Pluto’s fifth moon discovered
A new moon has been found orbiting Pluto, bringing the number of satellites known around the former planet to five. P5 – the moon’s temporary designation – is between 10 to 25 km across (less than the diameter of London’s North Circular Road), and was discovered by scientists at SETI studying images from the Hubble Space Telescope. The photos show the moon as a speck, even compared to Pluto’s other moons – not surprising, given that Pluto is over 4.5 billion km away.
Just one year ago, the same team discovered Pluto’s fourth moon, P4, while attempting to find rings around the dwarf planet. Such discoveries are vital, as NASA’s New Horizons probe (due to fly past Pluto in 2015) could be seriously damaged by debris even 1 millimetre across.
According to team leader Mark Showalter, the group intends to keep searching for other satellites before naming the new moons. Pluto and its moons are currently named after characters from the underworld of Greek mythology, and he wants any new names to fit that theme.
Solar panel windows a step closer
London’s Gherkin could soon be a lot greener, thanks to a team at UCLA. They’ve developed solar cells that are almost 70% transparent to visible light, giving them potential for use in windows.
While traditional solar cells absorb visible light (making them opaque), these cells absorb mostly in the infrared region, allowing them to generate electricity with only a minimal impact on their transparency. As polymer solar cells, they are also lightweight and relatively cheap to produce – two qualities that are vital for widespread adoption.
However, they are much less efficient than other solar cells, converting just 4% of the solar energy received into electricity. Despite this, the team is upbeat about the future – in cities, where roof space for solar panels is at a premium, windows that generate electricity could massively increase our use of renewables.
Growing algae could save our warming planet
Phytoplankton, a type of plankton that get their energy from photosynthesis, could be used as a tool to fight climate change. Like all photosynthesising organisms, phytoplankton pull carbon dioxide from the air, but when they die, they fall to the seabed, taking that carbon with them. Over time – and given enough plankton – this could reduce the level of CO2 in the atmosphere.
Currently, the natural phytoplankton population is too low to have an effect on our rising emissions, but since 2004, a study in the Southern Ocean has been looking at how to boost their numbers. While it’s known that raising iron levels in the water can help, the plankton are often eaten before they sink to the seabed. However, the team found that algae growing in silicon-rich waters incorporated the silicon into their cells, making them harder to eat, and more likely to sink.
Current estimates suggest a global programme of phytoplankton farming could cut 1 gigatonne of carbon a year from the atmosphere – about 10% of our emissions – so it wouldn’t be the only solution, but one part of a concerted effort to prevent climate change.
Huge underground water supply found in Namibia
Namibia, sub-Saharan Africa’s driest country, has discovered a vast aquifer that could supply its most vulnerable people with water for up to 400 years. The water reserve, spanning 2,800 km² (about twice the size of Greater London), contains around 5 billion cubic metres of water that’s been untouched for 10,000 years. Despite its age, it should be safe to drink as it was stored at a time before environmental pollution was an issue.
The biggest danger to the water supply is likely to be illegal drilling – the aquifer lies under a smaller saltwater store that could contaminate it if the two ever met. Strict guidelines are to be put in place to avoid such a disaster.
The discovery is a welcome one for the country, which relies on a single canal from Angola to supply its driest regions with water. Periods of drought brought on by climate change could be avoided by using the water as a buffer. However, experts warn that the supply should be used sustainably, to ensure future generations can enjoy its benefits.
IMAGE 1: P5 by NASA, ESA and L. Frattare
IMAGE 2: Transparent Solar Cells by UCLA
IMAGE 3: Assorted diatoms by Gordon T. Taylor/NOAA Photo Library
IMAGE 4: Kalahari C17 by Harald Süpfle (CC-BY-SA-2.5 Licence)