\documentclass{standalone}
%
\usepackage{tikz}
\usepackage{xcolor}
\definecolor{space}{HTML}{0A2543}
\definecolor{earth}{HTML}{0089FA}
\definecolor{mars}{HTML}{DC7B4E}
%
\usepackage{mathptmx}
\usepackage{fontspec}
\setmainfont{Montserrat}
%
\title{Diffusione della luce in atmosfera}
\begin{document}
	\tikzset{partial ellipse/.style args = {#1:#2:#3}{insert path={+ (#1:#3) arc (#1:#2:#3)}}}
	\begin{tikzpicture}
		%
		\draw [fill=space] (-14,9) rectangle (14,-7.1);
		%
		\coordinate (B') at (-14,9);
		\coordinate (D') at (14,9);
		\coordinate (S') at (14,-7.1);
		\draw [use as bounding box] (B') -| (D') |- (S') -| (B');
		\begin{scope}
			%
			\draw (-14,2) [fill=white, partial ellipse=90:-90:3 and 3];
			%
			\draw [fill=white!50!earth, opacity=0.4](-14,-3.44) -- (-14,-7.2) -- (14,-7.2) -- (14,6.25);
			\draw (10,-27.5) [fill=white!50!earth, opacity=0.4, partial ellipse=83.2:135:34 and 34];
			\draw [color=earth, fill=earth] (14,-2.8) -- (14,-7.2) -- (-4.7,-7.2);
			\draw (10,-27.5) [color=earth, fill=earth, partial ellipse=80.8:126:25 and 25];
			%
			\draw [color=white, ultra thick] (-11,2) -- (-6.9,2);
			\draw [color=blue, ultra thick] (-6.9,2) -- (-1.7,-5.4);
			\draw [color=red, ultra thick] (-6.9,2) -- (14,2);
			%
			\draw [<-, color=white, ultra thick] (-6.9,2) -- (-5.9,5);
			\node at (-5.9,6.4) {\textcolor{white}{\fontsize{20}{21}\selectfont La luce del Sole viene diffusa}};
			\node at (-5.9,5.5) {\textcolor{white}{\fontsize{20}{21}\selectfont dall'atmosfera terrestre}};
			%
			\draw [fill=white] (-14,-7.1) rectangle (14,-7.3);
		\end{scope}
	\end{tikzpicture}
%
\end{document}