Mars enthusiasts will have a chance to see their favorite planet up close, relatively speaking, when Earth and Mars have a close encounter in late August, according to experts at the University of Colorado at Boulder.
On Aug. 27 Mars will be roughly 34.6 million miles from Earth, the closest it has come in nearly 60,000 years. However, the planets come nearly this close to each other about every 15 years, according to Keith Gleason, manager of CU-Boulder's Sommers-Bausch Observatory.
"The approach this year is only about 1.9 million miles closer than it was back in 1988," he said. "But it is still the best opportunity of the decade for amateur and professional astronomers to view the red planet from Earth."
CU-Boulder's Sommers-Bausch Observatory will be open to the public from 9 p.m. to 1 a.m. on Friday, Aug. 29, for a special midnight viewing of Mars through the observatory's telescopes. There is no cost to visit the observatory.
People should look for Mars in the southeastern sky, where its bright orange glow will be hard to miss, according to Doug Duncan, director of CU-Boulder's Fiske Planetarium. On Aug. 27 it will rise shortly after 8 p.m. MDT, and anytime after 10:30 p.m. should be a good time to view the planet. Without a telescope, Mars will appear to be an orange glowing star.
"Mars is, alas, a small planet, so you will need a big telescope to see much of anything," Duncan said. "What you can hope to see is polar caps, orange desert and sometimes dark areas. It is cool to see a real polar cap on another planet, but it's not easy," he said.
On Aug. 27 Mars is at opposition, which means Earth lies directly in a straight line between Mars and the sun, Gleason said. The close encounter of Earth and Mars, technically referred to as a perihelic opposition, happens because Mars is in opposition and near its perihelion, or closest approach to the sun, at the same time.
When Mars nears its perihelion it is closer to the sun, and hence to Earth, than at other times in its orbit, he said.
"Both of these occurring at the same time is what brings the two planets this close together," Gleason said.
For more information about the Aug. 29 viewing at Sommers-Bausch Observatory call (303) 492-5002.