All About SpaceNo. 85的目錄

Welcome Dark energy: it's the mysterious force that's tearing the universe apart. But, as we explore in this issue, we're slowly but surely beginning to crack one of the biggest mysteries of the universe. What is it? How does it determine the fate of the universe? How will the cosmos actually end – will it be a Big Crunch or a Big Rip? Over on page 16 the astrophysicists have the answers – and precisely where we're at in our unravelling of this invisible portion of the cosmos. Of course, this is the last issue of the year, so it makes sense that we give you a round-up of the events that'll be happening throughout 2019, featuring the best stargazing events, rocket launches and even some brand-new missions on a…

Frozen river from space © NASA/ESA European Space Agency (ESA) astronaut Thomas Pesquet, who was aboard the International Space Station (ISS) for Expedition 50, captured this marvellous landscape of the 2,250 kilometre (1,400 mile) Dnieper River, which flows to the Black Sea from Russia. On 9 February 2017, Pesquet captured this unique winter landscape from an altitude of around 320 kilometres (200 miles) as the ISS travelled around the Earth at high speeds, completing 16 orbits of our home planet in just one day.…

Bon Voyage BepiColombo © ESA The collaborative mission between ESA and the Japan Aerospace Exploration Agency (JAXA) to travel to Mercury, BepiColombo, has recently begun its journey from Europe’s Spaceport in Kourou, French Guiana. At the tip of the Ariane 5 rocket was the spacecraft (inset), now on its way to one of the least-studied planets in the Solar System to take on the dangerous terrain close to the Sun. Reaching Mercury will take the best part of five years after flybys of Earth, Venus and Mercury before it can enter orbit.…

Uncovering ancient superclusters © ESO Astronomers utilised the powerful light-collecting abilities of the European Southern Observatory’s (ESO) Very Large Telescope to find a behemoth cosmic structure that was formed just two billion years after the Big Bang. This proto-supercluster of galaxies has been nicknamed Hyperion and, at an estimated mass of more than one million billion-times that of our Sun, is the 'heaviest' and largest structure to be found at such an incredible distance of 11 billion light years away, dating it at roughly 20 per cent the universe's current age.…

Exoplanet hunter heralds a new era in the search for worlds Deputy director of TESS says much has been learned from Kepler, ensuring discoveries will come quickly The deputy director of a NASA mission that is currently hunting for new planets has heaped praise on the legacy of the much-acclaimed Kepler mission. Massachusetts Institute of Technology (MIT) astronomer Sara Seager says Kepler – which officially came to an end on 30 October – opened scientific eyes to the unexpected, ensuring researchers are better equipped to process the data currently being sent home by the Transiting Exoplanet Survey Satellite (TESS). TESS, which launched back in April, is expected to identify as many as 2,000 to 3,000 new planets over its initial two years of operation by looking for dips in brightness…

Billionaire to fund a bold search for life Yuri Milner is set to fund a private mission to Saturn's sixth-largest moon, Enceladus A privately funded mission to seek faraway alien life looks increasingly likely to get off the ground thanks to backing from a billionaire investor. Breakthrough Initiatives' founder, the Russian-Israeli Yuri Milner, believes private backing for a mission would allow for greater risk taking, and he appears undeterred by costs that could exceed $100 million. Breakthrough Initiatives has already spent huge amounts of money in its search for intelligent creatures outside of Earth and it is also looking into developing a small, laser-sailing spacecraft named StarChip that can travel 4.37 light years away to the Alpha Centauri star system. Milner believes a new mission – which he says will…

Beyond Pluto Where is Ultima Thule? The Sun 1 The influence of our local star falls quickly the further you travel away from it. At the Kuiper Belt it looks like a bright star and provides illumination like dim moonlight. Earth orbit – 150mn km (93mn miles) 2 New Horizons left Earth on 19 January 2006, travelling faster than any spacecraft had previously to go directly into a solar-escape trajectory. Jupiter orbit – 778mn km (483mn miles) 3 The probe passed Jupiter in early 2007, receiving a gravity assist that increased its speed and shortened its flight time by three years. Orbit of Neptune – 4.5bn km (2.8bn miles) 4 Neptune’s ‘trojans’ – small bodies that orbit at the same distance as the planet – were also considered for investigation.…

space events 2019 SPACE EVENTS YOU CAN’T MISS Clear your calendars - these are the stargazing events and mission launches to look forward to next year Written by Nikole Robinson © NASA; ESA As the years pass and science and technology advance we see more and more missions launched that harness these leaps forward to expand our knowledge of space. As we head into 2019 things are no different, with a number of exciting launches planned over the year. This year a rise in commercial launches is highlighted with both unmanned and manned test flights planned by Boeing and SpaceX. Commercial space travel will change the way we explore the universe and lead us down the path of making space more accessible, so its development is imperative. For astronomy fans…

Saturn’s magnetic field What has Cassini told us about the field surrounding Saturn? © NASA/JPL-Caltech; Nicholas Forder; Tobias Roetsch; Axial alignment Cassini’s measurements confirm that Saturn’s magnetic field is curiously well aligned to its axis of rotation. Shaped by the Sun Saturn’s magnetosphere is sculpted into a teardrop shape by interactions with the Sun’s own magnetic field and the solar wind. Radiation belts Weak radiation belts lie just inside and outside the rings – the ring particles and moons tend to soak up the energetic particles that would otherwise create more intense belts. Internal generator The magnetic field is generated by masses of electrically charged fluid rotating inside the planet. Magnetic disc The outer reaches of the magnetic field are flattened into a disc-like structure with a ‘ring current’ flowing…

STARGAZER ESSENTIAL GUIDES AND ADVICE FOR AMATEUR ASTRONOMERS What’s in the sky? Jargon buster Conjunction 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. It is measured in hours, minutes and seconds since, as the Earth rotates on its axis, we see different parts of the sky throughout the night. Declination (Dec) This tells you how high an object will rise in the sky. Like Earth’s latitude, Dec…

STARGAZER Astroshots of the month Paul Swift Spain, Valencia “Having a good background in the arts and working professionally as a cinematographer and lighting cameraman, astrophotography made for a natural change in focus. I had always wanted to turn my camera to the skies - a move away from London to Valencia, Spain, presented me with the perfect opportunity to do just that. The combination of exploring deep space and the creative and technical art form that is astrophotography offered a powerful and alluring vocation. Any clear night I can be found setting up under darkening skies for an evening of photography and, who knows, perhaps a new discovery.” Rob Johnson Liverpool, United Kingdom Telescope: 14-inch Newtonian Reflector “I have been interested in astronomy since I was seven years old,…

Piece of Orion’s puzzle NASA’s Orion spacecraft will become a powerhouse for space exploration in the near future. Pictured here, the European-built Service Module can be seen on its way to Kennedy Space Centre in Florida, United States, from Hamburg, Germany. The European Service Module (ESM) was loaded onto an Antonov An-124 Ruslan aircraft and flown over the Atlantic in preparation for Exploration Mission-1, the first integrated flight test of NASA’s Deep Space Exploration Systems. The ESM in this case will propel, power and cool Orion during flight. ©ESA…

The cosmic cat and the silver spacecraft © NASA/JPL-Caltech NASA’s Spitzer Space Telescope has a canny set of instruments that can view many things in a light invisible to our eyes: infrared emission. Using its powers of heat surveillance, it images the famous nebula NGC 6334 - also known as the Cat’s Paw Nebula. The concentrations of gas in this image are where stars are born, and they illuminate surrounding dust to present the pink-red features. The green frame of the nebula is where the stellar radiation strikes large molecules, known as polycyclic aromatic hydrocarbons.…

The Jolly Roger of nebulae © ESO A celestial pirate lurks in the southern skies, captured here by ESO’s Very Large Telescope. Given the official designation of NGC 2467, this nebula has also been given the nickname of the ‘Skull and Crossbones’ Nebula and was imaged as part of ESO’s Cosmic Gems Programme. The collection of vivid colours is a region of active star formation with gas, dust and young stars all gravitationally bound and forming the sinister outline of a skull with a gaping mouth. It is this beautifully ominous shape that lends the nebula its nickname and has given astronomers a wealth of scientific data from which to make brand new discoveries.…

Earth’s water likely came from the Sun It's thought to have partially formed from the solar nebula as well as from water-laden asteroids Scientists from Arizona State University say Earth's water may have been formed in some small part by the swirling material and gas that was left over from the Sun's formation. According to academic researchers led by Jun Wu, most of Earth's hydrogen was carried by asteroids billions of years ago, but around one per cent of the water molecules on our planet came from the solar nebula as Earth siphoned dust and gas during its newborn, still-molten phase. They came to their conclusion after studying the ratio of hydrogen and a heavier isotope called deuterium, discovering that in the region where the mantle meets the core there…

Dark energy How the universe was shaped by dark forces Dark energy and dark matter have dominated the cosmos at different stages of its evolution The Big Bang The universe started with the Big Bang 13.8 billion years ago, followed by a fast burst of expansion called inflation. The earliest radiation we detect today, the Cosmic Microwave Background, was emitted 380,000 years after the Big Bang. Matter slows expansion The first stars formed from collapsing hydrogen 180 million years after the Big Bang. For a few billion years afterwards, the mass of ordinary matter and dark matter was sufficient enough to slow the expanding universe. The first atoms As the universe cooled from the hot Big Bang, the conditions were right for the first atoms to form – they were…

ASK Space Our experts answer your questions HUNT FOR LIFE Could there be life on Europa? Yes! Europa appears to have all of the ingredients that life requires: water, chemistry and energy. Europa’s ocean is two- to three-times all of Earth’s oceans combined, so liquid water abounds under its icy shell. Europa also appears to have chemical ingredients, seeded from the time that Jupiter and its moons formed or deposited periodically by comets and meteorites. “Europa appears to have all the ingredients that life requires: water, chemistry and energy” Volcanically active Io is also belching its guts out in the Jovian system, and Jupiter’s massive magnetic field helps implant those sulphur-rich ions into the surface of Europa; if these or the other oxidised molecules made by radiation make it into…

Cassini’s final photography Its dive towards Saturn produced a series of spectacular images © NASA/JPL-Caltech; Adrian Mann Cassini’s last view, taken from an altitude of 634,082 kilometres (394,000 miles), shows fine structure in Saturn’s inner rings above its turbulent cloudtops A final close encounter with the giant moon Titan tweaked Cassini’s orbit to send it hurtling into Saturn’s atmosphere Speeding past Saturn’s outer bright A ring, the probe caught a last view of the Keeler Gap, home to the tiny moon Daphnis Commencing its final dive, Cassini sent this stunning picture from high above Saturn’s northern hemisphere…

Exploring a planetary king Exploration of Jupiter has seen much progress – not as much as Earth, Mars or Venus, but it’s a close fourth. If a spacecraft can make it past the asteroid belt beyond Mars, then Jupiter is there to welcome it. Jupiter has been able to act as a valuable gravitational slingshot, also known as a gravity assist, which takes advantage of its intense gravity to alter a spacecraft's speed or path. The king of the Solar System has bestowed gravity assists to many spacecraft that aim to venture to the outer regions of our cosmic backyard, such as NASA’s Pioneer 10 and 11, the two Voyager spacecraft and the New Horizons mission, as well as NASA and the European Space Agency’s (ESA) Ulysses and Cassini-Huygens. The…

STARGAZER This month’s planets The swiftest planet in the Solar System returns to the dawn skies this month – make sure you’re in the right place to see it Planet of the month It seems like an age since Mercury watchers had anything to smile about. The closest planet to the Sun has been hard or impossible to see in the sky for months, either too close to the Sun to be seen or even hidden behind it. But finally this enigmatic, Sun-baked world is on view again, visible in the morning sky as a copper-hued star that is bright enough to be seen easily with the naked eye. At the start of our observing period Mercury will be rising in the southeast at around 6:30am, an hour-and-a-half before the…

How to… Photograph the Geminids With no Moon to spoil things, this 2018's meteor shower could be one of the best in years. Here’s how to see and image it… © Jeff Dai Every mid-December sky-watchers put aside their Christmas wrapping paper and head out into the countryside to watch shooting stars zip across the sky during the annual Geminid meteor shower. It’s one of the year’s most reliable meteor showers, and this year there’ll be no bright Moon to spoil things so we should be in for a real treat. This year’s shower peaks on the night of 13 December, but you’ll see more meteors than usual for a few nights either side of that date. December nights can be very cold, so wear lots of layers and make…

Deep sky challenge What wonders is Orion hiding? The mighty Hunter has a horde of little-known treasures for you to track down and enjoy As 2018 draws to a close nights are often sparkling clear and still, and everyone enjoys setting up their telescope on the frosty grass and gazing in awe and wonder at the green and grey billows and swirls of the Orion Nebula. But Orion has much more to offer than just that 1,400-light-years-distant stellar nursery. In and around it there are more subtle, more challenging wonders to hunt down. This month we will help you point your telescope towards objects famous and obscure. Most observers have heard of the Horsehead Nebula, but few have seen it – we’ll help you. We also have a beautiful double…

STARGAZER Camera advice Altair Astro Hypercam 183C Built to last, this CMOS camera is ideal for those unable to decide on which facets of the universe they’d like to shoot – whether it’s deep sky or the Solar System If you’re an astroimager who is always on the go then Altair Astro’s IMX183 is just the CMOS for you. What’s more, given its ‘single colour camera’ design, its 20 megapixels make it ideal for shooting both the Solar System and deep-sky targets. The camera is light, weighing in at just a third of a kilogram and requires no separate power supply. The Hypercam 183C isn't too involved when setting up - all that's required is downloading and installing a driver package before plugging in the USB 3.0 cable. Before we…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE A colourful encounter between river and sea © Alice Alonso/NC State Snapped by Landsat 8, an Earth-observation satellite that's operated by NASA and the United States Geological Survey, here is a stunning scene where the Gulf of Mexico meets with the Suwannee River. This striking image recently won this year’s Envisioning Research image competition held by North California State University. As water flows through the Suwannee River, it collects organic matter that degrades into a tannic substance that provides the dark colour permeating through the green-blue waters of the Gulf of Mexico.…

Square icebergs, straight ahead © NASA NASA’s Operation IceBridge undergoes airborne surveys of the Earth’s polar ice. In this image, scientists got the chance to investigate the northern Antarctic Peninsula on 16 October 2018 and spotted these unusually rectangular icebergs. This strange icy platform was captured by IceBridge senior support scientist Jeremy Harbeck who was particularly interested in the A68 iceberg, which is the size of the state of Delaware. Harbeck was surprised as he had "never seen an iceberg with two corners at such right angles."…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE Early Earth was ‘most likely’ purple A molecule which appeared before chlorophyll may have given organisms a rather unusual appearance Researchers funded by NASA are suggesting that our planet was once distinctly purple. Scientists say early life forms on Earth used a molecule called retinal to absorb the Sun's rays. Since retinal's pigments absorbed green and yellow light while transmitting red and blue, a purple Earth is believed to have been the result. The conclusion is based on the way that chlorophyll makes use of lower wavelength red and blue light rather than green, which is particularly rich in energy. Shiladitya DasSarma, professor of molecular biology at the University of Maryland, and her co-author Dr Edward Schwieterman, an astrobiologist at the University…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE Spacecraft makes the closest-ever solar approach The probe was exposed to intense heat and solar radiation in a complex solar wind environment, NASA says NASA's Parker Solar Probe has managed to survive a trip which took it closer to the Sun than any spacecraft before it. The vessel got within 24 million kilometres (15 million miles) of the surface of our star while enduring temperatures of some 2 million degrees Celsius (3.6 million degrees Fahrenheit) before indicating to controllers back on Earth that it was safe and still functioning. It's the first time a spacecraft has penetrated the outer atmosphere of the Sun, and it did so at 343,273 kilometres (213,200 miles) per hour at its closest approach – setting a speed…

Dark energy SHEDDING LIGHT ON DARK ENERGY Two decades after its postulation, dark energy still provokes more questions than answers - but we could just be making some headway in understanding it Reported by Graham Southorn © Tobias Roetsch Two decades ago, astronomers studying distant stars made a dramatic discovery. They were investigating the future of the universe, which was known to be expanding. Contrary to all expectations they discovered that the rate of expansion was actually speeding up – the universe was getting bigger, and faster. Today the focus is on finding the cause of this unexplained phenomenon, which has been given a suitably mysterious moniker: ‘dark energy’. The discovery that the universe was expanding ever faster came as a huge surprise. In fact, it was so significant that…

Big Crunch or Big Rip? How will the universe end? It depends on the nature of dark energy The universe with a cosmological constant We live 13.8 billion years after the universe started with a Big Bang. If the accelerating expansion we see today is caused by a cosmological constant, galaxies will grow increasingly further apart. The Big Rip Some scientists have suggested that a kind of dark energy called phantom energy is at work. This would make the expansion accelerate so much that it rips the universe apart faster than the speed of light. The Big Crunch Current observations suggest that the universe will carry on expanding. But what if dark energy grows less powerful in future, or becomes attractive? The universe could come back together in a Big…

Beyond Pluto BEYOND PLUTO As NASA’s New Horizons probe nears its second target, we investigate what’s lurking at the edge of the Solar System Reported by Ian Evenden © Adrian Mann The constellation of Sagittarius, the Archer, is a common sight in the winter sky, easily recognisable by the ‘teapot’ asterism that makes up its front half. Look in the Archer’s direction and you’re staring into the centre of the galaxy, the Milky Way contributing the ‘steam’ from the teapot’s spout. With a home telescope you might see the Lagoon Nebula within Sagittarius, or a globular cluster such as Messier 54. If you have access to billions of dollars’ worth of space telescope, however, you may discover other much smaller and fainter things. This is just what happened in 2014…

Reusable lunar lander THE REUSABLE LUNAR LANDER Lockheed Martin has announced a new single-stage design that would work well with NASA’s Lunar Gateway © Adrian Man © n NASA; Space sustainability is forever in the minds of scientists and engineers alike, and they are working together to improve the feasibility of numerous lunar trips. Space exploration has shown we are capable of taking man to the Moon and landing on it successfully. It has also revealed that it is possible to build and maintain a space station. When you combine this knowledge and extrapolate its capabilities for the future you get NASA’s proposed Lunar Gateway, which will advance human’s attendance in space, particularly within the vicinity of the Moon. A recent announcement was made at the 69th International Astronautical Congress…

Results from Cassini GRAND FINALE: THE RESULTS BRAND NEW DISCOVERIES AT SATURN Cassini may have plunged to destruction, but scientists are continuing to unravel some surprising findings from its final days Reported by Giles Sparrow © Dimitar Todorov / Alamy Stock Photo; Adrian Mann In more than 13 years orbiting the beautiful ringed planet the Cassini space probe transformed our understanding of both Saturn and its moons. When it disappeared for the last time into the gas giant’s upper atmosphere in September 2017 it marked the end of a remarkable and hugely successful mission. But while Cassini is gone, it’s certainly not forgotten; mission scientists are still sifting through the wealth of data it sent back, particularly during the ten-month ‘Grand Finale’ – a series of daredevil loops that…

Jupiter Planet Profile Jupiter The Solar System's planetary king is a complex world riddled with unanswered questions © NASA/JPL-Caltech “It is physically impossible to delve into the interior of Jupiter to reveal its true composition” The most well-known fact about Jupiter is that it is the largest planet in the Solar System - but its sheer size, which sees it stretch roughly 143,000 kilometres (89,000 miles) at the equator - doesn’t even allow astronomers to scratch the surface of the gas giant’s complexity. Even after much exploration of Jupiter thanks to missions from NASA and ESA, it still remains one mysterious ball of gas. It is physically impossible to delve into the interior of Jupiter to reveal its true composition; even a carefully designed human-made spacecraft would perish in its…

Moon tour Taurus-Littrow valley Visit the historic landing site of the final Apollo mission to the Moon © NASA On 11 December 1972 – incredibly almost half a century ago – the sixth and final Apollo landing took place when the lunar module Challenger, with astronauts Harrison Schmitt and Gene Cernan onboard, set down on the surface of the Moon. It was a bittersweet occasion for thousands involved in the Apollo program and for millions of people around the world; after the incredible success of Armstrong and Aldrin’s Apollo 11 mission, which saw the world holding its breath and then erupting with joy as the first boots stepped onto the dusty surface, the Apollo program had been cut short, and missions scheduled to follow Apollo 17 had been cancelled. After…

How to… Track Comet 46P/Wirtanen Fingers crossed, this month there might be a comet in the winter sky bright enough to be seen with just the naked eye Now, no promises, but at the time of writing it looks like there might be a comet in the December sky that will be bright enough to see with the naked eye. If our predictions are accurate this comet could be visible as a small smudge to your naked eye. If not then it should still be found fairly easily with a pair of binoculars or a small telescope. It’s a long time since we had a comet in our sky that was easily visible to the naked eye, at least up in the Northern Hemisphere. While it seems like southern observers…