# NASA Exoplanets - Nearest Planets Lookup

> NASA Exoplanets - Nearest Planets Lookup is a paid API for AI agents from exoplanets-nasa.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns the closest known exoplanets to the Sun sorted by distance in light-years, with optional size filtering, star type, orbital parameters, and habitable-zone position.

## Facts

- Endpoint: GET https://exoplanets-nasa.x402tookit.com/nearest-planets?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nasa-exoplanets-nearest-planets-lookup-f67ebc53
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XM4YzorNwgP_WrT9kNKLW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability nasa-exoplanets-nearest-planets-lookup-f67ebc53
```

Example prompt: Show me the 20 closest known exoplanets to our Sun, but only include ones between 0.5 and 1.6 Earth radii so they're likely rocky — I want to see their star types, orbital periods, and whether they're in the habitable zone.

## When to prefer this

Use this endpoint when you need a ranked, proximity-sorted list of confirmed exoplanets near the Sun with rich physical and orbital metadata. Ideal when filtering by planet size is important (e.g. selecting likely rocky worlds). Prefer over general exoplanet search endpoints when distance from Earth is the primary sorting criterion and you want habitable-zone context included automatically.

## Known failure modes

- No planets found matching filters (e.g. very narrow radius range with small search radius) — returns empty planets array
- Invalid parameter values outside allowed ranges (e.g. limit > 50, maxDistancePc > 25) — returns validation error
- Upstream NASA Exoplanet Archive unavailable — may return degraded=true with cached or partial data
- minRadiusEarth greater than maxRadiusEarth — returns error or empty result

## How this service works

Closest known exoplanets to the Sun in light-years, optional size filter, with star type, orbit and habitable-zone position.

## Output

A JSON array of up to 50 exoplanets sorted by proximity to the Sun, each entry including planet name, host star name, distance in both light-years and parsecs, star spectral type, planet radius and mass in Earth units, size class label, orbital period in days, semi-major axis in AU, insolation relative to Earth, equilibrium temperature in Kelvin, habitable zone position, discovery year and method. Also includes a summary, verdict, data source URL, and timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "limit": {
       "type": "integer",
       "description": "Planets returned, 1 to 50 (default 15)"
      },
      "maxDistancePc": {
       "type": "number",
       "description": "Search out to this many parsecs, 1 to 25 (default 10; 1 pc = 3.26 light-years)"
      },
      "maxRadiusEarth": {
       "type": "number",
       "description": "Only planets at most this many Earth radii, 0.1 to 30 (use 1.6 for likely rocky)"
      },
      "minRadiusEarth": {
       "type": "number",
       "description": "Only planets at least this many Earth radii, 0.1 to 30"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "planets": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "host": {
          "type": [
           "null",
           "string"
          ]
         },
         "name": {
          "type": [
           "null",
           "string"
          ]
         },
         "massEarth": {
          "type": [
           "null",
           "number"
          ]
         },
         "sizeClass": {
          "type": [
           "null",
           "string"
          ]
         },
         "radiusEarth": {
          "type": [
           "null",
           "number"
          ]
         },
         "discoveryYear": {
          "type": [
           "null",
           "number"
          ]
         },
         "massIsMinimum": {
          "type": [
           "boolean",
           "null"
          ]
         },
         "discoveryMethod": {
          "type": [
           "null",
           "string"
          ]
         },
         "distanceParsecs": {
   
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nasa-exoplanets-nearest-planets-lookup-f67ebc53/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from exoplanets-nasa.x402tookit.com](https://www.zero.xyz/host/exoplanets-nasa.x402tookit.com/llms.txt)