Earth Comparison

{
  "asOf": "2026-10-11T08:48:41.459Z",
  "degraded": false,
  "density": 0.8887,
  "densityGcc": 4.9,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "escapeVelocityKmS": 9.701,
  "escapeVelocityRatio": 0.8673,
  "formulas": "density = 5.514 M / R^3 g/cc; gravity = M / R^2 (Earth = 1); escape speed = 11.186 sqrt(M / R) km/s",
  "mass": 0.692,
  "notChecked": [
    "habitability: matching Earth's size or flux does not make a planet habitable",
    "composition: density hints at rock versus gas but does not identify it",
    "…1 more"
  ],
  "radius": 0.92,
  "radiusEarth": 0.92,
  "reasons": [
    "Ratios come from the radius and mass you supplied.",
    "Radius is within the range where planets are usually rocky (about 1.6 Earth radii or less)."
  ],
  "sizeClass": "Earth-size",
  "source": "computed locally",
  "summary": "Compared with Earth: radius 0.92x Earth (Earth-size); mass 0.692x; gravity 0.8176x; density 4.9 g/cc (Earth 5.514); escape speed 9.701 km/s.",
  "surfaceGravity": 0.8176,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://exoplanets-nasa.x402tookit.com/earth-comparison?massEarth=0.692&radiusEarth=0.92'

# 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/earth-comparison?massEarth=0.692&radiusEarth=0.92' \
  | 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%2Fearth-comparison
const res = await pay("https://exoplanets-nasa.x402tookit.com/earth-comparison?massEarth=0.692&radiusEarth=0.92");
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/earth-comparison?massEarth=0.692&radiusEarth=0.92")
    print(res.status_code, res.text)