Innholdsfortegnelse for May 2025 i BBC Sky at Night

Find it at www.skyatnightmagazine.com/bonus-content MAY HIGHLIGHTS Strange signals from the ‘Eye of God’ Astronomer Martin Guerrero discusses the X-ray signals that could indicate a planet torn apart by a dying star. Binocular and deep-sky tours Download and print off charts to help you find some of the best deep-sky targets listed in this month’s Sky Guide. Planet and solar observing forms Become a citizen scientist and keep records of your observations of the Sun and the planets. The Virtual Planetarium Pete Lawrence and Paul Abel guide us through the best sights to see in the night sky this month.…

Saturn unequivocally tops the charts as the Solar System’s moon collector after 128 new satellites were discovered around the planet. This brings its total moon count to 274, more than the rest of the Solar System combined. The gas giant previously gained 64 new moons following an observing run by the Canada–France–Hawaii Telescope between 2019 and 2021. “With the knowledge that these were probably moons, and that there were likely even more waiting to be discovered, we revisited the same sky fields for three consecutive months in 2023,” said Edward Ashton, who conducted the study while at the University of British Columbia, Canada. “Sure enough, we found 128 new moons. Based on our projections, I don’t think Jupiter will ever catch up.” Like the other gas giants, it’s thought that…

Measuring just 12.4km (7.7 miles) across, Mars’s diminutive moon Deimos is often overlooked. Tidally locked to the Red Planet, it is usually missed by spacecraft near Mars that only see the side of it that’s closest to the planet. However, when ESA’s Hera mission came within just 1,000km (620 miles) of it, it snapped some rare pictures of the moon’s ‘far side’. Hera, which launched in October 2024, passed Mars on 12 March during a gravitational-assist manoeuvre on its way to the asteroid Dimorphos. In 2022, NASA’s DART spacecraft deliberately smashed into asteroid Didymos’s moon Dimorphos as part of a planetary defence mission to test how we might one day deflect a potentially hazardous asteroid. Hera is currently en route to its job observing the effects of that impact, arriving…

When I was asked to join the presenting team on The Sky at Night, my PhD supervisor told me I’d landed the most coveted astronomy gig in the UK. I honestly don’t know if others covet it, but they should. The Sky at Night filming days are just so much fun. As a former teacher, science communication is something I rank as top-tier important. After all, when we introduce the recipe for ‘the scientific method’ in Year 7, the final step is communicating your results. In the world of research, this is often limited to presenting at a conference or publishing in scientific journals, with only a few results reaching the general public. But given that so many scientists are publicly funded through research councils, I’ve always been a vocal…

MESSAGE OF THE MONTH Email us at inbox@skyatnightmagazine.com Following the Sky Guide Challenge set by Pete Lawrence in the February issue, I thought I’d share some of my image trials of asteroids 28 Bellona and 8 Flora. I tried both luminance and RGB data to see how it might work, shooting half a dozen two-minute subs on each channel with my ZWO ASI533MM Pro mono camera and Sky-Watcher Esprit 8ED scope on a guided iOptron CEM26 EQ mount. I used PixInsight to align and annotate the final image with circles and dates for each capture point contained in the mosaic. The RGB image of asteroid Flora is rather interesting: each asteroid point is coloured. Instead of being just a grey, elongated egg with luminance data, each point shows distinct red,…

After years in NASA’s shadow and perhaps not being taken entirely seriously by some, the Chinese space programme is now advancing relentlessly. While China likes to keep its cards close to its chest when it comes to its space endeavours, we do know it has ambitious goals. Two Chinese Yutu rovers have trundled across the Moon and their Zhurong rover has driven across the rust-hued plains of Mars. Soon after landing, Zhurong even took a ‘selfie’ with a small camera it dropped onto the ground, striking a cheeky, head-tilted pose. China now has its own space station with a modular design like the ISS. Tiangong now has four modules, multiple solar arrays, docking ports and a robot arm. Its taikonauts are conducting exciting scientific research and learning a lot about…

Running up to its 50th birthday, ESA has announced a diverse range of future missions for its next halfcentury. These fall under two strategic science programmes: Cosmic Vision, ESA’s current planning cycle that will run missions until 2035; and largeclass missions for 2035–2050 that fall under the Voyage 2050 planning cycle. Cosmic Vision This programme asks four major science questions: ► What are the conditions for planet formation and the emergence of life? ► How does the Solar System work? ► What are the fundamental physical laws of the Universe? ► How did the Universe originate and what is it made of? Voyage 2050 This programme will turn its focus to three themes: ► Moons of the giant planets, which will build on the Cassini–Huygens Saturn mission and the Jupiter…

Minor planet 9 Metis reaches opposition on 8 May when it can be found moving through the stars of Libra. Throughout much of the month it’ll be contained within the triangle defined by mag. +2.8 Zubenelgenubi (Alpha (α) Librae), mag. +2.6 Zubeneschamali (Beta (β) Librae) and mag. +3.9 Gamma (γ) Librae, making it fairly easy to locate. At mag. +9.7, it’ll be too faint for binoculars but an easy target for a small telescope or smart scope. On 1 May, Metis is a little north of the point two-fifths of the way along the line from Gamma towards Zubenelgenubi, moving west-northwest to cross the line between Zubenelgenubi and Zubeneschamali on 19/20 May. It starts May shining at mag. +9.9, increasing marginally to mag. +9.7 at opposition before dropping slightly to…

Apart from the Sun and Moon, seeing stars and other astronomical targets during the day isn’t that common. It’s not that bright objects can’t be seen – they can. The issue is finding them. In order to see a bright star in the daytime sky, you’ll need a bit of optical assistance. Head outside on any clear, crisp day and, let’s face it, you won’t see any stars apart from the Sun. However, a telescope can reveal the intense, point-source light of a star embedded in a blue daytime sky. So how do you go about finding nighttime stars in the daytime? A permanently Go-To-enabled mount will do it with a degree of ease. If you have such a setup, give it a try on one of the brighter daytime…

If you’re an astrophotographer, polar alignment is a crucial step because it ensures your mount can accurately track the stars as Earth rotates, meaning they stay sharp and round during long exposures. Polar alignment involves aligning the mount’s polar axis with Earth’s rotational axis, keeping the object you’re imaging central in the field of view. The longer your focal length and exposure time, the more precise your polar alignment needs to be, because the narrower field of view at longer focal lengths will magnify tracking errors. Even a minor misalignment can cause star trailing at high magnifications. While traditional manual polar alignment using a polar scope is often effective, it can also be uncomfortable or awkward when you are craning your neck to look through a polar scope. Using polaralignment…

The Perseus Cluster Overall Photons, 19 locations worldwide, 3 November 2024–31 January 2025 PHOTO OF THE MONTH Overall Photons say: “Each of the fuzzy blobs in this image is a galaxy, together making up the Perseus Cluster. Most of the data for this was captured under suburban skies with less than ideal light-pollution conditions, but I’d say we pretty much nailed it!” Equipment: 19 setups, with telescopes ranging from 2.7 inches to 11 inches Exposure: 392h total Software: Siril, PixInsight, Photoshop About the group: “We are a collective of 19 astro imagers located all over the world, but mostly in Europe and the US, who collaborate to achieve hundreds or even thousands of hours of integration on deep-sky targets, trying to create results that are very hard to achieve alone.…

HUBBLE SPACE TELESCOPE, 3 MARCH 2025 Seen here is NGC 5042, an intermediate spiral galaxy lying some 48 million lightyears from Earth in Hydra. It reveals a creamy-coloured core full of ancient stars, while its spiral arms are home to many young, blue stars. Distant galaxies beyond can be seen as yellow and orange blobs. Take a look at the pinkish areas. These are HII regions, vast clouds of hydrogen ionised by ultraviolet light streaming from those hot, massive, blue stars. Those stars won’t live long, though, meaning the HII regions themselves will only be around for a few million years. In the context of the Universe, that’s just the blink of an eye. FREE BONUS CONTENT Explore a gallery of these and more stunning space images www.skyatnightmagazine.com/bonus-content Lifting the…

NASA has dismissed its chief scientist to comply with orders from President Trump, it was announced on 11 March. The order removed the Office of the Chief Scientist, a post held by Dr Katherine Calvin, who also served as the agency’s senior adviser on climate. Trump has referred to climate change as “a scam” and made other moves to stop federally funded climate research, including pulling the US out of the Paris Agreement for a second time and dismissing hundreds of employees from the National Oceanic and Atmospheric Administration (NOAA). The move may also signal an intention to shift NASA away from scientific research to exploration, as Trump indicated in a speech to a joint session of Congress on 4 March, where he said the US would “plant the American…

A pair of private lunar landers arrived on the Moon’s surface this March, though only one managed to stick the landing. The Blue Ghost lander from Firefly Aerospace touched down in Mare Crisium on 2 March at 07:34 GMT. The lander was carrying 10 NASA experiments as part of the agency’s Commercial Lunar Payload Services (CLPS) initiative, which uses private companies to support its lunar ambitions. Blue Ghost operated for a full lunar day (around 14 Earth days), but wasn’t designed to survive the long, dark night. “The science and technology we send to the Moon now helps prepare the way for future NASA exploration and long-term human presence to inspire the world for generations to come,” says Nicky Fox, associate administrator for science at NASA. “We’re sending these payloads…

The Search for Extraterrestrial Intelligence (SETI) is interested in finding alien civilisations by detecting signs of their activity. The use of radio telescopes to listen out for alien broadcasts dates back to the 1960s, but SETI researchers also look for evidence of enormous engineering projects. For example, an alien civilisation might construct a thin shell around its host star to harvest energy. Such a ‘Dyson sphere’ ought to be detectable as a warm source of infrared rays without a corresponding visible light source. Astronomers have looked for these telltale signatures but haven’t found any. Many of these ‘technosignatures’ discussed by SETI researchers relate only to advanced civilisations, far beyond our current level of technological ability (turn to page 65 for more on this). Sofia Sheikh, at the SETI Institute, California,…

Balancing on tiptoes, I peer into the aged metal telescope, its sheer size acting as a centrepiece in the small room that makes up the observatory. I squint, focusing on the bright-white planet that peeps through the slit in the building’s dome. Despite the continuous sheet of cloud blocking most of our starlight, Jupiter shines proudly through the field of view. Seeing this gas giant, I’m amazed that we’re able to see the Universe as if it’s in arm’s reach. At the Jeremiah Horrocks Observatory in Preston, fellow passionate stargazers are taking their seats around me for the annual Forest of Bowland Dark Skies Festival, a week full of astronomy-themed evenings and, in an ideal world, plenty of stargazing. Unfortunately, this evening’s dark sky is obscured by an opaque blanket…

Galileo This NASA mission, primarily aimed at studying Jupiter (and now infamous for the failure of its primary communications antenna dish to unfurl properly) encountered two asteroids: Gaspra in 1991 and Ida in 1993. The probe flew past the asteroids without stopping but provided fascinating images and very valuable data about their surfaces and composition. Rosetta Before going into orbit around comet 67P/Churyumov-Gerasimenko and dropping a small lander onto its dusty surface, this hugely ambitious European Space Agency probe flew by two asteroids, Šteins in 2008 and Lutetia in 2010, capturing detailed images and data before continuing to its cometary close encounter. OSIRIS-REx Launched in 2016, OSIRISREx arrived at the near-Earth asteroid Bennu four years later and collected samples that returned to Earth via a capsule in 2023. They included…

Heze, a Virgo star tha Heze (Zeta (ζ) Virginis) is located 11° north and slightly east of Spica (Alpha (α) Virginis), the quintessential star of spring. Spica shines at mag. +1.00 and is easy to locate with the naked eye. Heze is dimmer at mag. +3.4 but still easy to pick out in all but the most light-polluted skies. It’s a binary star 74 lightyears from Earth and its name is unusual in that its origin is unknown, first appearing in a version of Atlas Coeli, published in 1951. Of the two components in the Heze system, it’s the brighter one, Zeta Virginis A, that bears the name Heze. The companion, Zeta Virginis B, was only discovered in 2010 and our knowledge about it is incomplete, including an accurate determination…

We’ve mentioned Mars crossing the Beehive Cluster a few times in this issue (see page 46) and for good reason. Mars is bright and easy to find and, atypically for most deep-sky objects, the Beehive is bright and large too. This means it’s an event that can be enjoyed by many, even if you don’t have specialist kit. Binoculars will show the passage beautifully. In terms of photographing the crossing, the Beehive is quite photogenic, showing up in low-image-scale shots as a fuzzy patch. A bit of focal length is required to show the main stars nicely separated, but you don’t need a lot. As a consequence, with a camera set to high sensitivity, it’s possible to grab a shot of the cluster without tracking. Just remember the ‘500 rule’:…

Exploding stars could have been responsible for ravaging our planet’s atmosphere and causing two mass extinctions. The discovery comes from a recent survey of local stars, which aimed to measure how often supernovae happen in the vicinity of Earth. A supernova occurs when a massive star runs out of fuel at the end of its life and collapses before rebounding in a huge explosion that fires out radiation and stellar material in all directions. “Supernova explosions bring heavy chemical elements into the interstellar medium, which are then used to form new stars and planets,” says Alexis Quintana, who led the study while at Keele University. “But if a planet, including Earth, is located too close to this kind of event, this can have devastating effects.” If a supernova’s radiation were…

The colour of Mars’s surface is so iconic that it’s often simply referred to as the Red Planet. Now a new study has shown it might have taken on this distinctive hue much earlier in its history than previously thought. Though Mars is now bone dry, it appears the colour developed when the planet was still covered with water. Mars’s red colouration has been known about since ancient times as it is clearly visible from Earth, even to the naked eye. The cause of its distinctive colour, however, was only discovered when the first spacecraft arrived at the planet in the 1960s and ’70s. These pointed towards iron minerals which had become oxidised, or rusted. Over billions of years, these iron-rich rocks were ground down, coating the planet in its…

Asteroids were once dismissed by astronomers as “the vermin of the skies”, constantly getting in the way of more important observations. Not anymore. The former vermin have become one of the hottest areas of space research. Asteroids can reveal the history of our Solar System and offer a tantalising wealth of metals and minerals, not to mention their importance as a threat to our very existence on this planet. This month, China prepares to join in the quest to understand these space rocks with the launch of its most complex planetary mission to date, Tianwen-2. The spacecraft aims to visit not one but two asteroids, returning a fragment of one to Earth and cementing the nation’s place as a major player in space exploration. Cosmic time capsules The mission is…

In 2025, the European Space Agency (ESA) will reach a significant milestone: its 50th birthday. For the last five decades, ESA has brought together European countries for sustainable and collaborative space exploration, launching missions like the Cassini– Huygens probe in 1997, which ranged as far as the rings of Saturn. ESA emerged from the need for a multinational European space programme, particularly to compete with the strength of research being produced by the USA and Soviet Union after World War Two. The organisation can trace its roots back to two separate European space agencies set up in the 1960s: the European Launch Development Organisation (ELDO), which sought to develop a launch system; and the European Space Research Organisation (ESRO), which focused on developing spacecraft. In 1975, ELDO and ESRO were…

DON’T MISS Mars crosses the Beehive BEST TIME TO SEE: 1–9 May The Beehive Cluster, M44, in Cancer sits just 1.5° north of the ecliptic, which means it’s in a prime position for conjunctions with Solar System objects such as the Moon, main planets and minor planets. This month, the planet Mars makes a pass through the northern reaches of the cluster, creating a wonderful opportunity to photograph it in the act or, if the weather cooperates, to capture its passage towards, across and past the cluster’s stars. Mars is just coming off its last opposition, which occurred on 16 January. Mars reaches opposition once every 2.1 years and around this time the planet brightens noticeably and, through the eyepiece of a telescope, appears to grow in apparent size quite…

1.30 Herculis The distinctly orange star 30 Herculis lies 1° to the west-southwest of mag. +4.2 Sigma (σ) Herculis. The magnitude of this semi-regular variable SRb-type star has recently been changing between about mag. +4.4 and mag. +6.3, with a period of 62–89 days between maxima. Despite being a similar mass to the Sun, this red giant has a radius larger than Earth’s orbit, giving us an indication of how the Sun will evolve. □ SEEN IT 2. The Great Globular Cluster in Hercules M13 is called the Great Globular Cluster with good reason and is just visible to the naked eye with averted vision in a dark, transparent sky. Even with small binoculars, this mag. +5.8 cluster can be visible under urban skies, although not nearly as splendidly as…

For centuries, humanity has asked itself whether it is alone in its ability to comprehend and investigate the cosmos, and whether Earth is the sole bastion of life in the Universe or simply a single outpost among billions of inhabited worlds. In the past, the exploration of extraterrestrial life was firmly left to the realm of science fiction, but in recent years the hunt for aliens has become an increasingly focused area of rigorous scientific research - from looking for echoes of Earth’s habitats in our neighbouring worlds to searching for signals from distant star systems. We spoke with four of the leading figures involved in the hunt – an astrobiologist, an icy moon explorer, an exoplanet expert and a SETI searcher – to find out why we’re closer than…

It is one of the most famous popular science books ever written. Since its release in 1988, A Brief History of Time has sold over 25 million copies and been translated into 40 languages. It appeared on the Sunday Times bestseller list for a record-breaking 237 weeks – although it’s famously a book that a lot of people own but few have finished. Hawking’s attempt to explain his work on the Big Bang and black holes remains a challenging read for someone with no prior knowledge of astronomy. In the later part of his life, Hawking also wrote children’s books alongside his daughter, Lucy. Very few scientists – if any – have enjoyed the kind of cultural cut-through that Hawking achieved. Eddie Redmayne won the Oscar for portraying Hawking on…

Astronomy Photographer of the Year Advice from the Overall Winner of 2024’s competition An annular solar eclipse offers a rare chance to capture the famed ‘ring of fire’. Taken a step further, you can capture a sequence of photos as the Moon moves into and out of the eclipse, ultimately revealing a silhouette of the lunar surface. This shadowy effect is created by gaps that appear between ‘Baily’s beads’, spots of sunlight that form as the Moon’s rugged surface rapidly moves across the Sun’s edge. Here I’ll describe how I produced an image like this, ‘Distorted Shadows of the Moon’s Surface Created by an Annular Eclipse’, which won 2024’s Astronomy Photographer of the Year competition. It offers a unique glimpse of the Moon’s topography, thanks to Bailey’s beads, during the…

What is the EZIE mission? EZIE stands for Electrojet Zeeman Imaging Explorer. For the first time, we will image and map electrical currents inside the aurora, called electrojets. These are high-intensity currents that flow 100km (60 miles) above Earth’s upper atmosphere, in the ionosphere, near the North and South Poles. They push about a million amps of electric current around the poles every second. What creates these electrojets? They’re formed by interactions between the Sun’s energy, and Earth’s magnetic field and upper atmosphere. The Sun constantly sends out charged particles in a stream called the solar wind. When these reach our planet, our magnetic field guides them towards the Poles where they enter the ionosphere. As these particles move through the ionosphere, they create powerful electric currents. Electrojets and aurorae…