If you could investigate anything about the universe, what would it be? Read what kids had to say Put your face on the cover of the journal Science! Be on the Cover of Science

Special Issue Marks the Journal's 125th Anniversary

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If you could investigate anything about the universe, what would it be? The editors at the journal Science have a lot of ideas: What is the universe made of? How are humans different from other animals? Can the world's population continue to grow and consume more resources?

These are just a few of the 125 "big questions" of science, according to the Science editors. They put this list together in a special feature to mark the journal's 125th birthday on July 1st.

The feature is called "What Don't We Know?" but it also shows how much science has taught us over time. That's because when scientists solve one mystery, the answer usually brings up more new questions. A list of the big scientific questions in 1970 would be quite different from today's list.

"We may never fully answer some of these questions, but we'll advance our knowledge and society in the process of trying," said Donald Kennedy, Science's editor-in-chief.

Kids can offer suggestions for the greatest unsolved scientific mysteries too. Submit your ideas to http://www.eurekalert.org/scienceforkids/125th/.

If your questions aren't on Science's anniversary list, don't be surprised. These 125 scientific questions aren't the only ones we can't answer yet. Instead the list is a sampling from across all fields of science. Starting July 1st, the anniversary feature will be freely available at http://www.sciencemag.org/sciext/125th.

How do you think you might try to answer your own scientific questions? How long do you think it would take? Science's news team has written a special package of essays focusing on 25 of the questions that they think researchers have the best chance of answering in the next 25 years. Or, even if researchers haven't actually found the answer by then, they will probably be on their way.

Some of those questions are:

• What is the universe made of? In the last few decades, researchers have discovered that the ordinary matter that makes up stars and galaxies is less than 5 percent of everything there is. What exactly is the "dark" matter that makes up the rest?

• Why do humans have so few genes? To biologists' great surprise, once the human genome was sequenced in the late 1990s, it became clear that we only have about 25,000 genes - about the same numbers as the small, flowering plant Arabidopsis. The details of how those genes are turned on and off is a central question in biology.

• How much can human life span be extended? Studies of long-lived mice, worms and yeast have convinced some scientists that human aging can be slowed, perhaps allowing many of us to live beyond 100, but other researchers think our life spans are more fixed.

Science was founded by the famous inventor Thomas Edison, and its first issue appeared on July 3, 1880. That issue was 12 pages long, with articles on the possibility of electric-powered railroads, the latest observations of a star cluster called the Pleiades and advice to science teachers on the importance of studying animal brains.

To celebrate the journal's anniversary 125 years later, Science's editors first planned to select just 25 questions that would reveal the gaps in our scientific knowledge. But, they actually came up with more than 100 questions that were too interesting to leave out. Finally, they selected 125 questions for their list and took a closer look at 25 of them.

The American Association for the Advancement of Science (AAAS) is the world's largest general scientific society, and publisher of the journal, Science (www.sciencemag.org). AAAS was founded in 1848, and serves some 262 affiliated societies and academies of science, serving 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of one million. The non-profit AAAS (www.aaas.org) is open to all and fulfills its mission to "advance science and serve society" through initiatives in science policy; international programs; science education; and more. For the latest research news, log onto EurekAlert!, www.eurekalert.org, the premier science-news Web site, a service of AAAS.