Indholdsfortegnelse for No. 42 i All About Space

Rosetta comet has sinkhole jets ESA probe reveals dust jets that shed light on the diverse interiors of comets and meteorites Over a year into its study of Comet 67P/Churyumov-Gerasimenko, the ESA craft has finally discovered a series of active pits that are responsible for spewing clouds of dust and gas into space. Rosetta initially identified the remains of these jets floating around the comet, but thanks to some hi-res images taken from Rosetta’s on-board OSIRIS imager, scientists are now able to study the source of these high-powered jets. Located in the northern hemisphere of the comet, these pits range from a few tens to a few hundreds of metres in diameter and can extend up to 210 metres (688 feet) below the surface. So far, 18 pits have been…

Mission control The team pauses to celebrate as New Horizons returns historic images of Pluto Randy Gladstone Atmospheres theme team Randy Gladstone is an atmosphere expert. He is leading the team investigating the gases that surround Pluto, and is part of the team in control of the ultraviolet light-detecting Alice instrument. John Spencer Imaging team leader John Spencer is the resident geology expert of the team. His job is to interpret and report on the images captured by New Horizons’ on-board cameras, giving meaning to the landscape. Alan Stern Principal investigator Alan Stern is the principal investigator in charge of the New Horizons mission. His research career has focused on the outer Solar System and he still thinks of Pluto as a planet. Kimberly Ennico Deputy project scientist Kimberly Ennico…

Comets, asteroids & METEOR SHOWERS Racing through space and crashing into Earth’s atmosphere, All About Space discovers the space rocks that litter our Solar System Written by Gemma Lavender Every 133 years a comet that goes by the name of Swift-Tuttle makes its return to the inner Solar System. It last made an appearance 15 years ago. Each time it nears the Sun this speeding ball of ice, rock and dust grows a tail that deposits a glittering trail in its wake, replenishing it on each visit. Every year, our very own planet moves through this cloud, causing those dust particles to come crashing through the atmosphere. Most of them are tiny, just centimetres or even millimetres across, but as they burn up 100 kilometres (60 miles) above our heads…

Atomic Deep Space Clock To navigate the Solar System we will need razor-sharp timing. To that end, NASA’s super-accurate clock is designed for deep-space missions © Adrian Mann Iridium NEXT satellite A demonstration unit of the DSAC will be hosted on board an Iridium NEXT satellite; these are the second generation of satellites for the Iridium satellite phone system. Signal comparison Ground stations around the world will take measurements of the speed and position of the same GPS satellites and compare them to the DSAC. Small-scale A fraction of the size of its lab-based counterparts, the DSAC will be just 0.0056m3 (0.2ft3 ). It is smaller, lighter and more stable than any other atomic clock in space. Titanium vacuum case The DSAC is housed inside a vacuum case made of…

DEEP SPACE How many different types of black hole are there? Stephanie Wilkins Black holes come in many sizes, of which we choose to break down into three main types. These three flavours of black hole are determined by their method of formation and by extension, their initial size. The largest of these exotic objects are known as supermassive black holes, which are thought to be found at the centre of all galaxies. Although scientists aren’t completely sure of how they come to be, they believe that supermassive black holes are made as a part of galaxy formation. Stellar black holes, on the other hand, are made when a massive star dies. These stars must have a mass greater than around 20 solar masses in order that a black hole…

SOLAR SYSTEM What would happen if the Earth had three moons? Luke Swallow More than one moon would have some interesting effects on the Earth. If another two moons appeared tomorrow, we would be in for a rough week or two, with a newly captured body having huge effects on tides and potentially on volcanic activity as well. After that had all settled, the biggest effect of these moons would be on the tides. High and low tide would probably be more extreme: we may not have the regular cycle we have now as the water is affected by the gravity from the additional extraterrestrial bodies. If we had additional moons, we would have brighter nights too, which would affect the hunting patterns of nocturnal creatures. We would not expect…

SPACE EXPLORATION Have any studies on human health been achieved in space? Timothy Small Yes. Many technologies developed in space or through the space programme have been fruitful, resulting in some major breakthroughs including those in the fight against cancer. It’s thanks to low gravity as well as an environment with increased radiation that allows for the unique studies of the human body and its cells. Materials and machines developed through the space programme are often developed and used for biomedical purposes with examples such as synthetic bone and ligament materials being constructed. NASA funds several programmes that are steadily working towards understanding the causes of life-threatening diseases, such as cancer, and what we can do to fight it in the form of research that has been conducted both on…

SPACE EXPLORATION Can we use the hydrogen and oxygen found in space to make water? Sabrina Azombo While it is possible to make water from the hydrogen and oxygen atoms found in space in theory, actually doing it in practice is extremely difficult. To make water from hydrogen and oxygen atoms is a slow process under ‘normal’ temperatures. So, to speed things up, you need a catalyst – for example, lighting the pair. However, making water this way requires energy, which can be costly. A second problem is that when the reaction is kickstarted, a huge blast is created, which can be dangerous. Even if you found a way around these problems, bringing the hydrogen and oxygen to Earth would be complicated. Getting enough atoms would result in a heavy…

SPACE EXPLORATION Do astronauts play musical instruments in space? Henry Jamieson Yes, they do. In fact it’s a favourite pastime on the International Space Station. Canadian astronaut Commander Chris Hadfield, for example, has become quite well known for videos that he has recorded singing and playing a guitar on the Earth-orbit habitat. Other astronauts have also been known to play the trumpet. While playing a musical instrument is fine on the International Space Station in microgravity, playing one actually on a spacewalk would be a different experience since sound waves need to travel through air. For example, while the strings of a violin would vibrate properly, the near-vacuum of space would prohibit it from producing any sound. GL…

The phases of the Moon Waning gibbous Percentage viewable: 51-99% Number of days old: 16›21 Full Moon Percentage viewable: 100% Number of days old: 14 to 15 Waxing gibbous Percentage viewable: 51›99% Number of days old: 9›13 First quarter Percentage viewable: 50% Number of days old: 7›8 Waxing crescent Percentage viewable: 1›49% Number of days old: 1›6 New Moon Percentage viewable: 0% Number of days old: 0 Waning crescent Percentage viewable: 1›49% Number of days old: 23›29 Last quarter Percentage viewable: 50% Number of days old: 22…

How to view Neptune Grab this chance to see the outermost planet of our Solar System at its best On 1 September, Neptune reaches opposition. This means that it is directly opposite the Sun in our skies, so rises when the Sun sets and sets when the Sun rises. It also means that we are closer to it in our relative orbits, which in turn means it appears larger to us than at other times. However, it is the most distant planet in the Solar System and this increase in apparent size is therefore really quite small, at only two tenths of an arcsecond! Its distance from the Earth, at some 4.5 billion kilometres (2.8 billion miles), means that Neptune is very faint and cannot be seen with the naked…

Charles Messier The comet hunter who laid the foundations of modern stargazing Born in 1730 in Badonviller, France, Charles Messier was the tenth child of Nicolas Messier, a reasonably wealthy man who served the Princes of Salm. Sadly, six of Messier’s siblings died early in their lives and when Messier was aged just 11 his father tragically passed away. When he was only 14 Messier witnessed a great six-tailed comet race across the sky. The stunning sight prompted a fascination with the night sky and the phenomena it held. This interest was further spurred by an annular solar eclipse four years later. This avid curiosity was far from the administrative and methodical work his brother had been training him in, but Messier would find a way to combine his talents…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE First-ever photo of Earth from the Moon Photos of the Earth from lunar orbit might have been made famous by the Apollo 8 mission’s ‘Earthrise’, but astronaut William Anders’ iconic photo certainly wasn’t the first of its kind. A machine got there first – the unmanned Lunar Orbiter I, to be precise, which took this black-and-white photo of Earth from the far side of the Moon in 1966. Young at heart At the far-flung reaches of the Milky Way lies this star cluster, designated NGC 2367, found at the centre of an otherwise ancient and much larger group of stars that form a structure spanning hundreds of light years. At about 5 million years old, it’s a young cluster and each of…

Hubble glimpses distant galactic nursery A hyperactive dwarf galaxy is revealed outside the Milky Way This dramatic shot, captured by the Hubble Space Telescope last month, shows the infant dwarf galaxy NGC 1140 as it continues to produce new stars at an incredible rate. Located around 60 million light years away in the constellation of Eridanus, this miniature galaxy (which is ten times smaller than the Milky Way) has been fascinating astronomers ever since it was first discovered in 1785 by German-born British astronomer William Herschel. NGC 1140 also has an unusually irregular form for a galaxy of its size (much like the Large Magellanic Cloud located just outside the Milky Way). That irregularity is a by-product of the hyperactive nature of its composition, which is producing stars at a…

Pulsar bursts through stellar disc Astronomers witness a phenomenally powerful cosmic collision Astronomers behind the Chandra X-ray Observatory at Cape Canaveral captured an incredible stellar event recently – the moment a cloud of gas around a giant star was punctured by an energetic pulsar. The colossal collision took place in the double star system PSR B1259-63/ LS 2883, roughly 7,500 light years from Earth, which contains a giant star that’s 30 times bigger than our own Sun and a fast-moving, spinning pulsar travelling at 65 million kilometres (40 million miles) per hour. The impact was due to the rapid rotation of the pulsar (which spins 20 times a second) and its intense magnetic field, which brought its highly elliptical orbit into a path with the star’s gaseous disc. “These two…

Pluto has a heart What we knew Before New Horizons, our best images of Pluto were still a fuzzy blur, not even the Hubble Space Telescope could improve them much. All we knew was that it was reddish in colour, and that the blotchy patterns on its surface changed over time. What we now know The dwarf planet is much loved, and when New Horizons sped towards its closest approach, many people were delighted when it snapped images revealing that Pluto has a heart. The bright feature, found just above the equator, measures around 1,600km (1,000mi) across. Frozen nitrogen snows on Pluto What we knew Snow is unusual in the Solar System. On Earth, it seems very familiar, but there are only a few other places where any frozen flakes…

The surface is changing What we knew Pluto is 4.5 billion years old and 5.9 billion km (3.7 billion mi) from the Sun, so we thought it’d be cold and dead. Without any geological activity to reshape the surface, we expected it to be covered in craters. What we now know New Horizons spotted unusual frozen plains on Pluto’s surface. Smooth and uncratered, they were likely formed within the last 100 million years, making this one of the youngest features in the Solar System. It indicates that something is keeping the inside of the dwarf planet warm, we just don’t know how.…

Getting to Pluto 19 January 2006 After 16 years of abandoned projects and multiple name changes, the New Horizons spacecraft launches without a hitch from Cape Canaveral in Florida. 28 February 2007 NASA alters the course of New Horizons so it flies directly past the gas giant Jupiter. By using the planet’s gravity well, the craft saves three years of flight time. 2007-2014 For around seven years, New Horizons enters a state of hibernation. Despite being partially powered down it awakens for 50 days a year to ensure every component is still functioning. 14 July 2015 After almost a decade of flight through the depths of space, the New Horizons spacecraft makes its closest approach to Pluto. December 2014 As 2014 draws to a close, New Horizons is awakened from…

ONE YEAR IN SPACE Astronaut Scott Kelly is the first American to spend a year in space, but could his twin brother Mark’s activities on Earth be just as important? Written by David Crookes When Scott Kelly was chosen to spend 342 days in space, the prospect of being away from Earth for so long ensured his thoughts naturally turned to his two young daughters and his long-term girlfriend. But besides them, one other family member was also foremost in his mind: his twin brother, Mark. For if Scott was to embark on NASA’s One-Year Mission and be subjected to numerous tests designed to study how the human body adjusts to isolation, radiation, weightlessness and the stress of long-duration spaceflight, then he felt his brother could play a crucial role,…

SOLAR SYSTEM Why does Mars have a weak magnetic field? Phillip Wicks It is believed by scientists that Mars may have lost almost all of its magnetic field due to the disruption of its core in an event billions of years ago. A planet’s magnetic field, like Earth's, is caused by the convection and the movement of molten, iron compounds deep under its surface. As the planet spins, it allows this liquid core to act as a geodynamo, which in turn, creates a magnetic field. It is thought that although Mars once had a strong magnetic field it has since lost it and as a by-product of this, went on to lose its protective atmosphere before drying up. Without a liquid, metal core a planet cannot act as a dynamo…

ASTRONOMY What’s the best type of eyepiece that I can buy? Shaun Allen Unfortunately there is no single ‘best eyepiece’ since different eyepieces are used for observing different objects. Generally, though, we look for two factors: their magnification and their field of view. Magnification is, quite obviously, the amount that images are magnified when being observed. The full magnification of your telescope can be worked out by dividing your telescope’s focal length by the eyepiece focal length. Short focal length eyepieces increase this magnification. The other factor important in an eyepiece is the field of view. This is how much sky can be seen through your telescope with that eyepiece attached. When viewing objects like planets, it’s desirable to have higher magnification and when observing nebulae or star clusters, a…

DEEP SPACE Where are we located in relation to the entire universe? Samuel Collins © Celestron PR; ISRO; NASA; ESA; ESO Since we don’t think that the universe has a centre and we’re unsure of how big the universe really is, it is very difficult to say where we are. If you consider the universe on a large scale, it’s said that the cosmos is made of the same things and doesn’t really change in whichever direction you look. Zoom in on a smaller scale cal , and you will begin to notice the structures such as clusters of galaxies and, moving in even further, you will notice even smaller structures such as our own Milky Way galaxy. We have a fair idea of our surroundings in the universe –…

How do lunar eclipses work? Atmospheric refraction The Moon turns red as the Earth’s atmosphere filters and bends some sunlight towards it. Angled orbit The Moon’s orbit is tilted to the Sun-Earth line, meaning we don’t see eclipses every month. Maximum duration of total lunar eclipse It takes no more than 1 hour 40 minutes for the Moon to pass through the umbra. The penumbra We see partial lunar eclipses when the Moon spans the umbra and the penumbra. The umbra Total lunar eclipses occur when the Moon completely resides in the Earth’s shadow.…

Telescope advice : Visionary STARLA 80 A refractor telescope that’s ideal for observing the Solar System, the STARLA 80 is an affordable instrument for the beginner Telescope advice Cost: £199.99 (approx $310) From: Optical Hardware Ltd Type: Refractor Aperture: 3.15” Focal length: 35.43” Best for... Beginners Small budget Planetary viewing Lunar viewing Bright deep-sky objects The Visionary STARLA 80 from Optical Hardware Ltd is a good telescope for those on a tight budget who still want to view a variety of night-sky targets at naked-eye magnitude. This refractor is also ideal for children thanks to its lightweight build, for easy portability and its simple setup. Indeed, putting the telescope together is nothing short of a breeze and within ten minutes, without the supplied instructions, we had set up and were…

NASA is one step closer to discovering ‘Earth 2.0’ Say hello to Kepler-452b, an exoplanet that could be capable of supporting life The American space agency’s continuing mission to discover planets within the ‘circumstellar habitable zone’ of a star (a bracket of space where atmospheric pressure is sufficient enough to allow the existence of liquid water) has reached a new milestone with the addition of giant exoplanet Kepler-452b. Discovered alongside 11 other planets with similar characteristics, this new planetary body is the 1,030th addition to NASA’s journey to unearth an interplanetary locale that could potentially support human life and is the most Earth-like planet to have been located in the decades-long programme. “On the 20th anniversary year of the discovery that proved other suns host planets, the Kepler exoplanet explorer…

Earthly nutrient found in space-based dust Could vitamin B3, one of the many nutrients essential to human life, actually be extraterrestrial in origin? © NASA; JPL-Caltech; T. Pyle; ESA; CXC; PSU; G.Pavlov et al; MSSSS A new report from a research team at the Goddard Space Flight Center suggests the organic compound niacin (otherwise known as vitamin B3) may not have originated on Earth, but instead found its way here via passing meteorites and comets. The nutrient is used to build NAD (nicotinamide adenine dinucleotide), which is essential to the metabolism of most life forms on Earth. The research follows a similar project that analysed carbon-rich meteorites and discovered vitamin B3 was present in concentrations that ranged from 30 to 600 parts per billion. The research showed that B3 could…

There are huge ice mountains What we knew It was obvious from the moment of Pluto's discovery that it was going to be cold, but exactly how its frozen surface would look was a mystery. It was expected that Pluto would be flat and lacking any evidence of active geology. What we now know Pluto is home to jagged mountains, some taller than Canada's Rockies. NASA scientists think that they are made up of water ice, frozen so solid that it has the consistency of stone, covered in a thin layer of methane, carbon monoxide and nitrogen.…

The Medusa Nebula You’re looking at the eventual fate of our own Sun, billions of years from now ©ESO This is the most detailed image ever taken of the Medusa Nebula, or Abell 21, found 1,500 light years from Earth. When it was first discovered in 1955 it was thought to be a supernova remnant, but subsequent observations led astronomers to conclude that this large and dim celestial object is most likely to be a planetary nebula. These are relatively short-lived objects, lasting several tens of thousands of years and are formed at the end of a star’s life during the red giant phase, when the star throws off its outer layers leaving an exposed core to ionise the ejected gases, causing them to glow. In around 5 billion years…

How the Chelyabinsk meteor hit Earth 1 Origin The Chelyabinsk meteor was a 20m (66ft) wide asteroid known as an Apollo asteroid, which spends most of its time inside Earth’s orbit, closer to the Sun. 2 Unseen danger Since the meteor came from the southeast, out of the glare of the Sun, it effectively approached us in our blind spot, where our ground-based telescopes cannot look. 3 Fireball It entered the atmosphere at about 9.20am Yekaterinburg Time (YEKT) on 15 February 2013 at a velocity of 19km/s (12mi/s). It glowed so brightly that, to the people of Chelyabinsk, it looked brighter than the Sun. 4 Airburst At a height of 30km (18mi) off the ground, the asteroid exploded with the energy of 500 kilotons of TNT. A ball of extremely…

A day in the life of Scott Kelly How will the space twin be spending his time on the ISS? Waking up 0600-0730h The International Space Station works to the GMT timezone. Scott wakes from his small, private and well-ventilated soundproofed cabin and he embarks on his morning routine using his personal hygiene kit. He inspects the station, has breakfast and starts to plan his day with mission control. Exercise time 0730-0830h It’s important Scott exercises to help prevent bone and muscle loss. He uses a treadmill referred to as the TVIS (Treadmill with Vibration Isolation Stabilization) for 30 minutes. It is designed so microgravity science experiments in adjacent labs are not disrupted. This will be the first of two exercise sessions. Conducting research 0830-1030h Research is important and it…

10 UNBELIEVABLE SPACE MISSIONS The unique challenges of exploring space has led to some extraordinary, and often completely bonkers projects Written by Nigel Watson 1 Asteroid capture In 2014, NASA proposed an Asteroid Redirect Mission (ARM) to capture an asteroid and put it into lunar orbit. The mission is part of NASA’s strategy for the future exploration of Mars, and would also test technologies and techniques that could be used to protect the Earth from any potentially hazardous asteroids. After sifting through 400 ideas, and considering the best of them at two public workshops, NASA selected two prime concepts. The first was for an ARM spacecraft to capture a boulder-sized asteroid in free space, using a huge inflatable bag. The second proposal, would be to send an ARM spacecraft to…

DEEP SPACE How long do supernova remnants last? James Harman Supernova remnants – the material that’s left over from the explosion of a star – do eventually fade away and become invisible over a period of hundreds of thousands of years. Why supernova remnants fade away is because there was only a finite amount of energy that made them in the first place. This energy comes from the material that was ejected by the central star in the supernova explosion. As this material moves away from the centre and collides with the gas in the region surrounding the star, it will lose some of its energy as the gas is heated up. The heated gas then releases the energy in the form of light. All of the energy available is…

SOLAR SYSTEM How do we know how old the Earth is? Kenneth Styman The Earth is around 4.54 billion years old. We know this because we essentially find the oldest piece of the planet we can and then figure out how old it is using radiometric dating. Finding old rocks is, in theory, straightforward. However, in practice, it is quite difficult thanks to Earth’s tectonics, which are constantly recycling the planet’s rock before breaking it down into volcanic magma in the interior and then pumping it back out onto the surface. The oldest rock we’ve ever found is a tiny piece of zircon, a gemstone that was located in Western Australia. Based on this zircon rock, we know the Earth is at least 4.374 billion years old, give or take…

Guide to the Moon Take a bright night tour of our lunar neighbour with All About Space The Moon has to rank as one of the night sky’s most underrated observing targets. Perhaps it’s because we’re so familiar with its almost constant presence in our sky that we take it for granted. However, at a measly quarter of a million miles distant, it is the astronomical gift that keeps on giving. Approximately once a month (every 29.5 days to be precise) we see the Moon wax and wane through its cycle of phases. This constantly shifting appearance is the result of the lunar surface reflecting different amounts of sunlight our way as the Moon treks through its orbit around us. If viewing with the unaided eye, don’t just focus on…

How to spot the Apollo 11 landing site 1 Find the centre of the Moon Begin right in the middle of the Moon and move up the centre line until you're about level with the northern crater Copernicus. 2 Move right to find it Move your gaze over to the right until you come across a big dark sea. It should have another sea of about the same size joining it to the top left. 3 Locate the landing site The bottom of the Sea of Tranquility is split into two sections, the Apollo 11 landing site is the left-hand area. 4 Get observing! You won’t see any detail due to the landing site being very small, but it’s just to the east of the twin craters Sabine and Ritter.…

Guide to the Moon How to make a Moon mosaic A majestic Moon mosaic is the ultimate cosmic jigsaw puzzle – you even make the pieces © Cristo Sanchez; NASA; John Fowler The Moon is so close that getting a single, detailed image of all of its wonders is no mean feat. Instead, a lot of astronomers create a ‘Moon mosaic’ – a single large image made up of several smaller images all stitched together. One of the easiest ways to achieve this is by attaching a webcam to your telescope. You can even buy specialised Moon-imaging equipment such as Meade’s Lunar Planetary Imager, which plugs straight into your computer via USB. A place where you have a clear view of the Moon for several hours is also a favourable…

Binocular astronomy Binoculars are a really useful tool for amateur astronomers of all levels and experience. Here’s what you need to know about them… Nearly everyone who starts out in astronomy thinks that they must have a telescope. However, humble binoculars are incredibly useful for amateur astronomy and sometimes can even prove more effective than a telescope for viewing some objects. A telescope of good enough quality for viewing the night sky can cost in excess of £150 ($220), but binoculars of decent quality can cost less than half of that price and still be useful. So what makes binoculars so good for viewing many celestial objects in the night sky? First, they are really easy to use and require very little maintenance. All you need to do is hold…

Smartphone stargazing apps We test two smartphone-compatible astronomy apps, to find the best portable night-sky guide Mobile Observatory Cost: £3.56 / $4.60 From: Google Play Mobile Observatory is a good all-in-one for those who can’t decide which planetarium app to buy. On first impressions, Mobile Observatory seems to have it all: when it came to retrieving information about specific targets in real-time, the app didn’t disappoint. It provides an extreme amount of information, to the point that the developer has tried to cram everything onto the screen. It’s a bit much and may put off those just starting out in astronomy. If you’re considering a serious stargazing hobby, then we can highly recommend the app on the information it provides alone. However, if you’re just testing the waters, you are…