Category Astronomy/Space

Hubble revealed the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon this part March. The subterranean ocean is thought to have more water than all the water on Earth’s surface. Identifying liquid water is crucial in the search for habitable worlds beyond Earth and for the search for life, as we know it.

“This discovery marks a significant milestone, highlighting what only Hubble can accomplish,” said John Grunsfeld, assistant administrator of NASA’s Science Mission Directorate. “In its 25 years in orbit, Hubble has made many scientific discoveries in our own solar system. A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”

Ganymede is the largest moon in our solar system and the only moon w...

The most successful technique for finding planets beyond our solar system so far is transit photometry, which measures changes in a star’s brightness caused by a mini-eclipse. When a planet crosses in front of its star along our line of sight, it blocks some of the star’s light. If the dimming lasts for a set amount of time and occurs at regular intervals, it likely means an exoplanet is passing in front of, or transiting, the star once every orbital period.

NASA’s Kepler Space Telescope has used this technique to become the most successful planet-hunting spacecraft to date, with more than a thousand established discoveries and many more awaiting confirmation...

This unprocessed view of Saturn’s moon Enceladus was acquired by NASA’s Cassini spacecraft during a close flyby of the icy moon on Oct. 28, 2015.

NASA’s Cassini spacecraft has begun transmitting its latest images of Saturn’s icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles above the moon’s south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

“Cassini’s stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come,” said Linda Spilker, JPL.

Enceladus Up-Close During its closest ever dive past the active south polar region of Saturn’s moon Enceladus, NASA’s Cassini spacecraft ...

This image of asteroid 2015 TB145, a dead comet, was generated using radar data collected by the National Science Foundation’s 1,000-foot (305-meter) Arecibo Observatory in Puerto Rico. The radar image was taken on Oct. 30, 2015, and the image resolution is 25 feet (7.5 meters) per pixel. Credit: NAIC-Arecibo/NSF

Scientists observing asteroid 2015 TB145 with NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, HI, have determined that the celestial object is more than likely a dead comet that has shed its volatiles after numerous passes around the sun.

The first radar images of the dead comet were generated by the National Science Foundation’s 305-meter (1,000-foot) Arecibo Observatory in Puerto Rico...