# Intersecting a sphere with a line

I would like to replicate the following image in Tikz. Would anybody be able to help me? I've heard that drawing spheres and lines with good coordinate systems are hard...

• Your picture can easily be reproduced in TikZ. What have you tried so far? – Marian G. Apr 18 '19 at 19:41
• Your picture is unfortunately not an orthogonal projection. If I was you I would probably just take e.g. this code and minimally modify it to get a more realistic projection. – user121799 Apr 18 '19 at 20:21

Welcome to TeX-SE! This produces something of that sort. It employs tikz-3dplot for the orthonormal projections of the view and the 3d library for projections on appropriate planes.

\documentclass[tikz,border=3.14mm]{standalone}
\usepackage{tikz-3dplot}
\usetikzlibrary{3d}
\begin{document}
\tdplotsetmaincoords{105}{-10}
\begin{tikzpicture}[tdplot_main_coords,bullet/.style={circle,fill,inner sep=1.2pt}]
% parameters
\pgfmathsetmacro{\Angle}{20}
% axes
\draw[-stealth] (0,0,0) coordinate (O) -- (0,0,1.2*\Radius);
% sphere
\draw[ball color=gray,fill opacity=0.3,tdplot_screen_coords] (0,0)
% equator
\begin{scope}[canvas is xy plane at z=0]
\end{scope}
% plane that runs through the poles
\tdplotsetrotatedcoords{-130}{0}{0}
\begin{scope}[tdplot_rotated_coords,canvas is xz plane at y=0]