Caltech has taken over operation from NASA of the Galaxy Evolution Explorer (GALEX), a space telescope that for the last nine years has been surveying the cosmos in ultraviolet light. In this first agreement of its kind, NASA is lending the telescope to Caltech, which has led the mission and will continue operating and managing it through the support of private funders.

A team of astronomers has found that the most active galactic nuclei—enormous black holes that are violently devouring gas and dust at the centers of galaxies—may prevent new stars from forming. The team, which includes several researchers from Caltech, reported its findings in the May 10 issue of the journal Nature.

Last year, images from NASA's Mars Reconnaissance Orbiter captured sand dunes and ripples moving across the surface of Mars—observations that challenged previously held beliefs that there was not a lot of movement on the red planet's surface. Now, technology developed by a team at the California Institute of Technology (Caltech) has allowed scientists to measure these activities for the very first time. 

In sports, on a game show, or just on the job, what causes people to choke when the stakes are high? A new study by researchers at Caltech suggests that when there are high financial incentives to succeed, people can become so afraid of losing their potentially lucrative reward that their performance suffers.

By analyzing stalagmites, a team of Caltech researchers has determined that the climate signature in the tropics through four glacial cycles looks different in some ways and similar in others when compared to the climate signature at high latitudes. The results suggest that Earth's climate system might have two modes of responding to significant changes. 

What's it like to build an entire research program from scratch? It's all about becoming part of a community, according to three brand-new professors who chat about their experiences in "From the Ground Up," an article in the Spring 2012 issue of Caltech's Engineering & Science magazine.

Observations from NASA's Spitzer Space Telescope show that the Sombrero galaxy is actually two galaxies in one.Observations from NASA's Spitzer Space Telescope show that the Sombrero galaxy is actually two galaxies in one. With a halo of stars surrounded by the thin edge of a stellar disk, the galaxy resembles a big hat.

All animals seem to have ways of exchanging information—monkeys vocalize complex messages, ants create scent trails to food, and fireflies light up their bellies to attract mates. Yet, despite the fact that nematodes, or roundworms, are among the most abundant animals on the planet, little is known about the way they network. Now, research led by California Institute of Technology (Caltech) biologists has shown that a wide range of nematodes communicate using a recently discovered class of chemical cues. 

What happens to a stem cell at the molecular level that causes it to become one type of cell rather than another? In studies that mark a major step forward in our understanding of stem cells' fates, a team of Caltech researchers has traced the stepwise developmental process that ensures certain stem cells will become T cells—cells of the immune system that help destroy invading pathogens. 

The second-largest mass extinction in Earth's history coincided with a short but intense ice age. Although it has long been agreed that the so-called Late Ordovician mass extinction was related to climate change, exactly how the change produced the extinction has not been known. Now, a team led by Caltech scientists has determined that the majority of extinctions were caused by habitat loss due to falling sea levels and cooling of the tropical oceans.