# NASA Exoplanets – Planet Habitability Screen

> NASA Exoplanets – Planet Habitability Screen is a paid API for AI agents from exoplanets-nasa.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Checks whether a named exoplanet falls within its star's habitable zone and assesses its size class and rocky-planet plausibility.

## Facts

- Endpoint: GET https://exoplanets-nasa.x402tookit.com/planet-habitability?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nasa-exoplanets-planet-habitability-screen-7978b0f9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eh_SqYrcSoQsiWbPPSfdY

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-planet-habitability-screen-7978b0f9
```

Example prompt: Is TRAPPIST-1 e in the habitable zone of its star, and is it likely to be a rocky planet?

## When to prefer this

Use this endpoint when you need a quick, structured habitability verdict for a specific named exoplanet — including its orbital position relative to habitable zone edges, size class, and rocky-planet plausibility — without needing to supply stellar parameters yourself. Prefer this over raw archive queries when you want a pre-computed, human-readable summary with reasons.

## Known failure modes

- Planet name not found in NASA archive — returns null or empty fields
- Ambiguous planet name yields no match
- Missing orbital or stellar data causes degraded output with notChecked fields populated
- API returns null for key fields if NASA archive lacks radius or mass data for the planet

## How this service works

Habitable-zone screen for a named exoplanet: orbit versus the zone edges, size class and rocky-planet plausibility.

## Output

Returns a verdict (e.g. 'inside habitable zone', 'too hot', 'too cold'), the planet's orbital distance in AU compared to the habitable zone edges (Kopparapu 2013 method), size class (e.g. super-Earth, sub-Neptune), rocky-planet plausibility, mass and radius in Earth units, equilibrium temperature estimates, insolation ratio relative to Earth, host star name, data source URL, and a list of reasons supporting the verdict. May also flag if the data is degraded or the classification is controversial.

## 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": [
      "name"
     ],
     "properties": {
      "name": {
       "type": "string",
       "description": "Planet name, for example TRAPPIST-1 e or Kepler-442 b"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "host": {
       "type": [
        "null",
        "string"
       ]
      },
      "name": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "orbitAu": {
       "type": [
        "null",
        "number"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "hzMethod": {
       "type": [
        "null",
        "string"
       ]
      },
      "position": {
       "type": [
        "null",
        "string"
       ]
      },
      "massEarth": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeClass": {
       "type": [
        "null",
        "string"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "earthRatios": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "mass": {
         "type": [
 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nasa-exoplanets-planet-habitability-screen-7978b0f9/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)