# Plot Eclipse in Latex

I am trying to plot the picture below in latex and I am not good with graphs.

Here a try, but i'm also no expert. Trying is learning. It would be better to detect the intersection, but I don't know how...

\documentclass[border=2mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows}
%Ref: http://tex.stackexchange.com/a/228605/124842
\begin{document}
\begin{tikzpicture}
\def\firstellipse{(-5,0) ellipse (8 and 4.5)}
\def\secondellipse{(-6,-1) ellipse (3 and 2.5)}
\def\thirdellipse{(-4,-0.5) ellipse (3 and 2.5)}

% colour ellipses
\fill[white] \firstellipse ;
\fill[white] \secondellipse;
\fill[gray] \thirdellipse;

\draw[gray] \thirdellipse;

% colour intersection
\begin{scope}
\clip \secondellipse;
\fill[white] \thirdellipse \firstellipse;
\end{scope}

\draw \firstellipse \secondellipse;
\draw[gray,dashed]  \thirdellipse;

\node[draw, fill=white] at (-11.5, 2.8)   (b) {$SS_{TOT}$};
\node at (-6.5, -1.5)   (b) {$SSR(X_2,X_3)$};

%Ref:http://tex.stackexchange.com/a/107101/124842
\draw[black,solid,line width=1mm,fill=black,preaction={-triangle 90,thin,draw,shorten >=-1mm}] (1.5, 3.5) node[above]{$SSR(X_2,X_3)$} -- (-2,1) node[above, scale = 2.3] {};

\end{tikzpicture}
\end{document}