Todd Strandberg is executive director of RaptureReady.com, which publishes the Rapture Index.

David Reagan is founder and director of Lamb & Lion Ministries, a Christian organization that proclaims the imminent return of Jesus. It is based in McKinney, Texas.

Harold Camping is president of Family Radio and its attendant ministries. He predicted the Second Coming of Jesus on May 21, 2011, followed by the end of the world on Oct. 21, 2011. Camping previously predicted the end of the world in 1994. He lives in Alameda, Calif.

Irvin Baxter is founder and president of Endtime Ministries, a Christian non-profit organization located in Plano, Tex.

The website RaptureReady.com offers a Rapture Index that measures physical signs and events that indicate the Rapture may be near.

Prophecy News Watch compiles news its editors feel is relevant to the Christian apocalypse.

Midnight Call is an online magazine of Christian prophecy that watches world events with an eye toward the Second Coming of Jesus. Email through the website.

Apocalypse Soon is a website devoted to signs of the end. It’s written and compiled by Pietro Arnese, a Christian layperson.

An April 2010 survey from the Pew Research Center found that 41 percent of Americans believe Jesus will return by the year 2050, with breakdowns according to faith tradition. The data were drawn from a wider Pew survey on the public’s expectations of what life will be like at midcentury.