Even if we’ve been freezing all the way into March, at least it’s warming up in north Mars.
Summer arrived in the Red Planet’s northern hemisphere on Feb. 15 (Earth reckoning), and in a few weeks, on April 8 to be exact, the planet will be at opposition — meaning it will be directly opposite the sun in our sky. Since the sun will be shining pretty much directly onto the side facing us, Mars will be reflecting nearly the maximum amount of light it can at us at its present distance, shining brightly at magnitude minus 1.5, and it will be visible over most eastern horizons by around 8:30 or 9 p.m. It shows up a little later in my backyard because of age-old terrestrial flora, i.e., firs, spruces, pines and maples.
Since one Martian year lasts something less than two Earth years, summer goes on for nearly twice as long, and so the autumnal equinox in its northern hemisphere falls on our Aug. 17 this year. On a nice summer day near Mars’ equator, the temperature can reach up to 70 degrees Fahrenheit, but the atmosphere is around 100 times thinner than ours and can’t retain much heat. So even in low latitudes, the nighttime temperature can go to minus 100 F, about the average temperature in central Maine this winter. Just estimating.
It is generally thought that these conditions make it unlikely anything’s living on Mars, though not impossible. More and more information streaming back to Earth on light waves from robots indicates water is present — if not abundantly, then at least widely — and where there’s water, there’s the basic environmental element to support life, or to have supported life in some long-past Martian epoch.
Five robots are active right now at Mars. The Curiosity rover is tooling along near Mount Sharp. The Mars Exploration rover Opportunity has been sending back data for more than 10 years — even though it was expected to last only 90 days. The Mars Reconnaissance Orbiter is searching from aloft for evidence of ancient water. The European Space Agency’s Mars Express orbiter has been taking detailed pictures of the surface since December 2003, and the Mars Odyssey spacecraft has been making images since October 2001.
Meanwhile, back on Earth, some space scientists recently invigorated the debate about ancient Martian life by reporting in Astrobiology magazine that their study of a meteorite found in 2000 indicates Mars may well have supported life at some point. Yamato 00593 is one specimen of a kind of meteorite whose chemical composition indicates it originated on Mars and split off in an impact about 12 million years ago, traveled through space, and then crashed into Antarctica in the vicinity of the Yamato Glacier about 50,000 years ago.
Meteorite Yamato has tiny tunnel structures in it that resemble borings made by bacteria in basaltic material on Earth. It also has tiny spherules of high carbon concentration that might have formed as a result of biological processes. The research adds to a report in 1996 of similar findings in a different Antarctic meteorite also thought to have come from Mars. Some scientists are skeptical that the evidence necessarily points to biological origin, but the possibility is out there.
Anyway, northern summer is underway up on Mars. You can get a pretty good Earth-based look at it in the coming weeks, especially if you have a little backyard telescope or even just binoculars. And if the cosmic gears keep turning here the same way they turn Mars, summer eventually will come to the Northern Hemisphere on Earth, too, and the flora will again show signs of life. Just speculating.
Dana Wilde lives in Troy. His writings on the stars and planets are collected in “Nebulae: A Backyard Cosmography,” available from Booklocker.com and online book sellers. Backyard Naturalist appears the second and fourth Thursdays each month. You can contact him at firstname.lastname@example.org.