Patrick Rowans Skywatch: Curiosity rover marks 10th year exploring Mars – MassLive.com

NASAs Curiosity rover landed in Gale Crater on Mars on Aug. 6, 2012 at 1:32 a.m. 10 years ago this week. It is in good shape, and expected to continue its climb up Mt. Sharp for years to come.

Its successor, the Perseverance rover, set down in Jezero Crater in February, and Chinas first Mars rover, Tianwen-1 landed at Utopia Planitia in May.

Mars is currently in our morning sky, just one in a line of four planets (Venus, Mars, Jupiter, and Saturn) extending from north-northeast to southwest. In recent weeks, Ive made a point of getting outside around dawn to catch a few views, but had to jockey for position in various places on the street to see out between the trees and their mid-summer foliage. The neighborhood was utterly quiet in the morning twilight, so this did not present a problem.

Elusive Mercury was in this planet parade in early July, but low in the glow of sunrise. Uranus and Neptune are still in this line up, but too distant and dim to see without telescopes.

The planets constantly shift position in our sky and against the backdrop of distant stars because they are so much closer to us. Each world follows its own schedule, and shows little regard for our calendar an unruly behavior that prompted the ancient Babylonians to call them wild goats.

Now that we understand the planets and their orbits in fine detail, Mars, the second-smallest planet in the Solar System, has somehow managed to gained an outsized status. My Google search for Mars produced 1,750,000,000 results more than 2-1/2 times its nearest competitor Venus, with 650,000,000 results.

There are many reasons for this popularity. While not the brightest of the bunch, its unique rusty hue prompted its ancient designation as the god of war, and its modern nickname, The Red Planet. Remember when you look that we are seeing the actual color of Marss surface rocks and dirt through its mostly clear atmosphere.

(Only three celestial objects visible to the naked eye show us their bare rocky surfaces: The moon, Mars, and Mercury. Curiously, their names all start with the letter M, making them easy to remember.)

Mars also varies more in distance and brightness than any other planet. As Earth swings nearer to it in the coming months, we will see it brighten and move into our evening skies.

While its unique color and dramatic changes in brightness have intrigued people through the ages, our modern fascination got a kick start in the 1800s when Italian astronomer Giovanni Schiaparelli described its contrasting light and dark areas as seas and continents. He called the channels he saw through his new generation telescope canali. This was soon mistranslated into canals along with the idea of intelligent life there.

Enter Percival Lowell, an astronomer from Boston, who, from his private observatory in Flagstaff, Arizona, mapped hundreds of canals he believed Martians made to carry water from the poles to the equatorial regions. He promoted his ideas in several books.

These were the inspiration behind H.G. Wells The War of the Worlds in 1898, and Edgar Rice Burroughs Barsoom series starting with the novel A Princess of Mars. Burroughs used Schiaparellis names for Martian regions, and decided to make his Martians green the reason people still refer to aliens as little green men.

On Halloween Eve in 1938, Orson Welles and The Mercury Theater on the Air famously broadcast a radio version of The War of the Worlds, which convinced thousands that Martians were invading America.

Although most experienced astronomers never saw Marss supposed canals, questions persisted into the space age. I actually remember when the controversy was finally settled to everyones satisfaction in 1964 with the first ever close up images of Marss surface sent back by NASAs Mariner 4 fly-by probe. My Dad opened the glossy pages of Aviation Week and Space Technology magazine with me as soon as it arrived, but I could not see much in the grainy black and white images.

When he walked across the room and held up the pictures, craters emerge from the noise. This was history. The alleged network of lines crisscrossing the surface of Mars were merely an illusion due to the human tendency to connect faint groups of dark smudges, such as those seen on Mars through telescopes, with imaginary straight lines.

The deep sense of disappointment many felt at this discovery was short-lived because a new era of Mars exploration was underway, and new surprises awaited. When the twin Viking landers touched down on opposite sides of the planet in 1976, they essentially revealed Mars as we know it today. Color images and data from an array of scientific instruments transformed our understanding of that world and proved that robots would be capable explorers of the Solar System.

By 2015, with New Horizons flight past Pluto, NASAs probes had visited of every major planet in the Solar System.The beautiful dynamic world we found at Pluto was just the latest in a long string of crazy revelations about the worlds of our Solar System.

Why does Mars still beckon? Of all the planets in our solar system, it is, in some ways, the most Earth-like. Roughly halfway in size between Earth and the moon, it has characteristics of both. With so little atmosphere, it has craters like the moon, yet there is enough for weather, including clouds like on Earth.

Mars seasons span a Martian year roughly equal to two Earth-years, but the Martian day, or sol, is only slightly longer than a day on Earth: 24 hours and 39 minutes. Mars is half again as far from the sun as earth, so it gets about 40% of the sunlight reaching Earth although a person standing there would hardly notice the difference.

The reduced sunlight does affect temperatures however, exacerbated by Marss lack of a significant heat-retaining atmosphere. At ground-level the mostly carbon dioxide air is less than one percent as dense as Earths nitrogen-rich atmosphere. The weak sun and thin atmosphere allow temperatures to drop to minus 200 degrees Fahrenheit. The ground can reach a balmy 70 degrees Fahrenheit in summer, but temperatures rarely surpasses the freezing point.

We can relate strongly to those alien hills and valleys because the sky is not black like on the airless moon. More significantly, the Mars sky sometimes appears blue. Pictures of such obtained by the Curiosity rover are particularly striking to those of us still struggling with the fact that this is another planet! (See above picture.)

Most of the time however, Marss sky is some variation on salmon, brown, or butterscotch depending on the angle of the sun, the direction you are looking, and the amount of dust in the air. Sunsets on Mars are blue, as opposed to our reddish sunsets.

Curiosity found strong evidence that in the distant past, Mars had warmer temperatures and enough water in liquid form to support primitive life. Whether any ever existed remains a mystery, but Curiosity has found intriguing hints including this years discovery of a kind of carbon that on Earth is associated with life.

All these things and more make it easy to understand why Mars, with eight active orbiters, three rovers, and one stationary lander, is the busiest place in the Solar System other than Earth.

There are probably many worlds orbiting other stars that are more like Earth, but Mars may be the closest example we humans will ever see in detail. The few images of extrasolar planets so far obtained are unresolvable dots, and no telescope will resolve the continents and oceans of a planet like ours even around the nearest stars for a very long time.

The Curiosity rover has raised Mars exploration to a whole new level, and we are well on our way to making The Red Planet a part of our world.

Find rise and set times for the sun and moon, and follow ever-changing celestial highlights in the Skywatch section of the Weather Almanac in The Republican and Sunday Republican.

Patrick Rowan has written Skywatch for The Republican since 1987 and has been a Weather Almanac contributor since the mid 1990s. A native of Long Island, Rowan graduated from Northampton High School, studied astronomy at the University of Massachusetts-Amherst in the 1970s and was a research assistant for the Five College Radio Astronomy Observatory. From 1981 to 1994, Rowan worked at the Springfield Science Museums Seymour Planetarium, most of that time as planetarium manager. Rowan lives in the Florence section of Northampton with his wife, Clara, and their cats, Eli and Milo.

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Patrick Rowans Skywatch: Curiosity rover marks 10th year exploring Mars - MassLive.com