fixed the issue. Will look into that further There is a mistake somewhere in the conversion to utm. Try the utm module instead

```
import utm
lat1 = 50.0
lon1 = 10.0
lat2 = 50.5
lon2 = 10.5
x1, y1, z1, u = utm.from_latlon(lat1, lon1)
x2, y2, z2, u = utm.from_latlon(lat2, lon2)
print(distance_haversine(lat1, lon1, lat2, lon2))
print(distance_cartesian(x1, y1, x2, y2))
```

```
66012.51304805529
66047.84250743943
```