Tag Archives: Jupiter

Proposal for a Mission to Jupiter and Europa


Now that Curiosity is safely on Mars and ready to begin its exploration, an exploration that could go on for decades due to its nuclear power plant, I would like to propose the next major NASA endeavor.

It is time to return to Jupiter.  The Galileo mission (1995-2003) was a tremendous success even though the spacecraft was crippled by the loss of its high gain antenna.  Some 90% of the potential data was lost due to the failure of this vital communication link.

It’s time to go back to Jupiter again.  Only this time the mission will look more like the Cassini-Huygens mission to Saturn.  The next Jupiter mission should include an orbiter to survey Jupiter and its moons.  But this time let’s add a lander for Europa.  Europa is the most promising venue for extraterrestrial life in the solar system. A rover on Europa could explore the ice floes and run tests on the surface materials.  The reddish-brown gunk that emerges from the cracks in the ice floes and spreads across the surface of Europa may be a life form similar to an algae bloom.  We need to go there to check it out.  Also, the rover could measure the thickness of the ice.  This step would be in preparation for a following mission that will melt its way through the ice to place a submarine into the ocean below.

Life in the Solar System


By gregbentall on May 28, 2012 | Edit

One of the most poignant questions that we face is, “Are we alone?”  Space is so infinitely vast, with hundreds of billions of galaxies, each one home to hundreds of billions of stars.  With such vastness of space it seems hard to believe that there is not someone else out there.  But our chances of linking up may be near zero.  Perhaps other civilizations have come and gone while we were still in the age of the dinosaurs, or even in the Bronze Age.  We may never know.  Just as once oceans and mountain ranges separated one tribe of humans from another, so may the vastness of space and time separate us from other intelligent life.

Flying Saucer Attacks Vancouver

But the question of life in beyond the earth is becomes a much different question if we are speaking of simple life forms.  There may be simple life forms to be found on other bodies in our solar system.  There is a chance that we will find some primitive organisms on Mars.

Mars is a near miss in terms of the development of life.  It is possible and perhaps even likely that life evolved on Mars.  But Mars as a life bearing planet had one fatal defect.  It was simply too small to sustain life for the extended period that it takes to develop an intelligent, technological society.

Mars simply was too small and cooled too quickly.  In the beginning it had a magnetic field generated by its core of molten iron.  Our robotic missions to Mars have found evidence of a likely place for life to evolve.  But as the small planet cooled, it lost its magnetic field and the force field that it created.  With the force field gone, the solar winds were able to strip Mars of its atmosphere and liquid water, and to bombard the surface with lethal doses of radiation.

But there are other sites in the solar system that are even more likely to harbor current life forms, places such as Jupiter’s Europa or Saturn’s Enceladus.  Both moons contain vast amounts of liquid water.  And we have found that where there is water there is life.

Europa shows signs of a liquid ocean below its frozen ice caps. Could this reddish brown stuff emerging from the cracks in the ice flows and spreading on the surface be a life form???

But there are other sites in the solar system that are even more likely to harbor current life forms, places such as Jupiter’s Europa or Saturn’s Enceladus.  Both moons contain vast amounts of liquid water.  And we have found that where there is water there is life.

Europa is covered with a frozen ice cap, much like the one found at earth’s North Pole.  We know that there is liquid water below the ice cap because the ice flows jostle around without any fixed reference points.  This shows that the ice is free floating above a liquid ocean below.

The ice on Europa floats about in broken flows, separated by dark red bands at the fracture points.  Here is a thought.  What if the reddish-brown crud that we see at the cracks in the ice flows and spreading on the surface of Europa are actually primitive life forms, something like an algae or bacteria?  If so, we might then be looking at extraterrestrial life forms with our earthbound telescopes.  We will never know until we get there and explore.

Cryobot prototype (Photo credit: Wikipedia)

The ideal mission to Europa would be to send a robotic space probe equipped with a submarine.  First we would check the surface. Then the submarine would melt its way through perhaps six miles of ice in order to submerse itself in the ocean below.  What it would find there is anyone’s guess.  But we might be pleasantly surprised.  We might find some primitive, single cell life forms, but we might also find some more advanced live forms, such as tube worms, shrimp, and perhaps even something similar to a squid.

And, if we can find a second example of life emerging in our solar system, than we can safely conclude that life is ubiquitous throughout the galaxy.

Such a mission to Europa would cost less than one one-thousandths of the cost of a manned mission to Mars, and just might lead us to a vastly more significant discovery.

Greg

Extraterrestrial Civilizations


In 1961, Frank Drake formulated his famous equation to predict the likelihood of intelligent, technological life in the galaxy.  Since that time we have made numerous scientific advances.  In 1961 we had not found any extra-solar planets, and were not even sure if they existed.  Today we have found hundreds of extra-solar planets and now believe that there are planets surrounding most stars.

Drake made his calculation and came up with the number 10.  His answer was that there were ten civilizations in our galaxy with intelligent, technological societies with which we could communicate.

A technological civilization simply means a society capable of building radio telescopes to scan the heavens, for without such instruments any extraterrestrial contact is simply impossible. It should be noted that the first radio telescope on the earth was built in 1931.  So, by this definition, we have been a technological society for less than one hundred years, a brief moment in the history of the cosmos.

The equation

The Drake equation states that:

where:

N = the number of civilizations in our galaxy with which communication might be possible;

and

R* = the average rate of star formation per year in our galaxy

fp = the fraction of those stars that have planets

ne = the average number of planets that can potentially support life per star that has planets

f = the fraction of the above that actually go on to develop life at some point

fi = the fraction of the above that actually go on to develop intelligent life

fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space.

But now it would appear that Frank Drake was an optimist.  Steven Hawking has predicted that we might be alone in the Universe as the only technological society.

The nearest star to us is a red dwarf star named Proxima Centauri at a distance of 4.24 light years.  This is our nearest neighbor in interstellar space, but getting there would take us some 80,000 years traveling at space shuttle speed.  Just beyond Proxima Centauri is the binary star system Alpha Centauri A and B at 4.37 light years from our sun. And, what if we went there and found nothing?  What would be our next destination and how long would it take to get there?

We are learning how hard and slow the process is to evolve from primitive life forms to advanced, technological civilizations.  On earth this process took some four billion years.  This means that a planetary nursery must be maintained in a relatively steady state for billions of years in order for an intelligent, technological society to emerge.

Humanity went almost extinct 73,000 years ago from the great Toba super-volcano in Sumatra.  Some sources say that only around 10,000 humans were left on the planet, while other sources say that the human population dwindled down to a few hundred or even a few dozen.  After millions of years of evolution we almost died out, but a few survived and our species went on to build a radio telescope.

A sacred place

There are new factors, not found in the Drake Equation, that may set earth off as the sole technological society:

The earth is big enough to sustain its magnetic field and the shielding that it produces for billions of years.  Because the earth’s core is still molten, we have a magnetic shield that protects us from harmful radiation, coronal mass ejections, and the solar wind that could strip our planet of its atmosphere and water.  When Mars lost its magnetic shield that planet died of these effects.

The earth has plate tectonics that continuously recycle the continents and continuously bring new minerals to the surface.

The earth has a large moon that provides gyroscopic stability and prevents our axis from wobbling too much.  This provided for climactic stability over millennium in order that civilization may develop and thrive in one place without disruption or dislocation.  Imagine, for example, if the earth’s axis tilted so that Europe dropped down to the latitude of the Sahara Desert.  Any such civilization at that latitude would be doomed.

The moon was originally much closer to the earth than it is now.  In the early days the moons tidal pull upon the earth was much larger.  The effect of this tidal pool was to stir the waters in the inter tidal zone.  This tidal stirring, this mixing of nutrients, proteins, and amino acids may well have aided in the formation of life.

The earth has big brother Jupiter that protects us from asteroid bombardment by corralling many errant space rocks and ice balls before they hit the earth.  This was recently demonstrated by the Jovian capture and destruction of the Shumaker-Levi 9 comet.

The earth orbits a single star.  Any planets in multiple star systems would be at a distinct disadvantage.  It would be very difficult for a planet in a multiple star system, such as Alpha Centauri, to find a stable orbit in the “Goldilocks” zone where it is neither too hot nor too cold.  Also, it is likely that at some point in time the planet would be either torn apart by gravitational forces or slung out into the interstellar void.

Our sun will shine for another five billion years.  Our technological civilization is flourishing as our sun is in the middle of its useful life.  Scientists believe that the world will be habitable for at least the next billion years or so, unless we destroy ourselves earlier.  After the next five billion years we know that the sun will swell up into its red giant phase, with its outer edged touching the earth’s orbit.  Long before the sun reaches its full expansion the earth will become a scorched, lifeless cinder.

Other planets in our galaxy may not be so lucky.

Carl Sagan worried that we might have reached the required level of technological development (i.e. radio telescopes) just in time to destroy ourselves with nuclear weapons.  For today’s generation our main worry might be global warming.  It is sad, but it seems that achieving the technological pinnacle of a radio telescope gives us power over nature to destroy ourselves and our habitat.

Steven Hawking said that since we might be the only intelligent, technological society in the galaxy, we may want to survive and continue.

Greg