Method 1: When the Error Message States the Computer Is Locked by domain\username. 1  Press CTRL+ALT+DELETE to unlock the computer. 2  Type the logon information for the last logged on user, and then click OK. 3  When the Unlock Computer dialog box disappears, press CTRL+ALT+DELETE and log on normally.
Halley's comet returns in bits and pieces. Shooting stars should be visible October 21st & 22nd. October 20, 1998: The last time Halley's comet visited Earth, in 1986, many observers were disappointed because the famous comet was barely visible to the naked eye.
Comet Halley has a semimajor axis of 17.9 AU. (b)Find its perihelion and aphelion distances. Does Halleyâs Comet spend most of its time near its perihelion distance, near its aphelion distance, or halfway in between? Explain. Solution: We are told that Halleyâs comet has an eccentricity of 0.97 and in part (a), we calculated its semimajor axis to be 17.9 AU: perihelion distance = (17:9 AU) (1 0:97) = 0:537 AU