Oracle Database Discussions

Please can any one help me solve this problem? I have already checked the alert log file but there seem no luck for repairs
This problem came as a result of power cut.

Below is the result for connecting:

SQL> conn /as sysdba
Connected to an idle instance.

SQL> startup mount
ORACLE instance started.

Total System Global Area 612368384 bytes
Fixed Size 1250428 bytes
Variable Size 587205508 bytes
Database Buffers 16777216 bytes
Redo Buffers 7135232 bytes
Database mounted.
SQL>
SQL>
SQL> alter database recover;

Database altered.

SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced


SQL>