Innehållsförteckning för No. 60 från All About Space

Secrets of gravity SECRETS OF GRAVITY We seem to understand how it behaves, but scientists are now finding out how mysterious this 'force' really is Written by Kulvinder Singh Chadha © Tobias Roetsch It keeps us on the ground, creates tides, and holds planets in their orbits around stars and satellites revolving around the Earth. And maybe it did or didn’t cause that apple to fall on Isaac Newton’s head. We’re talking about gravity, of course. But amazingly, while we understand how gravity works, exactly how it is produced is still a source of great debate. Our current best theory of gravity is Albert Einstein’s general theory of relativity, which explains how mass bends space, and it is these bends in space that we experience as gravity. It’s a bit…

Spacequakes SPACEQUAKES They’re the TREMORS that SHAKE the very MAGNETIC FIELD OF OUR PLANET. AND THEY’RE GETTING WORSE Written by Jonathan O’Callaghan © Tobias Roetsch “ Swirling vortices of plasma inside the magnetised gas, some as wide as our planet, spin at the source of the spacequake in the vibrating magnetic field” Earth’s magnetic field is a strange place. Not only does it protect us from some of the more harmful radiation in the universe, such as solar radiation and cosmic rays, but it also plays host to some unusual phenomena that we’re only recently beginning to understand. One of these is the so-called spacequake, a consequence of some strange goings on around our planet – but a fascinating phenomenon all the same. Spacequakes are essentially large vibrations in Earth’s…

STARGAZER What’s in the sky? What’s in the sky? 6 JAN Comet 45P/Honda-Mrkos-Pajdusakova reaches its brightest at magnitude +6.4 in Capricornus 6 JAN Conjunction of the Moon and Ceres at a separation of 3°25’ in Pisces and Cetus 6 JAN Conjunction of Moon and Eris at a separation of 8°56’ in Pisces and Cetus 11 JAN Mercury hits its greatest brightness in the dawn sky at magnitude -2.2 12 JAN Venus reaches greatest elongation east and shines brightly at magnitude -5.1 12 JAN Venus and Neptune pass closely and within 0°21’ of each other in Aquarius 14 JAN Venus reaches its half phase in the dawn sky 14 JAN Comet 74P/Smirnova-Chernykh reaches its brightest at magnitude +12.9 in Gemini 14 JAN Conjunction of Ceres and Eris at a separation of…

Targets for tonight Grab your telescope or even a pair of binoculars and take a tour of the deep sky Pinwheel Galaxy (M101) Type of object: Spiral galaxy Constellation: Ursa Major (The Great Bear) Magnitude: +7.86 Horsehead Nebula (IC 434) Object: Reflection nebula Constellation: Orion (The Hunter) Magnitude: +6.8 The Trapezium Type of object: Open cluster Constellation: Orion (The Hunter) Magnitude: +4.0 Beehive Cluster (M44) Type of object: Open cluster Constellation: Cancer (The Crab) Magnitude: +3.7 Eskimo Nebula (NGC 2392) Type of object: Planetary nebula Constellation: Gemini (The Twins) Magnitude: +10.1 Meade LightBridge  Mini Price: Starting at £50 From: Hama UK Ltd…

Moon tour Langrenus crater This month we help you find one of the Moon’s best hidden gems… © James Stuby; NASA The Moon has many “celebrity” craters, like Copernicus, Tycho and Eratosthenes, which are big and bright enough to be obvious to the naked eye. However, these celebrities owe their fame to a stroke of good fortune: the bodies which blasted them out of the lunar surface millennia ago struck the face of the Moon pointing right at Earth. There are other craters just as big and interesting as Copernicus, but they are reduced to “B” or “C List” status because they were blasted out of areas not so well-placed for observation. Instead, we see them at an angle, foreshortened by the curve of the Moon’s limb. Langrenus is one…

Make the most of Earthshine Improving your pictures Combine your images to get the thin crescent Moon and Earthshine in one image… If you take just a single shot of the Earthshine, you may find that either the brightly lit crescent is overexposed and the rest of the Moon’s disc is properly exposed, or it may be that the crescent is properly exposed and the lunar disc is under-exposed. To get both parts of the scene properly exposed, two separate images with different exposure times are required. You’ll then need to carefully combine the two images in software such as Photoshop. You’ll also need to take the images very close to each other in terms of time, so that the light and the Moon position don’t change too much. 1…

Me & My Telescope Send your astrophotography images to photos@spaceanswers.com for a chance to see them featured in All About Space David Moug Manitoba, Canada “About five years ago I started off my hobby of astronomy with a pair of binoculars, doing simple visual observing in order to learn my way around the night sky. It wasn’t long before I joined a local astronomical group and, on interacting with other members, I became fascinated at how some were recording images of a variety of astronomical targets. Wanting to get involved, I started doing my own research into GoTo tracking mounts as well as auto-guiding setups for astrophotography.” Michael Saltsman Greater Manchester, UK “I am an estate agent by day and an astrophotographer by night. I studied photography at school but…

Celestron Cometron FirstScope 76 Designed with the beginner or casual astronomer in mind, this tabletop scope is portable, provides good night-sky views and doesn’t take up too much space “ This tabletop telescope comes with all of the accessories you need for any beginner wanting a fuss-free tour of the night sky” Telescope advice Cost: £72 / $90.75 From: David Hinds Ltd Type: Reflector Aperture: 76mm (2.99”) Focal length: 300mm (12”) Best for... Beginner Small budget Planetary viewing Lunar viewing Bright deep-sky objects There are several things that novice sky-watchers crave when choosing their very first telescope: portability, ease of use and a price that’s not going to break the bank. We’re pleased to say that the Celestron Cometron FirstScope ticks all of the boxes on these fronts. And, what’s…

In the shops The latest books, apps, software, tech and accessories for space and astronomy fans alike Filter kit Meade Series 4000 1.25” eyepiece and filter kit Cost: £200 From: Hama UK Ltd A selection of filters and eyepieces are a must for improved views of the night sky and Meade Instruments Ltd have ensured that the astronomer has everything they need for exquisite views of a selection of night sky targets, and at a modest price. What’s more, each accessory has a fitting of 1.25”, meaning that they can be fitted to a wide range of telescopes. Meade has also thrown in a robust carry case to keep the eyepieces and filters secure and protected from the elements. The Meade Series 4000 comes with 6mm, 9mm, 13mm, 18mm and…

New venture allows you to send your laugh into space Art project wants to launch a 3D-printed guffaw Whether you have an infectious laugh or a kooky giggle, the artist and coder Eyal Gever wants to hear from you. That’s because he is preparing to create the first piece of artwork in space and he’s going to do so based on someone’s laughter. Having launched an art project called #Laugh, he has created an app for iPhones, iPads and iPod Touches, which lets you produce a virtual star using the sound of your chuckles and submit it for consideration. The star forms in real-time, taking on various shapes and producing rings, spikes and other protrusions as you chortle. The laughter that generates the greatest number of likes from the general…

Heat bombs may roast the Sun’s atmosphere Has the mystery of why our star’s corona is hotter than the surface been solved? NASA researchers believe they may be able to part-explain a longstanding puzzle: the issue of why the temperature in the outer atmosphere of the Sun is up to 500-times higher than on its visible surface. By studying the observations made by the Interface Region Imaging Spectrograph (IRIS) mission, the scientists have found that heat bombs could be going off, spreading heat over a large area. The bombs, they say, are caused by blasts of energy from crisscrossing magnetic fields, which realign in the corona, the name given to the Sun’s upper atmosphere. It’s the same kind of magnetic reconnection that accounts for solar flares and if this didn’t…

Opportunity on Mars 13 YEARS OF DISCOVERIES MARS Designed to last 90 days, Opportunity has completed over a decade on Mars. All About Space looks back on how the record-breaking rover has changed the way we see the Red Planet Written by Colin Stuart 1 Martian solar day (Sol) = 1.027 Earth days © Adrian Mann PanCam A pair of colour cameras allowing Opportunity to take panoramic images of the Martian surface. The resolution of the cameras was designed to mimic the human eye. NavCam A pair of black and white cameras mounted on the mast of the rover helps scientists to see the rover’s surroundings and plan out its route across Mars. PanCam calibration target A sundial with different coloured corners and engraved with the message: “Two worlds one…

Secrets of gravity How does gravity work? Gravity has a lot of effects that we may not even think about 1 It gives us weight Although your mass – the amount of ‘stuff’ that you are made of – would remain the same wherever you are in the universe, your weight would vary considerably. Weight is a force determined by gravitational attraction. It’s the product of a large body’s ‘acceleration due to gravity’ (g) and your mass. So for example, if your mass – not weight – was 70kg and Earth’s g is 9.81ms2 , your weight would be 686.7 Newtons. 2 It causes objects to gravitate towards each other Although gravity is the weakest fundamental force, it is the longest ranging. Bodies with a significant amount of mass can…

SPACEQUAKES AFFECT THE EARTH What can these cosmic events do to our planet? GPS The Global Positioning System is also affected by the ionisation of the atmosphere, leading to some complications. Radio communications The ionisation of the atmosphere caused by spacequakes can hamper radio communications. Solar flare An incoming solar flare can reverberate Earth’s magnetic field, leading to a spacequake. Geomagnetic storm Spacequakes can be part of a broader phenomenon in Earth’s atmosphere called a geomagnetic storm. Power grids In rare events, a powerful spacequake can disrupt ground currents, and power grids, on Earth. Aurora Spacequakes can help funnel particles into the atmosphere, producing bright aurorae.…

Spacequakes THEMIS © Adrian Mann “THEMIS gave us our first glimpse of the elastic band-like snapping effect in Earth’s magnetic field that led to these events” Launch date: 17 February 2007 Launch vehicle: Delta II rocket Mass: 630kg (1,390lbs) Mission: Five satellites to study Earth’s magnetic field and observe any changes up close, including spacequakes, and their effect on our planet 17 October 2003 Halloween storms In 2003, a series of geomagnetic storms (later called the Halloween Storms) caused havoc with Earth’s magnetic field. 30 October 2003 Ejection The cause was a surprising outbreak of 17 solar flares on the Sun, which hit Earth’s magnetic field between 19 October and 7 November 2003. 5 November 2003 Energised Earth’s magnetic field was highly energised by the event, meaning the satellites and…

Interstellar planets Hunt for interstellar PLANETS Space is suspected to be filled with worlds wandering alone without their star, but could such loners ever shelter life? Written by Giles Sparrow “ Rogue planets are thought to be planets that formed from gas and dust, and were later ejected from their solar systems by close encounters with planetary neighbours or near misses with stars” In the past two decades, we’ve grown used to the idea of exoplanets – distant worlds orbiting their stars in alien solar systems. Some of these planets are very different from our own – scorched gas giants skimming the surface of their stars, or frozen balls of ice larger than the Earth. But perhaps the strangest exoplanets of all are those that drift alone through the darkness…

How to find a rogue planet Gravitational microlensing Microlensing is a distortion and magnification of a star’s light, which happens when another object passes in front of it and bends the paths of light passing near it through gravity. It’s been successfully used to find exoplanets orbiting other stars, but can also be used to detect interstellar planets, allowing astronomers to estimate how common they are. Unfortunately, microlensing events by interstellar planets tend to be one-offs, so it’s hard to learn much about the planets themselves. Direct imaging The direct detection of interstellar planets relies on long-exposure surveys of large areas of the sky looking for brown dwarfs and other faint objects. Infrared surveys are particularly useful since many of these objects emit more radiation as heat than they do…

Get into stargazing tonight Your targets for tonight Start your exploration with our pick of the top naked-eye objects Orion Nebula (M42) Constellation: Orion (The Hunter) Best seen: Throughout the night Magnitude: +4.0 Glance below the three stars of Orion’s Belt and you should be able to make out the Orion Nebula as a white smudge in a dark sky. Also visible from suburban areas with modest light pollution, the star-forming region is a huge cloud of gas that’s forming new stars about 1,300 light years away from us. The Winter Triangle Constellation: Orion (The Hunter), Canis Minor (Little Dog) and Canis Major (Great Dog) Best seen: Throughout the night Not strictly a constellation, but an asterism, you know that it’s winter when you can see the Winter Triangle dazzling…

How to star hop A handy technique for easy navigation of the night sky 1 Use a sky chart You’ll need a sky map before you begin star hopping. From a dark sky location, you’ll find it hard to read your sky map, so you should ensure that you use a red torch to preserve your dark-adapted vision. 2 Determine the field of view While it is usually written on the side of binoculars, it can be worked out for telescopes by dividing the field of view of your eyepiece (usually specified by the manufacturer) by the telescope’s magnification. You should ensure that you start off with the eyepiece with the lowest magnification. 3 Use a template Using a few square centimetres of clear plastic, a drawing compass and a…

Deep sky challenge The exotic night sky objects of Gemini Dig deep in the constellation of 'The Twins' and you’ll find some of winter's best-kept secrets © NASA; ESA; A. Sarajedini (University of Florida); G. Piotto (University of Padua); Andrew Fruchter (STScI); JPL-Caltech; WISE Team; Adam Block; Mount Lemmon SkyCenter; University of Arizona; WIYN; NOAO; NSF Gemini, also known as The Twins, sits nicely about half way up the sky at this time of year, and contains many lovely objects for those armed with a telescope. These vary from open star clusters to faint nebula and even a supernova remnant. The two bright stars that mark out the constellation are interesting too. Alpha Geminorum, known as Castor, is a lovely star system composed of three binary pairs all linked together…

HEROES OF SPACE Gordon Cooper He flew a solo mission in space and set flight endurance records © Daniel Roland; AFP; Getty Images Space is a lonely place and Gordon Cooper felt that more than most. As a NASA astronaut, he made two notable journeys skywards, his first being in 1963 as part of the United States’ first human spaceflight programme, Project Mercury, which saw him spend close to 34.5 hours on a solo mission. His second was as Command Pilot of Gemini 5 alongside Pete Conrad, when the pair established a new space endurance record of 190 hours and 56 minutes in orbit. Born on 6 March 1927 in Shawnee, Oklahoma, Cooper left school at the age of 18 and enlisted in the United States Marine Corps. Upon his…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE @ ESA; NASA Paris at night from the International Space Station ESA astronaut, Thomas Pesquet, who blasted into space as a crewmember of Expedition 50 and 51 missions, took this stunning image of the capital city of France. He journeyed into space with NASA’s Peggy Whitson and Roscosmos’ Oleg Novitskiy in late October 2016. Pesquet was so taken by the image that he decided to share it on social media, commenting: “A strange feeling: I think of what friends and family are doing now on Earth, while taking pictures of them from space… Hi Paris and France: you are beautiful tonight!” Pesquet’s mission is known as Proxima, which is the ninth long-duration mission for the ESA astronaut. He will perform over 50…

Observatory continues search for more gravitational waves A second science run at ground-based LIGO is underway in the search for space-time ripples Scientists are resuming their search for ripples in the fabric of space and time thanks to two newly upgraded detectors. Researchers at the Laser Interferometer Gravitational-wave Observatory (LIGO) made the first direct observation of gravitational waves on 11 February 2016 and followed it up with a second detection announced in June 2016. But with fresh tweaks to the detectors, LIGO began making observations again on 30 November, with the second scientific run set to run for six months. The Livingston detector, in Louisiana, is now 25 per cent more sensitive while the one in Hanford, Washington, is more stable. “With our improved sensitivity and a longer observing period,…

Astronomers see the birth of a giant galaxy A massive structure has been witnessed feeding on the gas around it A giant galaxy that is in the centre of a cluster of still-forming protogalaxies appears to be growing from cold molecular gas and not from violent collisions, according to new research. An object called the Spiderweb Galaxy, which is more than 10 billion light years away from Earth, is said to be feeding on the gas that exists between the infant galaxies within it. “This is different from what we see in the nearby universe, where galaxies in clusters grow by cannibalising other galaxies,” says lead study author, Bjorn Emonts, a researcher at the Center for Astrobiology, Spain. “In this cluster, a giant galaxy is growing by feeding on the…

0-3968 Sols Opportunity’s marathon Opportunity’s sheer tenacity means it has lasted a lot longer than mission controllers had originally envisaged. In 2015, after more than 11 years exploring Mars, the rover clocked up a total distance of 42.1 kilometres (26.2 miles) – the equivalent of running a marathon. On its journey from Eagle crater to Endeavour crater, it found signs of past water on Mars as well as clues as to the potential habitability of the Red Planet, including its salinity. 1 Eagle crater Opportunity landed in this 22m (77ft) wide crater, just south of the equator, where it found signs of acidic water in the area's past. 2 Endurance crater Opportunity spent May to December 2004 exploring this crater and found that liquid water was likely once present there.…

Titan Explorer’ s Guide Titan Pack your wet gear as we take you to the second largest moon in the Solar System and the only other planetary body to contain traces of water It’s not often a satellite upstages the planet around which it orbits, but then again, Titan is no ordinary moon. Locked in an elliptical embrace with the ringed body of Saturn, it remained one of the great mysteries of astronomy for centuries, before humans began pulling back those long settled veils during the Space Age. As the mysteries have slowly been unlocked – through the data collected by Pioneer 11, Voyager 1 and Cassini-Huygens – Titan has revealed some of the most fascinating topographical features beyond our own atmosphere. The moon boasts huge lakes of frozen water…

SPACEQUAKE VS EARTHQUAKE How a bad space weather day compares to the tremors that shake our planet’s surface Magnitude 6.9 earthquake Earthquake in China, 14 April 2010 Bad space weather day Bastille Day space weather event, July 2000 5 The energy in a spacequake is similar to a magnitude 5 or 6 earthquake 30,000km The distance above the Earth where spacequakes generally occur 32 million Approximate amount of energy (in kilograms of TNT) in a magnitude 7 earthquake 1 year Several million earthquakes occur around the world every year 1,000 km/s Speed of plasma ejected from the Sun that can cause spacequakes 24 hours It is not unconmmon for spacequakes to happen at least once per day…

Interstellar planets Wandering worlds we’ve found so far Cha 110913-773444 Distance away: 163 light years Discovery method: Direct observation Constellation: Chamaeleon Discovered in 2004, Cha 110913-773444 has the mass of about eight Jupiters, making it a candidate interstellar planet. Infrared observations show that it is surrounded by a faint disc of planet-forming material, perhaps moons in formation? WISE 0855-0714 Distance away: 7.27 light years Discovery method: Direct observation Constellation: Hydra Discovered in 2014 using WISE, this small object is a little over seven light years away. With a surface temperature of -30°C (-22°F), it’s either a cold, low-mass brown dwarf or an interstellar planet on our cosmic doorstep. PSO J318.5-22 Distance away: 80 light years Discovery method: Direct observation Constellation: Capricornus PSO J318 is the best-studied rogue interstellar planet so…

STARGAZER Get into stargazing tonight GET INTO stargazing TONIGHT In the midst of winter, now is the perfect time to head outside and get started in astronomy – whether you’ve got a telescope or not It’s a common myth that you need a telescope to be an astronomer. While it’s true that one of these instruments can reveal much more than the naked eye or, in some cases, a pair of binoculars can, you don’t need a telescope to enjoy the night sky. What’s even better is that taking your first tentative steps into stargazing is absolutely free. Beginners are often advised to just use their eyes before even considering to buy a telescope, in order to familiarise themselves with the night sky with the aid of nothing more than…

Get into stargazing tonight Getting closer to the universe with binoculars or a telescope If you’ve seen all of the targets available to you using the naked eye, then you’re ready to magnify your experience Of course, naked eye astronomy is a rewarding enterprise, but with the help of a telescope or binoculars, you can look further into the universe. If you’re not keen on purchasing a scope straight away, then binoculars with a magnification of at least 10x50 are portable and open up the opportunity to grab sights of night-sky objects that your naked eye is unable to resolve. An increased magnification means that you can also get better detail of targets than your unaided eye can make out – Jupiter, with its equatorial belts, and moons are an…

Planet of the month This month’s planets Planet-watchers are spoiled for choice as 2017 settles into its stride, with bright planets on view after sunset and before sunrise VENUS Right Ascension: 22h 42m 47s Declination: -08° 46’ 20” Constellation: Aquarius Magnitude: -5.1 Direction: Southwest The holidays might be over, and the New Year celebrations behind us, but as January 2017 gets into its stride, Venus is still a dazzling evening star high in the southwest after sunset. As soon as dusk falls, Venus can be seen glinting in the lavender sky like a silvery spark, and by the time the sky has darkened to deep purple, the planet is shining so brightly it shouts: “Look at me!” An hour after sunset Venus will be obvious to the naked eye from…

How to… Make the most of Earthshine We’ve probably all seen it at some point, the bright crescent Moon, but also a faintly lit disc. What is going on and how often can we see this? © Alamy; Alan Dyer You’ll need: • DSLR camera • Zoom or telephoto lens • Small telescope • Tripod On a clear early evening or early morning, at certain times, if you look out low down near the horizon and close to where the Sun is either setting or rising, you might spot a very thin crescent Moon. If you look more closely, you might notice that along with the brightly lit crescent, you can see a fainter glow over the whole disc of the Moon, allowing you to make out some of the…

How to… Use a planisphere You may have seen one or even owned one, but how do you use one of these star charts successfully? You’ll need: • A planisphere • A red torch A planisphere is a circular disc, usually made from plastic, which is designed to show you the constellations visible in the night sky at any given time of the year. On closer inspection, you’ll notice that it consists of two discs, one of which is transparent, with a central axis allowing them to rotate against each other. As you do this, you’ll notice that the ‘window’ that shows the constellations, and which has the central axis of the disc, is offset. This axis marks the position of the Pole Star and is the point about which…