diff --git a/gravity_simulation_ui.py b/gravity_simulation_ui.py
new file mode 100644
index 0000000..ec09ecc
--- /dev/null
+++ b/gravity_simulation_ui.py
@@ -0,0 +1,103 @@
+import bpy
+import numpy as np
+
+# UIプロパティ登録
+def register_props():
+    bpy.types.Scene.gravity_strength = bpy.props.FloatProperty(
+        name="重力定数 G",
+        default=1.0,
+        min=0.1,
+        max=5.0,
+        step=0.1,
+        precision=2
+    )
+
+# 軌道シミュレーション実行関数
+def calculate_orbit(context):
+    G = context.scene.gravity_strength
+    M = 1000
+    pos = np.array([5.0, 0.0])             # 初期位置（固定）
+    vel = np.array([0.0, 10.0])            # 初期速度（固定）
+    dt = 0.01
+    steps = 400
+    positions = []
+
+    # 既存オブジェクト削除
+    bpy.ops.object.select_all(action='SELECT')
+    bpy.ops.object.delete(use_global=False)
+
+    # 太陽（オレンジ）
+    bpy.ops.mesh.primitive_uv_sphere_add(radius=1, location=(0, 0, 0))
+    sun = bpy.context.object
+    sun.name = "Sun"
+    mat = bpy.data.materials.new("SunMat")
+    mat.diffuse_color = (1.0, 0.5, 0.0, 1)
+    sun.data.materials.append(mat)
+
+    # 地球（青）
+    bpy.ops.mesh.primitive_uv_sphere_add(radius=0.3, location=(pos[0], pos[1], 0))
+    earth = bpy.context.object
+    earth.name = "Earth"
+    mat = bpy.data.materials.new("EarthMat")
+    mat.diffuse_color = (0.2, 0.5, 1.0, 1)
+    earth.data.materials.append(mat)
+
+    for _ in range(steps):
+        r_vec = -pos
+        dist = np.linalg.norm(r_vec)
+        acc = G * M * r_vec / dist**3
+        vel += acc * dt
+        pos += vel * dt
+        positions.append(pos.copy())
+
+    # アニメーション設定
+    scene = context.scene
+    scene.frame_start = 1
+    scene.frame_end = steps
+    frame = 1
+    for p in positions:
+        earth.location = (p[0], p[1], 0)
+        earth.keyframe_insert(data_path="location", frame=frame)
+        frame += 1
+
+# UIパネル
+class GravityOnlyPanel(bpy.types.Panel):
+    bl_label = "重力定数で軌道観察"
+    bl_idname = "VIEW3D_PT_gravity_only"
+    bl_space_type = 'VIEW_3D'
+    bl_region_type = 'UI'
+    bl_category = 'OrbitSim'
+
+    def draw(self, context):
+        layout = self.layout
+        layout.prop(context.scene, "gravity_strength")
+        layout.operator("orbit.recalc", text="再計算")
+        layout.operator("screen.animation_play", text="▶ アニメ再生")
+
+# 再計算ボタン
+class RecalcOrbitOperator(bpy.types.Operator):
+    bl_idname = "orbit.recalc"
+    bl_label = "軌道を再計算"
+
+    def execute(self, context):
+        calculate_orbit(context)
+        self.report({'INFO'}, "軌道を再計算しました")
+        return {'FINISHED'}
+
+# 登録と解除
+classes = [GravityOnlyPanel, RecalcOrbitOperator]
+
+def register():
+    for cls in classes:
+        bpy.utils.register_class(cls)
+    register_props()
+
+def unregister():
+    for cls in reversed(classes):
+        bpy.utils.unregister_class(cls)
+    del bpy.types.Scene.gravity_strength
+
+# 登録して初回計算を自動実行
+if __name__ == "__main__":
+    register()
+    calculate_orbit(bpy.context)
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