Indholdsfortegnelse for July 2025 i BBC Sky at Night

A Soviet-era spacecraft designed to land on Venus in the 1970s has fallen to Earth, more than half a century after its mission failed. Kosmos 482 re-entered Earth's atmosphere in an uncontrolled fashion, its demise having been confirmed by both Roscosmos and European Union Space Surveillance and Tracking. Re-entry took place at around 06:16 UT on 10 May. While its final location has not been confirmed, Roscosmos has suggested it landed in the Indian Ocean, near the Indonesian capital of Jakarta. Kosmos 482 was launched by the former Soviet Union on 31 March 1972 as part of the Venera programme, a series of missions bound for Venus. Just days before, on 27 March 1972, the Soviets launched Venera 8, also to Venus, which successfully transmitted back data about Earth's ‘twin’…

Shimmering lights illuminate Jupiter's sky in this image snapped by NASA's James Webb Space Telescope. Hundreds of times brighter than similar lights seen on Earth, data in the newly released picture is illuminating details about Jupiter's magnetosphere. Aurorae capture the imagination of people around the world. They are created when high-energy particles collide with atomic and molecular gases near a planet's magnetic poles, and give rise to the beautiful, colourful bands we refer to as the Northern Lights. On Earth, the Northern Lights are usually caused by solar storms: charged particles from the Sun bombard the atmosphere, causing streaks of red, green and purple. Aurorae on Jupiter are significantly larger and brighter than those on Earth, because Jupiter's powerful magnetic field captures particles and accelerates them to immense speeds. The…

Iused to describe myself as ‘chronically late’. Having grown up in Uruguay, this was simply the norm. Timings there were as much a suggestion as red traffic lights were: open to personal interpretation. When I moved to the UK, I kept this habit up, putting my tardiness down to a cultural quirk until, in September 2016, a guy named Ian nearly gave up on me when I was 45 minutes late for a date. Reader, I married him – but only after a painstaking rebrand to become ‘anxiously early’. Who knew timekeeping was so important? Well, Maria Belville, for one. In June's episode of The Sky at Night, we celebrated 350 years of the Royal Observatory Greenwich, and something I learned from the programme team's dinner-party discussions was that time…

Water worlds beyond Earth are nothing new, with Jupiter's moon Europa and Saturn's moon Enceladus known to possess global oceans beneath their icy crusts, and perhaps the right kind of conditions for microbial life to evolve. Both worlds’ oceans may be potentially habitable since evidence has been found for requisite nutrients and heat. In December 2016, it was reported that beneath its icy crust, Pluto's internal heat could support a subsurface ocean at least 100km (60 miles) deep. In June 2020, it was theorised that this putative ocean might even have been habitable when it first formed. It could remain habitable today if conditions are warm enough and a source of geothermal heat exists at the ocean's base. Additionally, a life-enabling ocean would need to lack harmful toxins like hydrogen…

Thirty years ago, on the evening of 23 July 1995, amateur astronomers Alan Hale and Thomas Bopp were both independently looking at the same globular star cluster. Experienced observers who knew the sky well, Hale and Bopp each noticed a faint smudge close to the globular star cluster M70 that they couldn't find on any of their charts – and it was moving. Soon after, the object was confirmed as a new comet, named C/1995 O1 (Hale–Bopp) in honour of its discoverers. When it was first spotted, comet Hale–Bopp was just a magnitude +10.5 smudge, but once its orbit was calculated, it became apparent the new comet could be something special. The fact that it was already so bright, while still more than seven times further from the Sun than…

PICK OF THE MONTH Saturn Best time to see: 31 July, 03:00 BST (02:00 UT) Altitude: 31° Location: Pisces Direction: Southeast Features: Rings, subtle atmospheric features Recommended equipment: 150mm or larger After a relatively poor period where the main planets were clustered close to the Sun either in the evening or morning sky, some are now beginning to escape. Saturn isn't that well placed at the start of the month, reaching an altitude of around 23° in brightening twilight at 03:40 BST (02:40 UT) on 1 July, but achieves a decent position 31° above the southeastern horizon at 04:00 BST (03:00 UT) by the end of the month under relative darkness. Saturn's magnitude at the start of July is +0.7, the planet located to the southeast of the faint but distinctive Circlet asterism in Pisces.…

1. Stephenson 1 Stephenson 1 is a cluster that deserves to be better known. Delta (δ) Lyrae is a very wide (10-arcminute) and bright (mag. +4.3 and + 5.6) double star with a stunning colour contrast. It's not a true double: the difference in distance is about 200 lightyears. The open cluster Stephenson 1 lies immediately southwest of the pair, appearing as a granular patch of sky. Averted vision will reveal its brighter stars. □ SEEN IT 2. Barnard 144 Also known as the Fish on a Platter, this is the dark nebulosity that surrounds mag. +3.9 Eta (η) Cygni. It is named after “the man who never slept”, astronomer EE Barnard, whose study of Yerkes Observatory photographs of what were thought to be holes and voids in the Milky…

On 29 July 2021, more than four centuries after the invention of the telescope, the man who initiated a revolution in astronomy was finally honoured with a life-sized bronze statue. In the herb garden of the Middelburg Abbey, in the very southwest of the Netherlands, he sits on a bench, holding a small tube to his eye, gazing at the sky. No, it's not Galileo Galilei, although some popular books still suggest that the Italian astronomer was the one to build the first spyglass. And no, it's not the father of two boys who were playing with lenses and accidentally discovered the magnifying effect of their combination – that's a romantic, but completely apocryphal, 18th-century story. So, who really invented the telescope? A better question might be: why wasn't it…

San Juan County, Utah. I'm hiking deep inside Bears Ears National Monument in Utah, searching for calendars carved in rocks thousands of years ago. Here, in the Four Corners region of the American Southwest, where Utah, Colorado, Arizona and New Mexico meet, it's almost impossible to describe how far the sky stretches and how many stars one can see. The lack of buildings or mountains doubles the size of the horizon, and roads seem to go on forever, the asphalt stretching on and on. I follow a rough trail carved through piñon trees and sandstone towards River House Ruin, an ancient Ancestral Puebloan dwelling perched against the cliffs above the San Juan River. The Ancestral Puebloans, formerly called the Anasazi, were an indigenous people who lived in the Four Corners…

Step 1 For bias frames: pop the cap on your telescope or lens and set your capture time to the shortest possible for your DSLR. Set it for rapid burst exposures and hold down the trigger button. Let your camera continue until you have at least 20 images. Step 2 For dark frames: take them at the same time and temperature as your light frames. Replace the cap on your telescope or camera lens and keep your settings the same for both exposure and ISO. Set your camera running to capture at least 20 frames. Step 3 For flat frames (laptop method): open a blank word-processing document, ensuring it fills the screen. Set your DSLR to aperture priority; this adjusts the exposure time for the perfect flat image. Hold your…

VITAL STATS • Price £849 with windshield and ground mat • Style Portable observatory with removable roof • Footprint size 3.5m2 • Height 1.6m, up to 2.6m with windshield • Materials Aluminium poles, polyester 420D main canvas, PVC floor • Aperture 2.68m diameter • Weight Observatory 19.2kg; windshield and ground mat 6kg each • Supplier Widescreen Centre • Tel 01353 776199 • www.widescreen-centre.co.uk Ever-increasing light pollution and urban sprawl have prompted many of us to seek darker skies to put our equipment to better use. With several dark-sky sites accessible from where we live, we were excited to receive the Starpoint Australis Octans portable observatory for testing. The Octans is the larger of two models in the Starpoint Australis range and our review package included the optional ground mat and…

HUBBLE SPACE TELESCOPE, 28 APRIL 2025 Galaxies come in all sorts of shapes and sizes. They can be broadly classified as spiral, elliptical or irregular, but each of these still leaves plenty of scope for variety. Take, for instance, the spiral galaxy known as Arp 184 or NGC 1961. Something of a supernova hotspot, this spiral galaxy sits around 90 million lightyears from Earth in the constellation of Camelopardalis, the Giraffe. It earned its place in the Atlas of Peculiar Galaxies (compiled in 1966 by astronomer Halton Arp – hence the name) by having just a single spiral arm, where most spirals have two or more. FREE BONUS CONTENT Explore a gallery of these and more stunning space images www.skyatnightmagazine.com/bonus-content Dark horse VICTOR M BLANCO 4-METER TELESCOPE, 24 APRIL 2025…

For a long time, astronomers have expected frozen water may be scattered in systems around other stars. Now, for the first time, scientists have discovered definitive proof. Data from the NIRSpec (Near-Infrared Spectrograph) on the James Webb Space Telescope has confirmed the presence of crystalline water-ice in the dusty debris orbiting a Sun-like star called HD 181327. “Webb unambiguously detected not just water-ice, but crystalline water-ice, which is also found in locations like Saturn's rings and icy bodies in our Solar System's Kuiper Belt,” says Chen Xie, the lead author of the new paper and an assistant research scientist at Johns Hopkins University. The term water-ice is used by scientists to specify its chemical makeup, compared to the plethora of frozen molecules that are found in space, like dry ice…

Using data from Caltech's Palomar Observatory, astronomers have spotted a black hole moving through space and consuming a star 600 million lightyears away. It was found via observations of a tidal disruption event (TDE) called AT2024tvd. TDEs occur when a star approaches a supermassive black hole and gets violently ripped apart, causing outflows of radiation that can be detected by astronomers. Most supermassive black holes lie at the centres of their galaxies, but AT2024tvd was found strangely off to one side of its galactic centre. “AT2024tvd is the first offset TDE captured by optical sky surveys, and it opens up the entire possibility of uncovering this elusive population of wandering black holes with future sky surveys,” says Yuhan Yao, lead author of the study investigating AT2024tvd. A second, larger supermassive…

Suggestions of a ninth planet in our Solar System have been rumbling on for years now. Some astronomers argue that the clustering and orbital tilt of a group of trans-Neptunian objects indicate gravitational shepherding by an unknown planet. This hypothetical Planet 9, probably similar to Neptune, has been calculated to be on an elliptical orbit coming to around 300 AU (1 AU is the Earth–Sun distance). However, despite several surveys, no such remote new planet has been spotted, and the claim remains controversial. This lack of observational evidence isn't itself a damning outcome. The predicted orbit for Planet 9 is at least 10 times further from the Sun than Neptune, so the planet would reflect precious little light back to Earth. There's also a large degree of uncertainty around the…

As I sit in my garden in Pontypridd, south Wales, waiting for dusk to fall and the constellations of spring to appear, it's hard to ignore the sting of tears in my eyes when I think about astrophotographer Alyn Wallace. Alyn and I never met, but I will never forget when I heard the news that he had sadly passed away in Turkey on 28 March 2024, following a short illness. Despite not knowing him personally, he was a big figure in the astronomy and astro-imaging world – a talented man full of character, wit and infectious enthusiasm, deeply loved by his family, partner and friends. Alyn was only 34 when he died, but during his short time on this planet, his achievements reached stellar levels. Born in Pontypridd, Alyn…

Continuing its journey into the outer Solar System, on 1 January 2019, New Horizons flew within 3,500km (2,200 miles) of Kuiper Belt object Arrokoth, a near-pristine relic of the disc of material from which the Solar System formed. A ‘contact binary’, snowman-shaped Arrokoth resides 6.4 billion km (4 billion miles) from the Sun and 1.6 billion km (1 billion miles) beyond Pluto. Red-coloured Arrokoth measures 36km (22 miles) long, its two lightly cratered ‘lobes’ linked by a slender neck. The visit by New Horizons remains the most distant fly-by ever performed by a spacecraft. In April 2020, New Horizons and ground-based telescopes studied nearby stars Proxima Centauri and Wolf 359 to demonstrate easily observable stellar parallax. And it measured the cosmic optical background, revealing a sky 10 times darker than…

As you read this, the next Hale–Bopp is out there, in the deep dark of the Solar System, waiting to be found. But a human being probably won't be the first spot it, because in 2025 it's robots, not people, that hunt comets. Most are discovered by robotic survey telescopes, like Pan-STARRS and ATLAS. These networks image the sky night after night, looking for the appearance of fuzzy moving objects that could be comets. They don't need jackets to keep them warm, stools to sit on or flasks of coffee to keep them awake. They can scan the sky without blinking, hour after hour. And they find new comets almost weekly. Whenever it is found, the next potential Hale–Bopp will first be seen as an out-of-focus star on a survey…

Mercury Best time to see: 4 July, 40 minutes after sunset Altitude: 4° (Very low) Location: Cancer Direction: West–northwest Mercury is an evening planet, but poorly located and difficult to see due to its low altitude after sunset. This is despite reaching an impressive greatest eastern elongation on 4 July when it can be found 25.9° east of the Sun. On this date, mag. +0.6 Mercury sets 1 hour and 13 minutes after the Sun. Venus Best time to see: 31 July, 50 minutes before sunrise Altitude: 15° Location: Gemini Direction: East–northeast Venus is the brightest of the main planets, shining at mag. –4.0 at the start of July and dipping by just one tenth of a magnitude by the end of the month to mag. –3.9. This is still very bright and, under the right…

Technically, Pluto isn't a planet or an asteroid, but currently exists under the banner of a dwarf planet. Despite this, it's an object worth observing, especially if you've never recorded it before. Between its discovery in February 1930 and August 2006, Pluto was the ninth planet in our Solar System. But things got complicated as a number of other large bodies on the edge of the Solar System were discovered. If Pluto qualified as a planet, should these be considered planets too? In the end, the International Astronomical Union (IAU) produced a strict definition of a planet and, as a consequence, little Pluto was demoted to a new class of object known as a dwarf planet. Thought to be a frozen inert world, Pluto challenged that assumption in July 2015…

Viewing bright planets during the day is perfectly feasible, as long as you know where to find them. That might include Mercury, Venus, Mars and Jupiter, but Saturn pushes the limits somewhat. With a current magnitude around +0.5, it's a dim world for daytime viewing. But that's not to say it can't be done, and our challenge this month is to do just that. As the planet appears as a faint ghost of its former self during the day, one important and perfectly valid question that you could be asking yourself at this point is ‘Why bother?’. For general observations, there's little that can be done except gain a little kudos to be able to say you've seen it during the day. However, during July there are a number of…

Exploring ancient sites across the Four Corners can be awe-inspiring, but experts emphasise that visiting with a guide is essential. “We encourage anyone visiting these archaeological sites to go with a guide,” says Allison Yamamoto Sparks, with Utah's Canyon Country. “It's important to know how to visit these sites with care and preservation in mind. If you don't, you may miss some of the cool sites as well.” Guides act as protectors for these numerous fragile landmarks by ensuring responsible access to them, keeping them safe and whole for future generations to look at and learn from. They also have a great knowledge and understanding of the sites, so they can bring stories to life, share indigenous perspectives and reveal hidden details that casual visitors often overlook. Even small actions…

Noctilucent cloud season will be in full swing by the time you're reading this. Unfortunately, this doesn't guarantee displays, but rather indicates a period when displays are more likely. Despite being around 80km (50 miles) up in the atmosphere, from the UK they typically appear low above northerly horizons. But this isn't always the case and there have been sightings of them fairly high in the sky. In addition, their apparent altitude and azimuth aren't fixed and can change throughout the night, sometimes showing major changes either in the early period of the display or just before dawn truncates their visibility. Most low-light imaging equipment, including smartphones with night-capture modes, can record them, and doing so has become something of a summer ‘sport’. One major plus at this time of…

FREE BONUS CONTENT Find our extended Gallery at www.skyatnightmagazine.com/bonus-content PHOTO OF THE MONTH Planetary nebula PuWe 1 Andrea Arbizzi, Modena, Italy, December 2024–April 2025 Andrea says: “PuWe 1 is a tough, faint target and even more so from my Bortle 8 sky! But after 28 hours and some intensive processing, I was able to show this beautiful nebula that's normally drowned out by light pollution.” Equipment: ZWO ASI2600MC Duo camera, Askar FRA500 refractor, ZWO AM5N mount Exposure: Ha/OIII 163x 600”, UV/IR 98x 30”, total 28h Software: Astro Pixel Processor, PixInsight, Photoshop Andrea's top tips: “In order to capture this extremely faint planetary nebula, I had to use the Optolong L-Ultimate multi-narrowband filter, which lets through just 3 nanometres of light centred on the Ha and OIII wavelengths. The nebula would…

Scientists have long predicted that the Universe's lifetime is effectively forever – specifically, 101100 years. But now scientists from Radboud University have found that the Universe is decaying much quicker than previously thought, calculating that the last remnants of stars will perish in just 1078 years instead. “The ultimate end of the Universe comes much sooner than expected, but fortunately it still takes a very long time,” says Heino Falcke, black hole expert and lead scientist on the research. The researchers arrived at this shorter timeframe by considering evaporation due to Hawking radiation. Hawking radiation, proposed by Stephen Hawking in 1974, is a phenomenon where particles and radiation can escape from the immense gravitational pull of a black hole. If a black hole is emitting particles and radiation, it means…

A vast ball of hydrogen, long invisible to scientists, has been discovered just a stone's throw from Earth. Located just 300 lightyears away and one of the largest single structures ever discovered in the sky, scientists have named the cloud ‘Eos’ after the Greek goddess who personifies the dawn. The potentially star-forming cloud was discovered by hunting for its main constituent, molecular hydrogen, which can be detected by looking for ultraviolet light. Scientists estimate that its size on the sky is about the width of 40 Moons and is around 3,400 times more massive than our Sun. One of the closest molecular clouds to the Sun and Earth ever detected, Eos is crescent-shaped and sits on the edge of the Local Bubble, a gas-filled cavity in space that also encompasses…

Email us at inbox@skyatnightmagazine.com MESSAGE OF THE MONTH I'm responding to an article by Pete Lawrence in the April 2025 issue, titled ‘Flora crosses the Leo Triplet’ (Big Three, in the Sky Guide), which spurred me to have a look for this minor planet. I always read this section of the magazine first. I decided to try to image Flora with a Dwarf 3 smart telescope and got this picture (right). This shows the asteroid close to galaxy NGC 3628. Doug Bickley, via email, Treasurer, Wolverhampton Astronomical Society Congratulations on tracking down asteroid 8 Flora, Doug! That's a nice catch. It's impressive what the latest smart telescopes are able to pick up. – Ed. Tweet Karen Richards @kreacher37 • 13 May From NW England, my husband David photographed these craters…

Ten years ago, Pluto emerged from the gloom at the Solar System's ragged edge – and a new world came in from the cold. Five billion kilometres (3 billion miles) from Earth, on 14 July 2015, NASA's piano-sized New Horizons probe swept past the dwarf planet and glimpsed a crater-scarred landscape teeming with nitrogen glaciers, winding canyons, water-ice mountains and – maybe – a substantial ocean in liquid form. The title ‘planet’ has proven a thorn in Pluto's side. Discovered by Clyde Tombaugh in 1930 and named by schoolgirl Venetia Burney for the Roman god of the underworld, generations of children knew Pluto from classroom mnemonics as the Sun's ninth planet. In 1978, Jim Christy discovered Pluto's moon, Charon. The name honoured both the mythical ferryman of the dead and…

Cygnus, the Swan is associated with the Northern Hemisphere's summer night sky. Its main shape is a cruciform pattern known as the Northern Cross. Roughly halfway down its southern section, between Albireo (Beta (β) Cygni) and Sadr (Gamma (γ) Cygni), sits Eta (η) Cygni. This is a mag. +3.9 orange giant star of spectral type K0 III. Eta is 139 lightyears from the Sun and surrounded by a group of fainter stars: Eta B, C, D and E. The proper motions of C, D and E don't align with Eta, so these 11th, 10th- and 12th-magnitude (respectively) stars are line-of-sight companions; 12th-magnitude Eta B, separated from Eta by 7.8 arcseconds, looks like a true companion. Eta is about 10 times larger than our Sun and 60 times more luminous. It's…

There's more in the electromagnetic spectrum than meets the eye. William Herschel discovered infrared light in 1800. One year later, German physicist Johann Ritter discovered ultraviolet light. Both types of radiation can be observed using ‘normal’ telescope mirrors and special detectors. However, ultraviolet and the longer wavelengths of infrared are largely absorbed by Earth's atmosphere and can only be observed from space. To study cosmic microwaves (sub-millimetre and millimetre wavelengths) and radio waves (everything longer than about 3cm), large dish antennas and special receivers are needed. Radio astronomy was born in the 1930s and radio telescopes only started to yield serious results in the 1950s. At the short-wavelength end of the spectrum, X-rays and gamma rays can only be observed from space. X-ray telescopes often use ‘grazing incident mirrors’ to…

If you're an astrophotographer dedicating a lot of time to capturing deep-sky images, you'll want to ensure you're getting the best results from that hard-earned data. But that's not just down to the ‘light’ frames of your deep-sky target. It's also about collecting calibration frames. Calibration frames help to remove any artefacts introduced by your camera and/or telescope, often in the form of noise or vignetting. By capturing a set of images that only show these artefacts, you can effectively ‘subtract’ these from your image during the stacking process. The three core calibration frames are bias (or offset), dark and flat frames, and each captures a particular type of artefact. You should take fresh calibration frames for every new target you capture. Bias and dark are the easiest and require…

What did your research involve? It concerns star formation. How do small dust grains and diffuse gas form into a main-sequence star like the Sun? There are many methods we can use to study star-forming regions, but in this work we looked at spectral data, or ‘molecular fingerprints’, from the Milky Way's central molecular zone (CMZ). What and where is the central molecular zone? The CMZ is a region in our Galactic centre where large molecules are gathered at high densities. It is close to Sagittarius A*, the supermassive black hole at the centre of the Milky Way, and exhibits many extreme physical processes that make it a very interesting region for studying star formation. For example, there are high-energy phenomena in this region, as well as the remnants of…