Question: I'm taking a trip to Europe this summer through one of my teachers with other classmates. Can this exposure help in any way with admissions? Or is there anything I can do to make it matter?
College officials are quite accustomed to seeing all sorts of overseas travel on application forms, so you probably won't get any admissions boost from simply taking this summer trip. Moreover, the "Experiencing a New Culture Changed My Life" college essay (or some variation thereof) is common enough to make most admission officials start to snore (or at least roll their eyes).
But, of course, your pending trip may indeed change your life. It's certainly possible that your journey will spark a new passion (Impressionist art? medieval architecture? World War II history?) If, once you return, you parlay the experiences you have or the interests you ignite during your travels into additional activities (or a long-term academic or career goal) then this may be information you'll want to include in your applications, and it could make you a more attractive candidate at decision time
Conversely, if you already have a talent or hobby that could be expanded during your trip (photography, poetry, painting, cartooning, etc.), then you may be able to chronicle your travel experiences in a way that calls upon your current skills to create supplemental materials that might be application worthy.
Beware, however, that "service" trips are very popular these days. This is when high school students visit foreign lands (typically, Third World nations) and pay significant sums to "volunteer"--building houses, tending crops, teaching English, etc. So your admissions essay on the delights of a picnic lunch in the Jardin des Tuileries will be "competing" with one that chronicles digging latrines in a Paraguayan village at sunrise.
So keep in mind that admission folks have become pretty jaded when it comes to hearing about their candidates' adventures abroad. If you do decide to write a college essay on something you saw, did, or learned in Europe this summer, I recommend that you try to keep your subject matter very focused. ("Whole Sole," in On Writing THE College Application Essay by Harry Bauld is a great example of what I mean.) Talk about a specific subway ride or sculpture, the old lady who gave you directions in the market or the hotel clerk who smiled at your efforts to speak Spanish. Let this serve as a metaphor for how your horizons broadened, but avoid trite and obvious conclusions like "People are people wherever you go." Instead, allow your audience to read between the lines, and remember that most good essays "Show" and don't just "Tell."
Hope that helps. Safe travels!