Indholdsfortegnelse for No. 56 i All About Space

Discover the wonders of the universe Gemma Lavender Editor @ ESO; M. Kornmesser Just as we were going to print, the European Southern Observatory made an announcement that sent shock waves through the scientific community – and let’s be honest, the All About Space office, too. A planet, 1.3 times the mass of Earth, has been found around our nearest star. What’s more, the world, known as Proxima Centauri b, is in the habitable zone of its red dwarf, meaning that it could quite possibly hold liquid water on its rocky surface. This issue, we catch up with the team of astronomers who made the ground-breaking discovery. Turn to page 28 for the full details. The exciting news doesn’t stop there – this month, Matt Taylor of ESA’s Rosetta mission…

Reader Survey Four changes you asked for in 2015… Last year we used your input to make some fantastic improvements, including… 1 Bigger & better astronomy section Many of you are keen astronomers, so we made a brand new guide for all of your stargazing needs. 2 “How to...” astronomy tutorials We wanted to take you to the next level in your hobby, so we’ve provided comprehensive guides. 3 More in-depth reviews We test the latest astronomy kit, so you make the right choice when purchasing your telescopes and accessories. 4 Your space questions answered – even better! We restyled our Q&A section by packing it with infographics to answer your questions with impact.…

Ancient Venus was habitable and had liquid oceans New research suggests Earth’s evil twin had comfortable conditions for 2 billion years Venus roasts at 460 degrees Celsius (860 degrees Fahrenheit), has a carbon dioxide atmosphere and it lacks water. But for 2 billion years of its early life, it is likely to have been habitable with a shallow liquid water ocean, according to NASA’s Goddard Institute for Space Studies (GISS), New York. Using computer climate models to simulate the conditions of early Venus, and by hypothesising an atmosphere similar to Earth and adding radar measurements taken by the 1990s NASA Magellan mission, researchers have created a hypothetical glimpse of the past. Since the ancient Sun was 30 per cent dimmer, the study has showed Venus was once blessed with a…

How much it costs to land on a comet €1.4bn Rosetta The ESA mission has allowed us to land on the surface of a comet for the very first time in human history, when its Philae lander touched down on Comet 67P/Churyumov-Gerasimenko. 3.5 Space Shuttles The partially reusable low-Earth orbital craft cost €400 million ($450 million) each. European citizens Each person who was part of the European Union paid a small amount to the mission between 1996 and 2015, which equates to €0.20 per person per year.…

Exoplanet discoveries with the radial velocity method The way a planet tugs on its star has enabled a gaggle of alien worlds to be found 51 Pegasi b Orbital period: 4.23 days Mass: 0.5 Jupiters Type of planet: Gas giant The first planet discovered orbiting a Sun-like star in 1995 HD 209458 b Orbital period: 3.52 days Mass: 0.7 Jupiters Type of planet: Gas giant Discovered using radial velocity, it was later found to transit its star Epsilon Eridani b Orbital period: c.2,500 days Mass: 1.6 Jupiters Type of planet: Gas giant First suspected in the 1990s, its orbit overlaps an asteroid belt 55 Cancri e Orbital period: 18 hours Mass: 3.8 Jupiters (8 Earths) Type of planet: Super-Earth This was one of the first ‘Super-Earths’ to be found Iota…

Why we’re going to asteroid Bennu It's very mysterious right now but Bennu holds the key to many exciting future breakthroughs It could fuel future space missions There is a good chance that Bennu will contain a fuel source, pointing to the possibility of spacecraft using asteroids to 'gas-up', letting them travel much further in the future. Companies are seeking to mine it With its rich source of minerals, there is a clamour among companies and governments to take advantage of the resources that asteroids have to offer, and they’ll be keenly watching. There’s an opportunity to practise manoeuvres Bennu will allow scientists to practise navigating a craft around an asteroid. Since the gravity is low and there’s pressure from sunlight, it will provide ample teaching material for engineers. It…

SPACE EXPLORATION What are sounding rockets used for? Rayna Nash Sounding rockets are often used to bridge the gap between weather balloons at 40 kilometres (25 miles) and satellites at 120 kilometres (75 miles) altitude. Sounding rockets provide an easy route into the upper atmosphere, which enables studies to be carried out there. This can be very difficult using other technology, as most technology will not reach that high and the vehicles that do are often designed to go further or carry bigger payloads, and are subsequently much more expensive. Sounding rockets are not only featured in upper atmosphere research, but they are often used in microgravity experiments as their flight paths cause a few minutes of weightlessness onboard. As they can fly above the majority of the atmosphere, they…

SPACE EXPLORATION Do you need to work for an aerospace company to build a rocket? Darran James Technically, anyone can build a rocket, providing they have the knowledge and the funds. That being said, working for an organisation often makes that a little bit easier. But these organisations don’t have to be companies. For example, Space Agencies such as NASA, ESA, and JAXA are not really private companies, but will often design and build rockets. On top of the resources and logistical costs of a rocket, the technology can often be subjected to regulations. Due to the connection to weaponry, if a private individual or organisation started building rockets it may raise a few questions. It could also be argued that, as aerospace is defined as the branch of technology…

DEEP SPACE Why do we think binary code is a good means of communication with alien life? Dan Brown We believe that out of all of our communication methods, binary may be the one that requires the least interpretation. Using a language like English or Chinese or any other requires an understanding of characters, how we join those to make words, intention and meaning of words, context and many other facets to understand. Even native speakers of a language can often misinterpret what someone is saying. The thought behind binary is that it is the simplest form of communication we have. We also believe it is a form that evolves fairly naturally based on an understanding of mathematics and, as such, we hope this would mean that it is universal.…

SOLAR SYSTEM How are comets classified? There are more than 5,000 known 'dirty snowballs' knocking about the Solar System, all of which fit into a selection of categories Georgia Sackville Comets are best known for their tails, and their name actually comes from ancient Greek for “long-haired”. The largest ones are a bright presence in the night sky for a month or so as they make their closest approach to the Sun. They are icy bodies, dirty snowballs of water ice mixed with rock, dust, and frozen gases like carbon dioxide. The tail appears when the comet approaches the Sun and the surface layers turn to gas. This is then pushed away by the solar wind; it is mostly water and dust, though these can separate into two tails as…

Tycho crater Find one of the Moon’s most famous craters, 48 years after it was immortalised in a classic science-fiction film… © NASA Whichever way you look at the full Moon – with the naked eye or through binoculars or a telescope – all you’ll see are areas of light and dark. That’s because at full Moon, with the Sun blazing overhead, features on the lunar surface cast no shadows and show no surface relief. The rugged lunar highlands are splashes of white, and the lower, lava-filled 'seas' are patches of blue-grey. But around full Moon is actually a great time for beginners to find what many people consider the most famous lunar crater: Tycho. Tycho was named after the famous – or infamous – 16th century Danish astronomer Tycho…

Snapping star clusters Beneath the beautiful southern constellations, Ignacio Diaz Bobillo specialises in imaging distant nebulae and glittering star clusters Has astrophotography always interested you? I became interested in my early youth. I started with visual astronomy, using a small Newtonian telescope, but was soon intrigued by the possibilities of astrophotography and started with wide-field imaging using a telephoto lens. These were the days of film photography, and I had to venture into chemical developing. It was fun. Things have certainly moved on since then! Can you tell us about the equipment you use now? For the last six years I have used the same OTA, a 5-inch (127mm) Astro-Physics apochromatic refractor (AP 130 GT). It is a great telescope for astrophotography, as it is very versatile and can be…

The Northern Hemisphere The longer nights are now upon us, leaving astronomers to enjoy both Solar System and deep-sky objects © Wil Tirion; NASA; STScl; ESO; PESSTO; S. Smartt The constellations that are most common in the autumn skies are starting to wheel into view, offering a wonderful selection of galaxies, open and globular star clusters, as well as Mars, Saturn, Uranus and Neptune for those with binoculars and telescopes. The Great Globular Cluster in Hercules (M13) and Messier 56 in Lyra (The Harp), as well as open cluster IC 4665 in Ophiuchus (The Serpent Bearer) are splendid evening targets. If you’re keen to stay up into the early hours of the morning, then you’ll be rewarded as Taurus’ Pleiades star cluster (M45) and galaxies such as the Andromeda Galaxy…

Contributors Giles Sparrow Hot on the trail of the newfound world around Proxima Centauri, Giles gets the full details from the discoverers of the super-Earth, Proxima b, which could even host liquid water. Matt Taylor & the Rosetta team Rosetta project scientist Matt Taylor and his team report exclusively on the results from the comet chaser this issue - as the mission comes to an end. David Crookes Now that NASA’s asteroid sample return mission, OSIRIS-REx, is well on its way to asteroid Bennu, David uncovers how the mission will work out how life originated on Earth. Stuart Atkinson Stuart gets the details on how to create award-winning shots from none other than the winners of Astronomy Photographer of the Year. “We’ve found evidence of a planet with an orbital…

Rosetta’s journey From Earth to Comet 67P, the mission’s flight path broke records 150mn kilometres March 2004 On board an Ariane-5 rocket, the Rosetta spacecraft and the Philae lander launch from Guiana Space Centre in French Guiana. 319mn kilometres September 2008 Rosetta makes a flyby of asteroid 2867 Šteins after flying past Mars and entering the asteroid belt. The mission characterises the surface of the space rock during the seven-minute flyby. 410mn kilometres July 2010 Rosetta characterises asteroid Lutetia by flying within 3,162km (1,965mi) of it. The craft captures several stunning photos, revealing its irregular shape and heavily cratered surface. 671mn kilometres July 2011 Just over three years away from Comet 67P, the European Space Agency places Rosetta into a deep space hibernation mode. This is to save energy during…

Rosetta solves a mystery How a comet from the early Solar System is made Surface features and its ‘duck-shaped’ structure not only tell us how Comet 67P took shape but conditions during the early Solar System Elevated areas Bumps and higher regions on the surface of the comet, or spherical caps on the Bastet region on the smaller comet lobe, suggests that they are the remnants of smaller cometesimals, which built up Comet 67P and have been partially preserved today. Ejected dust and high porosity The nucleus and ejected dust consist of mostly porous material, an indication of low-speed accretion. This suggests comets didn’t form during the rapid initial growth of the trans-Neptunian objects (TNOs), as violent collisions would have compacted the material. However, TNOs may have assisted accretion by…

How close is the Alpha Centauri system? Our nearest neighbours in space form a triple star system whose other members dwarf Proxima Centauri What if Alpha Centauri was our Sun? If Alpha Centauri were at the centre of our Solar System, Proxima Centauri would lie further out than Neptune Sizing up our stellar neighbours The Sun Mass: 330,000 Earths Radius: 109 Earths Type of star: G2V yellow dwarf The Sun is a middle-aged star whose mass is tiny compared to the galaxy’s heaviest stars. Alpha Centauri A Mass: 1.10 Suns Radius: 1.23 Suns Type of star: G2V yellow dwarf With slightly more mass than our own Sun, Alpha Centauri A shines 50 per cent more brightly and is somewhat larger. Alpha Centauri B Mass: 0.91 Suns Radius: 0.87 Suns Type…

The Milky Way in numbers 120,000 Estimated diameter of our galaxy in light years – though outlying regions may stretch this to 180,000 light years 6.25 light hours Maximum diameter of central region containing 4mn solar masses of material – roughly the same size as the orbit of Uranus 13.7bn years Age of the oldest known star in a Milky Way globular cluster – thought to be significantly older than the galaxy itself! 40bn Estimated number of Earth-like planets orbiting in the habitable zones of stars in the Milky Way 550km/s Speed of the Milky Way’s motion through space, relative to surrounding galaxies 700 billion Suns Estimated total mass of the Milky Way, including stars, gas and unseen dark matter 88 per cent Estimated contribution of dark matter to the…

Mission manoeuvres 1 We have lift-off Atlas V launched OSIRIS-REx on 8 September 2016 from Cape Canaveral, Florida. OSIRIS-REx measures 6.2m (20.3ft) across, with solar arrays of 8.5m2 (91ft2). 2 On its way OSIRIS-REx will perform Deep Space Manoeuvres that will change its hyperbolic escape velocity of 5.4km/s (3.4mi/s) by a further 0.52km/s (0.32mi/s). 3 Gravity assist The spacecraft spends a year orbiting the Sun and it then uses the Earth for a gravity assist, taking the required energy needed to throw it into space. 4 Playing catch-up The craft has to rendezvous with Bennu. To do that it needs to catch up and then match Bennu’s velocity so that it joins the asteroid in its solar orbit. 5 Slowing down Once it reaches the critical moment, OSIRIS-REx will perform…

SOLAR SYSTEM If water didn’t form the gullies on Mars, then what did? Kenneth Scarlett The subject of water on Mars is a very hot topic at the moment. Initially, it was thought that these gullies were created by water, adding credit to the existence of liquid water on Mars. But recent studies have shown that, although the gullies look like those carved by water on Earth, the materials found in them don’t seem to be consistent with water being present at some point before. This seems contrary to the presence of the gullies in the first place. The most popular theory at the moment is that the gullies were caused by carbon dioxide ice, which is found on the surface. However, these theories are still unconfirmed. Hopefully, as we…

SOLAR SYSTEM What are the chances of a meteorite hitting a person? Meteor showers Meteor showers occur at the same time every year when the Earth passes through a region that has a large concentration of debris, shed from either a comet or an asteroid. From our location on Earth, meteors appear to originate from the same location year after year. Bolide Bolides are not too dissimilar to fireballs, however, their brightness is likened to that of a full Moon and even brighter than that. Bolides often explode in the planet’s atmosphere. Comet These bodies are made of ice, rock, dust and frozen gases. Comets have a nucleus and show off a brilliant tail when they get closer to the Sun. As they fracture and disintegrate, some comets leave a…

This month’s naked eye targets Early autumn skies contain some of the most wonderful sights of the year The Circlet asterism Pisces is quite large and faint, but the Circlet asterism is easily recognisable, helping you to find the rest of the constellation. Alpheratz This star is also known as Alpha Andromedae and marks the boundary between constellations Andromeda and Pegasus. Andromeda Galaxy (M31) The furthest object you can see with the naked eye, you can just about make it out as a misty patch from a dark sky site. The Square of Pegasus The four stars of this famous formation are easy to find as they are fairly high in the south at this time of year. Equuleus One of the smallest constellations in the night sky, Equuleus can…

Photographing Earth and space From his location in the Southern Hemisphere, Mark Gee captures stunning skyscapes that combine the beauty of the Earth and the night sky When did you begin photographing the sky? It wasn’t until I moved to Wellington, New Zealand, 13 years ago that I discovered astrophotography. I remember going to a remote seaside village and seeing the galactic centre of the Milky Way for the first time. I could hardly believe it was real and I spent the rest of that night looking up at the sky being totally blown away by how many stars I could see. I decided that I had to learn how to photograph what I saw that night. Can you tell us about your prize-winning photo? I photographed it in the…

“I didn’t have time to move. I had to take the picture from where I stood” Overall winner of Astronomy Photographer of Year’s Aurorae category in 2015, Percy from Australia headed over to Abisko National Park in Lapland, Sweden, to take his prize-winning shot. Using a Canon EOS 5D Mark III camera with a 24mm f/1.4 lens at ISO 2000 and using a four-second exposure, he recalls the moment he captured the Swedish Silk Skies: “After waiting many hours on top of the mountain for the aurora, I finally gave up and decided to call it a night. I packed up my gear and began to walk back. As I stumbled down the hill, I noticed the snow reflecting a green glow (you can see my footprints on the left).…

Me & My Telescope Send your astrophotography images to photos@spaceanswers.com for a chance to see them featured in All About Space Phil Howarth Dorset, UK “Recently, I’ve had an explosion of creativity and passion with capturing fragments of the night sky above us. With the spectacular Perseid meteor shower and perfect conditions for observing the night sky, I’ve been up late most nights to take in the views. Combining my interests in photography and astronomy has been a steep learning curve but experiencing the silence, solitude and breathtaking views has sparked a new chapter in my photographic journey.” Warren Keller West Virginia, USA Telescope: 16” RCOS Ritchey-Chrétien owned by the University of North Carolina “I’m an advanced astrophotographer and teacher and have been published as an author and photographer in…

New research suggests discovery of fifth force of the universe Possible finding could lead to a better understanding of dark matter  Scientists have long known about the four fundamental forces of nature but now it appears that there may well be a fifth force. According to theoretical physicists at the University of California in the US, evidence is pointing to the existence of a previously unknown, force-carrying subatomic particle – a particle that only interacts at short distances with electrons and neutrons. “There’s no other boson that we’ve observed that has this same characteristic" Researchers are dubbing this the ‘X boson’ and it is set to be revolutionary if proven. It would not only join the ranks of gravity, electromagnetism and the strong and weak nuclear forces, it could also…

News in Brief Probing empty space unveils dark energy Astronomers are looking at the empty spaces in between the universe’s visible matter as they seek evidence to test Einstein’s theory of relativity. They are searching for small deviations in the behaviour of invisible dark energy. “It’s easier to pick up on effects in the voids, where there is less distraction,” says Paul Sutter, researcher at the Ohio State University, US. Alien world secrets revealed by ‘failed stars’ Brown dwarfs are diverse with varying temperatures, different ages and dissimilar compositions. They also provide a natural link between astronomy and planetary science. A team led by the Carnegie Institution for Science, Washington DC, has been looking at these variables, discovering that the dwarfs’ atmospheric conditions may be behind many of their differences.…

‘Alien megastructure’ star exhibits more strange behaviour Tabby’s Star just keeps getting dimmer and dimmer © NASA; ESA; D. Coe; N. Benitez; T. Broadhurst; H. Ford; JPL-Caltech; Dana Berry; Skyworks Digita; CfA When NASA’s Kepler mission focused on the star KIC 8462852 (Tabby’s Star), its erratic flickering at 12,875 trillion kilometres (8,000 trillion miles) away startled astronomers. The star was seen to dim by over 20 per cent, which was at odds with normal stars. Since then, astronomers have sought an explanation. Could it be clouds of dust or a swarm of comets? Or could it be an alien megastructure aimed at collecting solar energy? The latter is unlikely, but it makes a good headline! The latest findings suggest that during the four years of Kepler’s mission, Tabby has lost…

Galactic weather The space in between stars is far from empty and because of this, the Milky Way has its own weather, of a sort. Stellar winds blow charged particles out from the surface of stars, which ultimately merge together to form a slow-moving interstellar medium. Cosmic rays are faster-moving particles that zip back and forth across space. Some cosmic rays originate in exploding supernovae, while others are accelerated by the intense magnetic fields that are found around neutron stars and black holes.…

YOUR QUESTIONS ANSWERED BY OUR EXPERTS In proud association with the National Space Centre www.spacecentre.co.uk Sophie Allan National Space Academy Education Officer Sophie studied astrophysics at university. She has a special interest in astrobiology and planetary science. Josh Barker Education Team Presenter Having earned a master’s in physics and astrophysics, Josh continues to pursue his interest in space at the National Space Centre. Gemma Lavender Editor Gemma holds a master's degree in astrophysics, is a Fellow of the Royal Astronomical Society and an Associate Member of the Institute of Physics. Robin Hague Science Writer Robin has a degree in physics with space technology and a master's in hybrid rocket engine design. He contributes regularly to All About Space. Tamela Maciel Space Communications Manager Tamela has a degree in astrophysics and…

DEEP SPACE If the Milky Way didn’t form, then would we still be here? Pam Lawrence This depends entirely on why the Milky Way didn’t form. If the Milky Way didn’t form due to a lack of material, gases and dust, then no, we would not be here. Generally, our understanding of galaxy formation is that it is the result of a huge cloud of material slowly being influenced by its own internal gravity. This pulls the clouds into the shapes and patterns we see. With a total absence of material, a galaxy would never form and we would not be here either. If the primordial Milky Way had the material but ended up forming in a different way, which resulted in a different structure, the answer is a little…

ASTRONOMY Why can I still see the Sun just before sunrise and just after sunset? The bizarre effect of seeing the Sun just before sunrise and just after sunset comes down to the fact the Earth has an atmosphere. If you closely watch the horizon around these times we can see this effect, and at its maximum, we can see the Sun for up to two minutes before or after we should be able to see it. The reason for this is something that we call refraction. As light moves through any sort of material, its speed and therefore its path can sometimes be altered. Think of how a straw looks bent when it is put into a glass of water. As the light passes through the Earth’s thick atmosphere…

ASTRONOMY What is meant by ‘aperture fever’? Christopher Hurt ‘Aperture fever’ is a term used in amateur astronomy circles. It refers to the desire to get bigger and better observing equipment. Many people recommend that anyone wishing to get into stargazing should begin with a small pair of binoculars. This enables you to see a little more than you can with the naked eye and offers a good starting point from which to progress. In astronomy, aperture refers to the size of the hole that light enters through. Generally speaking, as the aperture of the telescope gets bigger, you can see fainter and fainter objects in increasing detail. Aperture fever is used to refer to people who want to keep increasing the aperture of their equipment to get better and…

Jargon buster Conjunction This 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. Greatest elongation When the inner planets, Mercury and Venus, are at their maximum distance from the Sun. During greatest elongation, the inner planets can be observed as evening stars at greatest…

Chasing the Northern Lights James Woodend takes spectacular shots of the Aurora Borealis. How does he do it? What’s the background story behind your award-winning photograph? The image was taken at Jökulsárlón, South Iceland, at 1.42am on 9 January 2014. I had visited the ice lagoon at Jökulsárlón on several occasions – I knew exactly the location to take a good reflection photograph of an aurora but the conditions had always prevented me from getting the image I wanted. During January 2014, the lagoon was free from a covering of surface ice (rare in winter) and with no wind to ripple the surface, all I needed was a touch of moonlight, clear skies and an aurora to get the shot. The night in question was cloudy but there was a…

Shoot a penumbral lunar eclipse Running a few test shots beforehand will ensure great images on the night… To ensure that you get really good images at the time of the eclipse, take some test images with your camera on the evening before the event. This will give you an idea as to what settings to use regarding exposure time and the focal length of the lens or the setting on your zoom lens. Good focus is really important, so use your view screen at maximum magnification to make sure that your focus is as sharp as it can be. Don’t make the image too bright. It’s better to slightly under-expose than overdo it! 1 Pick your observing site Check the time of Moonrise as well as the maximum eclipse.…