PDC27 Epoch 1 Damage Risk Maps [EXERCISE ONLY]
***HYPOTHETICAL EXERCISE ONLY***
These maps represent asteroid impact damage estimates modeled for the PDC27 Hypothetical Asteroid Impact Exercise, as part of the 10th IAA Planetary Defense Conference (PDC 2027). This exercise assesses a realistic but fictitious hypothetical scenario, not a real asteroid threat.
DAMAGE RISK MAP OVERVIEW & CONTENTS:
These damage risk maps represent the potential range of local ground damage that could occur given the uncertain ranges of potential asteroid sizes, properties, and impact locations in the current scenario. This map set includes a damage risk swath covering the combined extent of regions that could potentially be at risk to damage, and examples of various damage footprint sizes over sample locations. These different swath and footprint examples can be displayed or hidden on the globe map by expanding and selecting different elements in the navigation panel folders. Information on each example set can be seen by clicking on the folder title in the navigation panel, which will display a pop-up text box.
*Tip: These maps work most reliably using the freely available Google Earth Pro desktop app. Functionality may vary by browser, OS, or internet connection if using the Google Earth web app.
ADDITIONAL REFERENCE INFORMATION:
Details about this scenario are available on the CNEOS PDC27 Scenario Website:
Summary of the Impact Risk Assessment at Epoch 1
Interactive Impact Risk Assessment Dashboard tool
Introduction to Impact Risk Assessment tutorial presentation
Details on the Probabilistic Asteroid Impact Risk (PAIR) model used to produce these results are published in Wheeler et al., 2024 [doi:10.1016/j.actaastro.2023.12.049]
[Produced by NASA's Asteroid Threat Assessment Project (ATAP), NASA Ames Research Center]

Ground Damage Level Key
Large impacts and airbursts can generate destructive blast waves and thermal heating that can cause various levels of injury, fatalities, structural damage, and/or fires extending far around the impact location. Blast damage from a large airburst is the predominant hazard for the asteroid sizes in this scenario. Damage sizes are estimated for four damage severity levels described below.

Ground Damage Risk Swath
The risk swath shows the extent of regions potentially at risk to local blast or thermal ground damage, including the range of possible damage sizes and possible airburst/impact locations. The black border bounds the range of airburst/impact locations modeled, and the shaded regions show the potential extent of damage around those locations, colored by the highest potential damage severity level. This risk swath shows the extent of local blast damage out to the 95th percentile of possible damage sizes within the regions.*
* These damage size percentiles represent the relative chance that the potential damage would be up to that size or smaller (i.e., the damage size that is larger than 95% of the possible range of cases) if an impact were to occur in that region. They do not indicate that damage is likely to occur in all the regions shown. The chance of impact occurring in any one region is a very small fraction on the total Earth impact probability (currently 19%).
Additional information on these damage risk swath maps is provided in the Introduction to Impact Risk Assessment presentation on the CNEOS PDC27 Scenario Website

Local Ground Damage (95th percentile extent)

Serious

Severe

Critical

Unsurvivable

Airburst/Impact Region

Ground Damage Sizes along Swath
These examples show different damage footprint sizes over sample impact locations along the risk corridor. These sample damage footprints represent the generalized damage size statistics among the impact cases modeled within a given impact region, rather than damage from a specific impact case. Clicking on the footprint damage levels will display a textbox with information about the damage area sizes.
Statistical damage sizes:
Damage size percentiles indicate the likelihood that the damage could be up to the given size or smaller when considering all the potential impact cases modeled within a region (e.g., the 95th percentile footprints show damage sizes that are larger than 95% of the modeled cases and smaller than 5% of the modeled cases). The largest sizes represent the largest damage among the probabilistically sampled set of cases modeled (not necessarily theoretical maximums or largest asteroid sizes). The damage sizes and shapes vary between locations due to the different entry angles along the corridor.
Sample footprint locations:
The sample damage locations shown represent some of the higher-population damage locations within each region along the swath. The locations were selected based on the highest population damage estimated for a median-sized outer damage area within 5° longitude spans along the swath.

Average Damage Sizes

Average at -53 deg longitude

Serious
Damage radius (circular): ~45 km (~28 mi)
Damage extents from center: ~38–52 km (~24–32 mi)
Total enclosed area: ~6300 sq. km (~2430 sq. mi)

Severe
Damage radius (circular): ~27 km (~17 mi)
Damage extents from center: ~23–31 km (~14–19 mi)
Total enclosed area: ~2240 sq. km (~870 sq. mi)

Critical
Damage radius (circular): ~10 km (~7 mi)
Damage extents from center: ~9–12 km (~6–8 mi)
Total enclosed area: ~340 sq. km (~130 sq. mi)

Unsurvivable
Damage radius (circular): ~0.5 km (~0.3 mi)
Damage extents from center: ~0.4–0.6 km (~0.3–0.4 mi)
Total enclosed area: ~0.8 sq. km (~0.3 sq. mi)

Average at -60 deg longitude

Unsurvivable
Damage radius (circular): ~0.6 km (~0.4 mi)
Damage extents from center: ~0.5–0.7 km (~0.3–0.4 mi)
Total enclosed area: ~1 sq. km (~0.5 sq. mi)

Average at -65 deg longitude

Damage radius (circular): ~0.7 km (~0.4 mi)
Damage extents from center: ~0.6–0.8 km (~0.4–0.5 mi)
Total enclosed area: ~1 sq. km (~0.6 sq. mi)

Total enclosed area: ~2 sq. km (~0.6 sq. mi)

Total enclosed area: ~0.3 sq. km (~0.1 sq. mi)

Average at 0 deg longitude

Average at 1 deg longitude

Average at 9 deg longitude

Damage extents from center: ~1–2 km (~0.8–1 mi)

Damage extents from center: ~0.7–1 km (~0.4–0.7 mi)

Total enclosed area: ~0.7 sq. km (~0.3 sq. mi)

Median (50th Percentile) Damage Sizes

Median 50th percentile at -53 deg longitude

Median 50th percentile at -60 deg longitude

Median 50th percentile at -65 deg longitude

Median 50th percentile at 0 deg longitude

Median 50th percentile at 1 deg longitude

Median 50th percentile at 9 deg longitude

25th Percentile Damage Sizes

25th percentile at -53 deg longitude

25th percentile at -60 deg longitude

25th percentile at -65 deg longitude

25th percentile at 0 deg longitude

25th percentile at 1 deg longitude

25th percentile at 9 deg longitude

75th Percentile Damage Sizes

95th Percentile Damage Sizes

Largest Modeled Damage Sizes

Largest Modeled at -53 deg longitude

Largest Modeled at -60 deg longitude

Largest Modeled at -65 deg longitude

Largest Modeled at 0 deg longitude

Largest Modeled at 1 deg longitude

Largest Modeled at 9 deg longitude

Damage Center Points along Corridor

Damage Center at -121 deg longitude
Entry Angle: 46 degrees
Entry Heading: 297 degrees
Entry Velocity: 18.22 km/s

Damage Center at -120 deg longitude
Entry Angle: 46 degrees
Entry Heading: 299 degrees
Entry Velocity: 18.21 km/s

Damage Center at -112 deg longitude
Entry Angle: 50 degrees
Entry Heading: 308 degrees
Entry Velocity: 18.17 km/s

Damage Center at 0 deg longitude

Damage Center at 1 deg longitude

Damage Center at 9 deg longitude

Ground Damage Sizes at High Population Regions
These examples show the statistical damage sizes grouped by location at high-population locations within several main geographic regions along the swath:
Western United States (Sacramento, CA)
Eastern Canada (Montreal, QC)
Mediterranean (Naples, Italy)

Sacramento CA, USA

Sacramento - Average

Sacramento - Median 50th percentile

Sacramento - 25th percentile

Sacramento - 75th percentile

Sacramento - 95th percentile

Sacramento - Largest Modeled

Montreal, Canada

Monteal - Average

Monteal - Median 50th percentile

Monteal - 25th percentile

Monteal - 75th percentile

Monteal - 95th percentile

Monteal - Largest Modeled

Naples, Italy

Naples - Average

Naples - Median 50th percentile

Naples - 25th percentile

Naples - 75th percentile

Naples - 95th percentile

Naples - Largest Modeled

Worst Damage Case Modeled
This example shows the damage footprint and approximate affected population estimates for the worst damage case (highest affected population) modeled in the current scenario set. Additional details can be seen by clicking on each damage level or airburst/entry marker on the map or navigation pane. (Tip: hiding the risk swath layer can make it easier to click on specific damage footprint areas)
Damage estimates:
Total estimated population in damage area: ~5.5M people
Affected population damage estimate: ~3.1M people
Damage level radii: serious ~90 km, severe ~50 km, critical ~30 km, unsurvivable ~11 km
Asteroid Properties:
Diameter: 85m
Energy: 43 Mt
Mass: 1.1e9 kg
Entry Properties:
Entry angle: 56°
Entry velocity: 17.97 km/s
Entry flight heading: 5° (~northward)
Effective Airburst Estimate:
Altitude: ~8.6 km (5.4 mi)
Yield energy: 43 Mt

Entry Point
Asteroid Diameter: 85 m
Asteroid Energy: 43 Mt
Airburst/Impact Altitude: 8.6 km (5.4 mi)
Estimated Affected Population: 3055422

Airburst Point
Asteroid Diameter: 85 m
Asteroid Energy: 43 Mt
Airburst/Impact Altitude: 8.6 km (5.4 mi)
Estimated Affected Population: 3055422

Damage Footprint

Total population enclosed: ~5498400
Population in serious damage region ring: ~981100
Population considered affected by serious damage (10%): ~98110
Total affected population from all damage levels: 3055400

Total population enclosed: ~4517300
Population in severe damage region ring: ~898700
Population considered affected by severe damage (30%): ~269610
Total affected population from all damage levels: 3055400

Total population enclosed: ~3618600
Population in critical damage region ring: ~2327200
Population considered affected by critical damage (60%): ~1396320
Total affected population from all damage levels: 3055400

Damage radius: ~11 km (~11 mi)
Total enclosed areas: ~350 sq. km (~140 sq. mi)
Population in unsurvivable damage region: ~1291400
Population considered affected by unsurvivable damage (100%): ~1291400

Entry and Burst Points along Swath
Examples of atmospheric entry points and airburst/impact points for a subset of modeled cases along the corridor of potential Earth-impact locations. The entry points show the set of 5000 sampled atmospheric entry points modeled in this assessment, and the burst points show the airburst/impact damage location for one nominal asteroid case (not all damage points for all asteroid cases modeled).

Example Entry Points (100km altitude)
Sampled atmospheric entry points at 100 km altitude (5000 points sampled)

Example Airburst Points
Example airburst points for nominal 80m asteroid case
(AsteroidID 630366)