Coming to a backyard near you

Field Notes

Over the next two months, backyard skygazers and professional astronomers alike will be focusing their attention and telescopes on Mars, as it heads for its closest encounter with Earth since 1990. In late April and early May, Mars will appear to the naked eye as a glowing red ember in the south amid the constellation Virgo. At that time, Mars will exhibit a wealth of detail even when seen through modest backyard telescopes.

"You can expect to see the planet's gleaming northern polar ice cap as well as subtle dark markings and the occasional hint of passing clouds," says Richard Talcott, Astronomy magazine associate editor.

Astronomers call these close approaches "oppositions," meaning that a planet outside Earth's orbit appears opposite the sun. Mars reaches opposition on April 24, and its elliptical orbit will swing it closest to Earth on May 1.

In early April, Mars can be seen easily with the naked eye in the constellation Libra, low in the eastern sky around 10 p.m. or 11 p.m. As Mars draws ever nearer to Earth, it will appear brighter and rise earlier.

Mars comes to opposition once every 26 months as Earth catches up and passes it. The next Mars opposition is June 13, 2001. And in August 2003, Mars will venture closer to Earth than it has for 5,000 years.