A watery ocean may lie beneath the surface of Saturn’s largest moon, Titan, scientists believe. Gravity measurements reveal deformations in Titan’s interior that suggest a layer of liquid ‘sloshing around’.

The ocean is thought to be made of water with a depth of a couple of hundred kilometres. It appears to cover the entire moon beneath 100 kilometres of ice.

The evidence comes from the American space agency Nasa’s probe Cassini, which made six fly-bys of Titan between 2006 and 2011.

Scientists used signals beamed back by Cassini to measure distortions in Titan’s gravitational field.

The data showed something strange happening in the moon’s interior which indicated the presence of liquid water.

Writing in the journal Science, the planetary experts led by Dr Luciano Iess, from La Sapienza University in Rome, concluded: ‘Such a large response to the tidal field requires that Titan’s interior is deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth.’ Read more

Among the most serious Earth science and environmental policy issues confronting society are the potential changes in the Earth’s water cycle due to climate change. The science community now generally agrees that the Earth’s climate is undergoing changes in response to natural variability, including solar variability, and increasing concentrations of greenhouse gases and aerosols. Furthermore, agreement is widespread that these changes may profoundly affect atmospheric water vapor concentrations, clouds, precipitation patterns, and runoff and stream flow patterns.

Global climate change will affect the water cycle, likely creating perennial droughts in some areas and frequent floods in others. (Photograph ©2008 Garry Schlatter.) Read more

Underground heat pump installation to extract heat from water flushed down the drain

Homes in Helsinki will soon be heated by heat extracted from waste water. After domestic waste water has been treated at the Viiki sewage works, it will pass through one of five heat pumps built under Katri Vala Park. Its heat is removed, concentrated and used in domestic heating. Read more

Chemical water pollutants are generally atoms or molecules, which have been discharged into natural water bodies, usually by activities of humans. Common examples of such chemical water pollutants are mercury emanating from mining activity, certain nitrogen compounds used in agriculture, chlorinated organic molecules arising from sewage or water treatment plants or various acids which are the externalities of various manufacturing activities.

Physical water pollutants are either (a) much larger particles or (b) physical factors such as temperature change, both of which while not typically toxic, cause a variety of harmful effects. Read more

Sea ice is frozen seawater that floats on the ocean surface. Blanketing millions of square kilometers, sea ice forms and melts with the polar seasons, affecting both human activity and biological habitat. In the Arctic, some sea ice persists year after year, whereas almost all Southern Ocean or Antarctic sea ice is “seasonal ice,” meaning it melts away and reforms annually. While both Arctic and Antarctic ice are of vital importance to the marine mammals and birds for which they are habitats, sea ice in the Arctic appears to play a more crucial role in regulating climate.

Because they are composed of ice originating from glaciers, icebergs are not considered sea ice. Most of the icebergs infesting North Atlantic shipping lanes originate from Greenland glaciers. Read more