def random_spherepos(n):
    """returns SkyCoord object with n positions randomly oriented on the unit sphere

    Parameters
    ----------
    n : int
        number of positions desired

    Returns
    -------
    c : ``SkyCoord`` object with random positions 
    """
    signs = np.sign(rand.uniform(-1,1,size=n))
    thetas = Angle(np.arccos(rand.uniform(size=n)*signs),unit=u.rad) #random b/w 0 and 180
    phis = Angle(rand.uniform(0,2*np.pi,size=n),unit=u.rad)
    c = SkyCoord(phis,thetas,1,representation='physicsspherical')
    return c