Summer doesn’t officially start until June 21, but the movie business operates on its own calendar. The foreign release of “Captain America: Civil War” this weekend and its domestic debut in five days kicks off Hollywood’s busiest season and signals that it’s popcorn movie time again.

The next four months will bring sequels aplenty, costumed vigilantes, and the destruction of several major cities. If movie studios have gamed out their major releases correctly, then they stand to profit handsomely from new Avengers, X-Men, Ghostbusters, and Star Trek installments. If not, they could be left holding a “R.I.P.D.”

Here are five burning questions that audiences will help answer at the multiplexes this summer.

1.) Does star power still matter?

George Clooney, Julia Roberts, Matthew McConaughey and Ryan Gosling are just a few of the A-listers who are betting that their names above the title still mean something. They are putting their clout on the line to try to attract audiences to films that are more challenging, provocative or just plain scragglier than comic-book movies and sequels.

“Money Monster,” the financial thriller with Clooney and Roberts, feels like a throwback to ’90s era hits such as “Conspiracy Theory” or “Clear and Present Danger.” “The Nice Guys,” a violent action-comedy with Gosling and Russell Crowe, overflows with dark jokes and ’70s pornstaches, but will have to duke it out with “The Angry Birds Movie” and the “Neighbors” sequel. Meryl Streep will attempt to find the funny in opera with “Florence Foster Jenkins.” Kevin Hart and Dwayne Johnson will try to put a fresh spin on the buddy cop genre with “Central Intelligence.” And McConaughey has perhaps the toughest challenge of all — trying to convince audiences accustomed to slick, diverting fare to revisit the Civil War with “Free State of Jones.” If the bets pay off, then these stars will justify the millions it takes to land them. If not, expect questions to be asked about their commercial appeal.

2.) Is there an animated film pile-up?

With four major animated releases all slated to hit theaters over the next four months — Disney/Pixar’s “Finding Dory,” Fox/Blue Sky’s “Ice Age: Collision Course,” Universal/Illumination’s “The Secret Life of Pets” and Sony’s “The Angry Birds Movie” — there certainly are signs of a potential traffic jam.

It’s not usually this congested. Last summer only fielded two major animated films, “Inside Out” and “Minions,” and the summer before was a virtual desert for animated fare with “How to Train Your Dragon 2” and “Planes: Fire and Rescue” (a C-grade Disney offering) serving as the genre’s representatives. It’s a sign of how competitive the space is becoming, as more studios invest in animated fare. At some point, is there a limit on how many movies families are willing to shell out to see in theaters?

3.) Does Steven Spielberg still have it?

The man who ushered in the summer blockbuster with “Jaws” hasn’t made one for an awfully long time. His last major popcorn season effort was 2008’s “Indiana Jones and the Kingdom of the Crystal Skull,” and since then he’s been more interested in serving as cinema’s preeminent historical chronicler with the likes of “War Horse,” “Lincoln” and “Bridge of Spies.”

But “The BFG,” an adaptation of Roald Dahl’s children’s book about an orphan’s bond with a giant, finds the “E.T.” filmmaker back on familiar terrain. The question is will audiences still respond to his brand of emotional uplift, particularly when there are so many animated films vying for family moviegoers’ dollars?

4.) How nostalgic are moviegoers?

“Independence Day: Resurgence” and “Ghostbusters” hope the answer is very. It’s been two decades since the first “Independence Day” made blowing up national monuments fun, and more than three since the initial iteration of “Ghostbusters” found humor in the paranormal. The audiences that enjoyed those films are getting on in years, grown with their own children, or shuffled off to the multiplex in the sky. But the studios behind these pictures believe that there’s enough goodwill around these brands to make these reboots and revisits into hits.

Absence certainly made the heart grow fonder in the case of last summer’s “Jurassic World.” More than ten years separated installments in the “when dinosaurs attack” franchise, and movie theaters reported that ticket buyers decided to turn the prehistoric beat down into a family affair. Moviegoers who remembered being dazzled by 1993’s “Jurassic Park” decided to take their own kids along, hoping to recapture the magic, propelling “Jurassic World” to north of $1.6 billion at the box office.

5.) Will this be the biggest Memorial Day Weekend in box office history?

What a difference a year makes. Last summer, Memorial Day ticket sales sank to their lowest levels since 2001, brought low by the failure of “Tomorrowland.” This time, expect the box office to hum as “Alice Through the Looking Glass” and “X-Men: Apocalypse” face off in one of the most fiercely competitive holidays in recent memory. The first “Alice in Wonderland” film grossed north of $1 billion, while the most recent “X-Men” was the most popular in franchise history, netting $747.9 million globally. These are some heavyweights.

Competition, in this case, may be a good thing. In 2013, “Fast & Furious 6” took on “The Hangover Part III,” and the clash of the titans resulted in a $314.2 million windfall over the four-day holiday. That stands as the biggest Memorial Day weekend of all time… at least for a few more weeks.