:

📖International and Policy Developments

☄️National Security Preparedness Roles in Planetary Defence

Join us live to learn more!
https://media.un.org/en/asset/k1a/k1aw0mpciy
https://twitter.com/UNOOSA/status/1643149248207224832

Again: This is only a test.
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RT @esaoperations
Day 1⃣of the #PlanetaryDefense Conference 2023!

The 5-day event happens every two years, bringing together asteroid experts and decision-makers from around the globe.

This year in Vienna, attendees will again have to deal with a fake #asteroidimpact scenario😲🌍☄️

🪨#PDC2023🪨 https://twitter.com/juaguispace/status/1642797841474113536
https://twitter.com/esaoperations/status/1642801453239619585