Indholdsfortegnelse for March 2025 i BBC Sky at Night

Find it at www.skyatnightmagazine.com/bonus-content MARCH HIGHLIGHTS Bending light to discover distant stars Mathilde Jauzac on how JWST used a light-bending gravity trick to find hidden stars in the ‘cosmic noon’. Download and print observing forms Keep track of your observations of the Sun and the planets through the eyepiece with our printable forms. Extended astro image galleries The best images of the cosmos by professional telescopes, spacecraft and BBC Sky at Night Magazine readers. The Virtual Planetarium Pete Lawrence and Paul Abel guide us through the best sights to see in the night sky this month.…

Our Moon could be a chip off the old block, according to a new study which shows it is mostly made of material that originated on the early Earth. As well as untangling how our lunar companion formed, researchers also found evidence of how water came to our planet. The prevailing theory is that our Moon was created when a Mars-sized protoplanet, named Theia, collided with the early Earth. The Moon then coalesced out of the combined debris. The study looked at 14 lunar rock samples, comparing them to similar minerals found on Earth by measuring levels of oxygen-17, a rare isotope of oxygen. Both lunar and terrestrial samples had very similar levels, suggesting they shared a common source. This would mean that most of the material which formed the…

A shower of sparkling fragments rained down from the sky after SpaceX's seventh test launch of its new Starship vehicle ended in a spectacular explosion. The largest and most powerful spacecraft ever lifted off from SpaceX's Starbase launch site in Texas on 16 January at 10:37pm GMT (4:37pm CST). Things seemed to be proceeding as planned, with Starship separating from its Super Heavy booster a few minutes into the flight. However, around eight minutes into the mission, the Starship upper stage stopped transmitting and the engines shut down soon after. Three minutes later, inhabitants of the Turks and Caicos Islands witnessed a fireworks display as the craft exploded overhead. Though there were no casualties, debris rained down on the islands and a flight diversion was put in place. The Federal…

Two years ago, I shared a groundbreaking discovery with BBC Sky at Night viewers and magazine readers: the first-ever use of gravitational lensing to uncover an ultramassive black hole, 33 billion times the mass of our Sun, at the heart of the galaxy Abell 1201. Gravitational lensing, where the gravity of a massive foreground object bends and magnifies the light from a background galaxy, revealed this colossal black hole through the distinctive distortions of the background galaxy's image. This discovery demonstrated gravitational lensing could unveil some of the most massive black holes in existence, but could we use it to find other lenses? Pivotal to the discovery was the unique geometry of the lens Abell 1201. The light from the background galaxy passed unusually close to the centre of the…

If you'd been standing on the floor of Jezero Crater on Mars on 18 February 2021, you'd have seen a strange sight: a large vehicle falling out of the peach-hued sky, swinging on the end of a metal line, hanging beneath a Thunderbirds-style contraption that looked more like a huge flying bedstead than a spacecraft. This was the Perseverance rover, a nuclear-powered geologist-biologist sent from Earth to look for signs of ancient Martian life. At the end of 2024, the rover finally left Jezero Crater, ready to start the next phase of its mission. But how did it get there and what has it learned over the past four years? Perseverance was sent to Jezero mainly because the crater contained an ancient river delta, a broad fan of sedimentary material…

The faceless figure tumbles in the half-light, arms flailing, helmet gleaming in the Sun's glare. Below, like a living map devoid of borders, lie the intense blues of the Mediterranean, the rolling greens and tans of Greece and Italy and, further east at his eyeline's periphery, the snow-dusted peaks of the Caucasus. Never before has a human's unhindered gaze seen so much or so far with such clarity, as half of planet Earth comes into view. Sixty years ago, this beguiling sight captivated Soviet cosmonaut Alexei Leonov, the first person to ‘walk’ in space. With stiff-limbed awkwardness, his spacesuit pressurised rigid as a board, he fiddled with the 5.5-metre (18ft) umbilical cable tethering him to the Voskhod 2 capsule. But his euphoria wouldn't last, and soon he'd be forced to…

The size of a football field, the International Space Station has been orbiting 400km (250 miles) above Earth for almost 25 years. When it passes overhead, the sunlight reflecting off its 35-metre-long (115ft) solar panels means that the station is bright enough to be seen with the naked eye, provided you know when and where to look. The ISS's orbit takes it over the heads of around 90 per cent of the world's population, so chances are that it has already passed above you without you knowing. It circles the globe every 90 minutes, granting the crew 16 sunrises and sunsets every day, and giving viewers from Earth plenty of opportunities to catch a super-bright overhead pass. If you want to catch a glimpse, timing is key. In the middle…

PICK OF THE MONTH Mars Best time to see: 1 March, 20:50 UT Altitude: 63° Location: Gemini Direction: South Features: Polar caps, surface markings, weather Recommended equipment: 75mm scope or larger Mars is a wonderful planet to observe through a telescope but it's also one that requires effort and timing. Its apparent size varies depending on how close it is to Earth. The best time to observe the planet is around opposition, which last happened on 16 January 2025. In the weeks that follow opposition, our view of the Red Planet changes quickly, its apparent size shrinking rapidly as it once again distances itself from Earth. On 1 March, Mars is able to reach a peak altitude of 63° in the early evening under dark-sky conditions. Through the eyepiece, the planet appears to have an…

1. The Leaping Minnow You'll find the first of this month's asterisms (star patterns) a little more than 4° east of mag. +2.7 Hassaleh (Iota (ι) Aurigae). This little group of fifth-magnitude stars, just over a degree long, includes 14, 16, 17, 18 and 19 Aurigae. In a pair of 10x50 binoculars (and with a bit of imagination), you should see that this group of stars forms the shape of a fish leaping out of the water. □ SEEN IT 2. The Cheshire Cat Look 1.5° to the east of the Leaping Minnow and you'll easily see yellow mag. +5.1 Phi (φ) Aurigae. This is the brightest star in a northeast-extending curve of mostly sixth and seventh-magnitude stars that covers about 1.5°. This is Alice's “grin without a cat”. There's…

As the late ex-Beatle George Harrison wrote, “all things must pass”. His lyrics resonate with our daily affairs but, of course, apply to the future of our Solar System too. Gloomy? Possibly. But while it's inevitable that all celestial objects will one day ‘pass’, our planetary neighbourhood is evolving, regenerating and recycling over aeons. How lucky are we, to understand and sometimes witness their passing in all its awesome splendour? In just a couple of decades, for instance, we could see Jupiter's legendary Great Red Spot (GRS) – a high-pressure Earth-sized anticyclone – morph from an oval to a Great Red Circle and possibly even disappear. Trapped as it is between two opposing jet streams acting like conveyor belts, this spinning wheel has, since perhaps the 17th century, circled the…

The most remarkable image to emerge from the data used to create the first World Atlas of the Artificial Night Sky Brightness, published in 2001, was the four views of North America that showed the growth of light pollution from the 1950s to the (then) far-off future of 2025. In one quarter of the image, the authors placed the view reflecting their 1997 data. In the other views they estimated back to the 1970s and the 1950s, and forward 25 years. Remarkably, their image that estimated the view for 2025 looks almost exactly like what the updated Atlas, published in 2016, went on to show. More than any other image from the altogether stunning Atlas, this one helps us see what we usually don't: that because of the often excessive…

If you've ever spotted the International Space Station (ISS) streak across the sky, you may have wondered how it's possible to photograph something that moves like a fast, bright star at the speed of 28,000km/h (17,500mph) in low Earth orbit. However, with a mid-sized telescope and some patience, you'd be surprised how straightforward it can be to manually capture this iconic spacecraft from your garden. If you live below 51° latitude north or south, the ISS will be visible overhead in phases for a few days straight and is most visible at dusk or dawn, when it reflects sunlight. For budding imagers, the best time to capture it is when the flyover is as high in the sky as possible, ideally 70° and above. When it's low on the horizon,…

PHOTO OF THE MONTH The Spider, Tadpole and Flaming Star Nebulae Andrea Arbizzi, Modena, Italy, 6, 7, 12, 20 and 21 December 2024 Andrea says: “In the constellation of Auriga, we find three wonderful nebulae: the small Spider Nebula (IC 417, on the left), the Tadpole Nebula (IC 410, centre) – the ‘tadpoles’ being the two central filaments – and the diffuse Flaming Star Nebula (IC 405, on the right).” Equipment: ZWO ASI2600MC Duo camera, Askar FRA500 refractor, iOptron GEM45 mount Exposure: Ha and OIII 118× 600”, SII and OIII 54× 600”, UV/IR cut 80× 30”, total 29h 20’ Software: Astro Pixel Processor, PixInsight, Photoshop Andrea's top tips: “Astrophotography is a challenging hobby with a steep learning curve. I started in 2020 and have learned that it requires patience, money…

JAMES WEBB SPACE TELESCOPE, 16 DECEMBER 2024 How soon after the Big Bang did the first planets begin forming around stars? For some time, helium- and hydrogen-rich stars in the early Universe were thought unlikely to host planets, because the protoplanetary discs around them contain very low levels of heavier elements such as iron and carbon, and dispersed within just two or three million years. So Hubble's 2003 discovery of a massive planet orbiting a very ancient star had astronomers puzzled. Now, JWST has given astronomers new insight into this mystery. It turned to NGC 346, an enormous star-forming region stretching 200 lightyears across. Its survey of NGC 346, which is also very low in heavy elements, revealed discs around stars up to 30 million years old. This suggests that…

The aurora is renowned as an explosion of colour, but it's the appearance of strange white-grey patches in it that is currently drawing the attention of astronomers. Commenting on the new study she led, Emma Spanswick from the University of Calgary says, “You'd see this dynamic green aurora, some of the red aurora in the background and, all of a sudden, you'd see this structured grey-toned or white-toned emission – almost like a patch – connected to the aurora.” The grey structures, known as structured continuum emissions, stretch anywhere between tens to hundreds of kilometres across the sky. The study found the grey patches show spectral similarities to traditional aurorae – where particles from the Sun interact with atoms in the atmosphere to make them glow – but also have…

While Saturn is the uncontested Lord of the Rings, it is by no means the only body in the Solar System to host a ring system. The flickering effect of stellar occultation – when a planet passes in front of a background star, briefly blocking it – revealed the presence of rings around Uranus in 1977 and Neptune in 1984. A set of tenuous rings were discovered around Jupiter too, during the Voyager 1 fly-by in 1979. But only in the last decade or so has it been realised that rings also exist around bodies other than the gas giant planets. In fact, as Bruno Sicardy, at the Observatoire de Paris, France, and his colleagues point out in a new research paper, a total of seven objects in the Solar…

By the time it rolled over the rim of Jezero Crater, Perseverance had taken 18 priceless samples of rock and dust, storing them in metal tubes that look like a cross between lightsabers and giant spark plugs. The eight most important tubes are stored safely onboard the rover, but 10 ‘backup’ samples were left at a site called Three Forks. Like a farmer planting seeds, Perseverance carefully dropped the precious tubes onto the ground one by one, spaced well apart, creating what NASA christened a sample depot. But what's going to happen to all these tubes? The original plan was for a complicated joint NASA/ESA mission to retrieve them using a new lander, a pair of Ingenuity-like helicopters and an ascent vehicle to blast off the surface of Mars carrying…

Though both Russia and NASA launched and operated their own small, short-term space stations throughout the 1980s, both nations wanted to create a more permanent space base. However, it soon became clear that the cost and complexity of such an endeavour were beyond the means of a single agency. In 1993, the pair announced they were joining forces along with the European, Japanese and Canadian space agencies to create what would become the International Space Station. The station was built from several modules, each launched individually, with the first arriving in orbit in 1998. By the time the ISS was fully assembled in February 2011, the station measured 109 metres (358ft) long and weighed in at 450,000kg (990,000lb). The ISS hadn't been sitting vacant, however, with the first crew arriving…

Mercury Best time to see: 8 March, from 30 minutes after sunset Altitude: 11° Location: Pisces Direction: West Mercury is an evening planet at the start of March, setting 1.5 hours after the Sun on 1 March when it shines at mag. –0.9. A 3%-lit waxing crescent Moon sits 7.3° to the east-northeast of Mercury on this date, both objects visible in the darkening evening twilight sky after sunset. On 2 March, Mercury sits just 1.9° from mag. +7.9 Neptune, with twilight causing major problems with the visibility of this distant ice giant. Mercury reaches greatest eastern elongation on 8 March when it appears separated from the Sun by 18.2°. On 12 March, now shining at mag. +0.7, Mercury sits 5.6° from mag. –4.2 Venus. From the middle of the month, Mercury's visibility…

Minor planet 8 Flora reaches opposition on 12 March when it can be found shining at mag. +9.6 within Leo, the Lion, south of Denebola (Beta (β) Leonis), the star that marks the end of the lion's tail. Flora begins the month as a mag. +9.8 object in Virgo, 2.3° west-northwest of mag. +4.1 Omicron (ο) Virginis and adjacent to the Virgo–Leo border. It's a solid target for a small telescope but too faint for average binoculars. Its track takes it in front of the mag. +10.4 edge-on spiral galaxy NGC 3628, the northernmost galaxy in the famous Leo Triplet group located within the ‘back leg’ of Leo, midway between mag. +3.3 Chertan (Theta (θ) Leonis) and mag. +4.0 Iota (ι) Leonis. NGC 3628 is known as the Hamburger Galaxy…

Venus has been an evening beacon in early 2025, but that's about to change as the planet heads towards inferior conjunction on 23 March, the position in its orbit closest to Earth. In recent weeks, Venus has been approaching us, moving along part of its orbit closest to Earth. Its apparent sunward crawl accelerates as it moves towards inferior conjunction. Our challenge is to follow it to this position. The orbits of Venus and Earth aren't coplanar; Venus's orbit appears to us as an ellipse. Different alignments between orbits vary the apparent width of the ellipse and under rare circumstances we see it sideways-on. When this happens, a transit of Venus occurs, the planet appearing to pass across the Sun's disc. This next occurs in December 2117. The minimum apparent…

Asteroids slamming Earth is not science fiction but science fact. Variously sized space rocks have constantly swiped our planet, so it's a case of when not if. The mountain-sized asteroid that struck just off Mexico's Yucatán Peninsula 66 million years ago left the approximately 150km-wide (90 mile) by 19km-deep (12 mile) Chicxulub crater and caused the extinction of the dinosaurs. It could happen again. Even a house-sized rock travelling at 30,000mph would pack the energy equivalent of the Hiroshima bomb and flatten reinforced concrete buildings 8km (5 miles) from ground zero. A 11–13km-wide (7–8 mile) asteroid walloping the surface would cause monstrous tsunamis, blast water and dust into the atmosphere, block sunlight and ultimately lower global temperatures. Most life would be extinguished, but it would take a 97km-wide (60-mile) asteroid…

Over the past few months, astronomers have been keeping an eye on Saturn's rings as they slowly disappear. This month, on 23 March, they will finally appear to vanish from view. Don't worry, their disappearance is only temporary as they'll be returning just a few months later. When Saturn's rings vanish like this, astronomers call the event a ring plane crossing and it's all down to how we view Saturn from Earth. Lying at an average distance of 1.43 billion kilometres (886 million miles) from the Sun, Saturn takes 29.4 Earth years to complete one orbit of our star, and as it does so, the planet experiences seasons and solstices due to its axis of rotation being tilted by 26.7°. Earth is also tilted in its orbit, by 23.5°, and…

Solar eclipses visible from the UK are relatively infrequent events. Add in our extremely unpredictable weather and you could almost class seeing one as quite a rare occurrence. Let's hope the weather is kind for the partial solar eclipse happening on 29 March, as a fairly decent amount of the Sun's disc will be covered by the Moon. You can find out more information about the eclipse on page 46, but here we're going to concentrate on how to record the event photographically. While a partial isn't a patch on a total solar eclipse, there's plenty to focus on that can elevate a partial eclipse photographically. For the 29 March event, there's another important factor to take on board, that we're at the predicted peak of Solar Cycle 25. This…

VITAL STATS • Price £1,699.99 (body only) • Sensor 35.9 × 23.9mm, 24.2MP full-frame CMOS • ISO range 100–102,400 (expandable to 204,800) • Frame rate 40fps burst • Resolution 6,000 × 4,000 • Body size 132.5 × 86.1 × 70.0mm • Connectivity Wi-Fi, Bluetooth, Canon Camera Connect app, RS-60E3, USB-C, audio/head phones, HDMI • Weight 461g (with battery and SD card) • Supplier Canon UK • Tel 020 7660 0186 • www.canon.co.uk Cameras have come a long way and, until recently, DSLRs, which use a flip-up mirror to see through the lens, have dominated the market due to their mix of capability and accessible pricing. But the digital age is maturing and mirrorless cameras are now becoming much more affordable. Here we look at Canon's mid-range full-frame offering, the EOS…

After spending over a decade mapping our Milky Way, the European Space Agency's Gaia satellite is now being put into retirement. The spacecraft has almost depleted its reserves of the cold nitrogen gas it uses to stay locked on target and will now be moved to a graveyard orbit. Launched on 19 December 2013, Gaia has spent the last 11 years tracking the position, motion, brightness and other characteristics of over two billion stars. It has amassed some 142TB of data, creating the most detailed 3D models of our Galaxy ever made. “Gaia has changed our impression of the Milky Way. Even basic ideas have been revised, such as the rotation of our Galaxy's central bar, the warp of the disc, the detailed structure of spiral arms, and interstellar dust…

Black holes are, by their very nature, difficult to see. Some, cloaked in clouds of dust, are even harder to find. But now a new study could have pinned down exactly how many black holes lie hidden from our view. Most large galaxies are thought to house a supermassive black hole with the mass of a billion Suns. This powerful gravity allows them to capture gas and dust, shrouding themselves with it. Close to the black hole, friction superheats this gas, causing it to glow incredibly brightly, while a cooler doughnut or torus surrounds it. When face-on to Earth, the bright central region is clear through the doughnut's hole, but when observed edge-on the dusty torus blocks the view. Fortunately for astronomers, absorbing this light heats the torus, causing it…

The scale of the Universe generates numbers that defy our comprehension. But don't think for a second that an inability to grasp the scale that such staggering figures represent is a failing. Think of it instead as an inspiration to evolve our technological capabilities until they span these cosmic gulfs, just like when we took that very first lunar step. Advances in several technologies allowed us to reach the Moon and, one day in the future, could see us set foot on Mars. But to develop a rocket with enough thrust, you must first measure the distance to your target, and that skill has its roots in being able to measure the size of our home planet. In ancient Greece, Eratosthenes, chief librarian at the Library of Alexandria, made one…

After a challenging 3.5-month journey up slopes with gradients as steep as 20 per cent to arrive at Lookout Hill and the rim of Jezero Crater, Perseverance has begun its next phase of operations. Its fifth science campaign, dubbed ‘Northern Rim’, starts with an area called Witch Hazel Hill, and the rover has already begun the 450-metre (1,500ft) journey towards this layered rocky outcrop. A feature unlike anything seen inside Jezero Crater, 100-metre-long (330ft) Witch Hazel Hill represents rocks from Mars's early crust. During the impact that created Jezero Crater 3.9 billion years ago, huge chunks of rock like it, from deep underground, were lifted to the surface, making it some of the oldest exposed bedrock on Mars. Each of the outcrop's layers was laid down at a different time…

DON'T MISS Partial solar eclipse BEST TIME TO SEE: 29 March, 10:00–12:15 UT There are two eclipses taking place this month, one well placed for UK viewing, the other not so optimal, setting just as the eclipse gets going. The better-positioned eclipse is on 29 March, when the Moon will pass across the disc of the Sun to cause a partial solar eclipse. Although it doesn't match a total solar eclipse, a partial eclipse of the Sun is still amazing to observe and there are many ways to do this safely. The event begins with first contact at 10:07 UT (time for the centre of the UK; timings vary by location), when the Moon's leading edge first makes contact with the edge of the Sun. After this, an ever-increasing bite…

Hydra, the Watersnake is the largest constellation in the night sky. Despite this, it's also one of the most obscure, its extended body zig-zagging to the east below Cancer, Leo, Sextans, Crater, Corvus and Virgo, defined mostly by indistinct stars. Two notable exceptions are a sideways teardrop pattern of stars south of Cancer that marks the creature's head, and Hydra's brightest star, Alphard (Alpha (α) Hydrae). Located 177 lightyears away, Alphard shines at mag. +2.0. Its name means ‘the individual’, referring to the fact that it sits in a region of sky with few other bright objects around it. One alternative name for it is Soheil al Fard, which translated into Latin as Soheil Solitarius, the bright solitary one. It's an orange-hued star of spectral type K3 IIIa, the IIIa…

Astronomers think the Solar System will remain stable for 40 million years but thereafter, with gravitational tugs between the planets nudging them from their orbits, things could go awry, resulting in catastrophic collisions between Mercury, Venus, Earth and Mars. Due to gravitational pulling from Jupiter, there is a small chance that Mercury's orbit will become seriously elongated within the next 5 billion years. If Mercury's eccentricity exceeds 0.6 (0 is a perfect circle while 1 is maximum elongation), it could cross Venus's orbit, destabilising the entire inner Solar System. Mercury and Mars, at just 6 and 11 per cent of Earth's mass respectively, would get tossed around but Venus, with 82 per cent of our planet's mass, would be harder to shift. Mars could be flung out of the Solar…

The moons of Saturn play an important role in shaping the planet's rings. Its inner moons sculpt the rings by creating sharp edges and gaps in between them, and have come to be known as shepherd moons. For example, Prometheus and Pandora keep the F ring in shape through their gravitational forces, while Pan orbits within the Encke Gap and Enceladus contributes material to the E ring by venting icy particles. Saturn has almost 150 known moons with confirmed orbits, which range in size from thousands of kilometres (Titan, Saturn's largest moon, is bigger than the planet Mercury!) down to a couple of hundred. These moons may have formed from collisions with other moons, the gradual clumping together of icy material or even from the Solar System's protoplanetary disc. But…

There are several ways to get colour into an astrophoto. You can use a one-shot colour (OSC) camera, which produces colour in much the same way a DSLR camera does. Or colour can be produced by combining three monochrome images taken through red, green and blue filters. Indeed, all CMOS and CCD colour astro cameras have a monochrome sensor; it's just overlaid with a matrix of tiny red, green and blue filters called a Bayer matrix. Colour images are then processed from this data by the camera's onboard computer. When it comes to your processing of astro images, splitting a colour image back into its red, green and blue components can be advantageous for many reasons. It allows the individual colour channels to be processed separately so we can be…

What is dark energy? Dark energy is an unknown quantity, introduced to explain how observed astronomical data aligns with our understanding of the standard model of cosmology. In the 1990s, scientists observed supernovae – exploding stars – and found from their observations that the Universe is expanding at an accelerated rate. You need something to explain that apparent acceleration. Dark energy is a mysterious substance which exists everywhere and has a repulsive quality or ‘negative pressure’. In other words, it's pushing outwards everywhere. It can be added to the equations to make them consistent but otherwise it's a mystery, which is unsatisfying to many scientists. What's wrong with our theory of dark energy? A huge question is the Hubble tension. The rate of the Universe's expansion appears to vary depending…