Taken from the book ‘al-Fiqhul-Muyas-sar’

Translation/amendments/extra points of benefit prepared by Yusuf McNulty
The definition of al-Kusoof, and the wisdom behind it:
Al-Kusoof (eclipse) is when the light of either the sun or the moon becomes covered, due to something out of the ordinary happening. 

Kusoof (solar eclipse – the sun becoming covered during the day).

Khusoof (lunar eclipse – the moon becoming covered during the night) both carry the same meaning in Arabic.

Allaah makes this happen in order to frighten His servants, so that they return to Him in repentance, just as the Prophet – sallallaahu alayhi wasallam, said: ((Indeed, both the sun and the moon are two signs from the signs of Allaah, He does not make them eclipse due to the death or life of anyone, but rather in order to terrify His servants.)) [1]

The ruling of Salaatul-Kusoof and the evidence for it:
Salaatul-Kusoof is waajib (obligatory), as stated by Aboo Awaanah in his Saheeh, and was also narrated from Aboo Haneefah. Imaam Maalik held it to be the same as Jumuah (in ruling). Ibnul-Qayyim strengthened the opinion regarding its obligation, and Sh Muhammad Ibn Saalih al-Uthaymeen agreed with Ibnul-Qayyim’s view. This is because the Prophet – sallallaahu alayhi wasallam, commanded with its performance, and he would set out for it immediately, and he informed that it occurs to frighten the servants (of Allaah). [2]
…It’s time:
The time of the Salaah begins with the onset of the eclipse, and lasts until the eclipse ends due to the Prophet’s statement: ((If you see anything of it (the eclipse), then pray up until it clears.)) [3]
The description of the Salaah and what should be recited 

within it:
🔸It is two rakahs,
🔸in the first rakah you should recite Soorah al-Faatihah loudly – regardless of whether it is night or day – and also another soorah, which should be long.
🔸 Then after that you make rukoo, and this should be prolonged.
 🔸Thereafter you rise up from the rukoo, say ‘samiallaahu liman hamidah’ and ‘rabbanaa wa lakal-hamd’, but there is no sujood just yet;
🔸 rather Soorah al-Faatihah is recited again along with another long soorah, however it should be a little bit shorter than the first (soorah recited). 
🔸Then you make rukoo again, and rise up from it as normal,
🔸 then sujood is performed, twice as normal, but they should be made long.
🔸 After standing up, you should pray the second rakah just as the first, except make it a little bit shorter, 
🔸and you end the Salaah with tashah-hud and tasleem as normal.
🍃Source: salafitalk.com

🖇Link: http://salafitalk.com/threads/1973-Salaatul-Kusoof-The-Eclipse-Prayer


Listen to this beneficial ​talk on the Eclipse: Here

Regarding Christmas..