At 11:30 a.m. Friday, West Des Moines Mayor Steve Gaer held a news conference attended by Gov. Terry Branstad, elected officials from Warren and Madison counties and host of economic development officials to announce the details of Microsoft Corp.’s mega data center project in his city. A short time later, word was circulating that the city of Altoona is preparing to annex about 200 acres that includes a sliver of Facebook Inc. property and a big chunk of development land west of Facebook and north of Interstate 80 for a data center, possibly an expansion of the Facebook data center. City Administrator Jeff Mark said he could not discuss any details about the company driving the annexation request because of the “secrecy that surrounds big projects these days.” Meanwhile, Van Meter also is attempting to annex about 1,000 acres south and east of the city to better position itself for a data center, City Administrator Jake Anderson said recently. The city already has a 200-acre site that has been certified for a data center. Anderson said the city wants to pick up additional ground near a MidAmerican Energy Co. substation that is east of town.