diff --git a/ecoscope/analysis/astronomy.py b/ecoscope/analysis/astronomy.py
index f9e0992f..825fb23d 100644
--- a/ecoscope/analysis/astronomy.py
+++ b/ecoscope/analysis/astronomy.py
@@ -1,7 +1,8 @@
 import warnings
+
 import numpy as np
-import pyproj
 import pandas as pd
+import pyproj
 
 try:
     import astroplan
@@ -109,4 +110,4 @@ def get_daynight_ratio(traj, n_grid_points=150) -> pd.Series:
     day_distance += (day_night_df.dist_meters * i).sum()
     night_distance += ((1 - i) * day_night_df.dist_meters).sum()
 
-    return day_distance / night_distance
+    return night_distance / day_distance
diff --git a/tests/test_astronomy.py b/tests/test_astronomy.py
index 9d483317..50f53e75 100644
--- a/tests/test_astronomy.py
+++ b/tests/test_astronomy.py
@@ -1,7 +1,8 @@
-import pyproj
 import pandas as pd
-from ecoscope.base import Trajectory
+import pyproj
+
 from ecoscope.analysis import astronomy
+from ecoscope.base import Trajectory
 
 
 def test_to_EarthLocation(movebank_relocations):
@@ -36,8 +37,8 @@ def test_daynight_ratio(movebank_relocations):
     trajectory = Trajectory.from_relocations(movebank_relocations)
     expected = pd.Series(
         [
-            2.212816,
-            0.656435,
+            0.451912,
+            1.523379,
         ],
         index=pd.Index(["Habiba", "Salif Keita"], name="groupby_col"),
     )