diff --git a/src/planets/Mars.ts b/src/planets/Mars.ts
index 25539c18..4b4952dd 100644
--- a/src/planets/Mars.ts
+++ b/src/planets/Mars.ts
@@ -49,4 +49,8 @@ export default class Mars extends Planet {
     ): number {
         return getApparentMagnitudeMars(distanceSun, distanceEarth, phaseAngle);
     }
+
+    public async getCentralMeridian(): Promise<number> {
+        return 0.0;
+    }
 }
diff --git a/src/utils/physicalObsCalc.test.js b/src/utils/physicalObsCalc.test.js
new file mode 100644
index 00000000..b4fce6a3
--- /dev/null
+++ b/src/utils/physicalObsCalc.test.js
@@ -0,0 +1,7 @@
+import {getCentralMeridianMars} from './physicalObsCalc';
+
+it('tests getCentralMeridianMars', () => {
+    const T = -0.0714441976;
+
+    getCentralMeridianMars(T);
+});
diff --git a/src/utils/physicalObsCalc.ts b/src/utils/physicalObsCalc.ts
new file mode 100644
index 00000000..ca6222be
--- /dev/null
+++ b/src/utils/physicalObsCalc.ts
@@ -0,0 +1,32 @@
+export function getCentralMeridianMars(T: number): number {
+    const lambda0 = 352.9065 + 1.1733 * T;
+    const beta0 = 63.2818 - 0.00394 * T;
+
+    console.log(lambda0, beta0);
+
+    const t = 0.005028; // TODO light time
+
+    const rightAscension0 = 316.55 + 0.00675 * (T - 1905);
+    const declination0 = 52.85 + 0.00347 * (T - 1950);
+
+    console.log(rightAscension0, declination0);
+    const JDE = 0;
+    // const t = 0; // Light time
+
+    const delta0Rad = 0.0;
+    const deltaRad = 0.0;
+    const alpha0Rad = 0.0;
+    const alphaRad = 0.0;
+
+    const W = 11.504 + 350.89200025* (JDE - t - 2433282.5);
+
+    console.log(W);
+
+    const term1 = Math.sin(delta0Rad) * Math.cos(deltaRad) * Math.cos(alpha0Rad - alphaRad)
+        - Math.sin(deltaRad) * Math.cos(delta0Rad);
+    const term2 = Math.cos(deltaRad) * Math.sin(alpha0Rad - alphaRad);
+    const zeta = Math.atan2(term1, term2);
+
+    const omega = W - zeta;
+
+}