Innholdsfortegnelse for Space.com Presents: Eclipses i Space.com Presents: Eclipses

Since humankind first began to study the skies, eclipses have fascinated and terrified astronomers in equal measure. Yet while it is easy to appreciate why many ancient civilisations viewed these awe-inspiring events as omens of disaster, thousands of years of closer examination have uncovered the science behind solar and lunar eclipses, and today we are able to predict them with incredible accuracy. However, it isn’t just Earth that can find itself cast into shadow: other planets also experience eclipses. In the following pages you will discover everything you ever wanted to know about these rare celestial alignments, tour the surface of the Moon, examine the depths of the Sun and meet the pioneers who dedicated their lives to enhancing our understanding of the stars.…

1 THEIA NEARS EARTH A Mars-sized object is on an unalterable collision course with early planet Earth. 2 EARTH IS HIT The impactor hit Earth in a head-on collision, vaporising both Theia and the mantle of Earth. 3 MATERIAL IS THROWN OUT The vaporised material from both bodies mixed and was thrown outwards into space. 4 DEBRIS GATHERS Smaller objects began to condense out of the vapour while continuing to orbit around Earth. 5 THE MOON Many of the smaller objects stuck together to form a protomoon in orbit around Earth. 6 OUR COMPANION IS FORMED Eventually all the pieces came together to form the basis of the Moon that we see today.…

The Moon has an external magnetic field. It’s less than one-hundredth that of Earth’s magnetic field and it’s not a dipolar magnetic field like Earth, which has a field that radiates from the north and south poles. Researchers believe the Moon once had a dipole magnetic field created by a dynamo — a convecting liquid core of molten metal. But we aren’t sure what powered that dynamo. It could have worked like Earth’s dynamo, which powers itself as elemental radioactive decay maintains convection in the core. The Moon could also have had a dynamo powered by the cooling of elements at the core.…

1 OCEANUS PROCELLARUM This mare is so large it was deemed to be an ocean. It covers about 4 million square kilometres (1.5 million square miles). 2 LUNA 9 Launched by the Soviet space programme on 31 January 1966, this site marks the first soft landing of an unmanned spacecraft on the Moon’s surface. 3 SURVEYOR 1 Launched on 30 May 1966, the first American soft Moon landing happened here. 4 COPERNICUS This crater is well known because it can be easily seen from Earth. It is a younger crater, about 800 million years old, with a prominent system of ejecta rays. 5 VALLIS ALPES This lunar valley bisects a mountain range called the Montes Alpes and extends over 166 kilometres (103 miles). 6 MONTES APENNINUS This mountain range is…

1 LAUNCH DAY Scheduled to launch in 2025, the third Artemis mission and second with crew on board will launch from the Kennedy Space Center in Florida. It will be monitored by the nearby Launch Control Center. 2 ENTERING ORBIT Once the rocket has taken Orion into orbit, its engines will shut down and it will separate from the capsule. These rocket components will fall towards the Pacific Ocean. Orion will then deploy its solar arrays.. 3 TRANS-LUNAR INJECTION Having made it into Earth orbit, the Orion vehicle will head to the Moon. During a 20-minute burn, the engines will fire to increase the speed, displacing the spacecraft from its low-Earth orbit. 4 TO DEEP SPACE Set on a precise trajectory, Orion will travel over 384,000 kilometres (239,000 miles). This needs to account…

15 It is very dangerous to look directly at the Sun without using special eclipse glasses or a telescope with a specialist solar filter. This is because the Sun is so bright it can damage your eyesight or even blind you. Even if 99 per cent of the Sun’s surface is blocked by the Moon, the remaining light can still burn your retina. Here are some safe ways to observe the Sun and eclipses: 1. If using eclipse glasses, check they do not have any damage. Even a pinhole could damage your eyesight. 2. Try projecting the image of the Sun through a telescope onto a piece of white card. Keep the finderscope covered in case children accidentally look through it. 3. You can also use specialist solar filters and…

As the world looks collectively toward the sky in eager anticipation of a solar eclipse, one of the sensations that observers can feast their eyes upon are Baily’s beads. Much like a radiant necklace within the cosmic jewellery box, these beads would not be out of place even in the grandeur of Andromeda herself. Within this rare, breathtaking yet fleeting moment, the Sun and the Moon combine in a dance of shadow and light to create a row of radiant beads. The opportunities to catch a glance of Baily’s beads are few and far between, with solar eclipses occurring between two and five times a year anywhere around the globe. These dazzling rays of light are created during annular solar eclipses and total solar eclipses. A total solar eclipse is…

The astronomers of ancient Babylonia (1894–1595 BCE) are renowned for their detailed surveys of the skies and accurate predictions of astronomical events. The Babylonians spent much time gazing up at the heavens and analysing such events as they illuminated the boundless canvas above daily life. By tracking the movements of the Sun and Moon, astronomers were able to produce the first known lunar and solar calendars and plan for optimal crop-growing seasons. By carefully plotting the movements of celestial objects across the sky, the Babylonians also documented early predictions of eclipses. Despite holding high importance, the occurrence of a lunar eclipse was not a celebratory event for everybody. In fact they were considered to be bad omens for Babylonian kings. After all, without fully understanding the presentations of the sky…

While the Greeks, Babylonians and Egyptians are all rightly credited for their groundbreaking studies of space, it should not be forgotten that there were many other ancient populations who spent much of their time trying to better understand the mysteries of the universe. The ancient Maya in particular were avid astronomers who interpreted and recorded every aspect of what they saw in the sky. By reading the planets, stars and Moon they believed they could interpret the actions and will of their gods. Not only did they dedicate many of their buildings to their studies and worship, they often planned life events to coincide with particular celestial moments. This included eclipses, but despite their entrancing nature, for the Maya these occasions inspired a sense of trepidation due to scary premonitions…

From the earliest recorded eclipses described on an ancient clay tablet in Ugarit in modern-day Syria to one that was linked to an uprising in an ancient Assyrian city and another that proved a fundamental scientific theory in the 20th century, here are some of the most famous eclipses ever seen. 1 GREAT AMERICAN TOTAL SOLAR ECLIPSE The first total solar eclipse visible in the United States in nearly four decades dazzled on 21 August 2017. During the so-called Great American Total Solar Eclipse, the 110-kilometre-wide (70-mile) shadow cast by the Moon darkened skies from Oregon to South Carolina, according to Space.com. During most solar eclipses the Moon takes just a ‘bite’ out of the Sun, resulting in what is called a partial solar eclipse. It’s rare to be able…

The blood-red colour of the Moon during a total lunar eclipse may be difficult to explain without a basic understanding of orbital mechanics, but flat-earth conspiracy theorists have come up with a very creative explanation of this phenomenon that enables them to circumvent science. Our natural satellite appears red during lunar eclipses for the same reason that sunrises and sunsets appear that shade here on Earth: because sunlight is scattered as it passes through the atmosphere. According to flat-earth conspiracy theorists, this astronomical phenomenon — known as a total lunar eclipse — is actually a rare opportunity to catch a glimpse of a mysterious “shadow object” that orbits the Sun and occasionally passes in front of the Moon from our point of view here on an allegedly pizza-shaped Earth. Although…

Because we can easily discern features on the Moon with the naked eye, it’s been a source of wonder to us since ancient times. The Moon is the brightest object in our sky after the Sun and influences everything from our oceans to our calendars. It’s always been ‘the Moon’ because we didn’t know that there were any others. Once Galileo discovered in 1610 that Jupiter had satellites we’ve used the word ‘moon’ to describe celestial bodies that orbit larger bodies, which in turn orbit stars. Since the Moon has always been so present it might not seem worth studying, yet there’s a reason why we continue to return to it – we still have plenty to learn from our satellite. The Moon is the fifth-largest and second-densest satellite in…

We all know that Earth only has one moon, and if you want proof of that, you just need to peer at the night sky. Can you see another? Astronomers are sticking to their guns by saying the Moon is Earth’s only natural satellite. Case closed — or so you’d think. In 2016, however, astronomers using the asteroid-hunting Pan-STARRS telescope in Hawaii discovered a rock orbiting the Sun while also repeatedly looping around Earth. Celestial objects such as these are called quasi-satellites, and while four others have been identified since 2004, this one was the closest and most stable ever seen. What makes it particularly interesting is its potential origin, although a recent breakthrough has gone a long way towards clearing up the mystery over what this object could be.…

A CAPTURED ASTEROID The study’s authors examined the possibility that Kamo‘oalewa was captured in its Earth-like orbit from the general population of near-Earth objects. But the paper says that simulations of such a scenario don’t match the low eccentricity and inclination displayed by Kamo‘oalewa. FRAGMENT OF AN ASTEROID There are two known asteroids that orbit the Sun at the Earth-Sun Lagrangian points L4 and L5. They have similar orbits to Earth’s, and it could be that Kamo‘oalewa is a splintered piece of one of them. A PIECE OF THE MOON The study strongly suggests that the asteroid is an ejected fragment of the Moon, probably caused by an impact. This is supported by the reflectance spectrum of Kamo‘oalewa being a near-perfect match in comparison to rock samples returned from the…

The Sun’s atmosphere is comprised of several different layers, but the main ones are the photosphere, the chromosphere and the corona. It’s inside these outer layers that the Sun’s energy, which has bubbled up from the Sun’s interior layers over the course of a million years, is detected as sunlight, according to the University Corporation for Atmospheric Research (UCAR), which is based in Colorado. THE SUN’S PHOTOSPHERE The photosphere is the lowest layer of the Sun’s atmosphere. The term photosphere means ‘sphere of light’ and is the layer where most of the Sun’s energy is emitted. It takes about eight minutes for sunlight from the photosphere to reach Earth. The temperature of the photosphere ranges from 6,125 degrees Celsius (11,000 degrees Fahrenheit) at the bottom to 4,125 degrees Celsius (7,460…

Thousands of years before the rise of the pharaohs, nomads to the south realised the sky changed with the passing of time and that this was cyclical. They noticed the reappearance of certain stars coincided with the changing seasons, allowing them to plan when to plant and harvest crops for a better yield — crucial in an arid environment. A stone circle unearthed at Nabta Playa is the earliest example of a calendar from the region. It denotes the summer solstice and with it the coming of monsoons. The megalith appears to have been aligned with the stars Arcturus, Sirius and Alpha Centauri during its use, with other stones potentially representing Orion’s Belt. By the Early Dynastic Period, around 3100 BCE, astronomical timekeeping had become much more refined. A new…

Indigenous groups throughout Australia have used the motions of the stars, Sun and Moon to make sense of natural cycles for thousands of years. Their understanding of celestial movements was relatively sophisticated, however, the appearance of an eclipse would understandably still cause panic, with many Aboriginal communities seeing them as a sign of black magic or worse, impending doom. Disaster could only be prevented by a wirreenun, a type of weather or rain man who would chant at the eclipsing Sun or throw a boomerang or sacred stones at it. In southeastern Australia many tribes believed that spirits held up the canopy of the sky and that the Sun’s disappearance was a result of some sort of magic.…

Since the dawn of civilisation, humans have been awe-struck by the dramatic impact of solar and lunar eclipses, celestial events that drastically alter the appearance of the Sun and the Moon. Most of us learn from an early age that a solar eclipse occurs when the Moon travels in between the Earth and the Sun, JAMIE and CARTER a lunar eclipse is the result of the Earth travelling between the Moon and the Sun. But for millennia these events baffled, terrified and captivated whole civilisations. In truth, a few pioneering astronomers from the ancient world understood the broad concepts and scientific models behind eclipses. Records suggest the Maya could predict the Moon’s blockage of the Sun, while the astronomical observations and mathematical techniques of the Babylonians and ancient Greeks were…

The name itself evokes awe and uncertainty, rather like the title of a horror movie. But in 2013, prophecies relating to a series of impending eclipses and their possible significance were preached to captivated audiences by Christian evangelical pastors John Hagee and Mark Biltz. Both believed there to be a correlation between key historical world events and eclipses occurring on Jewish holy days. They claimed that God, the Master Timekeeper, communicated with his flock on Earth through the use of heavenly bodies, particularly at a time when significant lunar and natural events were due to take place. There were to be four consecutive blood moons across an 18-month period, the first on 15 April 2014. This is called a tetrad, which comes from the Greek word tetras, meaning group of…

With the Sun being a dangerous object to look at, many might shy away from solar observing. However, provided you have the right kit and you ensure that you take care when viewing the incredibly bright surface, looking at our nearest star can be a truly breathtaking experience. Whether you have a solar telescope or a pair of glasses made especially for the event, with the total solar eclipse on the way all protected eyes will be on the Sun this April (if you're fortunate enough to be living somewhere in the path of totality of course). Given that it’s a great astronomical event — and unless you know a keen solar observer who will allow you to use their instrument — it’s tempting to rush out and buy a…

Along with the Sun, the Moon exerts serious force on Earth’s tides. Whether the tides vary widely or not much at all has a lot to do with the interactions between the solar and lunar cycles. When they are together, their combined effects produce tidal variations called spring tides (high tides are very high and low tides are very low). If the Sun and Moon are on the opposite sides of the sky, they nullify each others’ effects, producing neap tides, which have little variation.…

Although the Moon may seem like a solid rock, it’s actually differentiated like Earth; it has a core, a mantle and a crust. The Moon’s structure likely came from the fractional crystallisation of a magma ocean that once covered it. This probably happened not long after the Moon was formed about 4.5 billion years ago. As the magma ocean cooled, its composition changed as the different minerals within the melt crystallised into solids. The denser materials sank, forming the mantle, while less-dense materials floated on top and coagulated to form the crust. The core is probably very small, with a radius about 20 per cent the total size of the Moon. By contrast, most differentiated celestial bodies have cores about 50 per cent of their total size. The core itself…

The landscape of the Moon is dominated by three main features: maria, terrae and craters. The basalt maria appear dark due to their high iron content and are much more prevalent on the near side of the Moon. Other volcanic features on the surface include domes and rilles. Domes are shield volcanoes that are round and wide with gentle slopes, while rilles are twisting sinuous formations caused by channels of flowing lava. The lighter areas on the Moon are called terrae, or lunar highlands. They are made up of anorthosite, the type of igneous rock that dominates the overall crust of the Moon. While this type of rock can be located in some places on Earth, it’s not generally found on the surface due to plate tectonics and deposits. These…

Although there hasn’t been a manned mission to the Moon since 1972, and there were no soft landings at all until 1966, we’re still exploring our satellite. Currently the Lunar Reconnaissance Orbiter (LRO) is still circling the Moon. It launched on 18 June 2009 and became the first NASA mission to the Moon in more than a decade. The LRO is meant to be a precursor to future manned missions and was originally designed to spend just a year in orbit. However, the mission was extended several times. It was designed to extensively map the Moon in high resolution, explore the potential of ice in the polar regions, study deep space radiation and continue to map the surface of the Moon. The other current NASA mission is ARTEMIS, an extension…

Solar eclipses can be confusing. Almost everyone has heard of a total solar eclipse (also known as a total eclipse of the Sun), but it’s often mixed up with a ‘ring of fire’ annular solar eclipse (‘annular’ means ‘ring’). Both types of solar eclipses are described by astronomers as central solar eclipses, but the exact geometrical differences between them are slight. Even so, those differences have a huge effect on what observers see and feel. While one of the eclipse types can be described merely as a beautiful sight, the other is an awe-inspiring, multi-sensory experience. Here’s everything you need to know about the astronomical differences between a total solar eclipse and an annular solar eclipse to help you to better understand these remarkable events and — for our readers…

Eclipses are all a result of orbits. The Moon orbits the Earth once every 27.3 days. The Earth orbits the Sun once every 365.2 days. Their orbits are elliptical, meaning their distance from their parent body can change throughout an orbit. The tilt of the Moon’s orbit relative to the ecliptic (the path of the Sun through the sky) is 5.1 degrees. A solar eclipse happens only when the Moon crosses the ecliptic at the exact position that the Sun is in at that moment in time. THE MOON We cannot see the surface of the Moon during a solar eclipse because, facing away from the Sun, it is in darkness. ECLIPSE SHADOW Observers in the umbral shadow of the Moon will see a total solar eclipse. OUT OF THE…

It’s no secret that animals are highly sensitive creatures in tune with their surroundings, so it’s not surprising that an eclipse might influence their behaviour. Even so, these events can make animals (and plants) move in mysterious ways, and thanks to studies conducted during the solar eclipse of August 2017, we have plenty of evidence to support this. Several experimental projects were aimed at recording the responses of animals to the eclipse, including the iNaturalist app, which encouraged people to record observations during and after totality, says Rebecca Johnson, citizen science research director at the California Academy of Sciences in San Francisco. Johnson, along with colleagues, helped spearhead the effort to gather these observations and sift through them — once the Sun had returned. It turned out that the solar…

The great philosophers of ancient Greece saw the skies above them in a new light, with the celestial bodies simply something else to quantify using mathematical equations. With each new observation and discovery the gap widened between theology and theory. The stars had become a science, and ancient Greek astronomers would lay the groundwork for modern astronomy. But though scholars could see the universe beyond the gods and wanted to uncover its secrets, others still retained their faith in myth and legend. In the Greek pantheon, Helios was the personification of the Sun, flying across the sky from east to west each day in a flaming chariot drawn by winged horses. However, he held much less significance than the solar deities of previous cultures and was not worshipped heavily outside…

The phenomenon of an eclipse, be it total, annular or partial, marks a sacred moment in many people’s lives. Remembering where you were and who you were with during a celestial alignment is a lasting memory. That moment of complete silence when everything around you is falls still and it feels like the Earth has momentarily stopped breathing is a profound experience, doubly so if you attribute a deeper meaning to the stars. The Native Americans certainly do. In fact their knowledge and appreciation of the cosmos shapes how they live. Many Native Americans view eclipses as spiritual experiences. The Navajo, for example, look at the entire universe as being holistic. Therefore during an eclipse the Sun, Moon and Earth become aligned and interconnected in the cosmic order — a…

Not many people live to see the turn of a century, let alone a millennium, and even fewer witness a total solar eclipse during their lifetime. A combination of these events in 1999 meant people were in for a real once-in-a-lifetime experience. Though there are between two and five solar eclipses in any given year depending on the positions of the Sun and Moon, a total solar eclipse only occurs every 18 months or so, and in many cases totality passes over the sea, unpopulated or inaccessible areas. However, the path of the 11 August 1999 eclipse was special in that it passed over much of Europe, continuing over the Middle East and India, meaning it was easily viewable for millions of people. As such, it became one of the…

A total solar eclipse is a rare and magical experience for us Earthlings, largely because many of them occur over the vast oceans that cover approximately 70 per cent of our planet’s surface. So when the opportunity arises to watch this mesmerising aligning of the Earth, Moon and Sun there is an understandable sense of excitement – and there’s one coming on 8 April of this year. While it won’t be visible to the majority of the global population, a fortunate few (well, few million) in North America will be able to observe the eclipse in parts of Canada, the United States and Mexico. The 185-kilometre-wide (115-mile) path of totality will be passing over 15 U.S. states (including small parts of Tennessee and Michigan), and here is where the Moon’s shadow…