If you are the type of person who harbours a fear of inimical solar-system neighbours waiting for favourable orbit approaches to launch an attack against Earth, be on guard during the coming week.
Mars, named after the Roman god of war and with an orange-red colour often associated with anger (witness the 1959 science-fiction thriller The Angry Red Planet), will be in "opposition" on Friday (July 27).
This will afford viewers on Earth their closest and brightest view of Mars since 2003, when it was at its nearest point to our planet in 60,000 years.
If out-of-practice Mars inhabitants missed their brief saucer-launch window back then, they will be eager not to miss this opportunity, because the next record-breaking approach doesn't happen for more than two centuries, on August 28, 2287 (according to NASA, as detailed by space.com).
Those who pooh-pooh the idea of life on Mars were given pause, no doubt, by the announcement mere days ago that scientists have confirmed the existence of a 20-kilometre-long lake of liquid water—a prerequisite for life as we know it—underneath the planet's south polar icecap. David Bowie wasn't the only one to wonder: "Is there life on Mars?"
Opposition means that Mars and the sun are lined up on opposite sides of the Earth, with all three in a straight line. This is what happens on July 27, with Mars's actual closest approach taking place a few days later, shortly after midnight, at 12:50 a.m. (Pacific) on July 31.
This is when the planet will be at its brightest. It's reddish colour will be visible more than ever to the naked eye, and even a backyard medium-size telescope will be able to pick out darker features on the planet's surface.
Mars will be about 10 times brighter than usual, and when it comes its closest, it will be about 57 million kilometres away, a mere jump compared to its average distance of 225 million kilometres (and its farthest reach of about 400 million kilometres).
By coincidence, this Mars opposition comes at the same time as this month's full moon, which will also be undergoing (but not for unlucky North Americans) a total lunar eclipse—the longest such eclipse of the 21st century, and one in which viewers in the Eastern Hemisphere (Europe, Asia, Africa, Australia) will be treated to a vision of the lunar orb turning a deep-red colour alongside Mars, the so-called blood moon.
Mars will rise in the night sky at the same time that the sun sets, and it will set when the sun rises. It will remain bright until August 3. It will be the fourth-brightest object in our planet's night sky during this period, after the sun, the moon, and Venus.
And as Douglas Spencer warned Earth's inhabitants at the close of 1951's The Thing From Another World: "Watch the skies! Everywhere. Keep Looking. Keep watching the skies!"