While studying photographs taken in <a href="https://en.wikipedia.org/wiki/January" id="mwow" rel="mw:WikiLink" title="January">January</a>, <a href="https://en.wikipedia.org/wiki/Clyde_Tombaugh" id="mwpA" rel="mw:WikiLink" title="Clyde Tombaugh">Clyde Tombaugh</a> discovers <a href="https://en.wikipedia.org/wiki/Pluto" id="mwpQ" rel="mw:WikiLink" title="Pluto">Pluto</a>.