Hundreds of mystery fast radio bursts from space
Using a large stationary radio telescope in British Columbia, scientists have detected the largest cache of fast radio bursts discovered to date. The telescope, known as CHIME, for the Canadian Hydrogen Intensity Mapping Experiment, has detected 535 new fast radio bursts during its first year of operation between 2018 and 2019. The team announced its results during a virtual meeting of the American Astronomical Society on 9 June.
Detecting a fast radio burst is all about chance. The telescope has to point at the right place at the right time. Fast radio bursts, or FRBs, are oddly bright flashes in the radio frequency. They usually appear for a few milliseconds before vanishing without a trace.
These brief and mysterious bursts have been spotted in various and distant parts of the universe but their origins are unknown, and their appearance unpredictable.
Since the first was discovered in 2007, radio astronomers have only caught sight of around 140 bursts in their scopes.
Scientists with the CHIME Collaboration assembled the new signals in the telescope’s first FRB catalog. The new catalog significantly expands the current library of known FRBs, and is yielding clues as to their properties.
For instance, scientists found that the newly discovered bursts appear to fall in two distinct classes — those that repeat, and those that don’t.
Scientists have identified 18 FRB sources that burst repeatedly, while the rest appear to be one-offs. The repeaters also look different, with each burst lasting slightly longer and emitting more focused radio frequencies than bursts from single, non-repeating FRBs.
These observations strongly suggest that repeaters and one-offs arise from separate mechanisms and astrophysical sources. With more observations, astronomers hope soon to pin down the extreme origins of these curiously bright signals. More on Nature.
Mouse pups born from freeze-dried sperm that made space trip
Scientists have successfully produced mouse pups using freeze-dried mouse sperm that were kept in the International Space Station (ISS) for months.
The researchers wanted to know if space radiation affects fertility in mammals. Radiation can damage the DNA within cells, causing mutations. Space radiation in particular has been a major concern for countries that have sent many astronauts on lengthy missions into low Earth orbit.
These studies are also important because NASA and other space agencies are planning longer space missions to destinations such as the moon and Mars.
Researchers freeze-dried mouse sperm samples from 12 mice and sealed them within small lightweight capsules. These packets were transported to the ISS and stored for different amounts of time.
A portion of the samples returned to Earth after nine months in space, another set returned after two years and nine months, and the final set of mice sperm samples came back after five years and 10 months in space.
Researchers found that the trip to space did not damage the DNA of the sperms. They rehydrated the sperm with water, and then injected them into fresh mouse ovary cells.
After transferring them to female mice, the mothers became pregnant and eventually gave birth to healthy baby mice with no defects. More on space.com.
Polymer that mimics spider silk could replace single use plastics
A team from the University of Cambridge has created a polymer film by mimicking the properties of spider silk, one of the strongest materials in nature, that could replace plastic in many common household products.
The material was created using a new approach for assembling plant proteins into materials which mimic silk on a molecular level.
The team said that the method is energy-efficient, which uses sustainable ingredients and results in a plastic-like film. It can also be used to make water-resistant coatings.
The material is home compostable, whereas other types of bioplastics require industrial composting facilities to degrade. In addition, the material requires no chemical modifications to its natural building blocks, so that it can safely degrade in most natural environments.
The new product will be commercialised by Xampla, a University of Cambridge spin-out company developing replacements for single-use plastic and microplastics. The company will introduce a range of single-use sachets and capsules later this year, which can replace the plastic used in everyday products like dishwasher tablets and laundry detergent capsules. More on newatlas.com.
Takeaway foods are biggest contributor to ocean wastes
Takeaway food and beverage plastic containers dominate the litter in the world’s oceans, according to a study, which shows that a lot remains to be done to tackle non-biodegradable waste.
Single-use bags, plastic bottles, food containers and food wrappers are the four most widespread items polluting the seas, making up almost half of the human-made waste, the study states.
Just 10 plastic products, which included plastic lids and fishing gear, accounted for three-quarters of the litter, due to their widespread use and very slow degradation.
While some countries in Europe have banned the use of plastic straws and earbuds, the research showed that straws and stirrers made up 2.3 per cent of the litter and cotton buds and lolly sticks were 0.16 per cent.
The scientists said identifying the key sources of ocean plastic made it clear where action was needed to stop the stream of litter at its source.
Plastic bags and plastic bottles accounted for the highest amount of plastic wastes accounting for over 14 per cent and 12 per cent of the total plastic wastes respectively.
Over 9 per cent of the waste were plastic containers and cutlery. Scientists recommend that action to stop these items from reaching the ocean is required to make an impact on the volume of plastic garbage.
Plastic caps and lids, industrial packaging, glass bottles and drinks cans are some of the other items that account for vast amounts of plastic garbage floating in the oceans. More on The Guardian.
Lockdowns helped reduce ozone pollution at unexpected rate
NASA scientists have found that the lockdowns during the coronavirus pandemic cut local nitrogen oxide emissions, which in turn rapidly cut down the global effect ozone pollution.
Emissions of nitrogen oxides — which create ozone, a danger to human health and to climate — decreased 15 per cent globally, with local reductions as high as 50 per cent, according to a study led by scientists at NASA’s Jet Propulsion Laboratory in Southern California.
As a result of the lower nitrogen oxides emissions, by June 2020, global ozone levels had dropped to a level that policymakers thought would take at least 15 years to reach by conventional regulations.
The study shows that innovative technologies and other solutions intended to decrease nitrogen oxides locally have the potential to rapidly improve air quality and climate globally.
Ozone protects us from destructive solar radiation when it’s high above Earth in the stratosphere. Closer to the ground, though, it has other lasting impacts. Ozone at the surface was estimated to cause 365,000 deaths globally in 2019 by damaging the lungs of vulnerable people, such as young children and those with asthma.
Similarly, it damages the ability of plants to photosynthesize, reducing plant growth and crop yields. More on the dailynews.com.
(Edited by Arun Prashanth)