The first stage is to orbit a cubesat, a tiny, coffee can sized satellite that would contain two highly accurate accelerometers that would go into orbit around Europa and measure its gravity field. In this way the location of Europa's subsurface oceans would be mapped. Indeed it is possible that the probe might find an opening through the ice crust to the ocean, warmed it is thought by tidal forces.
The second stage is to deploy even smaller probes called chipsats, tiny devices that contain sensors, a microchip, and an antenna. Hundreds of these probes, the size of human fingernails, would float down on Europa's atmosphere to be scattered about its surface. While some might be lost, enough will land over a wide enough area to do an extensive chemical analysis of the surface of Europa, which would then be transmitted to the cubesat mothership and then beamed to Earth.
I want to go home.
I want sex.
I want a cookie.
What the f*$# is wrong with us? How much longer are we going to be in denial that there's a thing called "rape culture" and we ought to do something about it? ... To paraphrase the great John Oliver, listen up, fellow self-pitying nerd boys — we are not the victims here. We are not the underdogs. We are not the ones who have our ownership over our bodies and our emotions stepped on constantly by other people's entitlement. We're not the ones where one out of six of us will have someone violently attempt to take control of our bodies in our lifetimes.'"
Some pieces of software are intended to be feature-complete replacements for competitors. Others approach the same or similar tasks using very different methods. This doesn't change the relative merits of the software and soda analogies to books. Software is a much better analogy than soft drinks.
The rareness of feature-complete replacements for books, except in certain non-fiction areas, detracts from the software analogy to be sure. It still makes a lot more sense than 'coke vs. pepsi.'
The bottom line is that Google Search doesn't work very well - at least, not anymore. While it previously supported search expansions which could be taken advantage of by skilled searchers, it's since been focused on quick, lowest-common-denominator responses to the most common questions. As a result, searching for slightly abstract notions is virtually impossible, and some searches which should be straightforward also fail.
One example of a simple failure: "fireworks today" or "fireworks today san francisco" returned nothing after I chanced to see fireworks the other night. Using the date ("fireworks san francisco may 21 2014"), the only relevant result was a set of Coast Guard and DHS documents describing safety precautions for the event (Giants game). Of course, fireworks games are well publicized outside of interntal government safety documents.
A more abstract example: try to design a search for articles about names which are or have become insults, such as "Dick."