Rocks from Mars

Writing for National Geographic, Maya Wei-Haas reports on the first rock sample successfully collected from the surface of Mars in an article entitled ‘Mars rover grabs first rock sample, a major step in hunt for alien life’. NASA’s Perseverance rover landed on the rim of the Jezero Crater in February 2021. The robot is designed to better understand the geology of Mars and seek signs of ancient life.  

After a failed attempt in August, on 1 September the rover pulled a slim cylinder out of a 70-centimetre-long rock named Rochette, and stored it in its belly. Alexandra Witze, writing in the journal Nature, explains how the rover will wait many years until future spacecraft can retrieve the sample, along with any other samples the rover collects, and return it to earth.  

Scientists have said that the rock may have been part of an ancient lava flow and may have interacted with water a long time ago. Maya Wei-Haas writes that “scientists believe Mars was once blanketed in a thick atmosphere, which helped trap enough heat to keep water from freezing and produced enough pressure to stop the liquid from evaporating and escaping as gas”. Around 3 billion years ago—and for unknown reasons—the planet was parched, and Mars became a “red dustball”. Rocks from Jezero Crater, which is believed to have once been a lake, offer scientists the chance to study this transformation further.  

The rover will now head east, and will study the layered rock in the crater. These layers could have preserved traces of life in Jezero. Once it has gathered all its samples, Maya Wei-Haas reports that the “fetch rover” to collect the samples could launch around 2026.  

 Read the full articles:

Transport noise and dementia

The number of people with dementia around the world is expected to exceed 130 million by 2050. While research into the relationship between environmental factors (such as air pollution) and risk of dementia is increasing, studies into the impact of exposure to transportation noise and risk of dementia remains limited. In this study entitled ‘Residential exposure to transportation noise in Denmark and incidence of dementia: national cohort study’, published in the British Medical Journal, researchers in Denmark examined the relationship between long term residential exposure to transportation noise and a possible increased risk of dementia.  

Using the unique personal identification number system used in Denmark, the researchers studied adults aged above 60 living in Denmark between 1 January 2004 and 31 December 2017. Those with a dementia diagnosis predating January 2004 were excluded. Researchers estimated exposures to road traffic and railway noise at the most and least exposed facades of buildings for all residential addresses in Denmark. Modelling was also carried out on road traffic noise and railway noise at specific intervals over a ten-year period. Certain socioeconomic factors were considered to account for lifestyle factors influencing a diagnosis of dementia. Overall, nearly 2 million residents were included in the study.  

The study found consistent associations between transportation noise from two independent noise sources (road traffic and railway) and increased risk of dementia. Researchers also found that damaging effects of noise on sleep could also play an important role in increasing risk of dementia. The “highest and most consistent” risk in terms of dementia subtypes and the impact of noise was for Alzheimer’s disease. However, the increased risk spanned all causes of dementia and dementia subtypes.  

The authors argue that, if these findings are confirmed in further studies, healthcare costs attributed to transportation noise and subsequent increased risk of dementia would need to be taken into account by policymakers.  

Read the full article: Manuella Lech Cantuaria et al, Residential exposure to transportation noise in Denmark and incidence of dementia: national cohort studyBritish Medical Journal, 9 September 2021, vol 374