Skyfield is a pure-Python astronomy package that is compatible with both Python 2 and 3 and makes it easy to generate high precision research-grade positions for planets and Earth satellites.

from skyfield.api import load
planets = load('de421.bsp')
earth, mars = planets['earth'], planets['mars']
ts = load.timescale()
t = ts.now()
position = earth.at(t).observe(mars)
ra, dec, distance = position.radec()
print(ra)
print(dec)
print(distance)

The result:

10h 47m 56.24s
+09deg 03' 23.1"
2.33251 au

Skyfield’s only binary dependency is NumPy. Once that is available, Skyfield can usually be installed with:

pip install skyfield

Here are the essential project links:

• Home page and documentation.
• Installing Skyfield.
• Contributing to Skyfield.
• Skyfield package on the Python Package Index.
• Issue tracker on GitHub.