The NASA TV online video channel already starts the live coverage of the Phoenix landing at 6pm EST.
The first possible time for confirmation that Phoenix has landed will be at 7:53pm. The landing would have happened then 15 minutes earlier on Mars, but radio signals take 15 minutes to travel from Mars to Earth.
The Phoenix Mars Lander's mission is to see if there has been water on the red Planet. Phoenix will land near the Mars' north pole.
Watch the Phoenix Mars Landing tonight at NASA TV site. See also the NASA Phoenix blog.