README.md

---
license: cc-by-4.0
pretty_name: "MPC Comet Orbital Elements"
language:
  - en
description: "Orbital elements for all known comets from the Minor Planet Center. Includes perihelion distance, eccentricity, orbital angles, magnitude, and classification."
task_categories:
  - tabular-classification
  - tabular-regression
tags:
  - space
  - comets
  - orbits
  - mpc
  - orbital-mechanics
  - open-data
  - tabular-data
size_categories:
  - n<1K
configs:
  - config_name: default
    data_files:
      - split: train
        path: data/mpc_comet_elements.parquet
    default: true
---

# MPC Comet Orbital Elements

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

Orbital elements for **946** known comets published by the
[Minor Planet Center](https://www.minorplanetcenter.net/) (MPC).
Covers periodic, long-period, defunct, and interstellar objects.

## Dataset description

The MPC maintains the authoritative catalogue of comet orbits, updated as new
observations refine existing solutions and new comets are discovered. Each record
contains the six Keplerian orbital elements (perihelion distance, eccentricity,
argument of perihelion, longitude of the ascending node, inclination, and
perihelion date), plus absolute magnitude and slope parameter.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `periodic_comet_number` | Int64 | IAU periodic comet number (null for non-periodic) |
| `orbit_type` | string | MPC orbit type code: C (long-period), P (periodic), D (defunct), X (uncertain), I (interstellar), A (minor-planet-like) |
| `orbit_type_name` | string | Human-readable orbit type |
| `packed_designation` | string | MPC packed provisional designation |
| `perihelion_year` | int | Year of perihelion passage |
| `perihelion_month` | int | Month of perihelion passage |
| `perihelion_day` | float | Day of perihelion passage (TT) |
| `perihelion_date` | datetime | Perihelion passage date (truncated to day) |
| `perihelion_distance_au` | float64 | Perihelion distance (AU) |
| `eccentricity` | float64 | Orbital eccentricity |
| `arg_perihelion_deg` | float64 | Argument of perihelion, J2000.0 (degrees) |
| `lon_asc_node_deg` | float64 | Longitude of the ascending node, J2000.0 (degrees) |
| `inclination_deg` | float64 | Inclination to ecliptic, J2000.0 (degrees) |
| `epoch_date` | datetime | Epoch of osculating elements (perturbed solutions) |
| `absolute_magnitude_h` | float64 | Absolute (total) magnitude parameter H |
| `slope_parameter_g` | float64 | Photometric slope parameter G |
| `orbital_period_years` | float64 | Orbital period in years (Kepler's 3rd law, null for hyperbolic) |
| `is_hyperbolic` | bool | True if eccentricity >= 1.0 |
| `name` | string | Comet name / designation |
| `reference` | string | MPC reference for the orbit solution |

## Quick stats

- **946** comets total
- **639** periodic (P), **290** long-period (C), **3** defunct (D)
- **115** on hyperbolic orbits (eccentricity >= 1)
- Perihelion distances range from **0.0057** to **14.1** AU
- Closest perihelion: **C/2026 A1 (MAPS)** at **0.005738** AU

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/mpc-comet-elements", split="train")
df = ds.to_pandas()

# All periodic comets
periodic = df[df["orbit_type"] == "P"].sort_values("perihelion_distance_au")

# Hyperbolic / interstellar visitors
hyperbolic = df[df["is_hyperbolic"]].sort_values("eccentricity", ascending=False)

# Sun-grazing comets (perihelion < 0.05 AU)
sungrazers = df[df["perihelion_distance_au"] < 0.05]

# Distribution of inclinations
df["inclination_deg"].hist(bins=50)
```

## Data source

[Minor Planet Center — Comet Orbital Elements](https://www.minorplanetcenter.net/iau/MPCORB/CometEls.txt).
Format documentation: [Comet Orbit Format](https://www.minorplanetcenter.net/iau/info/CometOrbitFormat.html).

## Update schedule

Rebuilt monthly (static dataset).

## Related datasets

- [neo-close-approaches](https://huggingface.co/datasets/juliensimon/neo-close-approaches) — NEO close approaches from NASA JPL
- [mpc-asteroid-orbits](https://huggingface.co/datasets/juliensimon/mpc-asteroid-orbits) — MPC asteroid orbital elements

## Pipeline

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

## Citation

```bibtex
@dataset{mpc_comet_elements,
  author = {Simon, Julien},
  title = {MPC Comet Orbital Elements},
  year = {2026},
  publisher = {Hugging Face},
  url = {https://huggingface.co/datasets/juliensimon/mpc-comet-elements},
  note = {Based on data from the IAU Minor Planet Center}
}
```

## License

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