juliensimon/neowise-asteroid-properties

---
license: cc-by-4.0
pretty_name: "NEOWISE Asteroid Diameters and Albedos"
language:
- en
description: "Physical properties (diameters, albedos, beaming parameters) for 183,449 asteroids from WISE/NEOWISE infrared observations."
task_categories:
- tabular-classification
- tabular-regression
tags:
- space
- asteroids
- neowise
- wise
- nasa
- orbital-mechanics
- open-data
- tabular-data
size_categories:
- 100K<n<1M
configs:
- config_name: default
data_files:
- split: train
path: data/neowise_asteroid_properties.parquet
default: true
---

# NEOWISE Asteroid Diameters and Albedos

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

Physical properties of **183,449** asteroids derived from WISE/NEOWISE infrared observations,
spanning main-belt asteroids, NEOs, Hildas, Jupiter Trojans, Centaurs, irregular satellites,
and ambiguous objects. Includes effective spherical diameters, visible and infrared geometric
albedos, and NEATM thermal beaming parameters.

## Dataset description

The WISE (Wide-field Infrared Survey Explorer) and NEOWISE missions observed over 164,000
minor planets at thermal infrared wavelengths (3.4--22 microns). Thermal model fits to these
observations yield diameter and albedo estimates that are independent of visible-light
assumptions. This dataset combines all published NEOWISE diameter/albedo tables from the
PDS Small Bodies Node (V2.0), covering observations from January 2010 through December 2016.

Each record represents a single thermal-model fit for one object. The `fit_code` column
indicates which parameters were allowed to vary: D=diameter, V=visible albedo, B=beaming
parameter (or F=fast-rotating model), I=infrared albedo.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `object_id` | string | Primary identifier (asteroid number, satellite ID, or provisional designation) |
| `asteroid_number` | Int64 | IAU asteroid catalog number (null for unnumbered/satellites) |
| `prov_desig` | string | Provisional designation (null if none) |
| `comet_desig` | string | Comet designation for dual-nature objects (null if none) |
| `mpc_packed_name` | string | MPC packed-format designation |
| `population` | string | Dynamical population: main_belt, neo, hilda, jupiter_trojan, centaur, irregular_satellite, ambiguous, fixed_diameter |
| `absolute_mag` | float64 | Absolute H magnitude used as input to thermal fit |
| `slope_param` | float64 | G slope parameter for photometric phase correction |
| `mean_jd` | float64 | Mean Julian Date of observations used for fitting |
| `n_w1` | Int64 | Number of W1 (3.4 um) band measurements used |
| `n_w2` | Int64 | Number of W2 (4.6 um) band measurements used |
| `n_w3` | Int64 | Number of W3 (12 um) band measurements used |
| `n_w4` | Int64 | Number of W4 (22 um) band measurements used |
| `fit_code` | string | 4-char code: D=diameter, V=vis albedo, B=beaming/F=FRM, I=IR albedo, -=fixed |
| `diameter_km` | float64 | Best-fit effective spherical diameter (km) |
| `diameter_err_km` | float64 | 1-sigma diameter uncertainty (km) |
| `v_albedo` | float64 | Visible geometric albedo (best-fit or assumed) |
| `v_albedo_err` | float64 | 1-sigma visible albedo uncertainty |
| `ir_albedo` | float64 | Infrared geometric albedo (best-fit or assumed) |
| `ir_albedo_err` | float64 | 1-sigma infrared albedo uncertainty |
| `beaming_param` | float64 | NEATM thermal beaming parameter eta |
| `beaming_param_err` | float64 | 1-sigma beaming parameter uncertainty |
| `stacked_flag` | string | "S" if fit used co-added images on predicted position |
| `reference` | string | Short reference code for original publication |
| `notes` | string | Flags: OrbChange, NoOrb, BrokenLink (null if none) |

## Quick stats

- **183,449** objects across **8** dynamical populations
- **178,883** main-belt asteroids
- **1,523** near-Earth objects
- **1,860** Jupiter Trojans
- **182,002** objects with measured visible albedo
- Median diameter: **4.3 km** | Median V-albedo: **0.075**

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/neowise-asteroid-properties", split="train")
df = ds.to_pandas()

# Albedo distribution by population
df.groupby("population")["v_albedo"].describe()

# Large dark asteroids (low albedo, big diameter)
dark_big = df[(df["v_albedo"] < 0.05) & (df["diameter_km"] > 100)]

# NEOs with measured properties
neos = df[df["population"] == "neo"].sort_values("diameter_km", ascending=False)

# Diameter vs albedo scatter
import matplotlib.pyplot as plt
sample = df.dropna(subset=["diameter_km", "v_albedo"])
plt.scatter(sample["diameter_km"], sample["v_albedo"], s=0.5, alpha=0.3)
plt.xscale("log")
plt.xlabel("Diameter (km)")
plt.ylabel("Visible Albedo")
```

## Data source

[PDS Small Bodies Node — NEOWISE Diameters and Albedos V2.0](https://sbnarchive.psi.edu/pds4/non_mission/neowise_diameters_albedos_V2_0.zip)

Based on observations by the Wide-field Infrared Survey Explorer (WISE) and its NEOWISE
reactivation mission. See Mainzer et al. (2011), Masiero et al. (2011, 2014, 2017),
Grav et al. (2012), Bauer et al. (2013), Nugent et al. (2015, 2016).

## Pipeline

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

## Citation

```bibtex
@dataset{neowise_asteroid_properties,
author = {Simon, Julien},
title = {NEOWISE Asteroid Diameters and Albedos},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/neowise-asteroid-properties},
note = {Based on WISE/NEOWISE data from the PDS Small Bodies Node, Mainzer et al.}
}
```

## License

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