detection

Climate change and Antarctic meteorites

May 1, 2024 By EarthWise Leave a Comment

Researchers from Switzerland and Belgium have investigated the effects of the warming climate on access to meteorites in Antarctica. Meteorites are of great scientific interest because they provide unique information about the makeup of our solar system. Of all the meteorites that people have found, 62.6% of them were found in Antarctica.

Why is this? It is not because more meteorites land in Antarctica. Statistically, they can land anywhere on earth. Most end up in the ocean since the world’s oceans cover 70% of the planet.

Meteorites in Antarctica are more visible because environmental conditions are favorable for their preservation and their visibility. The arid and cold Antarctic environment helps to preserve meteorites and the lack of rocks and contrast with ice makes spotting meteorites much easier. The flow of ice sheets tends to concentrate meteorites in so-called meteorite stranding zones where the dark colored space rocks can be easily detected.

There are an estimated 300,000 to 800,000 meteorites in Antarctica. When meteorites warm up, they can transfer heat to the ice, which locally melts. Eventually, the meteorites sink beneath the surface. A recent study using satellite imagery, climate model projections, and AI predicts that for every tenth of a degree of increase in global air temperature, an average of 9,000 meteorites in Antarctica will disappear from the surface and will no longer be able to be found.

The study estimates that a quarter of Antarctic meteorites will be lost to glacial melt by 2050. If warming continues to accelerate, closer to three-quarters of the meteorites on the continent will be lost.

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Climate change threatens Antarctic meteorites

Photo, posted April 21, 2005, courtesy of Kevin Walsh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Detecting dangerous chemicals with plants

December 11, 2023 By EarthWise Leave a Comment

Researchers at University of California Riverside have been studying how to enable plants to sense and react to a chemical in the environment without damaging their ability to function in all other respects. Why do this? The idea is to be able to use plants as environmental sensors that can detect the presence of harmful substances.

The impetus for the work is presence of a protein in plants that senses a plant hormone called abscisic acid (or ABA) that helps plants acclimate to environmental changes. During drought, plants produce ABA causing the plant to produce ABA receptor proteins that close pores in its leaves and stems, keeping in moisture.

The UCR researchers demonstrated that these ABA receptor proteins can be trained to bind to chemicals other than ABA. This ability enabled them to create sensors for many chemicals, including banned pesticides.

In their recent publication, they demonstrated a green plant that turns bright red in the presence of azinphos-ethyl, a banned pesticide. The goal is to easily detect chemicals in the environment from a distance. A field of these plants would provide an obvious visual indicator of the use of a banned pesticide. The researchers also demonstrated the ability to turn a variety of yeast into a sensor that could respond to two different chemicals at the same time.

Ultimately, it would be extremely valuable to design plants that sense dozens of chemicals to they could be used as living sensors that persist for years and provide environmental information. The sensor plants are not being grown commercially at this time. That will require regulatory approvals that are likely to take years. But the discovery opens up real possibilities.

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Plants transformed into detectors of dangerous chemicals

Photo, posted August 29, 2013, courtesy of the United Soybean Board via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking down PFAS toxins

December 5, 2023 By EarthWise Leave a Comment

PFAS – per- and polyfluoralkyl substances – are a group of organic compounds that have been extensively used to provide water-, oil-, and dirt-resistance to a wide range of products ranging from non-stick pans, clothing, and packaging to paint, car polish, and fire-suppressant foam. Exposure to specific PFAS compounds is associated with multiple adverse health effects, including altered immune and thyroid function, liver disease, kidney disease, poor reproductive and developmental outcomes, and cancer. PFAS compounds do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

Government agencies such as the EPA in this country and the EU have set strict limits for allowable levels of PFAS in drinking water. Testing water for the trace amounts of PFAS that constitute the limits is time-consuming and expensive and requires complex equipment and experienced personnel.

Researchers at MIT have now introduced a technique for making a portable, inexpensive test that can easily and selectively detect PFAS in water samples. The test makes use of a special polymer containing fluorinated dye molecules that cause the polymer to fluoresce red. If PFAS are present in the sample, they enter the polymer and displace the dye molecules and switches off the red fluorescence.

The new technique is suitable for on-site detection in highly contaminated regions. Detecting smaller concentrations can be achieved with sufficient precision after pre-concentrating the samples using the process of solid-phase extraction.

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Tracking down Environmental Toxins

Photo, posted October 16, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Improved Radar For Cars | Earth Wise

December 31, 2020 By EarthWise Leave a Comment

Self-driving cars require a variety of sensor systems in order for the cars to safely navigate roads and deal with the wide range of objects and conditions that they encounter. Two competing technologies that cars use to identify and locate objects on the scene are radar and LiDAR.

Radar uses transmitted radio waves to locate objects and LiDAR bounces laser beams off of objects. Each has its shortcomings. Radar has the problem that only a small fraction of the transmitted signals gets reflected back to the sensor, so that there is frequently insufficient data to fully characterize a scene. LiDAR has the problem that it is an optical system that does not work well in fog, dust, rain, or snow. It is also much more expensive than radar.

Researchers at the University of California San Diego have developed a new system that they describe as a LiDAR-like radar. The system consists of two radar sensors placed on a car’s hood and spaced about 1.5 meters apart. This configuration enables the system to see more space and detail than a single radar sensor.

Having two radars at different vantage points with an overlapping field of view creates a region of high-resolution with a high probability of detecting the objects that are present. The system also overcomes noise problems of conventional radar systems.

The researchers developed new algorithms that can fuse the information from two different radar sensors and produce a new image free of noise.

Self-driving cars have to combine detection technologies like radar with cameras and ultrasonic sensors. Duplicating the capabilities that people use in order to safely drive a car is a complex problem requiring a combination of multiple sensors and sophisticated software.

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Upgraded radar can enable self-driving cars to see clearly no matter the weather

Photo, posted January 2, 2014, courtesy of Bradley Gordon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Finding Methane Leaks from Space | Earth Wise

December 23, 2020 By EarthWise Leave a Comment

There is growing concern about the climate effects of methane leaking from oil and gas wells. The 20-year global warming potential of methane is 84, meaning that over a 20-year period, it traps 84 times more heat per mass unit than carbon dioxide. Global methane concentrations have increased by nearly a factor of 3 since the industrial revolution.

More than a century of oil and gas drilling has left behind millions of abandoned wells, many of which are leaching pollutants into the air and water. In the U.S. alone, more than 3.2 million abandoned oil and gas wells emitted 280,000 tons of methane just in 2018. And the data is incomplete.

Part of the problem is finding out which wells are leaking. Ground-based sensors or airplanes and drones are effective ways to find leaks but considering how many wells there are to check, the costs are considerable, and the process is time consuming and complicated.

New technology is coming along that uses satellites to detect methane leaks. A Canadian company called GHGSat recently used satellites to detect what it has called the smallest methane leak ever seen from space and has begun selling data to emitters interested in pinpointing leaks.

Another company, New York-based Bluefield Technologies, plans a group of satellites for launch in 2023 that promises even finer resolution. The Environmental Defense Fund, with support from Jeff Bezos’ Earth Fund, plans to launch MethaneSAT in the next couple of years, which is designed to find small sources of methane.

Research at Stanford University determined that just 5% of methane leaks produce around half the total leakage.

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New Technology Claims to Pinpoint Even Small Methane Leaks From Space

Photo, posted June 8, 2011, courtesy of Jeremy Buckingham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Detecting Methane

December 23, 2019 By EarthWise Leave a Comment

Natural gas has become a huge industry in the United States, increasingly replacing coal in power plants, and otherwise contributing to energy independence. Unfortunately, it also contributes to climate change. Methane – the primary component of natural gas – is a powerful greenhouse gas that is estimated to be responsible for as much as a quarter of atmospheric warming.

Not all of the emissions from natural gas come from its use. In the United States, so-called fugitive emissions from the oil and gas industry total an estimated 13 million metric tons per year. These emissions basically consist of leakage of various types from the extraction, transportation, and processing of natural gas and cost the industry $2 billion in lost revenue each year. Globally, that figure is estimated to be $30 billion.

Research labs and startup companies are working on developing and deploying novel technologies to address the growing issue of methane leaks across the fossil fuel supply chain.

One company called LongPath Technologies – a spinout from the University of Colorado – uses frequency comb laser technology that can pinpoint a leak to about a 50 square-foot area from half a mile away. Other companies use different variations on laser absorption technology to be able to measure methane concentrations from a distance.

Methane is a much more powerful greenhouse gas than carbon dioxide, but it stays in the atmosphere for much less time. As a result, reducing methane emissions can pay off much more quickly than reducing carbon dioxide emissions.

The current EPA is trying to eliminate emissions regulations on the natural gas industry, but it is in the industry’s economic interest to curb those emissions even if they were unconcerned about the environment.

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Methane Detectives: Can a Wave of New Technology Slash Natural Gas Leaks?

Photo, posted October 22, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Exotic Pets Can Become Problems

August 26, 2019 By EarthWise Leave a Comment

Each year, millions of exotic animals are sold as pets around the world. The term “exotic” lacks a set definition but is generally used to refer to an animal that’s wild or more unusual than standard pets, like cats and dogs.

The exotic pet trade is a multi-billion dollar industry, involving tens of millions of individual animals from thousands of species, including reptiles, amphibians, fish, birds, and mammals.

Some of the exotic pet trade is legal, but a lot of it isn’t. Many animals are illegally captured from the wild to meet the global demand for exotic pets.

People often purchase exotic animals without completely understanding the consequences. Some exotic pets, for example, can live nearly twice as long as the average dog. Caring for exotic pets can be both expensive and risky, since they are largely undomesticated (and therefore can have unpredictable behavior).

As a result, it’s not uncommon for owners to release exotic pets intentionally. When this happens, the consequences can be catastrophic. Sometimes the animal dies from starvation or predation, but in other instances, the animal proliferates and becomes an invasive species.

Invasive species are the second largest driver of biodiversity loss worldwide, and they cost the U.S. $120 billion a year.

According to an academic review recently published in the journal Frontiers in Ecology and the Environment, the exotic pet trade is one of the primary causes of the spread of invasive species and has fueled the establishment of hundreds of them. Tegus, Burmese pythons, and red lionfish are examples of pets-turned-pests.

The best way to combat this trend is through education, detection, and rapid response.

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Why you should never release exotic pets into the wild

Photo, posted September 19, 2010, courtesy of Mike Baird via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Sensor For Spoiled Milk

June 20, 2019 By EarthWise Leave a Comment

A new sensor technology developed at Washington State University may eventually make expiration dates on milk a thing of the past. The sensor essentially can ‘smell’ whether milk is still good or has gone bad.

The sensor consists of chemically coated nanoparticles that react to the gas produced when bacterial growth on milk has taken place. When such bacteria grow, they produce a volatile compound that doesn’t smell good. So, when we open a carton of milk that has begun to spoil, our noses tell us so immediately.

The new sensor does not have to be in contact with the milk. It detects the volatile gases produced by the bacteria and it changes color. So far, it has only been demonstrated in a controlled lab environment.

To really be useful, the sensor would ideally be able to show how long the milk has before it spoils. Currently, it only shows whether it is ok or already spoiled. The researchers are working on the enhanced version of the sensor.

The researchers envision working with the dairy industry to integrate the sensor technology into a milk bottle’s plastic cap so that consumers can easily see how much longer the milk will stay fresh. Current expiration dates on milk are based on best-case scenarios. They are only accurate if the milk has been stored at the correct temperature the entire time. Unfortunately, milk can inadvertently spend time above refrigerator temperature during shipment or transportation home from the store. If the new sensor technology can be successfully developed, it will be possible to know for sure whether that bottle of milk is good.

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Sensor can detect spoiled milk before opening

Photo, posted March 8, 2011, courtesy of Roxanne Ready via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Earthquake Warning System

October 11, 2017 By EarthWise Leave a Comment

The destructive power of both hurricanes and earthquakes has made headlines in recent times. The slow development of the hurricanes in the Atlantic was monitored for days before they wreaked havoc on Caribbean islands and Florida cities. Earthquakes, on the other hand, occur suddenly and without warning. Except, that isn’t entirely true.