Indholdsfortegnelse for No. 64 i All About Space

For sale: International Space Station NASA ponders whether the artificial habitat should be saved or scrapped The question of what should happen to the International Space Station (ISS) remains up in the air. The ISS was due to be shut down in 2020 but it was granted a four-year life extension in 2015. Yet President Donald Trump signed the NASA Transition Authorisation Act of 2017 and he wants the space agency to begin charting the space station's future. In March, a congressional committee in the US heard from four space experts, putting forward arguments for saving or scrapping America‘s involvement in the multinational project. NASA says it is set to cost US taxpayers as much as $4 billion (£3.2 billion) each year, about half of the space agency’s human spaceflight…

United States told to prepare for a space war The strategy will protect both American assets and help prevent conflicts from flaring up in space © NASA; CXC; Pontifical Catholic University; F. Bauer et al.; U.S. Air Force; John Pinfield; JPL-Caltech; ASI; Cornell; Frank Vincentz A proposed space laser satellite defence system dating back to 1984 A top US military official has said America must come out and state that it is ready to fight a war in space, amid concern that some nations could pose a future threat to them. Navy Vice Admiral Charles A Richard, the deputy commander of US Strategic Command, says China and Russia were developing offensive space capabilities and weapons and that a strategy of “preparation without provocation” was required. Such a move is unlikely…

White holes Have we already discovered one? Detected in 2006, NASA’s Swift Gamma-Ray Mission could have uncovered a candidate for an 'inverse' black hole A possible white hole? Back in June 2006, the Swift satellite captured a burst of gamma rays that lasted for around 102 seconds in a galaxy some 1.6 billion light years away. Since no supernova was seen following the event, astronomers realised that they had come across a possible new object. In 2011, it was hypothesised that the burst was a white hole. Mission Profile: Swift Gamma-Ray Burst Mission Launched: November 2004 Operator: NASA Launch vehicle: Delta 7320 rocket Orbit: Low-Earth Super Swift telescope After being signalled by the Burst Alert Telescope (BAT) onboard the spacecraft, the Swift spacecraft slewed immediately to the burst. On detecting…

New moons around Uranus How Voyager found Uranus’ hidden moonlets The newly reported moonlets were discovered through reanalysis of data produced by Voyager 2’s Radio Science Subsystem (RSS) Voyager’s flightpath The spacecraft’s flyby of Uranus took it behind the planet at a speed of 16km (10mi) per second, passing twice behind each of Saturn’s rings. Narrow rings Most of the rings of Uranus are very thin – the alpha and beta rings are just a few kilometres across, despite having radii around 45,000km (27,962mi). Detection on Earth Density variations are detected as dips and peaks in radio signals received by NASA’s Deep Space Network. Voyager antennae Voyager 2 carried both S-band (2,295 megahertz) and X-band (8,415 megahertz) radio transmitters, whose signals were beamed towards Earth using the 3.7m (12ft) high-gain…

How Ceres’ cryovolcanoes may have vanished Many ice volcanoes could have existed on its surface but geological processes could have spelt their end 1 The beginnings of a cryovolcano Icy material found in Ceres’ mantle wells up and cracks the dwarf planet’s thin crust. The cryovolcano begins to form. 2 A peak forms If the icy material continues to rise, a distinctive peak eventually forms with steep sides. A cryovolcano has been made. 3 The ice volcano goes to sleep Over time, the cryovolcano is no longer being renewed with material from the mantle, and so it becomes dormant. © NASA; JPL-Caltech; UCLA; MPS; DLR; IDA; ESO; L. Calçada; Nick Risinger; JHUAPL; SwRI; Gregory H. Revera 4 The peak starts to flatten Since the cryovolcano is no longer active, it…

Planet of the month This month’s planets Ringed planet Saturn is a worthy target, while Venus continues to put on a splendid morning show for observers Saturn Constellation: Sagittarius Magnitude: 0.2 AM/PM: AM Saturn is a guest in the morning sky this month. It resembles a bright, yellow-white star among the spilled salt and pepper stars of the Milky Way’s star clouds in Sagittarius, a little to the right of the ethereal Lagoon Nebula (M8) and above and to the right of the spout of the famous ‘teapot’ asterism. At the end of April Saturn rises in the southeast around 12.30am, faithfully following Jupiter, which will have been above the horizon for several hours, and although it will not be as bright as Jupiter, the ringed planet will still be…

How to… Observe variable stars It can be fun to watch and record stellar changes in light output. Here's how to chart these impressive stars... © ESO; VVV consortium; D. Minniti You’ll need: • A star chart • A telescope or binoculars • Pen and paper • A camera (optional) There are a lot of stars in the sky that vary in brightness over time. These variations can be hardly noticeable or quite dramatic. They can take place over hours, days or even years and there are a number of causes for these variations and how often they happen; from eclipsing binary stars that block light from their companions, to stars ejecting carbon, in the form of soot, into their atmospheres. Variable stars are categorised into types and by their…

How to… Sharpen your night vision As darkness falls our eyes adapt to the low levels of light, which is an advantage to astronomers. Here’s how to make it work for you You’ll need: • A red light torch • 30 minutes of time You have probably noticed that when you’ve been out in the dark for a while, looking at the stars or even just walking home at night, when you get into a brightly lit building, it can hurt your eyes for a moment or two. This is because your eyes have got used to being in the dark and the sudden glare of light means that they quickly have to readapt to protect your retinas from possible damage. It works the other way around too. Coming out…

STARGAZER Me & My Telescope Send your astrophotography images to space@spaceanswers.com for a chance to see them featured in All About Space Jeff Johnson Las Cruces, New Mexico Telescope: Takahashi FS-60C refractor “I did my first 'real' astrophotography in 1996, when I used a 35mm SLR (film) camera to take photos of Comet Hyakutake. I took a tripod out into the desert here in Las Cruces and just experimented with exposures. Later, I bought a 10” Dobsonian for viewing, and within a week was taking pictures through the eyepiece for fun. Here is my latest image of the Horsehead Nebula (IC 434) and Flame Nebula (NGC 2024) in the constellation of Orion.” Matt Dieterich Montana, United States Telescope: TS GSO 8” Ritchey-Chrétien Astrograph “The Milky Way with incredible green airglow…

Titan’s lakes could fizz with nitrogen It could explain why islands seem to appear and disappear on Saturn's largest moon Titan's lakes and seas may be erupting due to the release of nitrogen, causing them to fizz and create ‘magic islands’, new research has found. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, say it is similar to opening a fizzy drink, with nitrogen rapidly separating from the extremely cold liquid methane and ethane in the moon’s lakes, rivers and seas. By simulating Titan’s surface conditions, they found slight changes in temperature, air pressure or composition caused the effect. “Our experiments showed that when methane-rich liquids mix with ethane-rich ones – from a heavy rain, or when runoff from a methane river mixes into an ethane-rich lake – the…

LAUNCH PAD your first contact with the universe Heftiest and purest ‘failed star’ discovered The record-breaking brown dwarf was found in the outermost reaches of the Milky Way A brown dwarf star just 750 light years away from Earth is the most massive and purest of its kind, according to a study involving a team of international astronomers. The star, which is named SDSS J0104+1535, is estimated to be about 10 billion-years-old and it is located in the constellation of Pisces in the Milky Way’s so-called ‘halo’. Not only is it 90 times bigger than Jupiter, it is said to be 250 times purer than the Sun. That means it is 99.99 per cent hydrogen and helium – the elements that were present in the wake of the Big Bang.…

White holes THE HUNT FOR WHITE HOLES The search for these eruptions in space-time has begun. But will they leave the pages of science fiction and enter reality? Written by Nicky Jenner © Tobias Roetsch “ White holes are a theoretical prediction based on time-reversal symmetry that forms the laws of nature” Prof Steven Giddings The cosmos is full of odd and extreme phenomena. Take everyone’s favourite behemoth: the black hole. These dark, mysterious types hungrily devour anything and everything within their reach. As in the Star Wars universe, there is a light side to accompany the dark – and the dark black hole has its light equivalent in the intriguing white hole. In simple terms, white holes are time-reversed black holes. If you were somehow able to film a…

White holes Linking white holes and black holes: the wormhole © Nicholas Forder Wormholes are based on Albert Einstein’s theories of general relativity, a theory that suggests that objects with a great gravitational field would create a depression in the fabric of space-time. It is this theory that is able to predict phenomena such as black holes. If the mass of a collapsed star is great enough, it can warp space-time to such an extent that matter is sucked into the hole created by the object’s gravitational mass. Back in 1916, physicist Karl Schwarzchild offered that where matter is sucked in, on the opposite end, matter is spat back out again, which could possibly be in the form of a white hole. The tunnel-like shortcut that connects them, known as…

MISSION PROFILE Juno Over nine months into its 20-month mission to study the secrets of Jupiter, the NASA spacecraft is already helping redefine our understanding of the gas giant Mission type: Space probe Operator: NASA Launch date: 5 August 2011 Target: Jupiter Arrival in orbit: 5 July 2016 Primary objective: To study Jupiter’s composition Status: Active In 2016, following five long years of travel through the deep, dark space of our very own Solar System, the NASA-operated Juno spacecraft finally established an orbit around the planet it was designed, built and launched to study: an impressive titan of a planet, Jupiter. Following in the footsteps of the famous Galileo spacecraft – and the many other craft NASA deployed far from Earth – Juno represents some of NASA’s most advanced technologies.…

SOLAR SYSTEM How big is the Solar System? The distances between the planets are vast, so to try and envisage the breadth of our Sun's system, we scaled it down Bert Gravett “Space is big”, as The Hitchhiker’s Guide To The Galaxy makes clear, but how big is very difficult to imagine. We’re used to seeing the planets of the Solar System laid out neatly in diagrams but while the planets are vast, the distances between them make even Jupiter seem tiny. Indeed, the Solar System is not evenly distributed either – the orbit of Mars, the other rocky planets and the Sun would fit inside a pea in the middle of a dinner plate if Pluto’s orbit matched the plate’s rim. This illustrates why space travel is so difficult…

Moon tour The full Moon We look at the whole of our lunar companion This month, instead of zooming in on one specific lunar feature, we’re going back to basics to look at the whole Moon. After all, the Moon is usually the first thing people starting out in the hobby of astronomy look at. The first thing you’ll notice is that the Moon appears to change shape during the month, growing from a crescent in the evening sky to a half disc, then to a full disc, before shrinking back to a crescent when it shines in the morning sky. This happens because, as the Moon orbits the Earth, more and more of its surface is illuminated by the Sun. When it first appears, low in the west after…

Observe variable stars Recording your observations The only way you can tell if a star is at its 'peak or trough' of brightness is by recording it The easiest way to record your observations of variable stars is to use a notebook and graph paper, so you can get a visual impression of how the star is behaving. If you draw out two axes on the paper, use the Y-axis for the brightness in magnitude and the X-axis for the time or date. You’ll quickly see that the light curve for each star is different, depending on the type of variable it is and its period. Always write on the graph which star you’re observing to avoid confusion, but above all, have fun! 1 Choose an easy-to-observe star Start with…

Telescope advice Meade ETX Observer series If you struggle to find your way around the night sky but don’t want to miss out on the best views, then look no further… “The overall build of the ETX90, in particular, is excellent, promising to last for years of astronomy” With a selection of refractors and Maksutov-Cassegrain optical designs that are slewed by a motorised mount, the Meade ETX Observer offers range in price and observation. Manufactured with apertures from 3.14” to 4.92", the optical system of these GoTo scopes provide views of a wide selection of Solar System and deep-sky objects, the larger your aperture, the greater the light gathering ability of the instrument and your chances of seeing faint, diffuse objects such as nebulae and galaxies. GoTo scopes are notorious…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE © NASA; ESA; Hubble The galaxies that defy cosmic convention A striking view of two interacting galaxies, located some 60 million light years away in the constellation of Leo, have been revealed to be quite unusual by NASA’s Hubble Space Telescope, making them quite hard to classify. In this image, you’ll see a diffuse and somewhat patchy blue glow covering the upper portion of the frame – this is known as NGC 3447, or often NGC 3447B for clarity since the former can apply to the overall mishmash of stars and gas. Meanwhile, the smaller lump, visible to the lower right, is NGC 3447A. We know for sure that they are two colliding galaxies, but how they appeared exactly before they began…

Betelgeuse The star that swallowed its companion To explain the supergiant’s high rotation speed, one theory suggests it once had a companion star 1 A smaller companion star nearby To explain its strangely rapid rotation speed, researchers have suggested that when it was first born, Betelgeuse may have had a companion star roughly the mass of our own Sun. 2 The giant star’s core shrinks When the red supergiant had exhausted all of the hydrogen fuel supplies in its centre, the core of Betelgeuse contracted, which triggered a chain reaction of events that will lead to its inevitable end. 3 The red supergiant expands Following the contraction of Betelgeuse’s core, the outer envelope of unburned hydrogen expanded drastically, bloating the giant star outward towards its companion. © Nicholas Forder 4…

NEW MOONS around URANUS The ice giant is home to a complex family of satellites and it seems that more are being discovered Written by Giles Sparrow © Tobias Roetsch “ Images snapped by Voyager during its close approach revealed many smaller moons inside the orbit of Miranda” The cold depths of our Solar System are home to two mysterious blue-green giants – the outer planets Uranus and Neptune. Each about four times the diameter of Earth, these dim worlds were only discovered in the era of the telescope and have only been visited by a single space probe – the plucky Voyager 2, which flew past Uranus in 1986 and Neptune in 1989. Voyager’s images of Uranus revealed what seemed to be a surprisingly placid turquoise world, with none…

Ceres’ vanishing volcanoes The curious case of CERES’ vanishing VOLCANOES Ice volcanoes on the cold surface of the dwarf planet seem to have disappeared. All About Space finds out why Written by Kulvinder Singh Chadha © Tobias Roetsch  Between Mars and Jupiter in the expanse of the Asteroid Belt, lies an unassuming-looking object made of ice and rock. First spotted by Sicilian astronomer Giuseppe Piazzi on the 1 January 1801, this 965-kilometre (600-mile) diameter ball could just have been considered a dead, grey rock in space. But as NASA’s Dawn spacecraft has recently discovered, Ceres has hidden a strange secret. It was – and possibly still is – an active world that may have had cryovolcanoes that have all pretty much disappeared. “ Ceres’ Ahuna Mons could have once had…

STARGAZER GUFDES AND ADVFCE TO GET STARTED FN AMATEUR ASTRONOMY What’s in the sky? Red light friendly In order to preserve your night vision, you should read our observing guide under red light Conjunction Jargon buster A conjunction is an alignment of objects at the same celestial longitude. The conjunction of the Moon and the planets is determined with reference to the Sun. A planet is in conjunction with the Sun when it and Earth are aligned on opposite sides of the Sun. Right Ascension (RA) Right Ascension is to the sky what longitude is to the surface of the Earth, corresponding to east and west directions. Ft is measured in hours, minutes and seconds since, as the Earth rotates on its axis, we see different parts of the sky…

Deep sky challenge Galaxies and clusters of early summer Train your telescope on a wealth of deep-sky targets, suitable for a range of apertures If you like looking at objects far out in deep space, then this time of the year has an abundance of galaxies and globular star clusters that are sure to delight. The area of sky around the constellations of Boötes (The Herdsman), Coma Berenices (Berenice’s Hair) and up to Ursa Major (The Great Bear) looks out past our own Milky Way and into the furthest reaches of the universe. Here, you can find a couple of spectacular globular star clusters along with some very attractive galaxies, including a famous face-on spiral galaxy known as the Whirlpool Galaxy. They can be quite hard to find but are…

HEROES OF SPACE Eugene Kranz Failure was not an option when the lives of the Apollo 13 crew were at stake © NASA Spaceflight does not come without risks and no matter how much preparation is made, disasters can happen. Eugene “Gene” Kranz knows this more than most, for as he was sitting in Mission Control, overseeing the Apollo 13 mission, he witnessed a crippling explosion 56 hours in, which put the crew in grave danger. It was 13 April 1970 and a live television broadcast from the craft had just ended. Viewers had been keen to find out more about Jim Lovell, John Swigert and Fred Haise’s journey to the Moon and there was much enthusiasm given that it was to be the third planned lunar landing. Running through…