Europa and the Hoagland Eccentricity

Since there are a bunch of Europa articles springing up in recent days, I thought I'd repost this just for historical clarification:

Europa and the Hoagland Eccentricity

by Jay Ingram

The Toronto Star

Sunday, March 9, 1997

Context Section - Page B8

Science

 

 

Ever since the announcement last summer that there might have been life in the past on Mars, the extraterrestrial-life bandwagon has been full speed ahead. Speculation abounds but a recent case illustrates that there are limits: speculation still has to look and sound like science.

At the annual meeting of the American Association for the Advancement of Science a couple of weeks ago, scientists discussed the possibility that life might have - and might still exist on Jupiter's moon Europa.

Europa is by any measure a bizarre solar system object. Its surface appears to be a huge badly flooded skating rink at the end of a busy weekend, a vast globe of ice criss-crossed everywhere by cracks. There are very few craters, suggesting that those that once existed (almost everything in the solar system is thought to have been bombarded early on) have been smoothed out by an ever-changing surface.

Support for this idea comes from recent photos by the Galileo spacecraft showing what look like knew ice floes covering over old cracks. Also some of the cracks seem wider and darker than others.

This visual evidence, together with theoretical estimates of the heat-generating tidal pull on Europa by nearby Jupiter have prompted speculation that under that crust of ice (possibly very far under) there is a vast singular ocean of liquid water.

The dark cracks might be Europa's counterpart of shifting ice pans in the dark Arctic, which sometimes break apart to reveal narrow channels of darker water between.

At the AAAS meeting, scientists were building on the idea of the moon-girdling ocean to suggest that undersea volcanoes on Europa, powered by Jovian tidal forces, once (or still) spewed forth organic matter into this ocean, just as happens at the hot vents under our oceans.

On Earth, these upwellings contain micro-organisms. On Europa, who knows? Maybe this unlikely moon is a reservoir of undersea life.

Or then again, maybe it isn't. The Europa discussion at the AAAS was partially prompted by yet another close approach that might confirm or deny some of these ideas.

But there is a more interesting background to the idea. Speculation about Europa is by no means new. In late 1979, a science writer in the United States named Richard Hoagland first broached the idea that there might be life under the ice there. The images that sparked his imagination had arrived at Earth from the Voyager spacecraft, the one that gave us our first views of Jupiter, Saturn and their moons.

Hoagland put his ideas on paper in a verbose article in a magazine called Star and Sky in 1980. It's intriguing to read the article now, partly because he so clearly anticipates the thinking today and partly because no one today seems to be acknowledging his priority.

Some of the details are dated (Hoagland leans heavily on electricity in the early Europan atmosphere to generate the life-forming organic molecules, while today, as I mentioned above, scientists rely on undersea volcanoes). But in most respects the two arguments are absolutely consistent.

So where is Hoagland today and why aren't the Europa theorists talking about him. Is it perhaps because in the intervening years he took on a much more notorious cause, the face on Mars? Yes, it is the same Richard who is the prime mover behind the idea that a Viking spacecraft photo of a flat-topped mesa on the surface of Mars is a huge carved face.

Where Hoagland sees physiognomy, scientists see a chance juxtaposition of geology and shadow. But that hasn't stopped him. Last time I checked, he'd identified a complex of temples and pyramids nearby.

So when it comes to Europa, why don't we hear about Richard Hoagland? I think it's because it's perfectly okay to speculate about extraterrestrial life; it's even okay to dream about it swimming under the Europan ice; but it's just not respectable to think about somebody carving a big face on Mars.

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Jay Ingram hosts the tv program '@discovery.ca' on the Discovery Channel in Canada.


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Original Europa Thesis Just Too Alien

by Terence Dickinson

The Sunday Star - Toronto
April 13, 1997
Context Section, page F8

At a news conference Wednesday, NASA scientists presented the latest images from the Galileo spacecraft that is in orbit around Jupiter. The photos, showing yawning cracks and blocks of ice the size of house on Jupiter's moon, Europa, offer the most compelling evidence yet that there is an ocean of water, possibly harboring life, beneath the frozen surface of this world, which is roughly the size of the Earth's moon.

It's a strange story, but 18 years ago I was there when the first person on Earth realised what Europa is really like. It was July 10, 1979, just hours after the American space probe Voyager 2 had cruised near Jupiter and its family of 16 moons. I was standing beside science writer Richard Hoagland at Voyager mission control at NASA's Jet Propulsion Laboratory in Pasadena, California, gazing intently at one of the television monitors displaying Voyager 2 images of Europa.

Nobody had ever seen anything like Europa before, Instead of the usual cratered landscape, Europa's surface is smooth, like a billiard ball. The highest resolution images did reveal some detail - low ridges and linear features covering the surface in apparently random patterns - but at first glance it was baffling. Then Hoagland said, almost in a whisper, "Its a crust of ice. And there's water below it."         

He stood there, thinking about what he had just said, then asked me if I would be interested in an article on the idea. At the time, I was editor of 'Star & Sky', an American popular-level astronomy magazine that has long since ceased publication. I readily accepted.

Later, as he was working on the article, Hoagland phoned me from his home in Oakland, California, to tell me, with growing enthusiasm, about how all the pieces fit. Europa, he said, had a rocky core that was heated by gravitational tugging from Jupiter's three other large moons. As those moons swung close to Europa, then retreated, the varying gravitational forces squeezed and relaxed the rocky core, heating it in the process.

This, he said, would melt the icy crust that apparently cloaks the Jovian moon. Only the outer surface, which is exposed to the intense cold of space, remains frozen. The ocean below could easily contain more water than is in Earth's oceans. And like in Earth's oceans, he went on, life could exist near volcanic vents.

Hoagland's ideas about Europa appeared as the cover story in the January, 1980, issue of 'Star & Sky'. Given the potential importance of the concept, I issued a news release to coincide with the issue's publication. It was picked up by all the major news services and the story ran in hundreds of newspapers. It appeared in 'The Toronto Star' on December. 27, 1979, under the headline 'By Jupiter! Maybe there is alien life in space'.  

Then, instead of Hoagland's ideas appearing in textbooks, NASA brochures and other publications about the solar system, they were ignored. Today, Hoagland almost never receives credit for his Europa work. Why? He was never part of establishment science and he has moved much further from it than he was back in 1979. Today, he champions the idea that aliens built a rock formation called the 'face' on Mars. Few scientists want to be even remotely associated with a "kook", no matter how brilliant his ideas.  

(Terence Dickinson is editor of 'Skynews Magazine' and the author of several guidebooks for backyard astronomers)