The blurry face of Mars prior to the Space Age

*****

I’d been thinking of Pluto all this past summer.

Ten years ago, July 14, 2015, at 7:49 a.m. EDT, the New Horizons probe made its flyby of Pluto, and with the images and data it returned, the one-time ninth planet, joined the solar system of known worlds.

I’ve been thinking of Mars, too, and how our view of it changed.  Yet this is not a story of any the planets — at least the solar system as we know it today.  This is not a story about major vs. dwarf planets.  Nor is it a story about the face of Pluto as revealed by New Horizons.  Nor is it a story of the against-all-odds development and flight of the New Horizon, a program often near death.

I’m not sure it’s a story at all.  

It’s a blurry picture of the solar system as it once was.

It’s not a picture, but a feeling.  Of distance.

The planets were more distant before the Space Age.  Even the largest telescopes showed blurry near-sighted images lacking intimacy, emphasizing the vast distances even of the nearest planet.  

Like the Voyagers looking back at the distant dim solar system, let’s glance over our shoulder and look back through time itself, a measure how far we’ve come.

Back to the old solar system, the one more of dream than substance.

Back to a time when our knowledge of each planet could be listed in a few words.  And what little information we had would prove incorrect.  I see the blank spaces in knowledge so expansive as to hold every dream the human mind and imagination capable of spinning.  The blank expanses filled will Jules Verne, H.G. Wells, Edgar Rice Burroughs and the other dreamers.  This story belongs to them.

Lets look into the old space and astronomy books — I’m holding one I bought when I was in eighth grade in 1968.  I must have purchased it at a long defunct department store in Painesville, Ohio, in 1968.  Basic Astronomy by Peter Van De Kamp, originally published in 1952, cost me $5.95 plus tax, a princely sum.  I carried it slung under my arm everywhere, even though when I tried to read it, I found much of it far beyond my 13-year-old level.   Yet I could understand his chapter on the planets, all that was known sketched in just 12 pages.  He divides the planets into two groups, “terrestrial planets” — Mercury, Venus, Mars, Earth and Pluto, and “major planets,” the gas giants.

Mercury is described in just 140 words, stating that the planet keeps one side facing the sun in a tidal lock.  Wrong.  Saying that Mercury and our Moon are somewhat similar — which will prove somewhat true, as both are heavily cratered.

Venus takes 280 words.  Van de Kamp says there’s evidence of clouds moving over the surface, that the planet appears to have a thick atmosphere.   Cloudy is the perfect metaphor for Venus.  He states that the planet’s year is  255 Earth days, but the length of its day is not known, probably not more than an Earth month.  (Actually, it’s day is longer than its year, lasting 243 Earth days).

Mars takes up a whopping 510 words.  He notes that thin clouds have been seen through telescopes, which are bright in violet light indicating they are composed of water or ice crystals.  The polar ice caps also showed brighter in violet, but their composition was indeterminate.  Spectroscopic study was “rather negative” for about water vapor and oxygen in the Martian atmosphere.

The temperature on Mars at noon might go as high as 50 degrees (C,) van de Kamp said, while at twilight it probably was minus 10 degrees (C) and at midnight minus 20 degrees (C) or less.  (Actually the temperature ranges from 20 degrees (C), [70 degrees (F)] in the day to minus 140 degrees (C ) [minus 220 F] at night.

He notes the misnamed “canals” of Mars and says recent observations “do not confirm” the sharpness of the lines.  They probably are surface features the eye cannot resolve.  “If some of the canals prove to be real, it is very likely that they will not prove to be sharp straight lines, but rather extended areas.  

The green areas on Mars “change in color with the Martian seasons,” which indicates “some sort of vegetation, probably hardy plants like lichens and dry mosses.”

So life on Mars!  What a dream.  

Basic Astronomy covers what van de Kamp calls the major planets in the same minor key.  He notes that all their densities are low, about that of water, all spin in rapid rotation, all have thick atmospheres.  He sketches Jupiter — 12 moons — in 380 words and Saturn — 9 moons — in 420 words.  Uranus and Neptune are lumped together as very much alike, 230 words

And distant Pluto was summed in total in just 90 words, as “little is known” about it.  Van de Kamp says its diameter is estimated at about 6,000 km.  “Hence Pluto is about the size of Mars, possibly larger.”  (Actually its diameter is just 2,370 km, [1,464 mi.]).

He says its surface temperature is below minus 200 C.  (Correct! — its average surface temperature is minus 225 degrees C) 

And that was it for Pluto!

*

In addition to exposing what little was known about the planet, Basic Astronomy shows how unimportant they were to the field.  Planetary sciences had yet to be born.

I’ve been thinking of two events fifty years apart

It’s July 14, 1965, Mariner 4 passed by Mars at a distance of 6,118 mi., and transmitted 22 grainy photographs to Earth.  At the slow data rate possible at the time, each image took 8 hrs. 35 min. to complete.  Instead of canals and the ruins of a dead civilization, the photos, the best of them, showed . . . craters.   Which led people to believe the entire surface was covered with craters.  Instead of a cousin of Earth, Mars became a twin of the Moon.  All because Mariner 4 happened to fly over an ancient crater area in the planet’s southern hemisphere.  The true nature of the planet’s surface remained hidden until Mariner 9 orbited the planet in 1971.

Fifty years, nearly to the day, after Mariner 4 swung by Mars, the last known planet was revealed in images and data transmitted, slowly it seemed, but quickly compared to Mariner 4, in the days following New Horizon’s encounter with Pluto.  Pluto now has a face — plains of frozen nitrogen, mountains of water ice.  And a heart — the heart-shaped expanse of frozen nitrogen.  The western lobe of the “heart,” forms a plain called Sputnik Planitia, composed of frozen nitrogen with traces of carbon monoxide and methane, filling a bowl-shaped impact basin.  It has dunes of frozen methane particles on its western edges, and icebergs of water ice.  Pluto, despite being downgraded from a planet to the status of “dwarf planet” in 2006, the year New Horizons was launched, has proved to be a very active world, forming a double planet with its largest moon, Charon.

Before being revealed, Pluto was believed to be a static, frozen world — a dead planet.  New Horizon’s geology and geophysics team leader, Jeff Moore said as Pluto was revealed, “Nature [is] outdoing our imaginations every time.”

Yes, yet the worlds of imagination persist.  As if Venus was a world of steamy jungles.  As if Mars was crisscrossed with canals.  And yes, as if Pluto was a full-fledged Mars-size planet at the imagination’s boundary to the solar system.  As if standing there, we peered  out into the beyond where everything was stars.  And no one knew if any of them held planets in their pools of untouchable gravity.

That is the world and vision I was born into, and have traveled far from, as have we all, even those born in this century.