Why the panic about interstellar comet 3I/ATLAS? – DW – 07/04/2025
Beyond the fact that this is the third known interstellar object to have entered our solar system, "we don't know very much," said Larry Denneau, co-principle investigator at ATLAS, a telescope in Chile that spotted 3I/ATLAS on July 1, 2025.
It's not exactly reassuring when scientists say "we don't know," but at least it's honest.
Astronomers do know that 3I/ATLAS is a comet that's about 670 million kilometers (416 million miles) away from the sun. Based on current projections, it poses no danger to planet Earth.
"Scientists are still determining the velocity and trajectory to a degree that will allow accurate predictions for the future," wrote Richard Moissl, who heads the European Space Agency's Planetary Defense office, in an email to DW.
The closest it will get to our planet is about 240 million km away, when it will fly by in October. That is more than 1.5 times the distance between us and the sun, and about 624 times the distance between the Earth and our moon. It is also thought to be about 20 km (12.4 miles) wide and traveling at about 60 km per second (an impressive 134,000 miles per hour).
But this is all relatively basic data — the very data that allowed astronomers at the Asteroid Terrestrial-impact Last Alert System in Chile to spot it. When they saw the object on an unusual trajectory, they immediately began to track and measure it.
Then, other astronomers based at telescopes in Hawaii and Australia, began monitoring the object's flight progress and confirm it as an interstellar comet.
"We are seeing an onset of [normal] cometary activity," wrote Moissl.
Comet 3I/ATLAS flew through the heliosphere to enter our solar system. The heliosphere is a barrier that protects us from interstellar winds and radiation.
The heliosphere is, however, an imperfect barrier — some interstellar radiation gets through, and it clearly doesn't stop icy intergalactic wanderers, like 3I/ATLAS.
Interstellar objects in our solar system are thought to be quite rare, though. The first known interstellar object was 1I/'Oumuamua, detected in 2017, and 2I/Borisov, detected in 2019.
"This is only the third interstellar [object] ever to be detected, hence a precise forecast of the expected frequency is not possible at this point," wrote Moissl.
But telescopes have got more technologically advanced and scientists do now scan the night sky continuously. So, we may begin to see more of them.
"The Legacy Survey in Space and Time at the Vera Rubins telescope in Chile goes online this year. It is more efficient than existing surveys and expected to detect several new Interstellar Objects over the next 10 years," said Moissl's colleague at ESA, Michael Kueppers.
Kueppers is a Comet Interceptor Project Scientist. Comet Interceptor is a spacecraft that will rest in a "parking orbit" and intercept distant comets and asteroids if they come too close to planet Earth. It's scheduled to launch in 2029.
The short (and obvious) answer is that comets, like 3I/ATLAS, 1I/'Oumuamua and 2I/Borisov, come from other planetary systems.
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
Much like comets and asteroids within our solar system, interstellar objects are considered to be untouched specimens from elsewhere in our galaxy, the Milky Way — if not fragments from the very beginnings of the universe.
Moissl said this new object "came roughly from the direction of the Galactic Center region," which, as the name suggests, is towards the center of the Milky Way. But astronomers do not know its precise origin or "home star".
Based on its brightness, 3I/ATLAS appears to be bigger than the other two stray comets — 1I/'Oumuamua and 2I/Borisov — which are thought to have entered our solar system from a different region of the Milky Way.
Astronomers will want to continue monitoring 3I/ATLAS to assess its composition and behavior. ESA said that as an active comet, it may heat up as it gets closer to Earth, and "sublimate" — that's when frozen gases on a comet turn into vapor, creating a glowing coma and trail of dust and ice particles.
You should be able to see it from Earth with a telescope by September. When it's closest to Earth, it will be hidden by the sun, but then reappear by early December.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
DW
14 hours ago
- DW
Microplastics in crops may threaten food production – DW – 08/13/2025
Research suggests tiny particles of plastic could hamper plant growth, with potentially serious consequences for global food supply and climate change. Cutting plastic production would help. Microplastics are believed to disrupt photosynthesis — the biological process central to life on earth that provides the basis for global food chains as well as the oxygen we breathe. The tiny shreds of plastics — often originating from the disintegration of larger plastic items — have found their way into the most remote corners of the planet and even human organs. Now there is growing concern that these particles, once inside plant cells, can interfere with photosynthesis — the process by which plants convert sunlight, water, and carbon dioxide into energy in the form of sugars. This may impede plant growth, with potentially serious consequences for food production and Microplastics can reduce photosynthesis by up to 12%, according to an assessment led by a team of mostly China-based researchers. The study, published earlier this year in the Proceedings of the National Academy of Sciences, analyzed terrestrial crops, marine algae and freshwater algae. Seafood yields could plunge 7%, and staple crops could see a loss of up to 13.5%, according to the study. The scientists behind the paper warned this could leave hundreds of millions of people without reliable access to food. But cutting microplastic levels by just 13% could prevent nearly a third of photosynthesis loss, they found. Still, Peter Fiener, a soil and water expert, warned that there isn't enough data to reliably project the paper's findings on a global scale when it comes to photosynthesis loss and the resulting impact on food production. Microplastics are usually absorbed through soil when a plant sucks up water and other nutrients through its roots, Fiener told DW, adding if the particles are small enough they can pass into its cells. To understand the impact microplastics are having on food production around the world you would "need to have a global map of the plastic contamination of our soils and we just don't have such a map," said Fiener, who is a professor at Augsburg University in Germany. One of the biggest problems is the lack of data for the Global South, said Victoria Fulfer, a microplastics scientist at 5 Gyres, a US nonprofit tackling plastic pollution. "The other issue is that microplastics are made up of hundreds of different polymers and thousands of chemical additives and so we obviously haven't been able to test as scientists the impact that all of these have on plants," said Fulfer. While research into the impact of microplastics on plant growth is a very new field, it's "definitely something that we need to be concerned about and need to be focusing on," Fulfer told DW. Microplastics absorbed by plants often come from tarps used to cover crops in agriculture and the spreading of fertilizers, said Fulfer. "But also microplastics are in our air and in our water." Agricultural mulch films are often used to cover crops and boost growth. While they're meant to be biodegradable, many still contain chemical additives and microplastics. As they break down, these substances seep into the soil, said Winnie Courtene-Jones, marine biologist and plastic pollution expert at Bangor University in Wales. Other sources include tiny fragments from car tires and fibers from clothing, which end up in sewage sludge later used as fertilizers. "So we're adding them directly to these ecosystems where the plants and the crops are growing and once they're at that small level of microplastics and nanoplastics, it's very difficult to get rid of them," said microplastics scientist Fulfer. Microplastics are usually defined as plastic pieces measuring between 1-5 millimeters, while nanoplastics are even smaller. Once in the soil, they can disrupt water movement and nutrient breakdown, affecting the growth of plants and other small organisms, said Courtene-Jones. Microplastics have been found throughout the human body and linked to a range of potential health problems, including strokes and heart attacks. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Plastics emit greenhouse gases through their production, transportation and also disposal. But Fulfer noted they may also impede climate change mitigation if they are reducing photosynthesis at scale. "So we're going to be taking up less carbon, emitting less oxygen because of these microplastics, particularly in those blue carbon ecosystems, which are our mangroves and our seagrass beds and our marshes — these are really important for climate change," said Fulfer. According to some estimates, mangroves and coastal wetlands store up to three to five times more carbon than an equivalent area of tropical forest. In separate research published last year Courtene-Jones and colleagues documented reductions in photosynthetic efficiency in coastal plant species due to the combined impact of flooding and microplastics in their soil. "I think there's the potential for microplastics to really exacerbate some of the responses that we're seeing to an already stressed system due to climate change," Courtene-Jones told DW. She added that microplastics affect soil stability, which might result in greater levels of coastal erosion especially as climate change leads to heavier rainfall over shorter time periods. While the full impact on food production remains unclear, microplastics in soil and crops will continue to accumulate without action, said expert, Peter Fiener. Recycling helps, he added, but cutting plastic production is even more critical. In the past two decades, global output of new or virgin plastic has surged. It's projected to increase two or even threefold by 2050, potentially tripling associated global emissions. About 99% of plastics are made from fossil fuels, and just 9% are recycled. This week, representatives from more than 170 countries are in Geneva, Switzerland, negotiating a binding treaty to curb plastic production and pollution. When it comes to preventing microplastics from harming plants "the biggest thing is just turning off that tap and having better regulation on the amount of plastic that we're producing," said Victoria Fulfer of 5 Gyres. Reducing plastic production was a sticking point in last year's stalled UN plastic treaty talks in Busan, South Korea, and remains a flashpoint in the Geneva negotiations.
DW
17 hours ago
- DW
Can Myanmar's 2025 quake data predict the next big one? – DW – 08/13/2025
Scientists say earthquake prediction is impossible but studying the 2025 Myanmar earthquake may help forecast when, and where, the next big tremor could strike. During the midday prayers on March 28, a magnitude 7.7 earthquake struck central Myanmar along the Sagaing Fault. With an epicenter close to Mandalay, the country's second-largest city, it was the most powerful earthquake to strike Myanmar since 1912 — causing widespread destruction of Mandalay's infrastructure while reports have put the death toll between 3,700 to more than 5,000 people. Its seismic impacts reached as far as Bangkok, Thailand's capital, where it collapsed a 30-story skyscraper, claiming at least 92 lives. Could seismologists have seen it coming? Scientists had been anticipating a large earthquake along a segment of the fault, which had not ruptured since a similarly destructive earthquake in 1839. But what they couldn't predict was when the earthquake would hit, its epicenter, or how destructive it would be. "Despite decades of effort, scientists still can't reliably predict exactly when and where earthquakes will strike," said Kit Yates, a mathematician at the University of Bath, UK. "The movements and interactions of the Earth's tectonic plates are incredibly complex. Distinguishing meaningful earthquake warning signs from background seismic noise — especially with added human activity — is extremely difficult," Yates told DW. Five months on from the Mandalay quake, scientists have been analyzing its destructive effects — and their findings could help predict features of earthquakes in the future. "The hope is that such [findings] might be used to forecast the time, magnitude and extent of future earthquakes," said Jean-Philippe Avouac, a seismologist at California Institute of Technology, US, who led a new study published this week in the journal PNAS. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Real-time footage of the quake revealed the Sagaing Fault's movement in stunning detail. The Mandalay quake hit like a rapid, pulse-like rupture along the fault line. Beneath people's feet, the ground moved three meters apart in just 1.3 seconds at the epicenter. In total the quake lasted 80 seconds, extending 460km (285 miles) down the fault, causing surface displacement six meters (20 feet) deep. Avouac's team compared this data to past earthquakes with similar features. They then created a computer model which contained several predictions about the Sagaing Fault. The key ingredient of the model was how it described tectonic changes caused by past earthquakes. Avouac described this as a "memory effect" in the Sagaing Fault. "This is a nice result to show that our simple model results in a memory effect [and] is consistent with [real world] observations," Avouac said. The model confirmed that a "supershear" rupture — which has amplified waves in the direction of the split — was anticipated on the fault because of its very straight geometry and its history of similar ruptures. Their model forecasts that large-magnitude earthquakes occur along the Sagaing Fault irregularly and with an interval of around 141 years — meaning the next quake to hit Myanmar could be in 2166, give or take 40 years. The model also identified features of the fault "slip" that helps refine forecasts about future ruptures. Instead of predicting quakes, seismologists are focused on forecasting seismic activity with better accuracy. Much like weather forecasts, they aim to estimate the likelihood of earthquakes over longer periods and in specific regions. "There are consistent relationships between the frequency and energy of earthquakes. This allows scientists to estimate how often large quakes might occur based on smaller ones, for which there is more data," said Yates. The hope is that models like Avouac's might be used to forecast the time, magnitude and extent of future earthquakes. "Such forecasts are crucial for disaster planning. A city like San Francisco, with a high probability of a major quake in the next 30 years, can justify major investment in preparedness," Yates said. Current models "can only make probabilistic hazard assessments with large uncertainties," said Avouac. Avouac said scientists are currently unable to forecast the time, location and magnitude of a future earthquake with enough precision to take action, like order evacuation of a city. Earthquakes are chaotic events, meaning even tiny changes in the initial conditions can lead to unpredictable shifts in seismic activity. "The challenge is that model needs to be tuned to the state of the fault at present, but we don't know how to measure the distribution of [tectonic] stress, and don't know enough [about] past ruptures to reconstruct them," Avouac said. Researchers are currently aiming to better understand how seismic activity can lead to different types of earthquakes in the hope they'll lead to more accurate hazard assessments in the view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
DW
06-08-2025
- DW
US scientists discover trees host up to 1 trillion microbes – DW – 08/06/2025
Healthy trees contain more than one trillion different bacteria, fungi and viruses, a new study has found. These wood microbiomes could hold clues about forest health and climate change. A new study has discovered that trees contain a rich and diverse microbiome inside their tree trunks, much like humans do in our bodies. An average tree contains approximately one trillion microbe cells, according to data acquired from sampling the DNA of 150 trees and published today in the journal . It found that healthy trees contain distinct microbiomes specialized to different parts of the tree and rich in fungi, bacteria, and viruses. The authors believe these could play a vital role in tree health. "Our study shows that each tree species hosts its own distinct microbial community that has evolved alongside the tree," said study co-author Jon Gewirtzman at Yale University, US. Katie Field, a plant biologist at Sheffield University, UK, who was not involved in the research, said the study "helps reredefine how we see trees — not just as standalone organisms, but as complex, integrated ecosystems that include a vast network of microbial life." "In the same way that human microbiomes are important for our health, this work suggests we may need to start thinking similarly about trees. It opens a whole new frontier for environmental microbiology, forest science, and even biotechnology," Field told DW. Microbes are an important part of plant life. The discovery of a 'wood-wide web' — a network that connects fungal filaments and tree roots in underground soil — led to the idea that other organisms aid plant growth and defence against pathogens. But little is known about the microbes living inside healthy wood. "The three trillion trees on Earth represent the world's largest pool of biomass, much of which hosts unique ecosystems we've never studied," said Gewirtzman. The researchers set out to study the microbiomes of trees in the Yale-Myers Forest in Connecticut, US. They took multiple samples from 150 trees across 16 species, including oaks, maples, and pines. Soil samples were also taken. They then extracted DNA from the wood and soil and analysed the data for evidence of DNA from bacteria, fungi, and viruses. They found that trees contain huge numbers of different microbe species — roughly one microbe for every 20 plant cells. This translates to between 100 billion and one trillion microbial cells on average, which is still far fewer than the 39 trillion inside humans. "This study provides some of the clearest evidence to date that the wood of living trees hosts distinct and adapted microbiomes, different to those of the surrounding soil, leaves, or tree roots," said Field. To play this audio please enable JavaScript, and consider upgrading to a web browser that supports HTML5 audio Microbes weren't equally distributed through the tree — specialized microbial communities existed in different parts of wood. The inner heartwood and outer sapwood contained completely different microbial communities. Denser heartwood was dominated by microbes that don't need oxygen, while the sapwood contained more oxygen-requiring microbes. Different microbiomes were also found in different tree species. Maple trees, for example, contained high abundance of microbes that are adept at breaking down sugars. Further experiments showed that different communities changed gas concentrations inside these woods. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Whether these specialized microbiomes affect the health of their tree hosts is unclear. More studies are needed to understand how microbiomes affect wider forest health, but the authors believe there is a link. "We know that certain microbes promote growth in certain model plants, including in major cereal crops and poplar trees, but there are thousands [of microbes] that we do not know the function of," Gewirtzman told DW via email. The study may also open new questions. For Field, this includes investigating the roles microbiomes play in tree aging, defence and decay. "There is also clear potential to explore whether managing or modifying wood microbiomes could help improve forest resilience or carbon cycling," said Field. Gewirtzman suggests it could also answer big picture questions about how climate change impacts trees, or whether tree microbiomes could be deployed for other purposes. "How will climate change affect these internal ecosystems and forest health? And can we harness these microbes for new forest management or biotechnology applications?" But Michael Köhler, a botanist at Martin Luther University Halle-Wittenberg, Germany, told DW it's far too early for Gewirtzman's group to start monitoring tree microbiomes to measure climate impacts and forest health. "We're investigating this at the moment — how climate change is affecting the microbiome of seeds and seedlings in grasslands," he told DW.
