I love watching the night sky and we are lucky that there are parts of our Blackstone Heritage Corridor where there is dark country, places sufficiently devoid of man-made lighting where one can still see the night’s sky. Not really an amateur astronomer – more of a celestial cheerleader, I find it easy to get caught up in information about astronomical occurrences.
Last weekend my husband Doug and I went to see the new film, The Martian. It had me on the edge of my seat – two thumbs up or 5 boxes of popcorn from this critic. On the ride home, I remembered that we have something special happening with Mars later this month, an unusual alignment of Jupiter, Venus and Mars, which provoked me to read more about Mars.
Mars is the fourth planet from the sun, a mere 136,764,000 miles away. A year on Mars is 687 Earth days, the time it takes for one revolution around our star. As Mars rotates on its axis, its day is slightly longer than one on Earth, 1.028 Earth days. It gets its name from the Greek word for war, Ares. Mars is called the Red Planet because its surface contains a significant amount of iron oxide. Those are the usual astronomical factoids about Mars.
There is so much more. Mars has two moons discovered in 1877 – Phobos and Deimos. They are quite small and not the rounded perfection of our own moon. Scientists speculate that Phobos and Deimos may actually be asteroids that fell into the Martian gravitational field.
Messages from Mars? Yes! Mars has three man-made orbiters – functioning spacecraft: the Mars Odyssey, the Mars Express and the Mars Reconnaissance Orbiter. Even the surface of the planet has been invaded by gadgets like the Opportunity, Spirit and Phoenix lander. So we are getting messages from above and on Mars – they just are not being sent by little green beings or Matt Damon.
Perhaps it is because Mars and other planets are so far away but I don’t generally think of them as three-dimensional. To me they are flat objects moving through the sky but that is wrong, of course. Not only are they three-dimensional, but some planets have extraordinary features. Mars has some of the most interesting geography in our galaxy.
Mars’ Olympus Mons is the highest mountain in the entire solar system, rising over 78,000 feet. It has a base that exceeds 500 kilometers. There is a huge crater in the southern hemisphere of Mars estimated at 6 kilometers deep and 2000 kilometers wide. Then there is the Valles Marineris, a configuration of canyons that is 4000 kilometers long and up to 7 kilometers deep. A kilometer equals 0.6 miles, so the Valles Marineris is as much as 3 miles deep.
We frequently complain about New England weather. Everyone is familiar with the old adage “wait a minute and it will change.” If we think our weather has great variances, think of what it must be like to plan a day on Mars where the temperature range is minus 207 to plus 81 degrees Fahrenheit.
Of course, we humans wouldn’t be able to enjoy much of the Martian weather since its atmosphere is very thin with only the smallest amounts of water, oxygen, argon and carbon dioxide.
Mars and Earth share some astronomic features. Each planet has two polar caps. The gravitational pull of Mars and Earth are similar.
Mars is the stuff of legends and tales. In the early 20th century, Percival Lowell, an astronomer, viewed what appeared to be canals on Mars. Mr. Lowell went on to extrapolate that if these were canals then they had to be created by intelligent life forms to conserve water. It was later explained that the lines viewed through the telescope were optical illusions and not canals. That didn’t stop the rumor mill and stories of Martians proliferated. H. G. Wells’ The War of the Worlds played into the fantastical story line.
And then there is the Martian Face. First viewed via telescope, this image of the Cydonia Mesas does have dark and light areas that could be interpreted as a human-like face. However, it is a big hill and not deliberately made, debunking the thought that Mars has its own Mount Rushmore.
So much for the Martian myths.
Now about that unusual alignment noted on our 2015 Blackstone Heritage Corridor Calendar. On October 28, set the alarms and get up before the sun. Just before dawn in the eastern sky there will be a rare occurrence. One will be able to see Mars, Venus and Jupiter near one another. The three planets will form a triangle. A three-for!