Ganymede, Jupiter's largest moon, is thought to have once had more water than all the water on Earth's surface.

But why? 

Ganymede is the largest moon in our solar system and the only moon with its own magnetic field. The magnetic field causes aurorae, which are ribbons of glowing, hot electrified gas, in regions circling the north and south poles of the moon. Because Ganymede is close to Jupiter, it is also embedded in Jupiter's magnetic field. When Jupiter's magnetic field changes, the aurorae on Ganymede also change, "rocking" back and forth so by watching the rocking motion of the two aurorae, scientists were able to determine that a large amount of saltwater exists beneath Ganymede's crust affecting its magnetic field.

Metastatic melanoma is the leading cause of skin cancer deaths in the United States because once has spread - metastasized - life expectancy for patients is dramatically shortened.

Melanoma diagnosis and treatment has progressed a lot and the future looks even brighter but the current reference therapy for patients diagnosed with metastatic melanoma is Dacarbazine (DTIC), which is associated with relatively poor patient outcomes.

Damage to the spinal cord is often permanent because injured nerve cells fail to regenerate due to scar tissue of their long nerve fibers.

Nerve cells are wire-like conductors that transmit and receive signals in the form of electrical impulses. This function can be impaired by accidents or disease. Whether or not the affected nerves can recover largely depends on their location: for instance nerve cells in the limbs, torso and nose can regenerate to some degree and regain some or all of their function. 

A new app for finding and mapping chromosomal loci uses multicolored versions of CRISPR/Cas9. The labeling system, developed by  the University of Massachusetts Medical School, could be a key to understanding the spatial and temporal regulation of gene expression by allowing researchers to measure the precise linear distance between two known points on different chromosomes or two locations on the same chromosome in live human cells. 

Why men have more heart disease than premenopausal women has been unclear, but a new study shows that the sex hormones testosterone and estrogen alter cardiovascular risk factors in a way that raises a man's risk of heart disease. Results of the study will be presented Saturday at the Endocrine Society's 97th annual meeting in San Diego.

Men have higher testosterone and lower estrogen levels than premenopausal women. Therefore, doctors have suspected that testosterone may promote cardiovascular disease or that estrogen may protect against it, or both, according to Elaine Yu, MD, MSc, the study's lead investigator and an assistant professor at Harvard Medical School, Boston.

A new study has found that high levels of blood lipids such as cholesterol and triglycerides can keep Vitamin E, an essential micronutrient, tied up in the blood stream, and prevent vitamin E from reaching the tissues that need it. That means measuring only blood levels may offer a distorted picture of whether or not a person has adequate amounts of the vitamin, and that past methods of estimating tissue levels are flawed.