A Japanese spacecraft has arrived at its target – an asteroid shaped like a diamond or, according to some, a spinning top.
Hayabusa 2 has been travelling toward the space rock Ryugu since launching from the Tanegashima spaceport in 2014.
It is on a quest to study the object close-up and deliver rocks and soil from Ryugu to Earth.
It will use explosives to propel a projectile into Ryugu, digging out a fresh sample from beneath the surface.
Dr Makoto Yoshikawa, Hayabusa 2’s mission manager, talked about the plan now that the spacecraft had arrived at its destination.
“At first, we will study very carefully the surface features. Then we will select where to touch down. Touchdown means we get the surface material,” he told me.
A copper projectile, or “impactor” will separate from the spacecraft, floating down to the surface of the asteroid. Once Hayabusa 2 is safely out of the way, an explosive charge will detonate, driving the projectile into the surface.
“We have an impactor which will create a small crater on the surface of Ryugu. Maybe in spring next year, we will try to make a crater… then our spacecraft will try to reach into the crater to get the subsurface material.”
“But this is a very big challenge.”
Why is this story important?
Scientists study asteroids to gain insights into the origins and evolution of our cosmic neighbourhood, the Solar System.
Asteroids are essentially leftover building materials from the formation of the Solar System 4.6 billion years ago.
It’s also thought they may contain chemical compounds that could have been important for kick-starting life on Earth.
They contain water, organic (carbon-rich) compounds and precious metals. The last of those has tempted several companies to look into the feasibility of asteroid mining.
He said asteroids with this general shape tended to be fast-rotating, completing one revolution every three or four hours. But Ryugu’s spin period is relatively long – about 7.5 hours.
“Many scientists in our project think that in the past the spin period was very short – it rotated very quickly – and the spin period has slowed down. We don’t know why it slowed down, but this is a very interesting topic,” he told BBC News.
Hayabusa 2 will spend about a year and a half surveying the 900m-wide space rock, which is about 290 million km (180 million miles) from Earth.
During this time, it will aim to deploy several landing craft to the surface, including small rovers and a German-built instrument package called Mascot (Mobile Asteroid Surface Scout).
Ryugu is a so-called C-type asteroid, a kind that is thought to be relatively primitive. This means it may be rich in organic and hydrated minerals (those combined with water). Studying what Ryugu is made from could provide insights into the molecular mix that contributed to the origin of life on Earth.
The surface of the asteroid is likely to have been weathered – altered by aeons of exposure to the harsh environment of space. That’s why Hayabusa 2’s scientists want to dig down for as fresh a sample as possible.
On the far side of the Moon lies the Maunder crater, named after two British astronomers – Annie and Walter Maunder.
Annie worked alongside her husband at the end of the 19th Century, recording the dark spots that pepper the Sun.
The name Maunder is still known in scientific circles, yet Annie has somehow slipped from history.
“I think the name Maunder is there and we have all rather forgotten that that’s two people,” says Dr Sue Bowler, editor of the Royal Astronomical Society magazine, Astronomy and Geophysics.
“She was acknowledged on papers, she published in her own name as well as with her husband, she wrote books, she was clearly doing a lot of work but she also clearly kept to the conventions of the day, I think.”
The ‘lady computers’
Annie Scott Dill Russell was born in 1868 in Strabane, the daughter of a Reverend.
Clearly of fierce intelligence, she won a scholarship to Girton College, Cambridge, and became one of the first female scientists to work at the Royal Observatory, Greenwich.
In the courtyard of the observatory, looking over the park, curator Dr Louise Devoy, tells me what little they know about her work.
“She was one of what we now call the ‘lady computers’ employed in the early 1890s by the then Astronomer Royal, William Christie,” she explains.
“I believe she came from Northern Ireland and she worked here for several years on very low pay just like many of the computers here, both male and female.
“In terms of what she actually did here, we have very little concrete record or photographs.'”
‘Grit and devotion’
Female scientists were hindered because of their gender until the 1920s and 30s, despite superb skills and experience, says Dr Devoy.
At Greenwich, employing women with a university education in mathematics was an audacious experiment.
Women were only considered because the Astronomer Royal needed skilled assistants but could afford only lowly computers – historically, schoolboys on a wage of £4 per month.
Maunder was offered a post as a lady computer, which meant a huge drop in pay for someone who had been working, briefly, as a school teacher.
Letters show that she appealed for more money but was turned down.
The lady computers would carry out routine calculations to turn raw observations into usable data. They were also trained to use telescopes.
At times, this meant walking through Greenwich Park at night without a chaperone, an activity that was frowned on at the time.
“In an age when many middle-class women were still chaperoned, the grit and devotion of these young women astronomers, clad in their clumsy long gowns as they worked at their telescopes or in the laboratories, were surely remarkable,” wrote the science historian and astronomer Mary T Brück.
In 1892, the names of Annie Russell and fellow Greenwich astronomer Alice Everett were put forward to become fellows of the Royal Astronomical Society.
However, they failed to gain enough of the popular vote in a secret ballot and were rejected.
The RAS had long argued that since the pronoun “he” was used in the charter, women could not be admitted alongside men.
Instead, Annie Russell and Alice Everett, who had studied together at Cambridge, joined the amateur British Astronomical Association (BAA).
Alice Everett grew tired of the low pay and left Greenwich, eventually developing an interest in the new field of television. Annie Russell stayed on.
“She was clearly very tough and wanted to follow her science,” says Dr Bowler.
“She sat the [difficult] mathematical Tripos at a time when women couldn’t actually be awarded a degree and there were even protests at Cambridge against the whole idea of giving women degrees.
“So she was clearly tough enough to do that and to do it well and to succeed then in getting employment as a scientist, which was fairly rare anyway – astronomy was still very much a gentleman’s pursuit.”
Studying the Sun
Annie Russell married her colleague Edward Walter Maunder in 1895.
Under civil service rules, as a married woman, she was forced to give up her paid position, bringing the age of lady computers to an end.
“She did come back as a volunteer during the First World War and then she was taken on as a paid employee later in the 1920s,” says Dr Devoy.
Annie worked alongside Walter taking photographs of the Sun, laying the groundwork for a modern understanding of solar activity.
“They would take photographs of the Sun every clear day just to note where the sunspots were and to sketch where they were,” says Dr Bowler. “But she also, as a trained mathematician, put quite a bit of effort into analysis. She wasn’t just writing things down; she wasn’t just Walter’s assistant.”
Annie Maunder went on many scientific expeditions to observe eclipses around the turn of the century, often as the only woman. She travelled to Lapland, India, Algiers, Mauritius and Labrador.
She even designed her own camera to take spectacular pictures of the Sun, including the first photograph ever of streamers from the Sun’s outer layer, or corona.
“She particularly caught an extremely long ray – a streak of the corona – coming out from the Sun, while it was eclipsed, that nobody had ever seen before – a feature of the corona that people just didn’t know about,” says Dr Bowler.
“I’ve seen photos of her adjusting the instruments. She’s taking her photographs. She’s not at all a passenger.
“It may have been only socially acceptable for her to go because she’s travelling with her husband but she was on official scientific expeditions and her photographs were acknowledged as among the best.”
The Heavens and Their Story
The conventions of the time meant that Annie’s photographs were published under her husband’s name and she could not speak at scientific meetings.
However, she was eventually made a fellow of the Royal Society in 1916, 24 years after first being proposed.
She was involved with promoting astronomy to a general audience as vice president of the BAA and edited the in-house journal.
In 1908, the Maunders published the book, The Heavens and Their Story, which was aimed at popular science.
The book was released under both their names, but her husband acknowledged in the preface that it was almost all her work.
The Maunders are also well known for the butterfly diagram, which shows how the number of sunspots varies with time, and the Maunder Minimum, a period in the 17th Century when sunspots all but disappeared.
Much of their work still holds true today.
This year, Annie’s name is being remembered through the inaugural Annie Maunder Medal, to recognise public engagement in science.
“She is an ideal person for that medal to be named after,” says Dr Bowler. “That’s largely what she was doing, certainly later in her career.”
Annie Maunder died in 1947, long after her husband.
On a leafy street near Clapham Common I find the Victorian terraced house where she spent her final years.
From the outside there is nothing to speak of the pioneering scientist.
Yet, despite perhaps not getting the recognition she deserved in her lifetime, she clearly left her mark on science.
“From her letters which are in the Royal Astronomical Society archives she was a very strong-minded, very decided personality,” says Sue Bowler.
“She didn’t mince her words. She’s really quite amusingly rude in some of her letters and very precise.
“I really admire her – she’s one of the people I would definitely have at my dream dinner party – I think she would be extraordinarily interesting.
“And her thoughts, her opinions about the paper based on her observations are very modern and form the basis for solar physics through a lot of the years following.”
Sir Isaac Newton’s three laws of motion were first published in 1687 and continue to give a pretty accurate account of nature (with a few exceptions, like the behavior of things in distant space or inside of atoms). They represent some of humankind’s first great successes at using simple mathematical formulas to describe the natural world and form an elegant and intuitive physical theory that paved the way for later advances in physics. These laws apply to objects in the real world and have allowed us to do things like simulate car collisions, navigate spacecraft, and play billiards really well. Whether we are aware of them or not, Newton’s laws of motion are at play in nearly every physical action of our daily lives.
The First Law
Newton’s first law states that unless a body (such as a rubber ball, car, or planet) is acted upon by some force, a body in motion tends to remain in motion and a body at rest tends to remain at rest. This postulate is known as the law of inertia. What this means, practically speaking, is that a rolling ball or other object only slows down because of forces like gravity and friction. Even more intuitively, a resting ball isn’t going anywhere unless given a nudge or a toss. Given this law, a ball thrown in the vacuum of space would, theoretically, keep traveling at the same speed for as long as it could avoid impacts with celestial bodies and their pulls of gravity!
The Second Law
Newton’s second law is a quantitative description of the changes that a force can produce on the motion of a body. It states that when an external force acts on a body, it produces an acceleration(change in velocity) of the body in the direction of the force. This postulate is most commonly written as F = ma, where F (force) and a (acceleration) are both vector quantities and thus have both magnitude and direction, and m (mass) is constant. Although it may sound a bit dense, Newton’s second law is one of the most important in all of physics and, like the first law, is also pretty intuitive. For example, think of a small rubber ball and a bowling ball. In order to get them to roll together at the same speed, you would need to push harder (apply more force) on the larger, heavier bowling ball because it has greater mass. Similarly, if the two balls are rolling together down a hill, you can predict that the bowling ball will hit a wall with more damaging force than the smaller ball. This is because its force is equal to the product of its mass and acceleration.
The Third Law
Newton’s third law states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. This is commonly referred to as the law of action and reaction (commonly stated as “every action has an equal and opposite reaction”). This idea is clearly seen in the recoil of a gun: the explosion of the bullet leaving the barrel causes the gun to quickly move in the opposite direction. A little less intuitive, but just as true, is the fact that a book resting on a table applies a downward force equal to its weight on the table, and the table applies an equal and opposite force to the book. This force occurs because the weight of the book causes the table to deform slightly so that it pushes back on the book like a coiled spring. If the table were unable to do so, the weight of the book would break it.
Despite the far-reaching consequences of Johannes Gutenberg’s printing press, much about the man remains a mystery, buried deep beneath layers of Mainz history.
The German city of Mainz lies on the banks of the River Rhine. It is most notable for its wine, its cathedral and for being the home of Johannes Gutenberg, who introduced the printing press to Europe. Although these things may seem unconnected at first, here they overlap, merging and influencing one another.
The three elements converge on market days, when local producers and winemakers sell their goods in the main square surrounding the sprawling St Martin’s Cathedral. Diagonally opposite is the Gutenberg Museum, named after the city’s most famous inhabitant, who was born in Mainz around 1399 and died here 550 years ago in 1468.
The printing press marks the turning point from medieval times to modernity in the Western world
It was Gutenberg who invented Europe’s first movable metal type printing press, which started the printing revolution and marks the turning point from medieval times to modernity in the Western world. Although the Chinese were using woodblock printing many centuries earlier, with a complete printed book, made in 868, found in a cave in north-west China, movable type printing never became very popular in the East due to the importance of calligraphy, the complexity of hand-written Chinese and the large number of characters. Gutenberg’s press, however, was well suited to the European writing system, and its development was heavily influenced by the area from which it came.
The German city of Mainz is most notable for being the home of Johannes Gutenberg, the inventor of the movable metal type printing press (Credit: Madhvi Ramani)
In the Middle Ages, Mainz was one of the most important cathedral cities in the Holy Roman Empire, in which the Church and the archbishop of Mainz were the centre of influence and political power. Gutenberg, as an educated and entrepreneurial patrician, would have recognised the Church’s need to update the method of replicating manuscripts, which were hand-copied by monks. This was an incredibly slow and laborious process; one that could not keep up with the growing demand for books at the time. In his book, Revolutions in Communication: Media History from Gutenberg to the Digital Age, Dr Bill Kovarik, professor of communication at Radford University in the US state of Virginia, describes this capacity in terms of ‘monk power’, where ‘one monk’ equals a day’s work – about one page – for a manuscript copier. Gutenberg’s press amplified the power of a monk by 200 times.
At the Gutenberg Museum, I watched a demonstration of a page being printed on a replica of the press. First, a metal alloy was heated and poured into a matrix (a mould used to cast a letter). Once the alloy cooled, the small metal letters were arranged into words and sentences in a form and inked. Finally, paper was placed on top of the form and a heavy plate was pressed upon it, similar to how a wine press works. This is no coincidence: Gutenberg’s printing press is thought to be a modification of the wine press. Since the Romans introduced winemaking to the region, the area around Mainz has been one of Germany’s main wine-producing areas, with famous grape varieties such as riesling, dornfelder and silvaner.
The page that is always printed at the Gutenberg Museum replicates the original style and font (Gothic Textura) of the 42-line Gutenberg Bible, the first major book ever to be printed using movable type in the Western world. It is the first page of St John’s Gospel, in the Bible, which begins: “In the beginning was the word…”
Gutenberg’s printing press made it easier for the Church to replicate religious manuscripts (Credit: Madhvi Ramani)
Writing is often considered the first communication revolution, while Gutenberg’s printing press brought with it the revolution of mass communication. After about 15 years of development – and huge capital investment – Gutenberg printed his first Bible in 1455.
“Gutenberg’s Bible is an extraordinary work of craftsmanship,” said Dr Kovarik, who suggests we can read a strong religious motivation into the perfection of his work. “This wasn’t unusual at the time – for example, a stonemason would try to achieve a perfect sculpture in a remote corner of one of the great cathedrals, not really for the people who would be worshipping there, but rather as an expression of personal faith.”
Gutenberg’s printing press brought with it the revolution of mass communication
Of his original print run of about 150 to 180 Bibles, only 48 remain in the world today. The Gutenberg Museum has two on display. Both are slightly different, because after printing, the pages would be taken to a rubricator (specialised scriber) who would paint in certain letters according to the tastes of their customers. Gutenberg’s Bibles turned out to be bestsellers.
At first, the Church welcomed the new availability of printed bibles and other religious texts. Printing enabled the Church to spread the Christian message and raise cash in the form of ‘indulgences’ – printed documents that forgave people’s sins. However, the disruptive power of the printed word soon became apparent. With the rapid spread of printing technology – by the 1470s, every European city had printing companies, and by the 1500s, an estimated four million books had been printed and sold — came the spread of new and often contradictory ideas, such as Martin Luther’s 95 Theses, in which he criticised the Church’s sale of indulgences. Luther is said to have nailed his text to a Wittenberg church door on 31 October 1517. Within a few years 300,000 copies of it had been printed and circulated, leading to the Reformation and a permanent split in the Church.
Of the 150 to 180 Bibles Gutenberg originally printed, only 48 remain in the world today (Credit: Ann Johansson/Getty Images)
But despite the far-reaching consequences of Gutenburg’s press, much about the man remains a mystery, buried deep beneath layers of Mainz history. A plaque marks the place where he was born on corner of Christofsstraße, but the original house is long gone. Today, a modern building stands there, occupied by a pharmacy.
Another plaque outside the nearby St Christoph’s Church marks the place where he was likely baptised. The church was bombed during World War II and remains in ruins as a war memorial, although the original baptismal font from Gutenberg’s time is still intact.
The graveyard where Gutenberg was buried has been paved over, and even though there are statues of him are everywhere in the city, we don’t know what he looked like. He is commonly depicted with a beard, but it is unlikely that he had one. Gutenberg was a patrician and during his time, according to my tour guide Johanna Hein, only pilgrims and Jews wore beards. In fact, the man we all know as Johannes Gutenberg was actually born Johannes Gensfleisch (which translates to ‘goose meat’). If it weren’t for the 14th-Century trend of people renaming themselves after their houses, we would perhaps be referring to his invention as the Gensfleisch Press today.
Despite the far-reaching consequences of his printing press, little is known about Gutenberg today (Credit: Madhvi Ramani)
But although the traces of the man have all but disappeared from the city, his influence can still be seen everywhere: a poster advertising cosmetics; a woman reading a newspaper in a cafe; the menu on a restaurant table. Furthermore, our current communications revolution, made possible by the internet, digital technology and social media, is a progression of what started with Gutenberg.
“Every time the cost of media declines rapidly, you enable more people to speak out, and you have a greater diversity of voices,” said Dr Kovarik, explaining that this impacts the distribution of power in society, and sparks social change.
Although the traces of Gutenberg have all but disappeared from the city, his influence can still be seen everywhere (Credit: Lebrecht Music and Arts Photo Library/Alamy)
Paradoxically, however, our digital revolution can also be seen as a return to the pre-print era, according to a theory called The Gutenberg Parenthesis by Dr Thomas Pettitt, affiliate research professor at the University of Southern Denmark, who argues that there are parallels between the pre-print age and our own internet age.
In the absence of print, news has lost its authenticity, and, as in the Middle Ages, is synonymous with rumour
“Print conferred stability on discourse; works in books were authorities; news in print was true. In the absence of print, news has lost its authenticity, and, as in the Middle Ages, is synonymous with rumour. We are now in a post-news phase, where purveyors of fake news can accuse the legitimate press of purveying fake news and get away with it,” Dr Pettitt said.
Whatever the impact of the 21st-Century digital revolution, just like the printing revolution before it, the effects will reverberate for hundreds of years to come.
In 1971, a group of construction workers began digging on the slopes of a hill named Mawangdui, near the Chinese city of Changsha. Since the workers were about to construct a spacious air raid shelter for a nearby hospital, they were digging deep into the hill. Before 1971, the Mawangdui hill was never considered a place worth the attention of archaeologists. However, this changed when the workers stumbled upon what appeared to be a tomb hidden beneath many layers of soil and stone. The construction of the air-raid shelter was canceled and, several months after the workers’ accidental discovery, a group of international archaeologists began excavating the site.
The tomb turned out to be so massive that the excavation process lasted for nearly a year, and the archaeologists needed help from as many as 1,500 volunteers, mostly local high-school students. Their painstaking work paid off because they discovered the majestic ancient tomb of Li Chang, the Marquis of Dai, who governed the province approximately 2,200 years ago, during the rule of the Han dynasty. The tomb contained as many as 1,000 precious artifacts, including golden and silver figurines of musicians, mourners, and animals, intricately crafted household items, meticulously designed jewelry, and a whole collection of clothes made from fine ancient silk.
However, the value of these items was immediately topped by the discovery of the mummy of Xin Zhui, the wife of Li Chang and the Marquise of Dai. The mummy, which is nowadays known as Lady Dai, the Diva Mummy, and the Chinese Sleeping Beauty, was found wrapped in 20 layers of silk and sealed within four elaborate coffins enclosed in one another. The outermost coffin was painted black to emphasize death and the passing of the deceased into the underworld. It was also adorned with feathers of various birds because the ancient Chinese believed that the souls of the dead have to grow feathers and wings before being able to become immortal in the afterlife. The inner coffins depict Lady Dai alongside various mysterious landscapes of the underworld.
The archaeologists were stunned by the pristine condition of the mummy. Well-preserved mummies had been discovered before the discovery of Lady Dai, but her condition was unprecedented. Her hair was intact and her skin was soft and moist, showing virtually no signs of decomposition. Furthermore, her muscles were in such good condition that her limbs were actually bendable after she was sealed in an underground tomb for more than two millennia. Researchers concluded that she was most likely immersed in some kind of an unidentifiable acidic liquid which completely prevented decomposition.
An autopsy of Lady Dai was performed in December of 1972. It revealed that she died in her 50s, most likely of a heart attack that resulted from poor health. According to historians, Xin Zhui was an esteemed noblewoman who lived a lavish life of privilege and luxury. She was extremely fond of music and had a whole troop of musician-servants who performed for her whenever she pleased. She was most likely a skilled musician herself, a player of the quin, an ancient Chinese seven-string instrument which has been associated with wisdom, intellect, and prosperity. Also, since she was the wife of the Marquis, she was able to enjoy various kinds of food which were unavailable to the common people of the time, such as different kinds of shellfish, venison, mutton, and foreign fruit.
The autopsy also revealed that Lady Dai’s blood was type A and that she most likely suffered from diabetes. Despite her ailments, she outlived her husband and likely even her son: both of them were found buried in the same tomb alongside her, but their remains had decomposed over time.
Also, the researchers who performed the autopsy discovered melon seeds in Lady Dai’s stomach and concluded that she ate a melon just two hours before death.
While eating it, she was most likely unaware that her death was imminent. Also, she was unaware that curious scientists would probe her stomach 2,000 years in the future. Nowadays, the mummy of Lady Dai and most of the artifacts recovered from her tomb can be seen at the Hunan Provincial Museum.