Indholdsfortegnelse for No. 146 i All About Space

SCAN HERE TO GET OUR DAILY NEWSLETTER Did you know that the Milky Way has between 100 and 400 billion stars? How about that it has an invisible halo? This issue, we’re taking a tour of our galaxy. From its spiral arms to the kinds of stars that you can find within it, this month we’re offering you a guide to everything you need to know about the mammoth structure we call home. Turn to page 14 to begin your exploration! Also this issue we have Ask Space, where our team of experts answer your questions, speak to Neil deGrasse Tyson about the multiverse and if we could be living in a hologram, our mysteries of the universe feature, a report on climate change in the Solar System and so…

The first official photo of Saturn from the James Webb Space Telescope does not disappoint. On 30 June, NASA released a stunning Webb image that shows the Ringed Planet in a whole new light. The photo, captured on 25 June by the observatory’s Near-Infrared Camera, “is already fascinating researchers,” NASA officials said. “Saturn itself appears extremely dark at this infrared wavelength observed by the telescope, as methane gas absorbs almost all of the sunlight falling on the atmosphere,” they added. “However, the icy rings stay relatively bright, leading to the unusual appearance of Saturn in the Webb image.” The newly released image was captured during a 20-hour-long Saturn-observing campaign. While Saturn’s rings are the clear star of the new photo, it also highlights Enceladus, Dione and Tethys, three of Saturn’s…

NASA has put out the call to double its options for new spacesuits on the International Space Station and for future Artemis astronauts to use while walking on the Moon. The space agency issued a new $10 million (£7.8 million) task order on 10 July for new suit options from Axiom Aerospace and Collins Aerospace, building upon already existing contracts with the companies to provide suit designs for extravehicular activities or spacewalks. NASA initially picked Axiom to build a Moon spacesuit for Artemis astronauts, while Collins has been working on a new suit for spacewalking astronauts working in weightlessness outside the International Space Station (ISS). Axiom will now redesign its Moon suit so it can also be used for ISS operations, while Collins will work to assess and modify its…

From our point of view on Earth, the Milky Way forms a belt of pale light that wraps around the sky, passing through familiar constellations such as Cassiopeia and Cygnus in the northern sky and the Southern Cross and Carina in the far south. Ancient Greek stargazers imagined it as a stream of milk spilt by Hera, queen of the gods, and named it ‘galaxias kyklos’, the Milky Circle. Later, Roman astronomers translated this to via lactea, the Milky Way. The Milky Way’s band forms a backdrop to many of the brightest stars in the sky, and binoculars or a telescope reveal that its light comes from countless stars too faint and close together to distinguish with the naked eye. It is also studded with so-called ‘deep-sky’ objects associated with…

The Milky Way and its immediate satellites form part of a small galaxy cluster called the Local Group, occupying a volume of space about 10 million light years across. The group contains several dozen galaxies in total, but these are mostly small ‘dwarf spheroidal’ star clouds. Aside from the Milky Way, the other major member is the Andromeda Galaxy – another spiral system that lies about 2.5 million light years away in the constellation of the same name. At roughly 150,000 light years across, Andromeda is even larger than the Milky Way, but astronomers still aren’t certain which galaxy is the more massive of the two. Andromeda and the Milky Way are currently approaching each other at a speed of about 110 kilometres (68 miles) per second, and are expected…

The transit timing method works by measuring a change in the regular transit of a planet. Essentially, as a planet swings around a star, if there are other objects in its vicinity then it can affect how often a transit is completed. This often indicates the presence of other planets in the system, but in theory the method could be used to hunt for large exomoons as well, revealing their tug on their parent planets. It’s hard to distinguish between an exoplanet and an exomoon via this method, though, so it might be difficult to make a discovery with it. Transit method Many exoplanets have been found using the transit method. As a planet periodically orbits its star, it causes a dip in the star’s light – or flux –…

Neptune was the first planet to have its existence predicted by mathematical calculations before it was actually seen through a telescope on 23 September 1846. Irregularities in the orbit of Uranus led French astronomer Alexis Bouvard to suggest that the gravitational pull from another celestial body was responsible. German astronomer Johann Galle then relied on subsequent calculations to help spot Neptune. Astronomer Galileo Galilei had sketched the planet, but he mistook it for a star due to its slow motion. Only one mission has flown by Neptune – Voyager 2 in August 1989 – meaning that astronomers have done most studies using ground-based telescopes. There are still many mysteries about the cool blue planet, such as why its winds are so speedy and why its magnetic field is offset. While…

Iime has been observed passing more slowly in quasars in the early universe. The observed time dilation comes as a T consequence of Einstein’s theory of general relativity combined with the expansion of space. “At its heart, this is another ‘Einstein is right again’ story,” Geraint Lewis, a cosmologist at the University of Sydney, said. Lewis and Brendon Brewer of the University of Auckland are co-authors on a new paper describing the confirmation of time dilation effects in the variability of quasars. A quasar is powered by an accreting supermassive black hole at the heart of an active galaxy. Because the accretion disc around the black hole is relatively small, fluctuations in the light emitted by the quasar can take place in just days. This makes them easier to track.…

“The portion of Jezero the rover and helicopter are currently exploring has a lot of rugged terrain” Thhe Mars helicopter’s two-month silent stretch is over. Ingenuity got in touch with its handlers on 28 June via its robotic partner, the Perseverance rover. It was the first such communication since 26 April, when the 1.8-kilogram chopper went dark towards the end of its 52nd flight on the floor of Mars’ Jezero crater. “The portion of Jezero the rover and helicopter are currently exploring has a lot of rugged terrain, which makes communications dropouts more likely,” Ingenuity team lead Joshua Anderson of NASA’s Jet Propulsion Laboratory said. “The team’s goal is to keep Ingenuity ahead of Perseverance, which occasionally involves temporarily pushing beyond communication limits,” Anderson added. “We’re excited to be back…

One of the brightest transient events is the result of a supermassive black hole beginning to feast on surrounding O matter, resulting in one of the most dramatic ‘switching on’ events ever seen. Transients are astronomical events or objects that change in brightness over short periods of time, and the one powered by this greedy black hole, J221951-484240, is one of the brightest transients ever recorded. The position of the black hole corresponds with the centre of a previously observed galaxy – just where a supermassive black hole would be expected to sit. However, astronomers still aren’t sure exactly what is causing the transient event witnessed in J221951. “Our understanding of the different things that supermassive black holes can do has greatly expanded in recent years, with discoveries of stars…

10 AUGUST Asteroid 10 Hygiea reaches opposition, glowing at magnitude +9.7 in Aquarius 12 AUGUST The Perseid meteor shower reaches its peak 14 AUGUST Globular cluster Messier 15 is well placed for observation in Pegasus 15 AUGUST Globular cluster Messier 2 is well placed for observation in Aquarius 17 AUGUST The Kappa Cygnid meteor shower reaches its peak 24 AUGUST The Moon will pass in front of Delta Scorpii, creating a lunar occultation 26AUGUST Asteroid 8 Flora reaches opposition, glowing at magnitude +8.5 in Aquarius 27AUGUST Saturn reaches opposition, shining at magnitude +0.4 in Aquarius 29 AUGUST Uranus enters retrograde motion, glowing at magnitude +5.7 in Aries “Asteroid 8 Flora reaches opposition, glowing at magnitude +8.5 in Aquarius” 30 AUGUST The Moon and Saturn pass within 2°16’ of each other…

1 Deneb (Alpha Cygni) Deneb is one of the three stars of the famous Summer Triangle. Its name means ‘tail of the Swan’, and it also stands at the head of the well-known asterism the Northern Cross. At magnitude +1.3 it’s the 19th-brightest star in the sky. It’s 1,400 light years from the Sun and around 200,000 times more luminous. 2 The Cygnus X star complex Running down the right side of the Northern Cross, the Cygnus star cloud looks like a long, misty patch of light to the naked eye. Look at it through binoculars and you’ll see it’s made up of countless millions of glittering, faint stars, all thousands of light years from Earth. 3 Vega (Alpha Lyrae) Icy blue-white Vega is the fifth-brightest star in the sky…

Reviewed by Robin Scagell DETAILS Cost: £379.95 / $469.95 From: Celestron Aperture: 4” Focal length: 25” The night sky is full of interesting objects that even a small telescope can show in detail,but actually finding them has always been a problem for beginners. The advent of computerised star catalogues loaded into telescope handsets made it possible to align a telescope on the sky by pointing it at just three bright stars. Once done, the handset could direct the telescope to any other object in its database, but it needed position encoders on its axes. And all this requires some user input – the date and time, the location and choosing the stars. Then along came ‘plate solving’ – the software to identify a field of view of stars in a…

A new image from the James Webb Space Telescope shows that when it comes to galaxies, appearances can be deceiving. The picture shows a serene-looking orange-red galaxy, but this cosmic spiral of gas, dust and stars hides a violent past, representing the wreckage of a massive collision between two earlier galaxies that occurred around 500 million years ago. The galaxy in question is NGC 3256, which lies around 120 million light years from Earth and is a member of the Hydra-Centaurus Supercluster. Hints at the chaotic past of this swirl-like galaxy are hidden within the Webb image in the form of long tendrils of shining dust and stars which extend outwards from the main body of the galaxy and the brightest portions of NGC 3256. The study of these cosmic…

KEEP IN TOUCH AllAboutSpaceMagazine @spaceanswers space@spaceanswers.com A stronomers have discovered the most reflective planet outside the Solar System ever seen. The ultra-hot extrasolar planet, or exoplanet, acts A like a cosmic mirror because it’s covered by reflective clouds of metal. The planet, designated LTT 9779 b, is located around 264 light years from Earth and reflects around 80 per cent of the light that shines on it from its parent star. As a comparison, Earth reflects just 30 per cent of the light that falls on it from the Sun. The ultrahot LTT 9779 b is so reflective that it’s the first exoplanet found that gives the Solar System’s shiniest planet, Venus, a run for its money – Venus has a thick layer of cloud that reflects around 75 per…

The oldest known stars of Population II have been shining for about 13 billion years, so by some measures the Milky Way isn’t much younger than the universe itself. However, the oldest disc stars are much younger – around 9 billion years old. Based on the process of galaxy formation, we can see in the distant early universe that it’s likely the Milky Way began life in the merger of several smaller irregular galaxies. Rippling shock waves compressed their gas to trigger enormous waves of star formation and create supersized star clusters, which eventually became today’s globular clusters. But the shock waves also heated the gas clouds until they were too hot and fast-moving to coalesce under gravity, expanding instead to form a hot halo around the chaotic central ball…

Stars in the Milky Way come in two main types, known as populations. The stars of Population I are found in the spiral arms and the galactic disc between them. They are generally brighter and hotter and contain greater amounts of heavy elements. Like all stars, Population I are dominated by the lightweight gases hydrogen and helium, but these heavy elements boost the rate of nuclear fusion in their cores – this is why Population I stars tend to shine hotter and brighter than Population II stars of a similar mass, but it also means they have shorter life spans. Population II stars are mostly crowded together in the central bulge, but they also form globular clusters – huge balls of hundreds of thousands of stars that follow their own…

Our galaxy holds a number of smaller galaxies in orbit around it. Many of these are little more than sparse clouds of stars, but the biggest and brightest are substantial irregular galaxies with abundant star formation. The Large Magellanic Cloud (LMC) even shows hints of a bar and spiral structure. The LMC and Small Magellanic Cloud lie about 160,000 and 210,000 light years from Earth and are currently in an unusually close approach to the Milky Way, resulting in distortion to their shapes and leaving a trail of gas known as the Magellanic Stream along their path. Some small galaxies that stray even closer to the Milky Way may eventually be torn apart by the encounter. The Sagittarius Dwarf Spheroidal Galaxy is an elongated cloud of stars on the opposite…

A weird, super-hot celestial body is breaking records and challenging astronomers’ understanding of the boundary between stars and planets. The object, called WD0032-317B, is a brown dwarf – atype of bright, gaseous ‘protostar’. Brown dwarfs typically have a similar atmospheric composition to Jupiter but are around 13 to 80 times larger. At that mass, these objects begin to fuse hydrogen isotopes in their cores. However, they aren’t quite massive enough to spark the kind of full selfsustaining stellar fusion that powers stars like our Sun – think of smouldering charcoal rather than a lit wood-fired oven. Brown dwarfs usually burn at around 2,200 degrees Celsius (4,000 degrees Fahrenheit). That’s fairly cool compared to most stars, whose surface temperatures reach about 3,700 degrees Celsius (6,700 degrees Fahrenheit). But WD0032-317B, which is…

A dark storm on Neptune mysteriously reversed A dark storm on Neptune abruptly switched direction, puzzling astronomers. Hubble first spotted the vortex in 2018. A year later, the storm began drifting towards Neptune’s equator, following the path of several storms before it. Usually these dark spots on Neptune live for a few years before either vanishing or fading away. However, the storm mysteriously stopped moving south and made a sharp U-turn, drifting back northwards. At the same time, astronomers spotted a second smaller dark spot on the planet. They theorise that this smaller ‘cousin’ may be a piece of the original vortex that broke off and drifted away. Neptune’s smallest moon has a violent past Hippocamp is believed to have a diameter of about 34 kilometres (21 miles). The tiny…

Professor Chris Jones of the University of Leeds has been fascinated by Jupiter for more P than 60 years. He says that he became interested in what lies beneath the gas giant’s surface when he was a child, and since then his work has included many studies into the Solar System’s largest planet. He’s well aware of the many mysteries surrounding Jupiter, such as how it formed, the nature of its core and how it became enriched in heavy elements compared with the Sun. Scientists have also wrestled with the mystery of Jupiter’s colour-changing stripes, but this is something that Jones has gone a long way towards answering. If you look at Jupiter, you’ll see many distinguishing features, not least the bands of colour and the famous Great Red Spot…

PLANET OF THE MONTH Even though it’s quite faint and never gets very high in the sky, Saturn, the famous Ringed E Planet, is still well placed for observation this month. Although it’s much fainter than Venus or Jupiter, which are both also on view this month, Saturn is still lovely to look at. To your naked eye the second-largest planet in our Solar System will look like a gold-hued star, already low in the southeast as the Sun sets. Shining at a very respectable magnitude of +0.5, Saturn will be an easy naked eye object, brighter than most of the stars in the sky. However, its low altitude means it will appear fainter than that figure suggests. The planet is currently in the zodiacal constellation of Aquarius, away from…

A stronomy is, very generally speaking, the study of the stars and everything to do with them – how they are born, live and die; how they work; the objects that go around them and much, much more. The sky throughout August and September offers the naked-eye observer some of the most beautiful stars in the sky, and the mottled band of the Milky Way too, itself made out of countless billions of stars. But beyond the stars, through their misty veil, lie objects that are as fascinating as they are faint, as beautiful as they are subtle. Four of our six challenging deep-sky objects this month are nebulae, one is a distant glittering star cluster and the sixth is another galaxy altogether, an elegant Catherine wheel of stars far…

Sega Toys Homestar Flux Cost: £169 / $229 From: Sega Toys 1 One of the sleekest-looking and most powerful star projectors around, the Homestar Flux, though compact, comes with a high price. More of a home planetarium than a simple star projector, we found that the Flux’s multilevel glass lenses produce realistic-looking night skies from the comfort of your own home – it’s also bright enough for rooms that aren’t totally dark. After adjusting the focus to suit your projection surface, you’ll see 60,000 stars – many more than its competitors. This globe-shaped product excels with the sheer number of distinct stars it projects, and it has some tempting science-based upgrade options. The Flux comes with two discs: the Northern Hemisphere and the Northern Hemisphere constellations. One shows a starry…

Brahe was born on 14 December 1546 in Scania, Denmark (now Sweden). At the age of 12 Brahe studied law at the University of Copenhagen as per his uncle’s wishes, but he quickly developed a love for astronomy. He soon realised becoming a great astronomer meant spending many nights poring over observational data and would often spend his evenings doing just that. His uncle wanted him in law, so when Brahe was sent on a study tour of Europe at the beginning of 1562, he was limited to performing astronomy in his spare time. Part of his nose was prosthetic, revealed in 2012 to have been made out of brass. Brahe had received this disfiguring wound from another Danish nobleman, Manderup Parsberg, on 29 December 1566, after the two disagreed…

Dark, billowing clouds sweep across a stunning new view of a large star-forming area of the constellation of Orion. These dense interstellar clouds of gas and dust comprise a dark nebula formally known as LDN 1622. Dark nebulae are so named because their thick interstellar dust obscures light from nearby stars and other neighbouring objects. LDN 1622 is located 1,300 light years from Earth in the nearby Orion molecular cloud complex, a star-forming region teeming with young stars. It’s located near the plane of our Milky Way galaxy, close to the belt and sword of the constellation. The recent image was taken using the Nicholas U. Mayall Telescope at Kitt Peak National Observatory in Arizona, which is operated by NOIRLab. Astronomers captured this view of LDN 1622 using the telescope’s…

Perseverance has found a diverse menagerie of organic molecules in a Martian crater. Organic compounds are molecules composed of carbon, and often include other elements such as hydrogen, oxygen, nitrogen, phosphorus and sulphur. Previously, scientists had detected several types of organic molecules of Martian origin – in meteorites blasted off Mars by cosmic impacts that landed on Earth, and in Gale crater on the Red Planet, which NASA’s Curiosity rover has been exploring since 2012. “They’re an exciting clue for astrobiologists, since they’re often thought of as the building blocks of life,” Sunanda Sharma, a planetary scientist at the California Institute of Technology, said. “Importantly, they can be created by processes not related to life.” As such, investigating what organic molecules exist on the Red Planet and how they were…

SPIRAL IN SPACE The shape of the Milky Way in the sky reveals that our Solar System is embedded in a broad but thin plane of stars. Looking away from the band of the Milky Way, we see past the relatively nearby stars that lie in our part of this plane into apparently empty intergalactic space. However, when we look across the plane we see many more stars extending to greater distances; their combined light forms the band of the Milky Way. Radio astronomy observations, which can see past dense clouds of stars and dust to map the distribution of hydrogen gas clouds across the plane, confirm that our galaxy has a spiral structure broadly similar to many other galaxies in the sky – in fact, it’s a type of…

Astronomers are still making new discoveries about the shape of the Milky Way. For instance, maps of gas flow near the centre of the galaxy first suggested the influence of a large bar of stars running across the bulge in the 1960s, but this bar was only confirmed using infrared observations in 2005. The bar is thought to create an alignment among the orbits of objects further out, producing the ‘density wave’ effect that generates the spiral arms. Improved maps of both hydrogen clouds and star distribution have also shown that the Milky Way’s disc has two components – acentral thin disc less than 1,000 light years deep and an outer thick disc around 8,000 light years deep. The sparse stars of the thick disc have fewer heavy elements than…

Stars close to the centre of the galaxy orbit faster than those further out – the Sun orbits the centre in roughly 212 million years. But when astronomers measure stars near the outer edge of the galaxy, they find the motion does not slow down as much as they would predict if the distribution of the galaxy’s mass matches that of its stars and other visible material. The faster motion of outlying stars suggests that there are vast quantities of mass further out – both beyond the visible edge of the galactic disc and in the apparently empty halo region above and below. The rotation patterns of our galaxy and others are a key piece of evidence for so-called ‘dark matter’, which is thought to account for five-sixths of the…

The very centre of our galaxy is home to a slumbering monster: a supermassive black hole. Objects like this are thought to lie at the hearts of most galaxies – they originated from the collapse of giant stars in the early days of the universe, then grew prodigiously by feeding on gas, dust and stars as galaxies coalesced, and by merging together as smaller galaxies collided to form larger ones. Today, most material stays well out of reach of the black hole, but radiation from a gentle stream of infalling gas turns it into a source of radio waves known as Sagittarius A*. Astronomers have confirmed the black hole’s mass by mapping the orbits of stars near the galactic centre, revealing that they orbit an invisible object with the mass…

Today, transporting people and cargo into space is an extremely expensive, dangerous and time-consuming enterprise. It relies on rockets that can only take relatively small loads into Earth orbit. To make space more accessible, scientists have put forward the idea of building space elevators. These would consist of cables made of carbon nanotubes that would carry an elevator from the Earth’s equator to a geostationary space station linked to a counter-mass. Linked to the space elevator is the concept of creating an orbital ring or orbital ring systems. As early as the 1870s, inventor Nikola Tesla thought that a solid structure built around the equator would “float freely and could be arrested in its spinning motion by reactionary forces”. Using this orbital ring, he predicted that passengers could travel at…

The world is currently in the grips of an artificial intelligence (AI) frenzy. Everyone is trying ChatGPT, AI stocks are surging T to record highs and people are worried about whether machines are coming for their jobs. Yet astronomers have been using similar techniques to unlock the universe’s secrets for decades. “It goes back over 30 years,” says Chris Impey from the University of Arizona. In 1990, Impey’s colleagues at the university’s Steward Observatory used an artificial neural network (ANN) to both divide galaxies into groups based on their appearance and to distinguish between stars and galaxies in images of the sky. An ANN is fed a series of training images and is then set free to analyse new data. It looks for connections between data points and is based…

Smaller planets might be born when gas and dust are squeezed between larger worlds, like the S filling in a cosmic sandwich. The newly suggested process, dubbed ‘sandwiched planet formation’, would occur in the massive discs of planet-birthing gas and dust that swirl around stars in their infancy. Around 4.5 billion years ago, the Solar System itself would have existed as one such disc around the infant Sun, from which the planets arose. This new theory of planet birth was developed by researchers at the University of Warwick. According to sandwiched planet formation, two large planets already present in the protoplanetary disc would restrict the flow of dust inwards through the flattened cloud of gas and dust. This results in matter collecting between the planets, with dense patches of the…

A steroids have more than enough gold, and other precious metals, to provide a few lifetimes’ worth of fortunes. But there are plenty of other reasons asteroids are valuable. But how do we get these metals from faraway asteroids? Perhaps the best way is to bring the space rocks to Earth. Most of the metals we use in our everyday lives are buried deep within our planet. And we mean deep: when the young Earth was still molten, almost all of the heavy metals sank to the core, which is pretty hard to get to. The accessible veins of gold, zinc, platinum and other valuable metals instead came from later asteroid impacts on Earth’s surface. Those asteroids are the fragmented remains of almost-planets, but they contain all the same mixtures…

“Hopefully we brought you guys some smiles and not a lot of nervousness” UNAUTHORISED SPACEWALK If you’re going to pull off a prank in space, do it in style, while wearing a pair of cool shades. In 2010, NASA astronaut Timothy Creamer, Japanese astronaut Sôichi Noguchi and Russian cosmonaut Oleg Kotov beamed a snapshot of themselves floating in space back to Mission Control for an April Fool’s Day prank. “You have a real problem, but you know it’s outside our capability to help you,” astronaut Shannon Lucid radioed the station crew, laughing all the way. The astronauts reassured Mission Control, claiming they were wearing sunscreen and eye protection and were securely tethered so as not to float away. “We wanted to welcome you guys to April, and hopefully we brought…

“The variations in the stripes seem to come from below, not from above” SPOT THE DIFFERENCE See the exact changes that took place more than ten years apart 1 Infraredimage The image on the left was taken in December 2011 by a ground-based telescope. It shows Jupiter at five micron wavelength radiation. 2 Changingcolour The image taken just over ten years earlier in May 2001 looks remarkably different. The North Equatorial Belt appears lighter. 3 Eastand west Clouds move quickly, blown by easterly and westerly winds. Close to the equator, the wind blows eastwards. It goes westward when going north or south. 4 Fastjets Fast jets of wind occur at the boundaries between the zones and belts which make up the bands. The belts are cyclonic and the zones are…

I fyou enjoy gazing up at the stars on a clear night, you might have seen what looks like a point of light streaking across the sky. “Did you see that? I think I just saw a shooting star,” you might have said to a fellow observer. Technically, these are not stars, but meteors, and they are often so fast and sporadic that your companion is likely to have missed your observation. Meteors are formed when a piece of space debris called a meteoroid, micrometeoroid or space dust burns up in Earth’s atmosphere. A streak of light can be seen when this happens due to the glow of the fragmenting object and the trail of burning particles that it leaves in its wake. Meteors can be seen racing across a…

If you’ve ever seen a documentary about the Moon, you’ll have seen someone enthusiastically hurling a stone into a tray full of flour to demonstrate how impact craters are formed. Of all the hundreds of thousands of craters on the Moon, one looks exactly like the feature these dramatic demonstrations produce – adeep, sharp-edged pit surrounded by rays of debris. Copernicus looks exactly like a lunar crater should: a great hole in the Moon with a dark, shadowed floor; a high, skyscratching rim and lots of bright rays of dust and pulverised rock splashing away from it. Its nickname, the Monarch of the Moon, is entirely justified – no other crater comes close to it for sheer ‘wow’ factor when seen through a telescope eyepiece. That’s why lunar observers go…