All About Space No. 103의 목차

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE Our Milky Way is being used to hunt for dark matter Words by Chelsea Gohd Source: Wikipedia Commons Scientists studying a mysterious signal from far-off galaxies didn’t find dark matter as they’d hoped. But the inventive new technique they used to detect this strange signal, which uses our own galaxy to hunt for dark matter, could elevate the hunt for the elusive material. For decades scientists have been searching for dark matter, an invisible material that doesn’t interact with light but which permeates our entire universe, influencing it with its gravity. And a signal coming from a nearby galaxy spotted in a 2014 study gave scientists hope that this was the long-sought evidence for dark matter. Some current models predict that dark…

LAUNCH PAD YOUR FIRST CONTACT WITH THE UNIVERSE Neutron star crash helped form our Solar System © ESO Astronomers are on the hunt for the remnants of the neutron-star collision that gave Earth its precious metals. When neutron stars merge they spew a wealth of short-lived elements into their surroundings, and these materials become part of later-forming solar systems. Now scientists are trying to close in on the merger that seeded our Solar System by tracing the elements produced by the original decaying material. From that work they believe the responsible merger occurred 100 million years before and 1,000 light years away from the birth of our Solar System. “It was close,” the project’s lead scientist Szabolcs Marka, who is a physicist at Columbia University, said. ”If you look up…

Holographic universe WELCOME TO THE HOLOGRAPHIC UNIVERSE According to current research, the reality of the cosmos may be stranger than you think Reported by Colin Stuart © Tobias Roetsch Picture a room filled with books. Then imagine that all the books suddenly disappear. All the information they contained would be lost, right? All the plot lines, characters and happy endings would vanish into thin air. But this library is different. Here all the information inside the room is also encoded on the floor, the walls and the ceiling. Even though the books themselves are gone, you can still retrieve all of the details they contained by looking at the surfaces that once enclosed them. Want to know how that story ended? Read the wallpaper. Whodunnit? Consult the carpet. Sounds downright…

What is the universe made of? There is much more to the cosmos than what meets the eye 68% Dark energy Dark energy makes up most of the universe. It is believed that this is the driving force behind the expansion of the universe, which Edwin Hubble observed in 1929. 27% Dark matter Dark matter refuses to be seen, but astronomers have observed its gravitational effects on galaxies and other astronomical observations. 5% Baryonic matter This is regular matter that can be seen and is composed of particles called baryons, but it only makes up a minute five per cent of the universe. 32% All matter Even when you combine all matter, it still only makes up a third of the entire universe. This shows the…

Saturn planet profile Saturn Saturn is famous for its rings, but there is more to it than meets the eye © NASA/JPL-Caltech The Ringed Planet is not only a fan favourite among astronomers because of its consistent visibility in the night sky, but also because it offers an enticing uniqueness. Along with Jupiter, Uranus and Neptune, Saturn is one of the gas giants – also known as Jovian planets – that sit in the outer regions of the Solar System. What is most intriguing about the two largest planets in our Solar System, Jupiter and Saturn, is that they are the bridge to understanding stars like our Sun. Although they are classified as planets, they have a more similar composition to the Sun than they do to Earth. Saturn is…

Facts about Saturn © Tobias Roetsch A day on Saturn is about ten hours and 40 minutes, but a year takes 29.5 Earth years. On 15 September 2017 the Cassini space probe performed a controlled entry into Saturn’s atmosphere as astronomers did not want to contaminate its moons. Saturn is tilted nearly 27 degrees with respect to the Solar System’s orbital plane. This means the Ringed Planet experiences seasons similar to Earth, which has a tilt of 23.5 degrees. Due to the perceived inclination of Saturn in relation to Earth, the rings ‘disappear’ twice every 29-and-a-half years. There are seven sections to Saturn’s rings, with A, B and C being the main rings, and D, E, F and G the fainter rings. This planet is named after the Roman god…

CREATING THE SOUTH ATLANTIC ANOMALY How does a weakness in the Earth’s magnetic field create some odd phenomena? © Getty Affecting spacecraft When spacecraft and satellites orbit within the South Atlantic Anomaly, protons smash into them and cause havoc with their onboard electronics. Van Allen belts The discrepancy between the magnetic and geographical poles means the Van Allen belts are not perfectly aligned either. Inner and outer The Van Allen belt is made of energetic charged particles captured and then held in place by Earth’s magnetic field. A prominent tilt Earth’s magnetic axis is titled away from its rotational axis by 11 degrees. Weak spot There is also a part of Earth, deep beneath the crust below the south of Africa, where the planet’s magnetic field is weakening. South Atlantic…

ASK Space Our experts answer your questions SOLAR SYSTEM © NASA /JPL-Caltech Do gas giants experience similar weather to Earth? The giant planets have deep, cloud-filled atmospheres that behave in much the same ways as Earth’s. Weather generally means storms and short-term cloud changes, and the driving physics are the same on any planet. The only differences are the lack of a solid surface and their large distance from the Sun. For the giant planets, the weather is observed from above the cloud tops, which are ammonia ice for Jupiter and Saturn, and methane or hydrogen sulphide ice on Neptune and Uranus. The main driver for weather events is likely a water cycle, just as on Earth. As on Earth we observe thunderstorms, cyclones and waves in the clouds which…

Moon tour Lunar lakes Small but perfectly formed, Lacus Spei and Lacus Temporis are worth a look at full Moon © NASA The Moon is famous for its dark seas, or mare, and even non-astronomers know the name of one: the Sea of Tranquillity is where Neil Armstrong and Buzz Aldrin landed in July 1969 on the Apollo 11 mission. Many of the seas have equally romantic names – the Sea of Crises, the Sea of Dreams, the Sea of Serenity – which is rather ironic considering they aren’t beautiful seas at all, but huge plains of ancient, dark, frozen lava. The largest lunar mare are clearly visible even to the naked eye, looking like dark blotches on the Moon’s bright face, and are especially prominent at full Moon. Much…

China’s new crew spacecraft to dock with Space Station ©ESA A next-generation crew spacecraft that China is preparing for a flight test this spring appears to be capable of docking with the International Space Station (ISS). An image posted by the Shanghai Academy of Spaceflight Technology (SAST) shows the new spacecraft’s docking system, which appears compatible with the International Docking System Standard (IDSS). NASA, the European Space Agency and Russia’s federal space agency, known as Roscosmos, use IDSS-compatible systems or adapters. These are in use on the ISS to facilitate rendezvous and docking with spacecraft. The new craft is designed to boost China’s capabilities in sending humans into orbit, reduce costs through partial reusability and allow astronauts to survive the radiation environment and high-speed re-entries of deep-space missions. It will…

Distant ‘quasar tsunamis’ are ripping their own galaxies apart At the centre of almost every galaxy in the universe is a supermassive black hole, gobbling up incredible amounts of matter and belching out incredible amounts of radiation. The biggest and hungriest of these gobblers – called quasars, or quasi-stellar objects, because they look deceptively like stars when seen through most telescopes – are some of the most energetic objects in the universe. © ESO As infalling matter swirls around the quasar’s maw at near-light speed, that matter heats up and flies outwards, propelled by the incredible force of its own radiation. All that intergalactic indigestion makes a quasar an awesome sight, capable of shining a thousand-times brighter than a galaxy of 100 billion stars. However, a series of new papers…

Future tech Nautilus-X NAUTILUS-X The artificial-gravity spacecraft that could take humans to the Moon and beyond When it comes to manned missions into deep space there is no shortage of proposals. People have dreamt up spacecraft with various fantastical elements, from futuristic propulsion engines to somewhat ambitious aesthetic designs, but one proposal that warrants a serious glance is Nautilus-X. It’s a spacecraft that builds largely on existing technology to make human exploration of the Solar System a realistic possibility, and at a reasonable price too. Drawn up by NASA engineers Mark Holderman and Edward Henderson, the name stands for Non-Atmospheric Universal Transport Intended for Lengthy United States Exploration. Nautilus-X would be capable of supporting a crew of six for missions lasting from one month to two years. Although it might…

Ann Druyan NAT GEO EXCLUSIVE: PART TWO ANN DRUYAN TALKS COSMOS POSSIBLE WORLDS Ann Druyan speaks to All About Space about the significant scientific impact of the Cosmos series, Carl Sagan and NASA’s historic Voyager missions Reported by Lee Cavendish The original Cosmos TV series was released almost 40 years ago. Has peoples’ interest in science and the universe increased in this time? I feel that there’s been a kind of war against science in the US. I certainly can’t speak for other countries, but what has changed is in 1980, when Carl Sagan and I did the original Cosmos, there was still a kind of great dream of a wonderful future. In episode four of the original series, we talked about climate change. The scientists well knew what we…

BUILDING THE SLS What makes the Space Launch System the most powerful rocket ever made? © Alex Pang 1 RS-25 engines Previously used as the main engine of the Space Shuttle, four RS-25 engines will power the core stage of the SLS. 2 Core stage The largest element of the SLS, the core stage is 65 metres (212 feet) tall and contains cryogenic liquid hydrogen and liquid oxygen that will mix and feed the four RS-25 boosters beneath it. 3 LH2 tank The largest of the components in the core stage, this tank contains the other element needed to fuel the RS-25 rockets below – cryogenic liquid hydrogen. 4 Intertank One of a number of components incorporated from the defunct Space Shuttle program, the intertank feeds fuel loads between the…

The history of Saturnian exploration © Adrian Mann Saturn has been extensively studied across centuries. When Galileo used his telescope in the early 17th century, the rings of Saturn became apparent. Fast forward to 2020 and there is a host of commercially available telescopes to see the planet in amazing clarity. There is also a team of ground- and space-based observatories that frequently capture observations of the planet to provide regular updates. In regards to space probe missions to Saturn, it has had a handful of human-made mechanical visitors over the last few decades. The first interplanetary investigator was NASA’s Pioneer 11 spacecraft; it became the first probe to encounter Saturn on 1 September 1979. After that were NASA’s two Voyager probes, which returned historic images of the outer Solar…

MYSTERIES OF THE UNIVERSE OF THE BERMUDA TRIANGLE OF SPACE There’s a portion of space above Earth where protection from high doses of radiation is significantly weaker Reported by David Crookes © Getty There’s a region in the western part of the North Atlantic Ocean where mysterious disappearances of ships, aeroplanes and people have been reported. It’s long been known as the Bermuda Triangle, and it has led to much speculation over the years over what exactly may be causing it. Could it be extraterrestrials, some force pulling objects under the sea or a link to the fabled lost city of Atlantis? Or could it simply be bad weather, human error or heavy traffic in the region? In truth, no one knows for certain, but more than 50 ships and…

THE THEORIES What is happening and what are the possible consequences? The Van Allen belt is at a low altitude We know that Earth’s magnetic poles are titled and we know that as a result the Van Allen radiation belt is tilted too. It’s also accepted through evidence that the South Atlantic Anomaly is at the spot where the Van Allen radiation belt is closest to the surface of our planet and that in that location there is a low magnetic field. This is the explanation for the so-called Bermuda Triangle of space, and we know it is growing as the magnetic field weakens. © NASA The answer could be deep underground Studies into why Earth’s magnetic field is weakening are important because the field offers us protection from solar…

STARGAZER What’s in the sky? ESSENTIAL GUIDES AND ADVICE FOR AMATEUR ASTRONOMERS © NASA, ESA & Hubble 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…

Old gas blob from Uranus found in Voyager 2 data Words by Meghan Bartels Buried inside data that NASA’s iconic Voyager 2 gathered at Uranus more than 30 years ago is the signature of a massive bubble that may have stolen a blob of the planet’s gassy atmosphere. The tiny wobble in the Voyager 2 data represents something much larger since the spacecraft was flying so fast. Scientists behind the new research believe the zigzag marks a plasmoid, a type of structure that wasn’t understood particularly well at the time of the flyby in January 1986. A plasmoid is a massive bubble of plasma, a soup of charged particles. Plasmoids can break off from the tip of the sleeve of magnetism surrounding a planet like a teardrop. Scientists have studied…

HOW A HOLOGRAPHIC UNIVERSE IS MADE Things would have taken an unexpected turn after the Big Bang It’s widely thought that the Big Bang – the event which created the universe – began with an infinitely dense point known as a singularity. Singularities are thought to be unpredictable, with the laws of physics breaking down. Some proponents of the holographic universe postulate that the universe began when a star in a four-dimensional universe collapsed to form a black hole. 3D representation of a 4D implosion © Tobias Roetsch Big Bang Around 13.8 billion years ago and in an infinitely dense moment, the universe is born from a singularity. Galaxy formation Gravity causes galaxies to form, merge and drift. Dark energy accelerates the expansion of the universe, but at a much…

Dark energy DARK ENERGY SOLVING THE ENIGMA Three exciting projects will soon survey the sky in order to answer an intriguing question: what is dark energy? Reported by Lee Cavendish © Tobias Roetsch The universe is a funny thing. Astronomers work their whole careers to understand what it’s made of, yet they are also open to the idea that they could be as far away from the truth as possible. The key to understanding the large-scale structure of the universe is figuring out what dark energy is. This mysterious form of energy is related to the expansion of the universe. After conducting experiments related to this expansion, astronomers have at least been able to determine that dark energy makes up 68 per cent of the universe. The rest is dark…

What is the fate of the universe? Astronomers are unsure about the future of dark energy, and it could play a huge role in the fate of the universe © Nicholas Forder Discovering a cosmological constant Einstein proposed a ‘cosmological constant’ along with his theory of gravity that could be causing a steady rate of cosmic expansion. The Big Rip If the rate of expansion due to dark energy continues to accelerate, it is possible that space-time will be slowly torn apart. The Big Crunch If dark energy ceases to expand the universe, this could cause the universe to collapse in on itself in a scenario opposite to the Big Bang.…

HOW A ROCKET ENGINE WORKS Before launch boosters, such as those that belong to the Saturn V, must go through several stages © Alex Pang 1 Getting pumped Keeping the weight of a rocket to a minimum is vital to getting it in the air. To do this, the fuel and oxygen propellants are liquefied with extreme cooling. The pumps begin by sending these to the combustion chamber. 2 Fuel injection On its way to the turbo pump, the fuel is then siphoned through coolant passages. The newly pressurised fuel then passes over the turbine, causing it to rotate. 3 Fired up The fuel and oxidiser components are pumped into the combustion chamber proper where they’re superheated into a high-pressure gas. 4 Chain reaction As the…

STARGAZER Meade 20-60x80 Wilderness An instrument that’s built to last, this spotting scope is ideal for the casual astronomer and serious wildlife watcher If you can’t quite commit to a full-blown hobby in astronomy but enjoy watching nature at play, then a spotting scope in the Meade Wilderness range could be the instrument for you. The 20-60x80 is an excellent specimen, featuring rugged, rubber armour to protect the optics from moisture, and it is finished to a high standard. The spotting scope is supplied with a high-quality 20-60x zoom eyepiece, a soft case and camera adapter, but unfortunately it doesn’t come with a tripod – something that this spotting scope requires for stable observations. For this reason we think that the Meade Wilderness is suitable for those interested in casual…