On the horizon: news from the frontiers of science
Water found in deep space; a history of hot food; why baseball careers last longer
Signs of water in deep space
Astronomers have uncovered what they say is the first convincing evidence for water vapor in the atmosphere of a planet beyond our solar system. The amount of water in the exoplanet's atmosphere is almost four times larger than theories about these planets – so-called hot Jupiters – had suggested.
Interest in finding water on exoplanets runs high. Water is a key ingredient for organic life. But life is unlikely on this planet: It's roughly 15 percent larger than Jupiter and whips around its parent star in about two Earth days, at a distance of some 3 million miles. Earth, by contrast, orbits 93 million miles from the sun. The astronomers reporting the discovery calculate that the daytime high temperature on the planet (known as HD 189733b) hits 1,700 degrees F. Nighttime temperatures fall to a mere 1,286 degrees F.
The astronomy team, led by scientists at the European Space Agency and University College London, used NASA's Spitzer Space Telescope for the study. As the planet passed in front of its star, the "backlighting" revealed features in the spectrum of the planet's atmosphere characteristic of water.
"The Holy Grail for today's planet hunters is to find an Earthlike planet that also has water in its atmosphere.... Finding the existence of water on an extrasolar gas giant is a vital milestone along that road of discovery," notes Giovanna Tinetti, the lead author of the paper detailing the results in today's issue of the journal Nature.
Spicy food dates back 1,500 years
Archaeologists have had a hot time unraveling the story of New World chilies. Pre-Columbian cultures have spiced their fare with them for at least 8,000 years. Researchers now are learning that the use of mixtures of chilies enjoy at least a millennium-old pedigree. Scientists with the Smithsonian Institution and the University of Michigan have discovered ancient dried chilies in a cave in the Valley of Oaxaca in southern Mexico. Their study suggests that the chili mixtures found in today's Mexican food date back at least 1,500 years. The team, led by Linda Perry, found 122 chilies representing at least seven cultivated types. "You don't grow seven different kinds of chilies unless you're cooking some pretty interesting food," she notes.
Between AD 500 and 1500, the cave – part of a complex of natural rock shelters in the area – probably was used for storage and as a temporary campsite by farmers who appear to have planted crops in a range of environmental zones. This approach would have led to a more varied diet and to a form of natural crop insurance. The results appear in this week's Proceedings of the National Academy of Sciences.
Baseball careers grow longer
Did you enjoy this week's Major League All-Star baseball game? We hope so. In seven years, some of the players you cheered may be off selling cars or opening restaurants. That's the implication of a study by three researchers at the University of Colorado at Boulder's Institute of Behavioral Science. Among the questions they asked: What's the average length of a position player's career in the majors (a position player is anyone but a pitcher). The three compiled statistics on 5,989 position players who first stepped onto a big-league diamond between 1902 and 1993. The average career was 5.6 years. About 20 percent of the players in the study lasted only a year.
But baseball careers are growing longer, notes William Witnauer, a grad student who did the research for his master's degree. Between 1902 and 1945, careers averaged 4.3 years – affected by two world wars, a major influenza outbreak, and the fact that ball-playing was part-time. "If your outside job was more lucrative, you quit baseball," Mr. Witnauer says. Between 1946 and 1968, careers lasted an average of 6.5 years. And from 1969 to 1993, with the emergence of free agency, players lasted an average of seven years. These and other results appear in the August issue of the journal Population Research and Policy Review.