juliensimon/neo-close-approaches

---
license: cc-by-4.0
pretty_name: "Near-Earth Object Close Approaches"
language:
- en
description: "All asteroid and comet close approaches to Earth within 0.05 AU (1900-2100) from NASA JPL CNEOS. Updated daily."
task_categories:
- tabular-classification
- tabular-regression
tags:
- space
- asteroid
- neo
- planetary-defense
- nasa
- near-earth-object
- open-data
- jpl
- cneos
- potentially-hazardous-asteroid
- tabular-data
- parquet
size_categories:
- 10K<n<100K
configs:
- config_name: default
data_files:
- split: train
path: data/neo_close_approaches.parquet
default: true
---

# Near-Earth Object Close Approaches

*Part of the [Orbital Mechanics Datasets](https://huggingface.co/collections/juliensimon/orbital-mechanics-datasets-69c24caca4ab3934c9856994) collection on Hugging Face.*


All close approaches of Near-Earth Objects (asteroids and comets) to Earth within 0.05 AU
(~7.5 million km), spanning **1900** to **2099**. Currently **41,851** recorded approaches
(31,943 past, 9,908 future predictions).

## Dataset description

This dataset contains every known close approach of a near-Earth object (NEO) to Earth,
computed by NASA's Center for Near-Earth Object Studies (CNEOS) at the Jet Propulsion
Laboratory. The data is recomputed continuously as new observations refine orbit
estimates and new asteroids are discovered.

Each record includes the closest-approach distance (with 3-sigma uncertainty bounds),
relative velocity, absolute magnitude, and — where available — measured diameter.
For objects without a measured diameter, we include estimates derived from
absolute magnitude using standard albedo assumptions.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `designation` | string | Primary designation (e.g. "433", "2024 YR4") |
| `orbit_id` | string | Orbit solution ID used for computation |
| `close_approach_jd` | float64 | Close-approach time (Julian Date, TDB) |
| `close_approach_date` | datetime | Close-approach date/time (UTC) |
| `distance_au` | float64 | Nominal approach distance (AU) |
| `distance_min_au` | float64 | Minimum possible distance, 3-sigma (AU) |
| `distance_max_au` | float64 | Maximum possible distance, 3-sigma (AU) |
| `distance_ld` | float64 | Nominal approach distance (Lunar Distances) |
| `velocity_relative_kms` | float64 | Velocity relative to Earth (km/s) |
| `velocity_infinity_kms` | float64 | V-infinity / hyperbolic excess velocity (km/s) |
| `time_uncertainty` | string | 3-sigma time uncertainty (e.g. "< 00:01" or "4_15:23") |
| `absolute_magnitude` | float64 | Absolute magnitude H (brightness proxy for size) |
| `diameter_km` | float64 | Measured diameter in km (null if unknown) |
| `diameter_sigma_km` | float64 | Diameter 1-sigma uncertainty in km |
| `full_name` | string | Full formatted name/designation |
| `estimated_diameter_min_m` | float64 | Estimated diameter (m) assuming albedo 0.25 (bright) |
| `estimated_diameter_max_m` | float64 | Estimated diameter (m) assuming albedo 0.05 (dark) |
| `is_pha` | bool | Potentially Hazardous Asteroid flag (H <= 22 and distance <= 0.05 AU) |

## Quick stats

- **41,851** close approaches (1900--2099)
- **4,245** involving Potentially Hazardous Asteroids
- **1,029** objects with measured diameters
- Closest recorded approach: **(2025 UC11)** at **0.02 LD** (0.000044 AU)

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/neo-close-approaches", split="train")
df = ds.to_pandas()

# Upcoming close approaches sorted by distance
upcoming = df[df["close_approach_date"] > "2025-01-01"].sort_values("distance_au")

# Potentially hazardous approaches
pha = df[df["is_pha"] == True].sort_values("distance_au")

# Large objects (estimated > 100m) passing within 10 Lunar Distances
big_close = df[
(df["estimated_diameter_max_m"] > 100) &
(df["distance_ld"] < 10)
]

# Approaches per decade
df["decade"] = (df["close_approach_date"].dt.year // 10) * 10
by_decade = df.groupby("decade").size()
```

## Data source

[NASA JPL CNEOS SBDB Close-Approach Data API](https://ssd-api.jpl.nasa.gov/doc/cad.html).
Orbits are continuously refined as new astrometric observations are collected by surveys
like Catalina Sky Survey, Pan-STARRS, and ATLAS.

## Update schedule

Daily at 10:00 UTC via [GitHub Actions](https://github.com/juliensimon/space-datasets).

## Related datasets

- [space-track-satcat](https://huggingface.co/datasets/juliensimon/space-track-satcat) — Full NORAD satellite catalog
- [space-track-tle-history](https://huggingface.co/datasets/juliensimon/space-track-tle-history) — 232M historical TLE records
- [space-launch-log](https://huggingface.co/datasets/juliensimon/space-launch-log) — Global launch history from GCAT
- [starlink-fleet-data](https://huggingface.co/datasets/juliensimon/starlink-fleet-data) — Daily Starlink constellation snapshots

## Pipeline

Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)

## Support

If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/neo-close-approaches) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.

## Citation

```bibtex
@dataset{neo_close_approaches,
author = {Simon, Julien},
title = {NEO Close Approaches},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/neo-close-approaches},
note = {Based on NASA/JPL Center for Near Earth Object Studies (CNEOS) data via the SBDB Close-Approach API}
}
```

## License

[CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)