# Buggy code
def M_to_E(M, ecc):
    """Eccentric anomaly from mean anomaly.

    .. versionadded:: 0.4.0

    Parameters
    ----------
    M : float
        Mean anomaly in radians.
    ecc : float
        Eccentricity.

    Returns
    -------
    E : float
        Eccentric anomaly.

    Notes
    -----
    This uses a Newton iteration on the Kepler equation.

    """
    E0 = M
    E = newton("elliptic", E0, args=(M, ecc))
    return E


# Traceback (FloatingPointError)
$ NUMBA_DISABLE_JIT=1 ipython --no-banner

In [1]: import numpy as np

In [2]: np.seterr(all="raise")
Out[2]: {'divide': 'warn', 'over': 'warn', 'under': 'ignore', 'invalid': 'warn'}

In [3]: import numpy as np
...: import math
...: from astropy import units as u
...: from poliastro.bodies import Earth, Moon
...: from poliastro.twobody import Orbit
...:
...: r=[8.e3, 1.e3, 0.]*u.km
...: v=[-0.5, -0.5, 0.]*u.km/u.s
...: orbit1=Orbit.from_vectors(Earth,r,v)
...: orbit2=orbit1.propagate(1.*u.h)
...:
...:
---------------------------------------------------------------------------
FloatingPointError                        Traceback (most recent call last)
<ipython-input-3-08d7b74965c9> in <module>()
8 v=[-0.5, -0.5, 0.]*u.km/u.s
9 orbit1=Orbit.from_vectors(Earth,r,v)
---> 10 orbit2=orbit1.propagate(1.*u.h)

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/twobody/orbit.py in propagate(self, value, method, rtol, **kwargs)
403                 time_of_flight = time.TimeDelta(value)
404
--> 405             return propagate(self, time_of_flight, method=method, rtol=rtol, **kwargs)
406
407     def sample(self, values=None, method=mean_motion):

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/twobody/propagation.py in propagate(orbit, time_of_flight, method, rtol, **kwargs)
177
178     """
--> 179     r, v = method(orbit, time_of_flight.to(u.s).value, rtol=rtol, **kwargs)
180     return orbit.from_vectors(orbit.attractor, r * u.km, v * u.km / u.s, orbit.epoch + time_of_flight, orbit.plane)

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/twobody/propagation.py in mean_motion(orbit, tofs, **kwargs)
118
119     if not hasattr(tofs, '__len__'):
--> 120         return mean_motion_fast(k, r0, v0, tofs)
121
122     results = [mean_motion_fast(k, r0, v0, tof) for tof in tofs]

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/core/propagation.py in mean_motion(k, r0, v0, tof)
33
34     # get the initial mean anomaly
---> 35     M0 = nu_to_M(nu0, ecc)
36     # strong elliptic or strong hyperbolic orbits
37     if np.abs(ecc - 1.0) > 1e-2:

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/core/angles.py in nu_to_M(nu, ecc, delta)
183     else:
184         D = nu_to_D(nu)
--> 185         M = D_to_M(D, ecc)
186     return M
187

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/core/angles.py in D_to_M(D, ecc)
155 @jit
156 def D_to_M(D, ecc):
--> 157     M = _kepler_equation_parabolic(D, 0.0, ecc)
158     return M
159

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/core/angles.py in _kepler_equation_parabolic(D, M, ecc)
26 @jit
27 def _kepler_equation_parabolic(D, M, ecc):
---> 28     return M_parabolic(ecc, D) - M
29
30

~/.miniconda36/envs/poliastro37/lib/python3.7/site-packages/poliastro/core/angles.py in M_parabolic(ecc, D, tolerance)
41     k = 0
42     while not small_term:
---> 43         term = (ecc - 1.0 / (2.0 * k + 3.0)) * (x ** k)
44         small_term = np.abs(term) < tolerance
45         S += term

FloatingPointError: overflow encountered in double_scalars

# Fixed code
def M_to_E(M, ecc):
    """Eccentric anomaly from mean anomaly.

    .. versionadded:: 0.4.0

    Parameters
    ----------
    M : float
        Mean anomaly in radians.
    ecc : float
        Eccentricity.

    Returns
    -------
    E : float
        Eccentric anomaly.

    Notes
    -----
    This uses a Newton iteration on the Kepler equation.

    """
    assert -np.pi <= M <= np.pi
    if ecc < 0.8:
        E0 = M
    else:
        E0 = np.pi * np.sign(M)
    E = newton("elliptic", E0, args=(M, ecc))
    return E