Minor Planet Center (via Asterank)

Getting Orbital Data

1. Fetch Recent Asteroids

http://asterank.com/api/mpc?limit=10

Returns 10 asteroids with full orbital parameters: a (semi-major axis in AU), e (eccentricity), i (inclination in degrees), H (absolute magnitude), diameter (estimated km), and albedo.

2. Query by Orbital Characteristics

Find near-Earth asteroids (eccentricity > 0.5, semi-major axis < 2 AU):

http://asterank.com/api/mpc?query={"e":{"$gte":0.5},"a":{"$lte":2}}&limit=20

The query parameter accepts MongoDB query operators: $gte (greater or equal), $lte (less or equal), $gt, $lt.

3. JavaScript — Find Large Near-Earth Objects

const query = JSON.stringify({
  "e": {"$gte": 0.5},
  "diameter": {"$gte": 1},
  "a": {"$lte": 1.5}
});
fetch(`http://asterank.com/api/mpc?query=${encodeURIComponent(query)}&limit=50`)
  .then(r => r.json())
  .then(asteroids => {
    asteroids.forEach(a => {
      console.log(`${a.principal_desig || 'Unknown'}:`,
        `diameter=${a.diameter}km,`,
        `orbit=${a.a}AU,`,
        `albedo=${a.albedo}`);
    });
  });

4. Python — Query by Albedo

import requests, json

query = json.dumps({"albedo": {"$gte": 0.3}, "e": {"$lte": 0.1}})
r = requests.get('http://asterank.com/api/mpc',
  params={'query': query, 'limit': 5})
data = r.json()
for ast in data:
    print(f"Designation: {ast.get('principal_desig', 'N/A')}")
    print(f"  Diameter: {ast.get('diameter', '?')} km")
    print(f"  Orbit: {ast.get('a', '?')} AU")