The coming weeks bring the return of an old friend to our skies.
Scientifically, culturally and historically, this body has permeated our lives through the years. It visits us every 26 months but remains part of our existence virtually on a daily basis, sharing the origins of its name with the third month of the year and third day of the week (Tuesday). It inspired a wealthy Bostonian to found an observatory in Flagstaff, writers to help solidify the science fiction genre, and generations of scientists to understand its physical characteristics.
On April 8, that old friend Mars will be at opposition, when it will lie opposite Earth from the Sun. These three bodies will be positioned nearly in a straight line and as the Sun sets in the west, Mars will rise in the east and reach its highest point in the sky at around midnight. These Martian oppositions occur every 26 months, and, in general, when planets are at opposition they also make their closest approaches to Earth.
But because planet orbits are elliptical rather than perfectly circular, the exact time and distance of closest approach varies.
During the 2014 opposition, Mars reaches its closest point to Earth on April 14 at a distance of 58 million miles. In comparison, the (in)famous 2003 Mars opposition, which triggered fantastically false claims that Mars would appear as big as the full moon, brought the Red Planet within 35 million miles of Earth.
April 14 will be quite a night for sky watchers, because not only does Mars make its closest approach to Earth in 2014, but it also happens to be only four degrees (about half the width of your fist held at arm’s length) from the full Moon; on the same night, the bright star Spica will be just two degrees from the Moon.
Furthermore, the Moon will undergo a total eclipse that evening, noticeably darkening beginning at about 11 p.m. This eclipse is the first of a tetrad, four consecutive total eclipses with no partial eclipses in between.
Some mystics have called this tetrad the Blood Moon prophecy, linking it to a Biblical prophecy of the End Times. The last tetrad occurred in 2003-04 and the next will be in 2032-33.
Mars is easily visible with the unaided eye, appearing as a bright, reddish point of light. Through a telescope it appears more Earth-like to us than most of the other planets because we can observe its surface, atmospheric clouds and hazes, and brilliant white polar caps. The latter are composed of frozen carbon dioxide and underlying water ice, and they wax and wane during the Martian year. In 2014, observers will enjoy an excellent view of the prominent north polar cap because it will be tilted toward Earth.
While the best viewing of Mars in 2014 will be around opposition, the planet will remain visible in the night sky through April 2015, when it will be lost in the Sun.
Kevin Schindler is communications manager for Lowell Observatory.