Swift sees double supernova in galaxy

13.10.2015 | 15:49

In just the past six weeks, two supernovae have flared up in an obscure galaxy in the constellation Hercules. Never before have astronomers observed two of these powerful stellar explosions occurring in the same galaxy so close together in time. The galaxy, known as MCG +05-43-16, is 380 million light-years from Earth. Until this year, astronomers had never sighted a supernova popping off in this stellar congregation. A supernova is an extremely energetic and life-ending explosion of a star. Making the event even more unusual is the fact that the two supernovae belong to different types

Female iguanas pay high costs to choose a mate

13.10.2015 | 15:49

Picking a mate is not easy — if you are a female iguana. In a study published in the 27th June issue of the online, open-access journal PLoS ONE, Maren Vitousek of Princeton University and colleagues found that female Galapagos marine iguanas spend a lot of energy picking a mate from a wide range of suitors — energy they could otherwise spend foraging, producing eggs, or avoiding predators. Scientists have generally assumed that being choosy about potential mates carries low costs for females

Wood ant queen has no egg-laying monopoly

13.10.2015 | 15:48

he reproductive monopoly of the ant queen is not as strong as is often thought. Dr Heikki Helanterä and Prof Lotta Sundström, biologists working at the University of Helsinki, Finland, investigated worker ovary development and egg laying in nine Northern European wood ant species of the genus Formica, and revealed wide spread reproductive endeavours by workers. For example, in species such as Formica cinerea, Formica pratensis, and Formica truncorum approximately one in five workers is fully equipped to lay eggs. Furthermore, genetic analysis of egg parentage showed that these workers are really laying eggs on a large scale. For example in the species with the most worker reproduction, Formica truncorum, as many as one in four of eggs are indeed laid by the workers

Earth and Mars are different to the core

13.10.2015 | 15:48

Research comparing silicon samples from Earth, meteorites and planetary materials, published in Nature (28 June 2009), provides new evidence that the Earth’s core formed under very different conditions from those that existed on Mars. It also shows that the Earth and the Moon have the same silicon isotopic composition supporting the theory that atoms from the two mixed in the early stages of their development