100 undiscovered galaxies may be orbiting the Milky Way, supercomputer simulations hint
The Milky Way may be surrounded by dozens of yet-to-be-detected satellite galaxies, scientists claim.
Using the highest-resolution simulation of our galaxy's dark matter — an invisible entity that shapes the large-scale structure of the universe — and new mathematical models, cosmologists predict that more than 100 additional satellite galaxies beyond the ones already cataloged may be swirling around our own.
If those galaxies are spotted by telescopes, they could offer support for the standard model of cosmology — the dominant model of our universe that explains how galaxies form. The researchers presented their findings July 11 at the Royal Astronomical Society's National Astronomy Meeting in Durham, England.
"We know the Milky Way has some 60 confirmed companion satellite galaxies, but we think there should be dozens more of these faint galaxies orbiting around the Milky Way at close distances," lead researcher Isabel Santos-Santos, a graduate student at Durham University, said in a statement. "One day soon we may be able to see these 'missing' galaxies, which would be hugely exciting and could tell us more about how the Universe came to be as we see it today."
According to the standard theory of cosmology, known as lambda cold dark matter (LCDM), both dwarf galaxies and large ones such as our own take shape within clumps called galactic halos. These vast spheres of stars float like leaves on a pond of dark matter, the mysterious substance believed to make up 85% of the universe's matter.
Dark matter doesn't reflect light, so it hasn't been observed directly. But scientists see evidence for it in the shapes of galaxies, the warping of starlight as it passes through them, and the acceleration of stars to otherwise inexplicable speeds as they orbit galactic centers.
Related: Scientists discover rare planet at the edge of the Milky Way using space-time phenomenon predicted by Einstein
This dark matter halo gives the Milky Way a hefty gravitational pull. The pull is so strong, in fact, that over the course of billions of years, it has captured a number of dwarf galaxies (those containing less than a few billion stars) as satellites.
Despite being predicted as plentiful by LCDM, satellite galaxies are faint and therefore hard to detect; many more should exist than astronomers have been able to observe or even simulate. Taken at face value, their absence is yet another crack of doubt in the standard model of cosmology.
But the scientists behind the new research propose a reason for this lack of supporting evidence, at least within simulations: They're not precise enough to model galaxy evolution, so the simulated halos get disrupted, leading to the loss of their satellite galaxies.
RELATED STORIES
—'This doesn't appear in computer simulations': Hubble maps chaotic history of Andromeda galaxy, and it's nothing like scientists expected
—Unproven Einstein theory of 'gravitational memory' may be real after all, new study hints
—Fast radio burst traced to the outskirts of an ancient 'graveyard' galaxy — and the cause remains a mystery
To better simulate the possible hidden galaxies, the astronomers turned to the Aquarius simulation, the highest-resolution reconstruction of a Milky Way dark-matter halo. They used the Aquarius simulation to run the GALFORM model — a code that tracks gas cooling, stars forming and matter clumping to form galaxies similar to our own.
According to the simulation, dwarf galaxies have been orbiting the Milky Way for much of the universe's life. Yet during their repeated passes, their dark matter and stars were gradually snatched away by the Milky Way's enormous galactic halo, causing them to appear extremely faint in the present day.
This means that anywhere from 80 to over 100 more dwarf galaxies might exist around our galaxy's outskirts, according to the researchers. If these galaxies are really there, it may not be long before they're detected; the new Vera Rubin Observatory, which is equipped with the largest digital camera ever constructed, could resolve some of these hidden galaxies.
"If the population of very faint satellites that we are predicting is discovered with new data, it would be a remarkable success of the LCDM theory of galaxy formation," co-researcher Carlos Frenk, a professor of astrophysics at the University of Durham, said in the statement. "It would also provide a clear illustration of the power of physics and mathematics. Using the laws of physics, solved using a large supercomputer, and mathematical modelling we can make precise predictions that astronomers, equipped with new, powerful telescopes, can test."
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
10 minutes ago
- Yahoo
Tech giant OpenAI signs deal with government to boost efficiency in public services
OpenAI has signed a deal with the government to use artificial intelligence (AI) in an effort to increase department efficiency. The new partnership will involve the ChatGPT creator exploring how AI can be used in areas such as education, justice, defence and security to make them "more efficient and effective". They will also explore investing in British AI infrastructure, such as data centres. Politics latest: Ministers want OpenAI to identify how advanced AI models could help improve services used by the public. Technology Secretary Peter Kyle said: "AI will be fundamental in driving the change we need to see across the country - whether that's in fixing the NHS, breaking down barriers to opportunity or driving economic growth. "This can't be achieved without companies like OpenAI, who are driving this revolution forward internationally. This partnership will see more of their work taking place in the UK." In an attempt to become a global AI hub, the government previously set out plans to invest £1 billion in infrastructure for AI development, with the plan to increase capacity 20-fold over the next five years. However, the creative industries have criticised their commitment to AI, which they say could be at the detriment of their jobs. Concerns around the amount of water needed to cool data centres and the amount of energy AI uses have also been raised as the government tries to tackle water shortages, pollution, and high energy bills. Read more:The wealth tax options Reeves could take to ease her fiscal bindUk gives final go-ahead to £38bn Sizewell C nuclear plant OpenAI, headed up by the American Sam Altman, also has plans to increase the size of its London office, which was the company's first international location two years ago. The government hopes the partnership will mean "world-changing" AI tech is developed in the UK. OpenAI will look to invest in and support AI "growth zones" across the UK, which will receive funding, the government said. Mr Altman said: "AI is a core technology for nation building that will transform economies and deliver growth. "Britain has a strong legacy of scientific leadership and its Government was one of the first to recognise the potential of AI through its AI Opportunities Action Plan. "Now, it's time to deliver on the plan's goals by turning ambition to action and delivering prosperity for all." The civil service already uses ChatGPT in its AI assistant, "Humphrey", to speed up admin tasks.


Medscape
11 minutes ago
- Medscape
Post-Cerclage Cervical Length as Predictor of Preterm Birth
TOPLINE: Post-cerclage cervical length (CL) was a significant predictor of spontaneous preterm birth (sPTB; < 34 weeks of gestation) in women who underwent cervical cerclage, predominantly outperforming pre-cerclage CL. METHODOLOGY: Researchers in the UK conducted a retrospective cohort study at four preterm birth prevention clinics between January 2008 and March 2021 to assess the predictive value of CL measurements, both before and after cervical cerclage, for sPTB (< 34 weeks of gestation). They included 331 women who underwent cervical cerclage and had both pre- and post-cerclage CL measured per the standardised protocol using transvaginal ultrasound as recommended by the Cervical Length Education and Review program. The primary outcome was sPTB (< 34 weeks of gestation), assessed using multivariable logistic regression modelling (adjusting for pre- and post-cerclage CL, gestational age at cerclage, and direction of the CL change) and receiver operating characteristic (ROC) curves. TAKEAWAY: Both pre-cerclage CL (area under the ROC curve [AUC], 0.635; 95% CI, 0.559-0.712) and post-cerclage CL (AUC, 0.677; 95% CI, 0.604-0.751) were predictors of sPTB. Adjusted models incorporating gestational age at cerclage demonstrated that both pre-cerclage CL (odds ratio [OR], 0.964; P = .018) and post-cerclage CL (OR, 0.940; P < .001) were significant predictors of sPTB. In a comparative model analysis, the effect of post-cerclage CL on sPTB was greater than that of pre-cerclage CL (OR, 0.943; P < .001 vs OR, 0.974; P = .058). Overall, sPTB was reported in 11.9% of women with history-indicated cerclage vs 24.3% of those with ultrasound-indicated cerclage and 36.8% of those with emergency cerclage (P = .003). IN PRACTICE: "Clinicians performing cervical cerclage should aim to maximize total CL when inserting cerclage and continue to monitor CL after cerclage insertion," the authors wrote. SOURCE: This study was led by K. E. Mountain and S. Ng, March of Dimes Prematurity Research Centre at The Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, England. It was published online on July 09, 2025, in Ultrasound in Obstetrics & Gynecology. LIMITATIONS: This study included only women who underwent cervical cerclage, limiting the use of pre-cerclage CL thresholds for decision-making guidance. Metrics related to the cerclage position within the cervical canal were not assessed. Additionally, the intervals between pre- and post-cerclage scans and cervical cerclage were not standardised. DISCLOSURES: This study was supported by the National Institute for Health and Care Research Imperial Biomedical Research Centre, London, and Tommy's Charity, London, UK. The authors reported having no conflicts of interest. This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
Yahoo
2 hours ago
- Yahoo
Billion euro deal: Sanofi buys UK biotech company to expand respiratory vaccine portfolio
In the race to develop next-generation respiratory virus vaccines, French pharmaceutical company Sanofi has agreed to buy Vicebio Ltd., a privately-held biotechnology company headquartered in London, UK. Sanofi said there will be an initial cash payment of $1.15bn (€980 million) for the deal, 'with potential milestone payments of up to $450 million based on development and regulatory achievements'. 'We are excited to join Sanofi', said Emmanuel Hanon, Chief Executive Officer at Vicebio, in a statement. 'Their global scale and deep expertise in vaccine development provide the ideal environment to fully realise the potential of our innovative technology." With the acquisition, Sanofi gets Vicebio's early-stage combination vaccine candidate for two respiratory viruses, the respiratory syncytial virus (RSV) and human metapneumovirus (hMPV). Respiratory infections, affecting millions globally, often appear as cold-like illnesses that could, in severe cases, lead to pneumonia. In respiratory medication, Sanofi already has several vaccines in its portfolio against flu and RSV prevention; this latest acquisition adds a non-mRNA vaccine to its pipeline. mRNA technology is relatively new for vaccines. It teaches the body how to make a protein that triggers an immune response to protect against a specific virus, instead of using a weakened or inactivated germ to trigger this reaction. With the current deal, Sanofi also gets access to Vicebio's Molecular Clamp technology, which stabilises viral proteins in their native shape, triggering a more effective immune response. This technology is expected to speed up vaccine development and simplify manufacturing and distribution. Related EU pharma chief calls for European Nasdaq to boost biotech innovation Doliprane-maker Sanofi confirms exclusive talks with US firm CD&R 'This acquisition furthers Sanofi's dedication to vaccine innovation with the potential to develop next-generation combination vaccines that could provide protection to older adults against multiple respiratory viruses with a single immunisation," said Jean-François Toussaint, global head of research and development vaccines at Sanofi. The transaction is expected to close by the end of 2025, and will not have a significant impact on Sanofi's financial guidance for 2025. The pharma giant's share price was down around 0.4% before 11:00 CEST in Paris.