The unusual behaviour is the first documented evidence of widespread interaction between the freshwater and saltwater animals.
The Cassini mission's data has provided scientists with several new insights, and Nasa says that it will continue to use and apply the information collected.
Greenpeace USA's Guide to Greener Electronics names and shames tech giants that failed to deliver on clean energy commitments.
Over 4,000 seed samples came from gene banks in Columbia and Peru and include varieties of wheat, beans, potato and more.
Ferocious wildfires have killed at least 36 people in Portugal, including a one-month-old baby, and at least three in Spain.
Tiangong-1, China's nearly nine-tonne space station, is currently out of control and has been gradually falling towards the Earth since last year, when engineers lost contact with it.
Analysis of the data collected by Cassini space probe during the Grand Finale revealed the phenomena.
In 1859 a powerful solar flare caused telephone wires to burst into flames. But in today's technology-reliant society, a comparable event would be far more damaging.
This year's most powerful Atlantic hurricanes – Harvey, Irma and Maria – caused so much damage that 2017 will almost certainly prove to be the costliest hurricane season on record.
Dolphin and whale societies are about as sophisticated as our own. They talk, have names, form allegiances, hunt together and work with other species. All they lack is thumbs.
Archaeologists found skeletons from the 13th to 6th centuries BC that bear the marks of severe trauma - but it appears these injuries weren't intended to kill.
For the first time ever, scientists have detected both gravitational waves and light from the same astronomical event, dubbed GW170817.
Nasa found that heat and droughts in the tropical regions of Africa, Indonesia and South America are responsible for the surge in the release of atmospheric CO2.
Hurricane Ophelia's winds fanned more than 140 wildfires across northern Spain and Portugal, killing three in Galicia and six in Portugal.
Storm Ophelia is set to hit Ireland and parts of the UK with gusts of up to 80mph from the Atlantic, causing schools and airports to close.
This was the second classified satellite launched via United Launch Alliance's Atlas V within three weeks.
Nasa's sounding rocket instrument detects signs of nanoflares.
Following Cassini, Nasa needs a new mission to look for life on Saturn's mysterious moons.
The fires have been spreading quickly, engulfing more than 214,000 acres of land and incinerating an estimated 5,700 structures.
The X3 is a Hall thruster, a type of ion thruster that creates propulsion by firing a stream of electrically charged atoms, called plasma, out of a nozzle.
A fleet of spaceplane could bring down the cost of space trip tickets of the company, according to the President.
Archaeologists have discovered a 5,000-year-old toy chariot and rattle while digging at the site of Sogmatar city in Turkey
Archaeologists may have discovered the first evidence of a long-lost satellite pyramid for Ancient Egypt's Queen Ankhnespepy II during excavation works south of Cairo.
A scientist said the public shouldn't worry too much about the supervolcano beneath Yellowstone National Park, saying it is unlikely to erupt in our lifetime, if ever.
Nasa astronaut Randy Bresnik shared a video of fidget spinners and ISS astronauts spinning in zero-gravity.
Oceans that contain clams and worms release 8 times more methane than those without, according to new research.
The program at China Conservation and Research Centre for the Giant Panda has its most successful year ever, with 42 cubs born in 2017.
Easter Island has been used as an example of humankind's selfishness; a moral tale of the dangers of environmental destruction. But new research is painting a different picture.
The star, nicknamed Kronos after the child-eating Titan of Greek mythology, is the clearest and most dramatic case observed to date of a sun-like star consuming its own planets.
The week's best news and sport photos, from California wildfires and Vietnam floods, to the battle for Raqqa, Kenya election protests and Rohingya Muslim refugee crisis.