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Institute of Astronomy

 

Observatory marks 230 years of recording weather

10 hours 47 min ago

The building holds the longest sequence of continuous weather data anywhere in the UK and Ireland.

LIGO has spotted the most massive black hole collision ever detected

10 hours 47 min ago

A puzzling gravitational wave was detected, and astronomers have determined that it comes from a record-breaking black hole merger

Hubble Snaps Galaxy Cluster’s Portrait

Sat, 12/07/2025 - 10:38
Explore Hubble

2 min read

Hubble Snaps Galaxy Cluster’s Portrait This NASA/ESA Hubble Space Telescope image features the galaxy cluster Abell 209. ESA/Hubble & NASA, M. Postman, P. Kelly

A massive, spacetime-warping cluster of galaxies is the setting of today’s NASA/ESA Hubble Space Telescope image. The galaxy cluster in question is Abell 209, located 2.8 billion light-years away in the constellation Cetus (the Whale).

This Hubble image of Abell 209 shows more than a hundred galaxies, but there’s more to this cluster than even Hubble’s discerning eye can see. Abell 209’s galaxies are separated by millions of light-years, and the seemingly empty space between the galaxies is filled with hot, diffuse gas that is visible only at X-ray wavelengths. An even more elusive occupant of this galaxy cluster is dark matter: a form of matter that does not interact with light. Dark matter does not absorb, reflect, or emit light, effectively making it invisible to us. Astronomers detect dark matter by its gravitational influence on normal matter. Astronomers surmise that the universe is comprised of 5% normal matter, 25% dark matter, and 70% dark energy.

Hubble observations, like the ones used to create this image, can help astronomers answer fundamental questions about our universe, including mysteries surrounding dark matter and dark energy. These investigations leverage the immense mass of a galaxy cluster, which can bend the fabric of spacetime itself and create warped and magnified images of background galaxies and stars in a process called gravitational lensing.

While this image lacks the dramatic rings that gravitational lensing can sometimes create, Abell 209 still shows subtle signs of lensing at work, in the form of streaky, slightly curved galaxies within the cluster’s golden glow. By measuring the distortion of these galaxies, astronomers can map the distribution of mass within the cluster, illuminating the underlying cloud of dark matter. This information, which Hubble’s fine resolution and sensitive instruments help to provide, is critical for testing theories of how our universe evolved.

Text Credit: ESA/Hubble

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Media Contact:

Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight CenterGreenbelt, MD

Share Details Last Updated Jul 11, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms Keep Exploring Discover More Topics From Hubble Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.


Hubble Gravitational Lenses


Focusing in on Gravitational Lenses


Shining a Light on Dark Matter

Lonely spacecraft can navigate the stars

Sat, 12/07/2025 - 10:35

Nature, Published online: 11 July 2025; doi:10.1038/d41586-025-02108-6

NASA’s New Horizons probe, which hurtled past Pluto in 2015, demonstrates that it can sail through interstellar space using its onboard camera.

We may have finally solved an ultra-high-energy cosmic ray puzzle

Sat, 12/07/2025 - 10:33

The IceCube neutrino detector has allowed researchers to resolve a debate about what types of particles make up ultra-high-energy cosmic rays – but much remains unknown about these rare events

Mystery interstellar object could be oldest known comet

Fri, 11/07/2025 - 11:00

Scientists have been racing to discover the origins of 3I/Atlas since it was spotted last week.

NASA’s James Webb Space Telescope Inspects Cat’s Paw

Fri, 11/07/2025 - 09:42
To celebrate its third year of revealing stunning scenes of the cosmos in infrared light, NASA’s James Webb Space Telescope has “clawed” back the thick, dusty layers of a section within the Cat’s Paw Nebula (NGC 6334). NASA, ESA, CSA, STScI

NASA’s James Webb Space Telescope team released this image of the Cat’s Paw Nebula on July 10, 2025, in honor of the telescope’s third anniversary. Webb’s NIRCam (Near-Infrared Camera)  revealed never-before-seen structural details and features: Massive young stars carve away at nearby gas and dust, while their bright starlight produces a bright nebulous glow represented in blue. As a consequence of these massive stars’ lively behavior, the local star formation process will eventually come to a stop.

Take a tour through this section of the Cat’s Paw Nebula.

Image credit: NASA, ESA, CSA, STScI

The cosmos is vast, so how do we measure it?

Fri, 11/07/2025 - 09:41

The awe-inspiring distances of the cosmos are hard to visualise, so how can we be certain we are measuring them correctly? Chanda Prescod-Weinstein explains

Interstellar visitor 3I/ATLAS might be the oldest comet ever seen

Fri, 11/07/2025 - 09:41

Astronomers tracking an interstellar object flying through the solar system think it comes from a star at least 8 billion years old, almost twice the age of our sun

Astronomers found a completely new type of plasma wave near Jupiter

Fri, 11/07/2025 - 09:41

Observations from NASA’s Juno spacecraft reveal that Jupiter’s strong magnetic field and the unique properties of its plasma can produce a truly novel kind of extraterrestrial wave near its poles

Giant radar satellite set to probe Earth’s shifts and shudders

Fri, 11/07/2025 - 09:40
Science, Volume 389, Issue 6756, Page 118-119, July 2025.

First returned rock samples shine a light on the Moon’s ‘dark side’

Wed, 09/07/2025 - 17:10

Nature, Published online: 09 July 2025; doi:10.1038/d41586-025-02050-7

Soil samples from the far side of the Moon provide clues about the origin of lunar asymmetry and the effects of ‘mega-basin’ impacts on the evolution of rocky planets

How to chart a moral future for space exploration

Wed, 09/07/2025 - 10:27

Nature, Published online: 08 July 2025; doi:10.1038/d41586-025-02070-3

Expanding human influence in outer space will require an ethical compass that is more expansive than the one conventionally used.

Stellar Duo

Wed, 09/07/2025 - 10:26
ESA/Hubble & NASA, J. Bally, M. Robberto

NASA’s Hubble Space Telescope captured a bright variable star, V 372 Orionis, and its companion in this festive image in this image released on Jan. 27, 2023. The pair lie in the Orion Nebula, a colossal region of star formation roughly 1,450 light-years from Earth.

V 372 Orionis is a particular type of variable star known as an Orion Variable. These young stars experience some tempestuous moods and growing pains, which are visible to astronomers as irregular variations in luminosity. Orion Variables are often associated with diffuse nebulae, and V 372 Orionis is no exception; the patchy gas and dust of the Orion Nebula pervade this scene.

Text credit: European Space Agency (ESA)

Image credit: ESA/Hubble & NASA, J. Bally, M. Robberto

Did something just hit Saturn? Astronomers are racing to find out

Tue, 08/07/2025 - 09:10

Around seven asteroids or comets are thought to hit Saturn ever year, but we have never spotted one in the act. Now, it seems one astronomer may have caught the moment of impact and the hunt is on for other images to verify the discovery

NASA’s Hubble and Webb Telescopes Reveal Two Faces of a Star Cluster Duo

Tue, 08/07/2025 - 09:09
Explore Hubble

3 min read

NASA’s Hubble and Webb Telescopes Reveal Two Faces of a Star Cluster Duo A vast network of stars, gas, and dust is strung among a duo of star clusters in this combined image from NASA’s Hubble and Webb space telescopes. Open clusters NGC 460 and NGC 456 reside in the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. This highly detailed 527 megapixel mosaic consists of 12 overlapping observations and includes both visible and infrared wavelengths. To view some of its incredible detail, download the 40.1 MB file and zoom in. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)
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A riotous expanse of gas, dust, and stars stake out the dazzling territory of a duo of star clusters in this combined image from NASA’s Hubble and Webb space telescopes.

Open clusters NGC 460 and NGC 456 reside in the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. Open clusters consist of anywhere from a few dozen to a few thousand young stars loosely bound together by gravity. These particular clusters are part of an extensive complex of star clusters and nebulae that are likely linked to one another. As clouds of gas collapse, stars are born. These young, hot stars expel intense stellar winds that shape the nebulae around them, carving out the clouds and triggering other collapses, which in turn give rise to more stars.

In these images, Hubble’s view captures the glowing, ionized gas as stellar radiation blows “bubbles” in the clouds of gas and dust (blue), while Webb’s infrared vision highlights the clumps and delicate filamentary structures of dust (red). In Hubble images, dust is often seen silhouetted against and blocking light, but in Webb’s view, the dust – warmed by starlight – shines with its own infrared glow. This mixture of gas and dust between the universe’s stars is known as the interstellar medium.




Hubble (ACS) Webb (NIRCAM)

This Hubble image shows a duo of open clusters, NGC 460 and NGC 456. The nebulae’s glowing gas, ionized by the radiation of nearby stars, is distinct in Hubble’s view. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)

In Webb’s infrared view of open clusters NGC 460 and NGC 456, dusty areas are visible as bright structures glowing red. Many background galaxies are visible, their infrared light passing through the region’s obscuring clouds of gas and dust. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America) Hubble (ACS)Webb (NIRCAM)

This Hubble image shows a duo of open clusters, NGC 460 and NGC 456. The nebulae’s glowing gas, ionized by the radiation of nearby stars, is distinct in Hubble’s view. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America) In Webb’s infrared view of open clusters NGC 460 and NGC 456, dusty areas are visible as bright structures glowing red. Many background galaxies are visible, their infrared light passing through the region’s obscuring clouds of gas and dust. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)
Hubble (ACS)
Webb (NIRCAM)

Hubble and Webb view a duo of open star clusters
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Image Details

Slide to switch between Hubble and Web images. Hubble’s view captures visible light and some infrared wavelengths, while Webb’s view is exclusively infrared. The nebulae’s glowing gas, ionized by the radiation of nearby stars, is distinct in Hubble’s view. Dusty areas that appear dark in the Hubble image are visible as bright structures in the Webb image, and more background galaxies are visible since infrared light from fainter and farther galaxies can pass through the obscuring clouds of gas and dust.

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The nodules visible in these images are scenes of active star formation, with stars ranging from just one to 10 million years old. In contrast, our Sun is 4.5 billion years old. The region that holds these clusters, known as the N83-84-85 complex, is home to multiple, rare O-type stars, hot and extremely massive stars that burn hydrogen like our Sun. Astronomers estimate there are only around 20,000 O-type stars among the approximately 400 billion stars in the Milky Way.

Clouds of ionized gas dominate open cluster NGC 460 in the Hubble image (left), while tendrils of dust are on display in the Webb image (right). Together, the two images provide a more comprehensive look at the region. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America) The Hubble image of NGC 456 (left) shows a puffy, bluish cloud of ionized gas, while the Webb image (right) displays the same cluster’s cavern-like outline of dust. NASA, ESA, and C. Lindberg (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)

The Small Magellanic Cloud is of great interest to researchers because it is less enriched in metals than the Milky Way. Astronomers call all elements heavier than hydrogen and helium – that is, with more than two protons in the atom’s nucleus – “metals.”  This state mimics conditions in the early universe, so the Small Magellanic Cloud provides a relatively nearby laboratory to explore theories about star formation and the interstellar medium at early stages of cosmic history. With these observations of NGC 460 and NGC 456, researchers intend to study how gas flows in the region converge or divide; refine the collision history between the Small Magellanic Cloud and its fellow dwarf galaxy, the Large Magellanic Cloud; examine how bursts of star formation occur in such gravitational interactions between galaxies; and better understand the interstellar medium.

Explore More
Hubble’s Star Clusters


Exploring the Birth of Stars


Hubble’s Nebulae

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Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight CenterGreenbelt, MD
claire.andreoli@nasa.gov

Share Details Last Updated Jul 07, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms Keep Exploring Discover More Topics From Hubble Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.


Hubble’s Cosmic Adventure


Hubble’s Night Sky Challenge


Hubble’s 35th Anniversary

Meteorite causes rethink of how and when our solar system formed

Sat, 05/07/2025 - 11:28

Rocky bodies called protoplanets were thought to have formed slightly earlier in the inner solar system than those beyond the asteroid belt, but now a meteorite from the outer solar system is rewriting that view

Rare find: interstellar visitor seen blazing through our Solar System

Fri, 04/07/2025 - 10:59

Nature, Published online: 03 July 2025; doi:10.1038/d41586-025-02141-5

The comet-like body called either C/2025 N1 or 3I/ATLAS is now zipping past Jupiter.

Hubble Observations Give “Missing” Globular Cluster Time to Shine

Fri, 04/07/2025 - 10:58
Explore Hubble

2 min read

Hubble Observations Give “Missing” Globular Cluster Time to Shine This NASA Hubble Space Telescope image features a dense and dazzling array of blazing stars that form globular cluster ESO 591-12. NASA, ESA, and D. Massari (INAF — Osservatorio di Astrofisica e Scienza dello Spazio); Processing: Gladys Kober (NASA/Catholic University of America)
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A previously unexplored globular cluster glitters with multicolored stars in this NASA Hubble Space Telescope image. Globular clusters like this one, called ESO 591-12 or Palomar 8, are spherical collections of tens of thousands to millions of stars tightly bound together by gravity. Globular clusters generally form early in the galaxies’ histories in regions rich in gas and dust. Since the stars form from the same cloud of gas as it collapses, they typically hover around the same age. Strewn across this image of ESO 591-12 are a number of red and blue stars. The colors indicate their temperatures; red stars are cooler, while the blue stars are hotter.

Hubble captured the data used to create this image of ESO 591-12 as part of a study intended to resolve individual stars of the entire globular cluster system of the Milky Way. Hubble revolutionized the study of globular clusters since earthbound telescopes are unable to distinguish individual stars in the compact clusters. The study is part of the Hubble Missing Globular Clusters Survey, which targets 34 confirmed Milky Way globular clusters that Hubble has yet to observe.

The program aims to provide complete observations of ages and distances for all of the Milky Way’s globular clusters and investigate fundamental properties of still-unexplored clusters in the galactic bulge or halo. The observations will provide key information on the early stages of our galaxy, when globular clusters formed.

Explore More
Hubble’s Star Clusters


Exploring the Birth of Stars

Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight CenterGreenbelt, MD
claire.andreoli@nasa.gov

Share Details Last Updated Jul 03, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms Keep Exploring Discover More Topics From Hubble Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.


Hubble’s Cosmic Adventure


Hubble’s Night Sky Challenge


Hubble’s 35th Anniversary

Contract signed for construction of CTAO-South roads and telescope foundations

Fri, 04/07/2025 - 10:57

This week, a major contract, worth several million Euros, has been signed between ESO and a consortium of Chilean companies for the construction of telescope foundations for the Cherenkov Telescope Array Observatory’s (CTAO’s) southern hemisphere array (CTAO-South) at ESO’s Paranal Observatory in Chile. The contract includes more than 50 foundations for CTAO-South telescopes, as well as approximately 17 km of roads connecting these foundations to the support facilities. ESO, a founding member of the CTAO European Research Infrastructure Consortium and host of its southern array, signed the contract on behalf of this international organisation. The construction of this important civil infrastructure is expected to take one year, paving the way for the first telescopes to be erected on site. Therefore, this milestone marks the beginning of the array’s construction in the southern hemisphere. 

The CTAO will be the largest and most powerful ground-based observatory for gamma-ray astronomy. It is composed of two telescope arrays—CTAO-South, and CTAO-North in La Palma, Spain. One located in the southern hemisphere and the other in the northern hemisphere, both will keep a watchful eye out for an elusive form of radiation called Cherenkov radiation. When cosmic gamma rays reach the atmosphere and interact with it, they generate a cascade of ultra-energetic particles; as they move through the air, these particles create a faint blue flash of “Cherenkov light”. By analysing this faint light, astronomers can infer much about the cosmic sources, like supermassive black holes and supernova remnants, that emitted the original gamma rays. 

To capture Cherenkov radiation, the CTAO-South site will consist of 51 individual telescopes of different sizes to detect both bright and faint events. The site will cover an area of about 3 square kilometres and is located about 10 kilometres away from Cerro Paranal, the home of ESO’s Very Large Telescope. Once built, the CTAO will make data and analysis software publicly available for the entire global scientific community to share, strengthening worldwide collaboration and helping to answer questions across both astronomy and particle physics, like the hunt for dark matter, the mechanics of supernovae, and how dense neutron stars collide. 

The CTAO will be the first observatory of its kind, able to observe the high-energy Universe with unparalleled sensitivity. Its location near Cerro Paranal, far from light pollution sources and under one of the world’s darkest and most pristine night skies, is key to detecting the extremely faint Cherenkov blue light. 

More information 

In January 2025, the CTAO was established as a European Research Infrastructure Consortium (ERIC) by the European Commission. The Founding Members of the CTAO ERIC are Austria, the Czech Republic, the European Southern Observatory (ESO), France, Germany, Italy, Poland, Slovenia, and Spain. Additionally, Japan is a Strategic Partner, and the accession of Switzerland and Croatia as Founding Members is being processed.