Welcome to American Mosaic from VOA Learning English!

　　I'm June Simms.

　　On our show today, we play some of the biggest hit songs of the summer.

　　And we visit a natural history museum in Los Angeles County, California, where living things are part of the show.

　　But first, we tell about new efforts to send humans to the planet Mars!

　　Sending Humans to Mars!

　　The International Mars Society recently held a four-day conference in the American state of Colorado. During the meeting, the American-based Mars Society announced a competition for university students around the world. The group is urging the students to help with plans for sending humans to Mars. Avi Arditti has more.

　　About six months ago the non-profit Inspiration Mars Foundation proposed sending humans to Mars within five years. Under the plan, a spacecraft would carry a woman and a man to within 160 kilometers of the red planet. Then, it would return them to Earth.

　　The crew is expected to be American. But the process of getting to Mars is an international effort.

　　The president of the Mars Society, Robert Zubrin, made the competition announcement. He has asked that teams of students design a two-person Mars flight operation that could launch in 2018.

　　The designs will be judged on cost, quality, simplicity and timing. The Mars Society, Inspiration Mars and the American space agency will choose the judges.

　　Mr. Zubrin says both the competition and a Mars flight have the power to excite creative thinking.

　　"The challenge of humans to Mars could inspire a new generation to want to develop their minds to become scientists, engineers, technological entrepreneurs, researchers."

　　The competition is open to university engineering students worldwide. The teams must be mostly students although some professors, university alumni and others can take part. Competition finalists will present their plans at the space agency's Ames Research Center in California.

　　The Inspiration Mars Foundation is the idea of businessman and space tourist Dennis Tito. Robert Zubrin admits he does not belong to the group. But he says he thinks its idea of a trip to Mars is a realistic possibility. I'm Avi Arditti.

　　New Natural History Museum Comes to Life

　　Many large American cities have a natural history museum, where visitors can see things like old dinosaur bones. Most of these museums have changed very little over time. At some, parents can take their children to see some of the same scientific exhibits they saw when they were growing up.

　　But some museums are making changes, in ways that might surprise you. The Natural History Museum of Los Angeles County in California is one of them.

　　Some first time visitors to the museum are surprised to find live animals, including rats, snakes and turtles. One of those visitors was Tim Waters.

　　"I wasn't expecting to see this in a museum."

　　Jonathan Gillett is assistant collections manager at the museum. He says the new exhibit, called "Becoming LA," tells the history of Los Angeles in an unusual way.

　　"Not only are we interpreting natural history. We also as a part of our mission statement are interpreting cultural history as well. So it shows the way that the environment has influenced people and how people have influenced the environment."

　　The collection includes a wooden cross from the 1700s, when Spain established Roman Catholic communities in California. There is also a car that was made locally in the early 1900s.

　　The history of Los Angeles would not be complete without some objects from Hollywood. So the exhibit includes a camera that was used to film silent movies and clothing worn by the famous silent movie actor Charlie Chaplin.

　　"Hollywood was incredibly close to a lot of other natural habitats that could stand in for other places around the world."

　　Kristin Friedrich is the Director of Communications at the Natural History Museum of Los Angeles County. She says "Becoming LA" tells not only about the city's past but about the creatures that live there today.

　　"In the cracks of sidewalks or in the chimneys of buildings in Los Angeles, there's incredible life. And a lot of these species that we explore here find ways to live in the city like we find ways to live in the city."

　　The museum has live plants and animals in a garden just outside the main building and an indoor nature laboratory. Kristin Friedrich says this is different from what visitors expect to find at a natural history museum.

　　"Traditionally, the natural history museum is a 19th century model. Back then, you would put dead things in a cabinet and you would have a text panel and people would walk around and look in very dark halls."

　　She says natural history museums are reinventing themselves, exploring ideas like conservation and humans' effect on the environment.

　　Tim Waters says he likes the museum.

　　"This whole exhibit was an on-going history, and so it's giving us not just an ancient history but our place and how we form history."

　　His 8-year-old son Wyatt likes some of the older exhibits.

　　"I think the dinosaur exhibit is a little bit more interesting than this exhibit."

　　Do not fear, Wyatt. The ancient creatures are not going away -- they are just sharing the museum with newer animals.

　　Best Hit Songs of Summer 2013

　　Monday is Labor Day in the United States. Summer will continue for a few more weeks after the holiday. But for most Americans, this weekend marks the end of the season. On Tuesday, children return to school. Many community swimming pools close. And vacations are done.

　　So we come to our final show on the songs that defined the summer of 2013. Jim Tedder tells us about some of these summer anthems.

　　Early in the season we named some of the songs we thought might prove popular. We were correct in our prediction that the Daft Punk song, "Get Lucky" would be among the summer anthems. Billboard Magazine rated it at number two.

　　Next on Billboard's list is "Radioactive," from the Las Vegas, Nevada based group Imagine Dragons. The four member band released its first full length album last September. Now the band is performing a series of concerts around the world.

　　Miley Cyrus is the first woman on Billboard's list of top summer singles. Her song "We Can't Stop" is number four. It also won the best summer song at the Teen Choice Awards earlier this month.

　　Selena Gomez also had a huge summer hit. "Come & Get It" is edgier than most of her other work. Gomez sings about a love relationship that has ended, but the rejected partner is willing to wait for its return.

　　Billboard Magazine says the number one song of summer 2013 is "Blurred Lines" by Robin Thicke. There have been some questions about whether "Blurred Lines" is based on a song made famous by Marvin Gaye. Robin Thicke was accused of violating copyright laws, which he denies. His music video was also criticized as sexist for its use of unclothed women. The singer says that was his wife's idea.

　　We leave you with the summer anthem, "Blurred Lines."

　　I'm June Simms. Our program was written by Christopher Cruise and Caty Weaver.

　　Do you have a question about American life, people or places? Send an e-mail to learningenglish@voanews.com. We might answer your question in a future show. You can also visit our website at 51voa.com to find transcripts and audio of our programs.

　　Join us again next week for music and more on American Mosaic from VOA Learning English.