Sayyiduna Abu Musa (may Allah be pleased with him) said: The sun was eclipsed in the time of the Prophet (peace and blessings be upon him). He (peace and blessings be upon him) rose in alarm, fearing (peace and blessings be upon him) that it might be the Hour itself. He (peace and blessings be upon him) came to the mosque and led a prayer with long standing, bowing and prostration. I had never seen him (peace and blessings be upon him) do so in any prayer. Then he (peace and blessings be upon him) said: "These are signs of Allah; they do not appear because of anyone's death or life, but Allah sends them to frighten His servants by them. When you see anything of this, then hasten to the remembrance of Allah, to supplicating Him and seeking His forgiveness."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخسوف / 6363