Indholdsfortegnelse for No. 157 i All About Space

ISSUE 157 Did you know that stars have a habit of oscillating? These balls of hot gas vibrate in such a way that they’re releasing waves trapped in their interiors, a phenomenon that gives way to something commonly referred to as starquakes. While they’re analogous to earthquakes on our planet, our experts this issue warn us to err on the side of caution when we visualise them. “I know it’s a good way of catching people’s attention to call them starquakes, and there are some analogies with earthquakes, but we generally talk about starquakes as the oscillations of stars,” University of Toulouse scientist Sébastien Deheuvels tells us. “Perhaps the most common analogy that we make is with musical instruments – when you pluck a guitar string, the whole string of…

You may not know this, but Earth’s magnetic field has a tail. As the Sun’s solar wind hits the planet, it leaves behind a sort of long shadow that trails out in our planet’s wake. Scientists call this magnetic tail the magnetotail. Typically, the magnetotail is strewn with magnetic storms. But for the past several years, scientists have known of a mystery in the magnetotail: a missing storm. They have found a signature of a storm, but no storm to actually go along with it. NASA’s Magnetospheric Multiscale (MMS) mission is now on the case. MMS consists of four satellites that were all launched on the same Atlas V rocket in 2015. Since then, the quartet has been studying Earth’s magnetopause: the frontier of the region dominated by the planet’s…

The outer halo of the Milky Way is filled with magnetic fields that take the shape of vast doughnuts with diameters ranging from 12,000 to 100,000 light years, with the heart of our galaxy at their centre. These doughnut or ‘toroid’ shaped magnetic fields of the Milky Way are responsible for constraining the physical processes surrounding gas and dust that exist between stars, known as the interstellar medium, and also govern the propagation of charged particles called cosmic rays that travel through the universe at near-light speeds. The discovery could help better understand the origin and evolution of magnetic fields in the cosmos, a mystery that has baffled astronomers for decades. The new study was led by National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) scientists Xu Jun…

1 f-mode waves Surface gravity waves are created at the surface and move across the star like waves on the ocean. 2 p-mode waves Pressure waves are most similar to sound waves, generated by local pressure changes inside the star. 3 g-mode waves Gravity waves are generated where gravity counteracts the internal buoyancy of rising gas. 4 Layering The passage from one internal layer of a star to another with different properties can deflect waves, or even reflect them completely. 5 Core chemistry The speed at which waves travel straight through the core reveal its composition and likely age. 6 Rotation The rotation of the core influences waves passing through or near it, creating patterns that can reveal its rate of spin.…

The prospect of sending probes on an interstellar mission is often accompanied by thoughts of high costs, decades of planning and large spacecraft. That’s not necessarily the case, though, according to the Institute for Interstellar Studies (i4is), whose goal is to ultimately take humanity out beyond the Solar System. “We believe it’s possible to actually launch probes into deep space, whether it’s outside the Kuiper Belt, into the Oort Cloud or beyond, within the next 10 to 20 years,” Kelvin Long, the executive director of i4is, tells All About Space. i4is has proposed a spacecraft called Project Dragonfly. This innovative vessel would consist of a central hub that contains all the instrumentation, and in front of it would unfurl a large, thin sail made of material such as mylar, aluminium…

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Recent reports of the James Webb Space Telescope detecting signs of life on a distant planet outside the Solar System are somewhat premature. That’s the conclusion of research conducted by scientists from the University of California, Riverside (UCR). While likely to disappoint all of us eager for the confirmation of extraterrestrial life, it doesn’t mean Webb won’t find traces of life in the atmosphere of an exoplanet in the future. The excitement around the potential detection of life signs on an exoplanet started in 2023 when Webb detected potential biosignature elements in the atmosphere of the exoplanet K2-18 b, a super-Earth located around 120 light years from us. Though many exoplanets are extreme, violent or at least ‘alien’ in nature – whether they’re blasted by intense radiation from their stars,…

1 Today’s universe The present-day universe, with complex structures separated by large gaps in space but a broadly uniform structure on the very largest scales. 2 Looking back in time The speed of light means we see distant parts of space as they were long ago, turning the universe into a cosmic time machine. 3 Universe of matter Our universe is dominated by matter: Standard Model particles that include the positively charged proton and negatively charged electron. 4 Cosmic fog A dense fog of subatomic particles prevented radiation from travelling in straight lines in the very early universe. 5 Early era Particle accelerators can collide particles with energies approaching those of the early universe. 6 First atoms About 400,000 years after the Big Bang, subatomic particles coalesced into atoms, mostly of…

Time travel One way of reaching the CPT symmetric anti-universe would require travelling backwards in time, past the Big Bang and surviving in a realm of antimatter without being instantly annihilated. Powerful magnetic fields can be used to keep matter and antimatter apart from each other. Wormholes These hypothetical shortcut passages through space and time look like black holes at either end, but lack the deadly singularity in the middle. Wormholes might exist naturally or be manufactured by advanced civilisations, but they would only be useful for hopping around ‘our’ universe – they could never link to the anti-universe. Interstellar travel Our universe extends far beyond the limits of what we can see, and may be effectively infinite. That would mean a multitude of other ‘observable universes’ beyond our own,…

PLANET OF THE MONTH Rather by default, our planet of the month this issue is Saturn. It’s not particularly well placed for observation, but it is slightly better placed than the other planets. It’s not particularly or unusually bright either, but it is easily visible to the naked eye. In mid-June, at the start of our observing period, Saturn is a slightly yellow-hued morning star, rising in the east around three hours before sunrise. But due to its position in Aquarius it won’t actually climb very high into the sky, as it moves southwards before the sky brightens with the approach of dawn, so if you have trees, buildings or hills on your horizon in that direction you might struggle to see it. By 1 July Saturn will be rising…

Summer in mid-northern latitudes gives us short nights that are never truly dark, which can wreak havoc on your viewing plans. However, they are dark enough to see some real celestial wonders. The Milky Way arcs almost from north to south at this time of year and brings with it all kinds of deep-sky gems, including open star clusters, globular star clusters and nebulae on which to feast your eyes. Down near the southern horizon you will find the constellations of Scorpius and Sagittarius, which are packed with many such objects. For example, there’s open star cluster Messier 7 – this object can be challenging for Northern Hemisphere observers as it is so close to the horizon during this time of the year. On the other hand, the exquisite Eagle…

15 May 2024 A massive icy crater stares up at a Mars orbiter A massive impact crater dominates a new view from the ExoMars Trace Gas Orbiter (TGO). The result of an ancient asteroid impact, the crater is located in Mars’ Utopia Planitia. That’s the largest known impact basin in the entire Solar System, with a diameter of roughly 3,300 kilometres (2,000 miles), or twice the size of Earth’s Sahara Desert from north to south. Interesting ice-related features on and below the surface of the crater give insight on the Red Planet’s watery past. “This remnant of an ancient impact is just one of the many scars asteroids have inflicted upon the Red Planet,” European Space Agency (ESA) officials said. “Water, volcanoes and impacts from asteroids shaped the Martian surface…

India is preparing to launch a family of seemingly science-fiction robots to Mars, perhaps as soon as late 2024. The Mars Orbiter Mission 2 (MOM 2) – or Mangalyaan 2, which is Hindi for ‘Mars craft’ – is set to include a rover and a helicopter, just like a robotic NASA duo already on Mars – the Perseverance rover and now-grounded Ingenuity helicopter. A supersonic parachute and a sky crane that will lower the rover onto the Martian surface will also be part of Mangalyaan 2, Indian Space Research Organisation (ISRO) officials said during a presentation at the Space Applications Centre in Gujarat. NASA pioneered the use of a Mars sky crane in 2012 with its Curiosity rover and employed it again in 2021 to get Perseverance down. The Ingenuity…

A scientist has learned more about the violent processes that rip atmospheres away from planets, finding that squashing and squeezing by a parent star can contribute to this process. The research, conducted by Guo Jianheng from the Yunnan Observatories of the Chinese Academy of Sciences, could help astronomers better determine which exoplanets to look at more closely as they expand their search for life beyond the Solar System. There are multiple ways that planets can lose their atmospheres to space, including the upper atmosphere leaving the planet as a whole, called hydrodynamic escape. This process is thought to be more extreme than the process by which our Solar System’s planets leak particles into space today, causing a planet to lose mass while also impacting its climate, and thus its habitability.…

Campante says that though the frequencies of the starquakes the Sun experiences aren’t audible to humans, this could be changed if we sped up the three millihertz signal by about 100,000 times. Then we could create a 300 hertz signal – or 300 oscillations per second – which would be well within our hearing range. “Different musical instruments have distinct and recognisable pitches. For fun, let us associate the Sun with a trumpet,” Campante explains. He says smaller stars would have higher pitch overtones, so if the Sun is a trumpet, then smaller stars like red dwarfs would be a higher pitched instrument like a cornet. The converse is also true. Larger stars than the Sun experience starquakes with lower pitch overtones. If the Sun were a trumpet, then a…

The Curiosity rover has detected intriguing chemical evidence in the form of anomalous amounts of manganese oxide, pointing to Mars having had not only a habitable environment billions of years ago, but also one possibly inhabited by microbes. NASA’s Curiosity is exploring the giant 154-kilometre (96-mile) diameter Gale crater, where the rover landed in 2012. Curiosity’s discoveries have already established that the crater was at least partially flooded long ago – although the evidence for this has been contested. However, the rover’s latest findings not only strengthen the argument for an ancient lake, but also suggest that conditions within the lake were conducive to life. The evidence is associated with the compound manganese oxide. Curiosity first found small quantities of manganese oxide in Gale crater in 2016, but now it…

Using NASA’s Chandra X-ray Observatory, scientists have discovered a new cosmic ‘exhaust vent’ funnelling hot gas away from Sagittarius A* (Sgr A*), the supermassive black hole that sits at the very heart of our Milky Way. The newly discovered vent is linked to a chimney-like formation orientated at a right angle in the Milky Way’s disc. The Chandra observation reveals how a ‘tunnel’ at the centre of our galaxy helps channel matter to its outer regions. Many supermassive black holes are voracious consumers of gas, dust and even the stars around them. The supermassive black hole at the heart of the Milky Way, Sgr A*, on the other hand, is a light eater. It consumes so little matter, in fact, that if it were a human, it would sustain itself…

In just under half a decade, a 305-metre (1,000-foot) wide asteroid named after the Egyptian god of chaos and destruction, Apophis, will pass within 48,300 kilometres (30,000 miles) of Earth. Scientists don’t intend to allow the rare close passage of a space rock of this size to go to waste. On 13 April 2029 – a Friday, no less – when Apophis makes its closest approach to Earth, it will become so prominent over our planet that it will be visible with the unaided eye. NASA’s OSIRIS-APEX will be on hand to meet the near-Earth asteroid (NEA) personally. But if things shape up, that NASA mission could be joined by a host of little satellites during its rendezvous. Under the auspicious ‘NEAlight’ project, a team from Julius-Maximilians-Universität Würzburg (JMU) led…

The lunar landscape down towards and around its south pole is wild, craggy and rugged; a raw, bare-rock wilderness of walled plains, huge craters and towering mountains all blasted out by a brutal asteroid bombardment many millennia ago. Down in the southern lunar highlands there are too many craters to count: they overlap and overlay each other. The most ancient, large craters have smaller, younger craters inside them, and many of those smaller craters have even smaller, even younger craters inside them. Exploring this cluttered landscape through a telescope is both thrilling and bewildering – there’s just so much to see! Naturally, the huge impact craters of Clavius, Maginus and Tycho draw the eye, but a little further to their north and east lies a much smaller crater with a…

The constellations of Lyra, Aquila, Hercules, Sagittarius, Scorpius and Ophiuchus are in easy reach this month. What’s more, these star patterns are packed with night sky objects. Fans of tight-knit globular star clusters should turn their attention to the constellations of Ophiuchus and Hercules, where they will be rewarded with sights of the extremely stellar-rich Messier 10, Messier 12, Messier 14, Messier 13 and Messier 92. Meanwhile, astrophotographers will get great enjoyment from the binary star system Rho Ophiuchi in Ophiuchus, which is surrounded by a red emission nebula and very impressive light and dark brown dust lanes. Cygnus is also a gold mine, with the Veil Nebula, Fireworks Galaxy and the Crescent Nebula being excellent choices for observation in particular. Using the sky chart This chart is for use…

The US Department of Defense is developing a plan to use the ever-growing American commercial space industry for national security purposes. The plan, known as the Commercial Augmentation Space Reserve, or CASR, would allow the US Space Force to use the capabilities of the commercial space sector through “prenegotiated contractual agreements which would be activated in times of crisis or conflict,” according to the service’s Commercial Space Strategy document, which was released in April 2024. Such a plan would combine military, commercial and civil satellites operated by the US and its allies into one “hybrid space architecture,” as the Pentagon’s Defense Innovation Unit refers to it. CASR just moved closer to becoming a reality. The House Armed Services Subcommittee on Strategic Forces released a draft of its policy language for…

There might be total darkness in the depths of the sea, but the Sun still impacts the abyss. During this month’s solar storms – which resulted in aurorae lighting up half of the planet on 10 May – Ocean Networks Canada’s (ONC) deep-sea observatories recorded disturbances in Earth’s magnetic field. The ONC observatories are located from the Arctic to the Antarctic and have more than 12,000 sensors recording data, including compasses used to measure ocean currents. Concurrent with this month’s explosive solar activity, the compasses recorded significant anomalies – dramatic shifts in Earth’s magnetic field. One compass at the NEPTUNE observatory near Vancouver Island changed direction between 30 and -30 degrees. This wasn’t the first time the team had seen solar-influenced anomalies in underwater compass readings. In late March, while…

Shell burning Deep inside the star lies a burnt-out core of helium surrounded by a hydrogen-burning shell that generates energy. High-density star KIC 11026764 has just begun the journey to become a red giant. Its relatively high density produces high-frequency seismic waves. Small giants Comparatively small red giants generate relatively high-frequency waves, though still much lower than those of subgiants. Weak waves The waves in small red giants are also comparatively weak, with small amplitudes. Larger giants As a red giant brightens and swells in size, its surface cools because there is a far larger surface area for energy to escape through. Slower and stronger Seismic waves in bigger red giants are more powerful, but have lower frequencies as they move more slowly in the low-density stellar interior. Strange giant…

The smallest starquake recorded to date was detected in March 2024 and originated from Epsilon Indi, an orange dwarf star about 71 per cent the width of the Sun. “This makes Epsilon Indi at once the smallest and coolest dwarf star observed to date with confirmed solar-like oscillations. In other words, these are the tiniest starquakes ever detected,” Campante says. “To give a flavour of the extreme precision level of these observations, the frequency of oscillations was 5,305 microhertz, and their peak amplitude was just 2.6 centimetres (one inch) per second, a mere 14 per cent of the oscillation amplitudes measured for the Sun. This is an outstanding technological achievement.” At the opposite end of the scale is a special form of starquake experienced by a neutron star. Detected in…

In the 109 years since it was first formulated, general relativity has remained our finest description of gravity on a galactic scale. And time and again, experiments have confirmed its accuracy. “This model of gravity has been essential for everything from theorising the Big Bang to photographing black holes,” Robin Wen of the University of Waterloo’s mathematical physics program said. “But when we try to understand gravity on a cosmic scale, at the scale of galaxy clusters and beyond, we encounter apparent inconsistencies with the predictions of general relativity. Gravity becomes around one per cent weaker when dealing with distances in the billions of light years. We are calling this inconsistency a ‘cosmic glitch’. It’s almost as if gravity itself stops perfectly matching Einstein’s theory.” “Scientists are aware there are…

JUST STEPPED OUT FOR A WALK Astronauts train for many years for the chance to go to space, with no guarantee of actually flying, so being given a place on a mission to live on the International Space Station (ISS) for a few months is a dream come true. But some astronauts get to do even more – they wriggle into a spacesuit and go outside on an extravehicular activity (EVA), or spacewalk. This image, taken on 23 May 2017 during the 201st spacewalk of the ISS program, shows NASA astronaut Jack Fischer waving at his colleagues watching from inside the space station as he worked outside the US Destiny laboratory. Fischer was attaching antennae to the exterior of the ISS during an unplanned EVA to repair and replace a…

STEP ONE Magma ocean Just like the primitive Earth, early Venus was still largely molten as a result of the high-energy impacts that formed the planet in the first place. This led to a widespread ocean of magma across the planet, leading to very high temperatures. STEP TWO Gas and steam Impacts added additional material to Venus, including a significant amount of water. Coupled with the heat from the magma ocean and Venus’ proximity to the Sun, an early atmosphere began to form around the planet, largely made of carbon dioxide and steam. STEP THREE Cooling and condensing Over time, the number of impacts began to die away; the unbattered planet began to cool down and a solid crust formed on the surface. Steam started to condense out of the…

Our universe encompasses everything around us. Its laws of physics control every possible interaction, from the gravitational attraction that keeps planets in orbit around the Sun to the complex chemistry that gives rise to life. But for astronomers and physicists there are still some big questions about why the universe is the way it is. One of the most famous is the mystery of dark matter, which only makes its presence felt through the influence of its gravity. Another is the dominance of a certain set of subatomic particles – the familiar ones such as electrons, protons and neutrons that we call ‘matter’ – when there was nothing in the Big Bang itself to prevent the formation of equal amounts of ‘antimatter’. A new theory developed by two Canadian physicists…

Pluto used to be thought of as the ninth planet in the Solar System, but in 2006 the International Astronomical Union created an official definition for planets and decided Pluto didn’t fit all of the conditions. The upshot was a reclassification of the body discovered by Clyde Tombaugh at Lowell Observatory in 1930, with Pluto being labelled a ‘dwarf planet’ instead. But that’s not to say a ninth planet doesn’t actually exist. In fact, as time goes on, there’s more and more evidence to suggest one is very much out there. The search for a ninth planet has been ongoing for some time. American astronomer Percival Lowell spent the last decade of his life looking for a hypothetical planet beyond Neptune – the so-called Planet X. It was thought that…

1 Deneb (Alpha Cygni) At magnitude +1.25, Deneb is the 19th-brightest star in the sky. A blue-white supergiant more than 100 times wider than the Sun, it’s between 55,000 and 200,000 times more luminous than our own star. It will become the Pole Star around the year 9800. 2 CygnusX Look below Deneb and you’ll see what looks like a long, misty ‘cloud’ to the naked eye. Through binoculars this is revealed to be a haze of countless millions of stars, looking like diamond dust spilled on black velvet. Sweep along it slowly with your binocular for stunning views. 3 Messier 13 Also called the Great Globular Cluster in Hercules, this is an enormous cluster of stars 145 light years wide and 22,200 light years away. This ancient star cluster, which looks like…

Everything about the polycarbonate and aluminium SkyMaster Pro 20x80 screams quality, from the waterproof rubber covering to Celstron’s own XLT multicoated optics, attached objective lens caps and accessories. As with all large objective binoculars for astronomy, the SkyMaster Pro 20x80 uses a Porro prism design, largely because it allows in the most light possible. That’s critical when going hunting for deep-sky objects. Porro prism binoculars are generally bigger than the rival roof prism optical design, and their 2,450-gram bulk is not inconsequential. However, with 80-millimetre objective lenses and 20x magnification, binoculars like this will always need to be mounted on a tripod. To make that easy, Celestron has fitted the SkyMaster Pro 20x80 with a centre support rail. It sits in the gap between the two tubes, stretching from the…

From an early age it was apparent that Dryden was gifted. By the age of 22 he held a PhD in physics and mathematics and was the director of the Aerodynamics Division at the National Bureau of Standards. His aptitude with mathematics and aerodynamics saw him become a member of the National Advisory Committee for Aeronautics (NACA), the precursor agency to NASA, in 1939, and ten years later he was its director. During his time at NACA he oversaw, among other things, the hugely successful X-15 rocket plane program. With the launch of the Soviet Sputnik 1 on 4 October 1957, the American space program, and the lack of a dedicated space agency, shot to the top of the national agenda. Dryden was vilified in the press for allowing the…