Planets throwing rare get-together [size=-1]BY BOB CURTRIGHT[/size] [size=-1]The Wichita Eagle[/size] Venus, Saturn and Mercury will be do-si-doing in the western sky this weekend, creating a conjunction that won't be seen again for 65 years, said Martin Ratcliffe of Exploration Place. The celestial show gets under way tonight as the sun is setting. Look to the west and you'll see Venus -- Earth's next-door planet -- appear first as a bright point right above the horizon, he said. As the sky darkens, Saturn, the ringed planet, and Mercury, the closest to the sun, will pop into view. "The challenge of seeing them is that the twilight will be so bright. When it's darker, the planets will be lower in the sky. You'll need a clear western view," Ratcliffe said. But the three will be visible to the naked eye, so a telescope won't be required. The planets will appear so close -- about 1 ½ degrees apart -- that they can be easily hidden by your thumb held at arm's length, he said. "For people not familiar with degrees, one-half degree is about one moon width." That means that the planets will be about three moon widths apart that first night. On Sunday night, right after sunset, the triangle made by the three planets gets even smaller -- only one-half degree apart or one moon width. And on Monday night, Venus and Mercury will converge while Saturn hovers only one-tenth of a degree away. After that, the three will begin moving apart, and Venus and Mercury won't be that close again until 2070. For those who miss the real event this weekend, you can catch the conjunction in "Stars Over Kansas," which shows daily at Exploration Place. The conjunction is part of the show that is updated quarterly to preview celestial events visible over Wichita. "It's quite a spectacular view because we also fly above the solar system in 3-D to show how the line-of-sight effect works for a conjunction," Ratcliffe said. This conjunction will be gone when "Stars Over Kansas" is updated in mid-July, he said. For further information or show times, go online to www.exploration.org and click on "Stars Over Kansas."