Planet Habitability

{
  "asOf": "2026-10-11T08:48:46.408Z",
  "conservativeZoneAu": [
    0.358,
    0.656
  ],
  "controversial": false,
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "earthRatios": {
    "density": 0.9808,
    "densityGcc": 5.408,
    "escapeVelocityKmS": 14.84,
    "escapeVelocityRatio": 1.327,
    "mass": 2.36,
    "radius": 1.34,
    "surfaceGravity": 1.314
  },
  "equilibriumTempK": {
    "archiveValue": 241,
    "earthLikeAlbedo0p3": 232.8,
    "zeroAlbedo": 254.5
  },
  "host": "Kepler-442",
  "hzMethod": "Kopparapu et al. 2013, ApJ 765, 131: S_eff = S0 + aT + bT^2 + cT^3 + dT^4, T = Teff - 5780; distance = sqrt(L / S_eff)",
  "insolationEarth": 0.699,
  "luminositySolar": 0.1169,
  "luminositySource": "archive luminosity (log10 solar)",
  "massEarth": 2.36,
  "massIsMinimum": false,
  "name": "Kepler-442 b",
  "notChecked": [
    "atmosphere, magnetic field, water, tidal locking, flares and stellar activity: none are known for most planets",
    "whether the planet is rocky: a radius under about 1.6 Earth radii makes a rocky planet likely, but mass is often unknown",
    "…2 more"
  ],
  "optimisticZoneAu": [
    0.27,
    0.682
  ],
  "orbitAu": 0.409,
  "orbitSource": "archive semi-major axis",
  "position": "INSIDE_CONSERVATIVE_ZONE",
  "radiusEarth": 1.34,
  "reasons": [
    "Method: Kopparapu et al. 2013 climate-model flux limits (moist greenhouse and maximum greenhouse for the conservative zone; recent Venus and early Mars for the optimistic zone), scaled by stellar lumi…",
    "Radius 1.34 Earth radii is within the range where planets are usually rocky (about 1.6 or less).",
    "…2 more"
  ],
  "sizeClass": "super-Earth",
  "source": "NASA Exoplanet Archive (Caltech/IPAC)",
  "sourceUrl": "https://exoplanetarchive.ipac.caltech.edu",
  "starTempInModelRange": true,
  "summary": "Kepler-442 b orbits at 0.409 au; the Kepler-442 habitable zone spans 0.358 to 0.656 au (conservative) and 0.27 to 0.682 au (optimistic): inside conservative hz. Size class: super-Earth.",
  "verdict": "INSIDE_CONSERVATIVE_HZ"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://exoplanets-nasa.x402tookit.com/planet-habitability?name=Kepler-442+b'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://exoplanets-nasa.x402tookit.com/planet-habitability?name=Kepler-442+b' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fexoplanets-nasa.x402tookit.com%2Fplanet-habitability
const res = await pay("https://exoplanets-nasa.x402tookit.com/planet-habitability?name=Kepler-442+b");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://exoplanets-nasa.x402tookit.com/planet-habitability?name=Kepler-442+b")
    print(res.status_code, res.text)