Following almost three decades of planning and construction the world’s highest observatory has begun operations. The University of Tokyo Atacama Observatory (TAO), which is located at an altitude of 5640 m on the summit of Cerro Chajnantor at Atacama in northern Chile, officially opened today. The infrared telescope will be used to better our understanding of the universe as well as the origin of life.

At such a height, the clear skies and little water vapour in the atmosphere make Atacama one of the best places in the world for ground-based infra-red astronomy.  Built by the University of Tokyo, the telescope, which can be remotely controlled, includes a 6.5 m primary mirror that has been developed at Richard F. Caris Mirror Lab at the University of Arizona.

The observatory features two spectrographic instruments. The Simultaneous-color Wide-field Infrared Multi-object Spectrograph (SWIMS) will cover a wavelength range of 0.9 to 2.5 micrometres to observe a large areas of the sky. SWIMS will be used to study galaxies as well at the evolution of supermassive black holes that exist at their centres.

The Mid-Infrared Multimode Imager for gaZing at the UnKnown Universe (MIMIZUKU), meanwhile, will operate between 2-38 micrometres. MIMIZUKU will be used to better understand the chemical nature of organic dust in the universe, which can reveal details about the evolution of different materials, including those that led to the creation of life.

Takashi Miyata, from the University of Tokyo who is managing the observatory’s construction, has been working on the TAO for over 20 years and says he is “very excited” about the start of observations.

“Thanks to the height and arid environment, TAO will be the only ground-based telescope in the world capable of clearly viewing mid-infrared wavelengths,” he adds. “This area of the spectrum is extremely good for studying the environments around stars, including planet-forming regions”.

Given the issues working at such an altitude, Yuzuru Yoshii from the Univeristy of Tokyo notes that construction “was an incredible challenge”. He adds there were also political issues that had to be respected.

“I have liaised with Indigenous peoples to ensure their rights and views are considered, the Chilean government to secure permission, local universities for technical collaboration, and even the Chilean Health Ministry to make sure people can work at that altitude in a safe manner,” notes Yoshii. “Thanks to all involved, research I’ve only ever dreamed about can soon become a reality, and I couldn’t be happier.”

For the last three years, Naveen Chandra has been spending most of his days running simulations at the Research Institute for Global Change in Japan. He is trying to recreate the last 50 years of the earth’s atmosphere on a supercomputer roughly the size of an auditorium.

Dr. Chandra has been trying to answer a question that came out of his team’s research. During 2019-2020, these researchers examined the concentration of methane in the atmosphere and how it changed with time. Until the 1990s, the concentration increased, then stabilised for a bit, and then started to increase again around 2007. According to recent estimates, the atmospheric concentration of methane today is three-times what it was 300 years ago.

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Where is this methane coming from? That’s what they wanted to know.

Evolving understanding

Methane is the second most abundant anthropogenic greenhouse gas after carbon dioxide (CO2) but it warms the planet more. Over a century, methane has a global warming potential 28-times greater than CO2, and even higher over shorter periods like two decades.

It wasn’t until recently that policymakers began to focus on methane vis-a-vis addressing global warming. At the U.N. climate talks in 2021, member countries launched the ‘Global Methane Pledge’ to cut the gas’s emissions and slow the planet’s warming. Yet our understanding of methane also continues to evolve.

For instance, Dr. Chandra and his team recently reported that microbes have been the biggest sources of methane in the atmosphere, not the burning of fossil fuels.

The sources of methane

Scientists are increasingly recognising various sources of methane, most of which fit in two categories: biogenic and thermogenic. When fossil fuels such as natural gas or oil are extracted from deep within the earth’s crust, thermogenic methane is released. Biogenic methane comes from microbial action.

The microbes that produce methane are archaea — single-celled microorganisms distinct from bacteria and eukaryotes — and are called methanogens. They thrive in oxygen-deficient environments, such as the digestive tracts of animals, wetlands, rice paddies, landfills, and the sediments of lakes and oceans.

Methanogens play a crucial role in the global carbon cycle by converting organic matter into methane. While methane is a potent greenhouse gas, its production by methanogens is an essential part of natural ecosystems. But human activities like agriculture, dairy farming, and fossil fuel production have further increased methane emissions.

Both biogenic and thermogenic activities produce different isotopes of  methane. Tracking the isotopes is a way to track which sources are the most active.

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Modelling with a supercomputer

According to Prabir Patra, principal scientist at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and one of the lead authors of the study, carbon-13 is key. (Atoms of this carbon isotope have 13 nucleons: 6 protons + 7 neutrons.)

If there are fewer carbon-13 atoms than a certain level in a group of 1,000 methane molecules, the methane is from a biological source. If the methane is from thermogenic sources, such as trapped fossil fuels or geological activities, there will be more carbon-13 atoms in 1,000 molecules.

Dr. Chandra and Dr. Patra worked with scientists from Austria, Japan, the Netherlands, and the U.S. to collect data from the 12 monitoring sites worldwide tracking atmospheric parameters since the 1990s. Then they sorted the methane isotope data by year and ran it through a program they had developed to recreate the atmosphere from 1980 to 2020 on a supercomputer.

“One year of data analysis takes about 4-5 hours,” Dr. Chandra said.

Data mismatch

Finally, the team compared their own results with two emissions inventories, called EDGAR and GAINS, and found some discrepancies. EDGAR had reported that methane emissions from oil and natural gas exploration had increased between 1990 and 2020. GAINS had recorded a large “unconventional” rise in emissions since 2006. Their findings disagreed with both inventories.

Dr. Patra said combining the numbers for all biogenic and thermogenic isotopes should match the total emissions in a year. They also took insights from other available data like, number of rice fields, wetlands, dairy farms, biomass burning and likewise sources of methane emission, and estimated the emissions by those sources. But when they ran their atmosphere models with this data, the year-wise total methane emissions overshot the total production.

In fact, the models said methane emissions from fossil fuels declined between 1990 and the 2000s and that they’ve been stable since. They also found microbes were producing more methane than fossil fuels.

Need for local data

One possible reason could be an increase in cattle-rearing in Latin America and more emissions from waste in South and Southeast Asia, Latin America, and Africa, the study’s authors wrote in their paper. They added that the number of wetlands worldwide had increased as well.

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Studies in the past have pointed to microbes like anaerobic archaea as potentially top contributors of atmospheric methane using satellite data. But according to Dr. Patra, “Most studies which use satellites cannot measure the actual [changes over time] of methane.” Satellite data is interpreted using models “and thus are prone to uncertainties.” He said ground models are required to confirm these interpretations.

He added that their own atmospheric model was also only the beginning. The data for it came from observatories located in far-flung places. “If you really want to ask what is from the wetland, what is from the rice fields, we need measurements in those exact locations,” per Dr. Patra. “We don’t have that kind of observation at all anywhere in the world to make that kind of measurement. We can only speak for global emissions.”

But what we do know is: “If you want to reduce methane, anthropogenic activity should be first controlled. And we can clearly outline what is anthropogenic here. Waste and landfills, rice fields, enteric fermentation, oil and gas, and coal,” he said.

Monika Mondal is a freelance science and environment journalist.

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Barbra Streisand has offered an explanation after asking Melissa McCarthy if the Bridesmaids star had taken the weight loss drug Ozempic.

On Monday, McCarthy posted a picture of herself and director Adam Shankman as they attended a charity gala in honour of renowned choreographer Matthew Bourne.

Fans and famous faces flocked to the comments section – including Streisand, whose now-deleted post received attention for the wrong reasons.

The Funny Girl star wrote: “Give him my regards did you take Ozempic?”

The comment was soon spotted by McCarthy’s followers, one of whom wrote on Twitter: “Omg somebody please teach Barbra Streisand how to send a DM.”

Streisand’s post was later deleted and she’s now explained why she wrote it in a post on X.

The 82-year-old wrote: “OMG – I went on Instagram to see the photos we’d posted of the beautiful flowers I’d received for my birthday!

“Below them was a photo of my friend Melissa McCarthy who I sang with on my Encore album. She looked fantastic!

“I just wanted to pay her a compliment. I forgot the world is reading.”

McCarthy, 53, has not responded to either of Streisand’s posts.

Ozempic – a treatment originally designed for people with diabetes – works by suppressing the appetite and lengthens the amount of time food stays in the stomach, leading to weight loss – at least for as long as you carry on taking it.

It has been banned as a treatment for obesity in the UK due to high demand for the drug causing a global shortage.

Numerous Hollywood stars are rumoured to have used Ozempic to lose weight – but just a handful of celebrities have admitted it publicly.

Read more:
Ozempic to Wegovy – what are the weight loss injections?
Ozempic takes over the internet despite health warnings

Stephen Fry was prescribed the drug in the US “years ago” and said earlier this year that side effects included vomiting up to five times a day.

Oprah Winfrey has said she has also taken weight loss drugs, though she’s declined to specify which one.