Around 245 BCE Ptolemy III, ruler of the Ptolemaic Kingdom in Egypt, made a decision that still puzzles many historians: After pursuing a successful military campaign against the kingdom’s nemesis, the Seleucid Empire, centred mainly in present-day Syria and Iraq, the king suddenly decided to return home. This about-face “changed everything about Near-East history,” says Joseph Manning, a historian at Yale University.

For scientists trying to understand what ancient Mars might have been like, the red planet sends some mixed signals. Water-carved valleys and lakebeds leave little doubt that water once flowed on the surface. But climate models for early Mars suggest average temperatures around the globe stayed well below freezing.

How can a bee fly straight home in the middle of the night after a complicated route through thick vegetation in search of food? For the first time, researchers have been able to show what happens in the brain of the bee.

On May 29, 2006, mud started erupting from several sites on the Indonesian island of Java. Boiling mud, water, rocks and gas poured from newly-created vents in the ground, burying entire towns and compelling many Indonesians to flee. By September 2006, the largest eruption site reached a peak, and enough mud gushed on the surface to fill 72 Olympic-sized swimming pools daily.

An estimated 5.5 million Americans live with Alzheimer’s disease, a type of dementia that causes problems with memory, thinking and behavior. Although treatments can slow the worsening of symptoms, scientists are still working to better understand the neurodegenerative disease so that curative and preventative medicines can be developed. A new imaging system could help speed new drug development by offering a better way to monitor the brain changes indicative of Alzheimer’s in mouse models of the disease. 

Every year, millions of tonnes of plastic debris ends up in the sea - a global environmental problem with unforeseeable ecological consequences. The path taken by plastic to reach the sea must be elucidated before it will be possible to reduce the volume of plastic input. To date, there was only little information available on this. It has now been followed up by an interdisciplinary research team who were able to show that plastic debris is primarily carried into the sea by large rivers.

Carbon dioxide measured by a NASA satellite pinpoints sources of the gas from human and volcanic activities, which may help monitor greenhouse gases responsible for climate change.

Late last month, a stratovolcano in Bali named Mount Agung began to smoke. Little earthquakes trembled beneath the mountain. Officials have since evacuated thousands of people to prevent what happened when Agung erupted in 1963, killing more than 1,000 people.

The strong El Niño event of 2015-2016 provided NASA and NOAA an unprecedented opportunity to test the effectiveness of the newest observation tool to measure global atmospheric carbon dioxide concentrations -- NASA’s Orbiting Carbon Observatory-2 satellite or OCO-2.

Observations of carbon dioxide concentrations over the tropical Pacific from the satellite were validated by data from NOAA’s Tropical Pacific Observing System of buoys, which directly measure carbon dioxide concentrations at the surface of the ocean.

NASA-NOAA's Suomi NPP satellite provided a visible picture of newly formed Tropical Storm Lan in the Northwestern Pacific Ocean.

The desalination industry, a critical source of potable water in many arid regions, generated more than $13 billion last year and is expected to double within a decade. Most desalination plants today use a process called reverse osmosis (RO), which forces water through huge rolls of membranes, leaving the salt behind. One of the most expensive operational challenges for such plants is the fouling of these membranes by microorganisms.