Indice dei contenuti per No. 114 in All About Space

WELCOME ©Getty As you read through this issue of All About Space, you’ll notice there’s something a little different. This month, we’ve launched our very own augmented reality (AR) experience, enhancing your journey through the universe with the aid of your smartphone. This issue – and for many editions to come ― scan the QR code and you’ll be able to play videos, see spacecraft in three dimensions as they leap off the page and much more. Turn to the contents page for a quick tutorial and look out for the ‘AR’ stamps as you move through the magazine. This month we’ve got plenty to keep you entertained throughout lockdown ― whether you’re keeping out of the harsh wintry weather or have been gifted with crystal-clear skies for a spot…

Broadcaster’s satellite fails in orbit Words by Amy Thompson ©Maxar Technologies SiriusXM’s newest satellite, SXM-7, has suffered undisclosed failures during in-orbit testing, the company revealed in a filing with the US Securities and Exchange Commission on 27 January. “During in-orbit testing of SXM-7, events occurred which have caused the failure of certain SXM-7 payload units. An evaluation of SXM-7 is underway. The full extent of the damage to SXM-7 is not yet known,” SiriusXM said in the filing. At this time, it’s unclear if the satellite can be recovered. The satellite, which was built by Maxar Technologies, launched on a SpaceX Falcon 9 rocket on 13 December. The company has said the failure was unrelated to the launch vehicle and that a full evaluation of the satellite is underway. The…

Students help discover four new planets Words by Mike Wall Two Massachusetts school students – 16-year-old Kartik Pinglé and 18-year-old Jasmine Wright ― have helped discover four new alien planets. Pinglé and Wright did their otherworldly work via the Student Research Mentoring Program (SRMP) at the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology (MIT), which links up local high-school students with scientists for year-long projects. “By the end of the program, the students can say they’ve done active, state-of-the-art research in astrophysics,” SRMP director Clara Sousa-Silva, a quantum astrochemist at MIT, said. Pinglé and Wright worked with Tansu Daylan, a postdoctoral researcher at MIT’s Kavli Institute for Astrophysics and Space Research. Daylan and his colleagues scrutinised observations of the Sunlike star HD 108236 made by NASA’s Transiting…

THE INTERNATIONAL SPACE STATION: USING SPACE FOR HUMANKIND CUPOLA Agency Country An observatory module whose seven windows are used to conduct experiments, watch dockings and make observations of Earth – it provides spectacular views. COLUMBUS Agency Country Europe’s largest contribution, it allows research to be carried out in a weightless environment and outside in space thanks to four exterior mounting platforms. ZVEZDA Agency Country The first fully Russian module provides living quarters, life-support systems, electrical power distribution and data- processing, flight-control and propulsion systems. KIBO Agency Country Kibo, which means ‘hope’, is Japan’s first human space facility. Experiments on board focus on space medicine, biology, Earth observations, material production and communications research. ZARYA Agency Country The first component launched, Zarya was US-funded and Russian-built. It provided electrical power, storage, propulsion…

WHAT WEAPONS WILL BE USED? © Tobias Roetsch 1 Missiles Missiles launched from the ground or aircraft can blow up satellites, but it’s a very expensive and uncertain way of attacking them. Many satellites are in geostationary orbit, 36,000 kilometres (22,370 miles) up — a very long way for a missile to fly. 2 Lasers Powerful lasers can blind or even destroy satellites, and they can be shone from the ground or other satellites. Satellites may also be able to fire lasers to destroy things on Earth. 3 Rods from space Satellites equipped with metal rods — likely made from tungsten — could fire these at high speeds and angles. The kinetic energy would be the destructive force, with no need for explosives. 4 High-velocity particle beams Intense beams of…

Future tech Starship STARSHIP MISSION CONSTRUCTION KIT SpaceX is building Starship specifically to reach Mars, but it could transform space travel as the first mass-produced spacecraft Over the last 18 years, SpaceX has cut the cost of space access dramatically, forcing competitors to reluctantly follow its lead, but it is with the new Starship and Super Heavy that SpaceX could revolutionise space travel. Elon Musk’s overarching goal with SpaceX is to establish a self-sustaining city on Mars and make life multi-planetary. The biggest obstacle to this is space transport; the Falcon 9 was designed from a clean sheet to prove the technology and build SpaceX as a business that could reach for Mars. SpaceX focused on fast, simplified manufacturing and operations to bring costs down, but probably its biggest innovation…

WHERE IS PROXIMA CENTAURI? 1 THE SUN The heat and light from our G-type star has nurtured life on Earth and possibly nurtures primitive life forms elsewhere in the Solar System. 2 ALPHA CENTAURIA 4.36 light years from our Sun, with Alpha Centauri B it forms a binary pair in Centaurus. They are both similar star types to our Sun. 3 ALPHA CENTAURI B This star is slightly smaller than its sibling Alpha Centauri A. The binary system rotates a common centre of gravity every 80 years. 4 PROXIMA CENTAURI At 4.24 light years away, Proxima is the closest star to us. The red dwarf star has two exoplanets. Proxima b is slightly bigger than Earth. 5 SIRIUS Located in Canis Major, Sirius is 8.6 light years away and is…

NAME THAT SPACE ROCK What’s the difference between an asteroid and a meteor? © Getty © Getty © Getty Astronomers designate the rocks that float around in the Solar System and enter Earth’s atmosphere according to their behaviour and size: most objects larger than one metre (3.2 feet) in diameter that aren’t a dwarf planet or planet are asteroids. Meteoroids are smaller than this, but larger than a grain of sand. Micrometeoroids are even smaller than that. Comets are asteroid-like objects made up of ice and dust that have two tails and produce a coma – a small bubble of atmosphere – when they pass close to the Sun. When any of these objects enter Earth’s atmosphere and begin to burn up, producing a streak of glowing particles, they’re known…

GALAXY PROFILE The Milky Way Our galactic home is constantly surprising us, and it hasn’t finished yet ©Getty ©NASA The Milky Way is a barred spiral galaxy with large pivoting arms stretching out across the cosmos. Our Solar System is about 25,000 to 30,000 light years from the centre. Life in the outskirts is good. We find ourselves nestled in one of the smaller neighbourhoods, the Orion-Cygnus Arm, sandwiched between the larger Perseus and Carina-Sagittarius arms. If we were to travel inwards towards the centre we would find the Scutum-Centaurus and Norma arms. On a clear night devoid of light pollution, we can catch a glimpse of the bright lights of the galaxy streaking across the night sky. Our window into the universe, this milky-white band of stars, dust and…

Focus on NEW LAW PROTECTS APOLLO SITES FROM MOON MISSIONS Future launches to the lunar surface will be required to leave these iconic locations untouched ©NASA Preserving the historic sites where humans first landed on the Moon is now not only a good idea, it is also the law. The US has enacted its first legislation that requires American companies and other entities working with NASA on new missions to the Moon to avoid disturbing the US hardware that was left there 50 years ago. The ‘One Small Step to Protect Human Heritage in Space Act’ became law on 31 December. “I have long advocated for the preservation of the Apollo artefacts, which hold deep cultural, historical and scientific value for not only the US, but for all of humanity,”…

WHERE DID DARK ENERGY COME FROM? © Getty UNDERSTAND THE THEORETICAL MODEL OF DARK ENERGY 0 SECONDS BEFORE THE BEGINNING 1 All the matter and energy in the universe exists within a single infinitesimal point, a gravitational singularity a billionth the size of a proton. Possibly due to a quantum fluctuation, a period of rapid expansion – ‘inflation’ – begins. 10ˉ⁴³ SECONDS GRAND UNIFICATION EPOCH 2 The universe is still at an infinitesimal size. At these incredible energy levels, the universe’s four fundamental forces are unified. Gravity will soon separate and act independently, followed by electromagnetism. 10ˉ³² TO 10ˉ¹² SECONDS THE QUARK EPOCH 3 As the universe begins to expand, its ‘supercooled’ elementary particles form as a ‘hot soup’ of ionised plasma. Matter particles can interact with the Higgs field,…

Focus on SUPER-EARTH SEEN ORBITING ONE OF OUR GALAXY’S OLDEST STARS The new discovery has highlighted that the universe has been birthing rocky worlds for a long time One of the oldest stars in the Milky Way galaxy hosts an unusually hot, rocky super-Earth planet. Known as TOI-561b, this exoplanet is about 50 per cent larger and three-times more massive than Earth. It whips around its host star in a very close orbit, taking less than 12 hours to complete one lap. Given this close proximity, TOI-561b has an average surface temperature of over 1,726 degrees Celsius (3,140 degrees Fahrenheit), which is too hot to host any form of life as we know it. Researchers also found that TOI-561b’s density is similar to that of Earth’s. “This is surprising, because…

Astronomy ASTRONOMY WITHOUT A TELESCOPE You don’t always need optical aid to see beautiful things in the night sky ― just wrap up warm, go outside and look up Written by Stuart Atkinson ©Getty When people hear the term ‘astronomer’, most automatically picture someone peering into a telescope. But you don’t need a telescope to see many amazing and beautiful things in the night sky. You can see many of the wonders of the universe using just your own eyes, or a pair of binoculars. The telescope has allowed astronomers to see the planets of our Solar System in stunning detail and observe stars, nebulae and galaxies so far away that their dim light has taken millions or even billions of years to reach us. Telescopes make such faint objects…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE ©NASA 8 JANUARY 2021 Return to sender This image captures the moment Northrop Grumman’s Cygnus space freighter departed the International Space Station (ISS) after a lengthy three-month stay. Cygnus successfully delivered over 3,500 kilograms of scientific equipment and supplies while attached to Canadarm2, the ISS’ robotic arm. Canadarm2 lends a helping hand to the Space Station by aiding in maintenance, moving supplies and ‘catching’ visiting vehicles. The freighter was released from the robotic arm on 7 January 2021, but it wasn’t sent away empty handed: the ISS crew loaded Cygnus with the Saffire-V investigation, the SharkSat- hosted payload, and a large amount of rubbish to be used in an extended mission in orbit. The junk safely burned up on re-entry. 27 JANUARY…

OSIRIS-REx to leave asteroid in May to deliver samples Words by Mike Wall NASA’s asteroid-sampling OSIRIS-REx probe will spend two extra months at its target space rock before heading back to Earth. OSIRIS-REx snagged lots of dirt and rock from the 1,640-foot (500-metre) wide near-Earth asteroid Bennu in October 2020 ― so much stuff, in fact, that the probe’s sample collector was overflowing. The original mission plan called for OSIRIS-REx to leave Bennu’s vicinity with this precious cargo on 3 March. But the departure date has been pushed back to 10 May, NASA officials announced on Tuesday 26 January. “Leaving Bennu’s vicinity in May puts us in the ‘sweet spot,’ when the departure manoeuvre will consume the least amount of the spacecraft’s onboard fuel,” said Michael Moreau, OSIRIS-REx deputy project…

Martian mineral found in Antarctic ice Words by Nicoletta Lanese Scientists boring into ice have unearthed a mineral that’s rarely seen on Earth but found in abundance on Mars. The yellow-brown mineral, jarosite, requires both water and acidic conditions to form – environments that are hard to find now on the Red Planet. After the Opportunity rover first discovered jarosite on Mars in 2004, the mineral turned up in several Martian locations, leaving scientists wondering how it had become so common. Some theorised that when ice covered the planet billions of years ago, dust containing the required minerals – iron, sulphate and potassium ― may have been trapped inside. “Mars is such a dusty place – everything is covered in dust,” said Giovanni Baccolo, a geologist at the University of…

HOW LONG DOES IT TAKE TO REACH PROXIMA CENTAURI? Although it’s the nearest star to our Solar System, the time it would take to get there using our current technology is still staggering. At a distance of 4.24 light years — 1.3 parsecs or 268,770 astronomical units — that sounds fairly close, but when we consider that this equates to 40,208,000,000,000 kilometres (24,984,092,897,478 miles) away then things ‘ are put into perspective. At best it would take us several thousand years to get there. © Alamy; © Getty; Souce: Wikipedia Commons © Cmglee; © Sunil Gupta…

HOW A METEOR FALLS Incredible things happen to an object travelling at up to kilometres (44.7 miles) per second through Earth’s atmosphere ©Alamy 1 Drifting Objects in space can be drifting for billions of years before their trajectory puts them on a collision course with Earth. 2 Atmospheric entry As the object zips into the atmosphere at high speed, friction with the air causes the surface to melt and vaporise. 3 Shooting star Most objects disintegrate, but some will go on to shine with an intense light and leave a short-lived streak of glowing debris. 4 Fireball Larger objects glow with such energy that they briefly outshine the Sun. They can also burn in different colours and produce shock waves. 5 Dark flight If anything of the meteor remains after…

Arecibo WHAT’S NEXT FOR ARECIBO? PUERTO RICO’S HUGE TELESCOPE LIES IN RUINS, BUT IS THIS REALLY THE END? Reported by Ian Evenden ©Getty ©Getty After almost 60 years, it looks like time to say goodbye to the iconic Arecibo telescope. The dish, which reclined in a sinkhole on the Caribbean island of Puerto Rico, was just too badly damaged when its support cables snapped following earthquakes and hurricanes. If it cannot be repaired, then what does the future hold for the observatory? “The damage to the telescope cannot be repaired,” says Rob Margetta of the National Science Foundation (NSF), the body that administers the telescope in partnership with the University of Central Florida. “It suffered extensive damage due to the 2020 collapse. The telescope’s instrument platform was also a complete…

MEET FAST: ARECIBO’S REPLACEMENT CHINA’S GIANT RADIO TELESCOPE COULD CARRY ON ARECIBO’S PIONEERING WORK ©FreeVectorMpas 1 LOCATION The scope sits in a natural sinkhole in Pingtang County, Guizhou, China 2 DISH 500 metres (1,640 feet) in diameter, the dish is made of 4,450 movable triangular panels, each 11 metres (36 feet) a side. Steel cables support the dish. 3 WINCHES Underneath the dish are 2,225 winches that pull on joints between panels, deforming it to focus on specific areas of the sky. 4 ROBOT Hanging 140 metres (459 feet) above the dish is a feed cabin moved using a robot along cables from six support towers. 5 RADAR Unfortunately, FAST doesn’t have the radar transmitting capability that was a valuable part of Arecibo’s instrument cluster. 6 WAVELENGTHS FAST observes at…

WHAT IS STRING THEORY? 1 STRING THEORY String theory expands upon existing theories of matter, adding an extra fundamental level beyond that of fundamental particles. 2 MATTER: THE ICE CUBE The everyday matter we see around us is made up of molecules. In the example of the ice cube, it consists of molecules of H2O. 3 MOLECULES: H2O These molecules are composed of atoms bonded together. For water, this means one oxygen atom bonding to two hydrogen atoms. 4 ELECTRONS, PROTONS AND NEUTRONS Within these atoms is an internal structure made up of electrons with a negative charge orbiting a nucleus. This consists of nucleons: protons and neutrons. 5 NEUTRONS AND PROTONS: QUARKS The nucleons are made up of ‘flavours’ of quarks. A neutron contains two down quarks and an…

MYSTERIES OF THE UNIVERSE WHAT IS STEVE? Photographers who began taking images of unusual lights in the night sky suddenly found themselves to be citizen scientists Reported by David Crookes © Krista Trinder; Getty For a long time, photographers have been snapping away at the glowing green dancing lights that are often seen in high-latitude regions of our planet’s night sky. Known as aurorae, these light displays attract many thousands of enthusiasts. But when a growing number of people also began to see a thin purple ribbon of light, interest in this natural celestial phenomenon began to pique even further. Appearing for as little as 20 minutes to as much as an hour, the mysterious purple arcs were reported 30 times across 2015 and 2016, mainly by aurora chasers from…

THE THEORIES What could be causing these beautiful light shows above Earth? 1 It’s an aurora If it is an aurora – and the general consensus is that it is not, even though it is made of light and driven by the auroral system according to MacDonald – then it’s certainly far from being a normal one. ©NASA 2 It has moving points of light Small green streaks within STEVE may be due to moving points of light. These could appear elongated when photographed because the camera is causing them to blur, but some images don’t seem to confirm this. ©NASA 3 Turbulence is to blame The purple emissions could be due to ions moving at supersonic speeds. The green emissions may be present simply because of slower moving structures.…

STARGAZER ESSENTIAL GUIDES AND ADVICE FOR AMATEUR ASTRONOMERS What’s in the sky? © NASA/JPL 2 MAR Comet C/2020 R4 (ATLAS) reaches perihelion in Aquarius at magnitude +12 2 MAR Mercury reaches half phase (dichotomy) in the morning sky, shining brightly at +0.1 4 MAR Asteroid 4 Vesta reaches opposition in Leo, glowing at magnitude +6.2 6 MAR Mercury reaches greatest elongation west in the morning sky, glowing at +0.1 9 MAR Conjunction between the Moon and Saturn in Capricornus Source: Wikipdepia Commons © Stefen2499 10 MAR Close approach of the Moon and Saturn, within 3°35’ of each other in Capricornus ©NASA/JPL 10 MAR Conjunction between the Moon and Jupiter, within 4°02’ of each other in Capricornus 19 MAR Conjunction between the Moon and Mars in Taurus © NASA/JPL 19 MAR…

STARGAZER In the shops The latest books, apps, software, tech and accessories for space and astronomy fans alike 1. For observing Astrogloves Cost: £19.99 (approx. $27.35) From: astrogloves.net Designed by UK amateur astronomer Martin Hall, these are the perfect addition to your astronomy kit bag. The semi-fingerless design – whereby your thumb and first two fingers of each hand are free – allows you to maintain control while changing eyepieces, tightening clamps and focusing your telescope on those cold winter nights. The sturdy gloves are made from durable neoprene and feature double-layer spandex backs. The palms are made from padded synthetic leather. They’re available in three sizes: small, medium and large. 2. For a treat Martins Chocolatier Luxury Chocolate Planets Cost: £13.99 (approx. $19.10) From: Martin’s Chocolatier Gift someone the…

LAUNCH PAD Twisted space light could reveal brand-new physics Words by Mara Johnson-Groh YOUR FIRST CONTACT WITH THE UNIVERSE ©ESA/NASA/JPL-Caltech Atwist in the universe’s first light could hint that scientists need to rethink physics. Two Japanese scientists looked at the polarisation, or orientation, of light from the cosmic microwave background radiation, some of the earliest light emitted after the universe’s birth. They found that the polarisation of photons, or light particles, might be slightly rotated from their original orientation when the light was first produced. And dark energy or dark matter may have been responsible for that rotation. Dark energy is a hypothetical force that is flinging the universe apart, while proposed dark matter is a substance that exerts gravitational pull, yet does not interact with light. The rotated signature…

LAUNCH PAD Extreme black holes probably have ‘hair’ Words by Mike Wall YOUR FIRST CONTACT WITH THE UNIVERSE Black holes may not be so simple after all. According to a leading idea known as the ‘no-hair’ or ‘black hole uniqueness’ theorem, black holes can be fully characterised using just three data points ― their mass, spin and electric charge. There’s no other observable information to be had about these light-gobbling behemoths, which therefore seem to be sleekly and uniquely ‘bald’. But new research casts doubt on the no-hair idea, or at least its universal application: computer simulations suggest that ‘extreme’ black holes ― the ones whose spin or electrical charge is fully maxed out – do sport a few wispy hairs here and there. “This new result is surprising because…

SPACE WARS SEVERAL COUNTRIES ARE SPENDING A LOT MORE ON MILITARY SPACE, WORRYING PEACEMAKERS Reported by Ian Parker IS PLANET EARTH READY FOR A COSMIC BATTLEGROUND? ©Tobias Rocts. Years ago, Buzz Aldrin said: “Once you have stood on another celestial body and looked back at the Earth, you realise how small, precious and fragile it is amid the vastness of space. We shouldn’t be fighting over it.” Buzz was a successful fighter pilot before he became an astronaut, and the experience of walking on the Moon changed him hugely. The moonwalkers went there in peace for all humankind. If NASA plans work out, they will do it again. Most have always had philosophies and feelings which transcend national, cultural and racial barriers. It comes with the turf. Space agencies around…

Focus on WEIRD GAS GIANT HOLDS SOLAR SYSTEM’S SECRETS A gigantic alien world’s long orbit may tell us more about the outer planets in our solar neighbourhood ©NASA/JPL-Caltech Scientists have managed to measure both the size and orbit of a gas giant exoplanet nearly 1,300 light years away from Earth. Dubbed GOT ands for Giant Outer Transiting Exoplanet Mass, the planet is roughly five times the mass of Jupiter. Usually scientists struggle to measure the size of giant gas planets, like Jupiter and Saturn, because they’re far away from the stars they orbit. Yet this planet showed up in what researchers call our ‘solar neighbourhood’ in 2010, when NASA’s Kepler space telescope first discovered the object. Astronomers then noticed periodic decreases in the brightness of a nearby star, called Kepler-1514,…

Proxima Centauri SIGNAL FROM PROXIMA CENTAURI Could a recently detected signal from a nearby star system be from extraterrestrials? Reported by Nigel Watson ©Tobias Roetsch Unusual signals from outer space are exciting as they indicate something new and unexpected, and might even turn out to be much anticipated communication from an extraterrestrial civilisation. There was even more speculation surrounding the recent detection of signals from the direction of Proxima Centauri because it is our closest stellar neighbour. They were spotted by student Shane Smith, working under the Breakthrough Listen program, as he went through the slow and laborious process of searching through data that was originally collected to detect stellar-flare activity. The data was collected by the Parkes radio telescope in New South Wales, Australia, during a 26-hour observation period…

Meteorites DEATH FROM ABOVE CAN METEORITES KILL? what are the chances of being struck. by a falling piece of space rock? Reported by Ben Biggs ©Tobias Roetsch On 22 August 1888, a fireball was witnessed over the city of Sulaymaniyah in what is northern Iraq today. It was part of a shower of meteorites that lasted ten minutes, during which time many impacted Earth. To the relief of the citizens below, this blazing celestial missile zipped overhead, missing the city and slamming into a nearby hillside. Unfortunately one man was killed, and another was seriously injured. This event is described in three contemporaneous letters that were found in an archive recently, thought to be the earliest evidence of someone being killed by a meteorite fall. But this isn’t the last time…

METEORITE TYPES STONY They’re mostly made of silicate minerals and fall into two main categories: chondrites, ancient space rocks that date from the beginning of the Solar System, and achondrites, which do not contain chondrules – tiny grains – and come from Mars, the Moon or asteroids. IRON These are made mainly of iron-nickel metal and come from the cores of ancient asteroids that melted in the heat of the early Solar System. Their metal cores can sometimes be encased in minerals and have a crust, similar to the structure of terrestrial planets. x3©Alamy STONY-IRON Stony-iron meteorites are more or less equal parts metal and rock and may have gemstone inclusions. Some can be particularly beautiful – when cut and polished, the olivine crystals inside allow light to pass through…

ARECIBO’S BEST BITS MAPPING ASTEROIDS Using its ability to send out radar signals, Arecibo imaged many near-Earth asteroids. It discovered that they often orbit in pairs or trios, rather than being lone rocks hurtling through space. ©NASA CUTTING THROUGH VENUS’ CLOUDS The powerful radar at Arecibo could see into places nothing else could. It produced images of the surface of Venus we could never see any other way due to the planet’s thick, opaque atmosphere. ©NASA ROTATION OF MERCURY In 1964, Arecibo was able to determine that the rotation period of Mercury was 59 days instead of the previously believed 88 days. This proved that it was not tidally locked to the Sun. ©NASA THE CRAB NEBULA PULSAR Studying this pulsar in 1968, Arecibo was able to time its pulses…

HOW DARK ENERGY BEHAVES ©NASA/ESA 1 THE COSMIC TUG OF WAR In many ways, dark energy can be considered the evil counterpart of gravity. Gravity’s influence draws matter in the galaxy together; dark energy works to push it apart. 2 HOLDING IT TOGETHER Astronomers calculated that the gravitational influence of visible matter alone wasn’t enough to hold galaxies together, even before accounting for dark energy. 3 DARK MATTER BOOSTS GRAVITY There’s an unseen form of matter exerting its influence. Dark matter accounts for about 80 per cent of the matter in the universe. 4 THE DARK UNIVERSE AT WAR As dark matter outweighs ordinary matter, it’s dark matter’s gravitational influence that dark energy is working against. 5 THE SPACE BETWEEN US Dark energy seems to expand the very space between…

HOW STEVE’S LIGHT IS LIKELY TO BE GENERATED Charged particles collide and heat up, causing them to emit a distinctive light in the night sky 1 Let there be light The Sun sends a flowing river of charged particles called the solar wind towards Earth, applying pressure on our planet’s magnetic field. 2 To the dark side The charged particles, or plasma, are sent to the far, night-time side of Earth, where the magnetic field is stretched into the shape of a teardrop with a long tail. 3 A point of friction When the charged particles in the Earth’s ionosphere close in, the oppositely directed magnetic field lines collide and reconnect in a process known as magnetic reconnection. 4 Near the equator STEVE’s arc aligns east- west, and it is…

ASK Space Our experts answer your questions © NASA/JPL/University of Arizona PLANETS Have we seen aurorae on other worlds? Anyone who has ever witnessed an aurora will know just how magnificent this natural phenomenon is. Sometimes forming a diffuse green glow on the poleward horizon, or if conditions are just right a spectacular overhead explosion of colour in the night sky, the privilege of witnessing an aurora first-hand is something many wish for. Aurorae are the stunning result of a complex chain of interactions that start at the Sun. Solar particles travel outward from the Sun, in what is known as the solar wind, and interact with Earth’s magnetic field. While most of the solar wind is deflected by this magnetic barrier, under certain conditions, some of it can break…

STARGAZER This month’s planets As NASA’s Perseverance rover touches down on Mars this February, the Red Planet is also a great target for observers not long after sunset Planet of the month Our planet of the month is Mars, not just because it is an easy naked-eye object after sunset, but because it will be in the news a great deal as NASA’s latest rover, Perseverance, begins its mission to look for signs of life on the Red Planet, having landed in Jezero crater on 18 February. Mars is an evening object, looking like an orange ‘star’ to the naked eye. It can be found quite high in the southwest as soon as the sky begins to darken, in the busy constellation of Taurus, and will be visible until around…

STARGAZER Deep sky challenge Taurus’ treasures There’s more to the Bull than the glittering Hyades and Pleiades star clusters Sourece: Wikipedia Commons © Juan lacruz “THE CRAB NEBULA’S MISTY BEAUTY IS RESERVED FOR OBSERVERS BLESSED WITH DARK SKIES” Many constellations are famous for one or two special deep-sky objects. Summer favourite Lyra is famous for the smoky circle of the Ring Nebula (Messier 57), while in winter Orion’s Orion Nebula and fainter Horsehead Nebula always delight observers, and to their east the squashed box of Cancer is home to Messier 44, the Beehive Cluster. Mention Taurus to a deep-sky observer and they will wax lyrical about the beauty of its two large, bright open star clusters: the V-shaped Hyades cluster and the ‘mini Big Dipper’ of the Pleiades cluster. However,…