NASA spacecraft finds possible Mars caves

An orbiting spacecraft has found evidence of what look like seven caves on the slopes of a Martian volcano, the space agency NASA said on Friday.
The Mars Odyssey spacecraft has sent back images of very dark, nearly circular features that appear to be openings to underground spaces.
"They are cooler than the surrounding surface in the day and warmer at night," said Glen Cushing of the U.S. Geological Survey's Astrogeology Team and Northern Arizona University.
"Their thermal behavior is not as steady as large caves on Earth that often maintain a fairly constant temperature, but it is consistent with these being deep holes in the ground."
The holes, which the researchers have nicknamed the "Seven Sisters," are at some of the highest altitudes on the planet, on a volcano named Arsia Mons near Mars' tallest mountain, the researchers report in the journal Geophysical Research Letters.
"Whether these are just deep vertical shafts or openings into spacious caverns, they are entries to the subsurface of Mars," said USGS researcher Tim Titus.
"Somewhere on Mars, caves might provide a protected niche for past or current life, or shelter for humans in the future."
But not these caves.
"These are at such extreme altitude, they are poor candidates either for use as human habitation or for having microbial life," Cushing said. "Even if life has ever existed on Mars, it may not have migrated to this height."

NASA Astronomers Find Bizarre Planet-Mass Object Orbiting Neutron Star

In this artist depiction of the SWIFT J1756.9-2508 system, the foreground object is the planet-mass object. The pulsar, located at the upper right, is tidally distorting the companion into a teardrop-shaped object, and ripping gas from it. This material flows in a stream toward the pulsar and forms a disk around it. Eventually, enough gas builds up in the disk to produce an outburst bright enough to make the system visible from Earth. Credit: Aurore Simonnet/Sonoma State University

Using NASA's Swift and Rossi X-ray Timing Explorer (RXTE) satellites, astronomers have discovered one of the most bizarre planet-mass objects ever found.The object's minimum mass is only about 7 times the mass of Jupiter. But instead of orbiting a normal star, this low-mass body orbits a rapidly spinning pulsar. It orbits the pulsar every 54.7 minutes at an average distance of only about 230,000 miles (slightly less than the Earth-Moon distance).