Answer the following question: Read the following article and select the best answer. Article: Have you ever seen a 250-mile-wide bath sponge? Well, take a look at Hyperion, one of Saturn's moons. Recent photos of the hamburger-shaped moon reveal a strange world covered with large and small craters . The photos were taken by high-tech cameras aboard the spacecraft Cassini, which has been exploring Saturn and its moons since 2004. Scientists studying the photos have recently identified something surprising: dark and reddish material on Hyperion's surface. They believe that the substance may be organic material, including combinations of the chemical elements hydrogen and carbon. That's important because all life, including human life, is built from organic building blocks. "Organic material is the key to understanding life in the solar system. When we try to understand how life formed on Earth and whether life could form on other planets, this is one of the things we look at," says Dr. Amanda Hendrix. She is a planetary scientist who works on the Cassini project. So how did such material get on a lifeless moon circling Saturn? Scientists suspect it was deposited by meteors . "Craters on Hyperion are the result of meteoroid impact," said Dr. Hendrix. "A meteoroid is the leftover material from the formation of planets." The largest crater on Hyperion is 75 miles across and 6 miles deep! But even though Hyperion looks like a sponge, it most likely doesn't feel like one. Cassini has found that the moon is made mainly of ice. Cassini may give scientists many more surprises. It is scheduled to orbit Saturn until next year, but NASA scientists also hope to extend the spacecraft's mission until 2010. Unlike Earth, which has only one moon, Saturn has 48 moons. The extra two years will give scientists an opportunity to learn more about Saturn's many moons. "This mission not only has given us a lot of answers but also has posed a lot of new questions," says Hendrix. Question: What would be the best title for the passage? - Exploring Saturn in a Manned Spaceship - Looking for Life on Saturn - Uncovering Saturn's Secrets - Finding Various Craters on Hyperion
Answer:
Uncovering Saturn's Secrets