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A global ocean lies beneath the icy crust of Saturn's geologically active moon Enceladus, according to new research using data from NASA's Cassini mission. 

Researchers found the magnitude of the moon's very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present. 

The finding implies the fine spray of water vapor, icy particles and simple organic molecules Cassini has observed coming from fractures near the moon's south pole is being fed by this vast liquid water reservoir. The research is presented in a paper published online this week in the journal Icarus.

Phenomenally durable crystals called zircons are used to date some of the earliest and most dramatic cataclysms of the solar system. One is the super-duty collision that ejected material from Earth to form the moon roughly 50 million years after Earth formed. Another is the late heavy bombardment, a wave of impacts that may have created hellish surface conditions on the young Earth, about 4 billion years ago.

Both events are widely accepted but unproven, so geoscientists are eager for more details and better dates. Many of those dates come from zircons retrieved from the moon during NASA's Apollo voyages in the 1970s.

Un nuevo estudio ha encontrado que los vientos fuertes están removiendo grandes cantidades de nieve de la Antártida, lo que podría aumentar las estimaciones de lo que el continente podría contribuir a elevar el nivel del mar. Hasta ahora, los científicos habían pensado que la mayor parte de la nieve arrastrada por el viento era simplemente depositada en otras partes de la misma superficie. Sin embargo, el nuevo estudio muestra que en ciertas partes, llamadas zonas de socavación, casi el 90 %, aproximadamente 80 mil millones de toneladas por año son eliminadas en lugar de ser vaporizadas. El hallazgo significa que los científicos deben ajustar sus modelos de cuánta masa está perdiendo la Antártida, y lo mucho que puede perder en el futuro. El estudio aparece esta semana en la revista Geophysical Research Letters.

Tattoos really are more than skin deep—and that raises questions about their safety.

Many people enjoy the aesthetic beauty of tattoos. But the brightly colored inks that make tattoos so vibrant and striking also carry health concerns, report authors of a new paper related to tattoo safety.

According to the Pew Research Center, 45 million Americans have at least one tattoo; roughly $1.65 billion is spent on tattoos each year in the U.S.

New research by Dana-Farber Cancer Institute scientists raises the prospect of cancer therapy that works by converting a tumor's best friends in the immune system into its gravest enemies.

In a study published in the journal Science, an international collaboration of investigators from Dana-Farber, Harvard Medical School, Boston Children's Hospital, and the University of Strasbourg uncovered a mechanism that allows key immune system cells to keep a steady rein on their more belligerent brother cells, thereby protecting normal, healthy tissue from assault. The discovery has powerful implications for cancer immunotherapy researchers say: by blocking the mechanism with a drug, it may be possible to turn the attack-suppressing cells into tumor-attacking cells.