The great Moon hoax of 1835

Tall tales about the moon

Photo: Contributed

Today, we are all familiar with the enormous amount of fake and misleading material clogging up the Internet.

However, what was probably the most widely believed fake news story in astronomy happened back in the 19th century. It sold many thousands of newspapers as readers devoured each instalment of what was a work of fiction.

In 1833, British astronomer John Herschel finished cataloguing objects in the northern sky and decided to do the same for the southern sky too. That would require moving to the Southern Hemisphere, so in 1834 he and his family moved to the southern tip of South Africa.

It so happened that around the same time, the British Admiralty decided an observatory should be set up in the Southern Hemisphere to help advance navigation. That complemented the work of the Royal Greenwich Observatory, operating on the outskirts of London, in the Northern Hemisphere. The observatory was very close to Herschel's home, so it was inevitable that he and Thomas Maclear, the director of the observatory, would end up working together on a number of projects, some astronomical, and some not.

Robert Locke was a reporter for a New York newspaper. For some reason, he latched on to Herschel's move to South Africa and wrote an article about his going there with an amazing new telescope, which he planned to use to observe the Moon. It was so powerful it would even show insects (if any) crawling around on the lunar surface.

This was rubbish. Even today we cannot make such a telescope. Locke came up with a fictitious “Dr. Grant,” who went with Herschel and would report back on the astronomical discoveries as they rolled out. Grant "reported" the telescope would soon start to show the most amazing things. There then followed a series of articles extolling the capabilities of the marvellous new telescope. Interest was huge. America was agog, and wanted to read more.

As one might expect, Herschel and his telescope produced no such revelations, so Locke filled the gap with his imagination. He first reported the dark patches we see on the face of the Moon, and named after seas, were in fact really water oceans, not the plains of solidified lava we know them to be today.

At the time, few members of the public knew what those dark patches were, so the idea they were really oceans was widely accepted. Locke went on write about plants and forests on the lunar surface. The telescope was so powerful, individual flowers could be seen and identified.

Understandably, public interest was intense. However, to sustain this level of excitement, new, more dramatic discoveries were needed. So Locke put his imagination to work again. He reported the observation of amethysts, 30 metres tall, sticking up out of the sea. This was certainly amazing stuff, but what the public really wanted to know was if there was animal life on the Moon, especially people.

Further articles described large, bison-like animals, grazing close to the edge of lunar woodland. There were lots of other animals too, including huge beavers that walked on two feet, carrying their young in their arms. As one might have expected, there were also unicorns.

Finally, Locke reported Hershel saw people, just like us but with bat wings, because the lower lunar gravity made flight possible. On the Moon we would weigh about a sixth of what we weigh here on Earth.

To dig himself out of the hole he had dug himself into, he said the telescope had been destroyed in a fire.

Rather belatedly the newspaper called in experts to evaluate the articles and Locke admitted it was a hoax. Surprisingly, it all calmed down, everybody had a good laugh and Herschel himself largely ignored the whole thing.

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•Saturn lies in the southeast after sunset, with Jupiter in the east.

•Venus rises in the early hours.

• The Moon will reach its last quarter Dec. 4.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

Astromomy is a changing science

Learning more about space

Photo: Pixabay

It was a clear, sunny day on Mars, with just a few streaks of cirrus cloud. A range of low hills defined the horizon.

That was one of the images sent back to us by one of the robots we have exploring the Red Planet. Then we have pictures transmitted back from Titan, Saturn's largest moon, showing the rocky bed of a dried up stream. We have rock samples from the Moon, from an asteroid, and close-up images of many bodies in the Solar System. We even have images from the surface of Venus, sent back before the spacecraft melted.

For most of its history, astronomy consisted mainly of observing dots in the sky. Our ancestors assessed their brightnesses and recorded their positions. They noticed that some dots were in groupings that did not change. Those were stars, and those groupings became the constellations we know today.

There were a few other dots that moved to and fro along a defined path in the sky. Those were the planets. One thing our ancestor astronomers noticed was the heavens were orderly, stable and highly predictable. This contrasted strongly with the unpredictability of life down here on the ground.

The relative stability of the heavens is why people panicked when something new turned up in the sky, such as a comet. Later, when telescopes were invented, we could see that planets are different from stars, and we could even see surface features on some of them. The Moon changed from a smooth heavenly body to a rock ball, pocked with craters and old lava flows.

In those days, sciences like geology, meteorology and biology, were aimed at better understanding our own planet. Applying them to other worlds was left largely to science fiction writers. Now things have completely changed. Thanks to improved telescopes, spacecraft observing bodies in the Solar System from up close, or even landing on them, we can now study other worlds almost as freely as we can study our own. We can now buy textbooks on the geology of Mars, or the Moon. We can even study the weather on other worlds. They have become places we can relate with ours.

Not long ago, we thought there were planets orbiting other stars, but we did not know. Since then, we have discovered thousands of them. Almost every star has planets, some of which could be like our own. We even know whether some of these planets have atmospheres, and scientists are actively searching those atmospheres for chemical markers of life. We now know we live on one world among many, orbiting one star among billions, in one galaxy among billions. It is hard to imagine our planet could be the only inhabited one.

Thanks to our rapidly expanding knowledge of other worlds we can apply what we used to think of as the “earth sciences,” such as geology, to other worlds. This is making it possible to compare the forces moulding other planets with those shaping ours.

These comparisons are raising important questions, such as if Venus, Earth and Mars were similar when they formed, why are they so different now? We thought we knew why our Solar System is structured as it is, and assumed other systems would be similar. However, now we know the Solar System is by no means typical. Few extrasolar planetary systems are anything like ours.

On Feb. 14, 1990, NASA's Voyager 1 spacecraft, then around six billion kilometres away and leaving the Solar System, looked back and took a picture of the Earth. It showed our planet as a tiny, faint blue dot against the blackness of space; it was just another dot in the sky.

Astronomy has changed from a science aimed at improving our understanding of what is going on "out there", to a science that is also improving our understanding of what is going on “down here.”

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• Saturn lies in the south after sunset, with Jupiter in the east.

• Venus rises in the early hours.

• The Moon will be full on Nov. 27

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

Space telescope gives a closer look at the birth of stars

The birth of a star

Photo: Contributed

James Webb Space Telescope

Stars are the universe's Swiss Army knives.

Starting from the primordial hydrogen dating back to the beginning of the universe, they produce all the elements required for making planets and living things. In addition they provide the light and heat needed for that life to form and thrive.

Without stars the universe would be a dark, cold place, without even the ingredients for life.

Because they are so important in the universe, stars attract a lot of scientific interest. We have a lot of observational information on stars during their lives, and on how their lives end, because the mass ejections, explosions and brightness variations are relatively easy to observe, as are the stellar remains, such as white dwarf stars, neutron stars and supernova remnants.

Observing star birth is more difficult, since the big event is discreetly hidden inside clouds of gas and dust.

There is, however, a solution. If you have ever driven in fog and found wearing orange or red glasses makes it easier to see, you were seeing the answer. The problem is mostly due to a process called “scattering,” where the light is radiated off in all directions by tiny dust particles, or water droplets in the case of fog.

Scattering is strongly dependent on the wavelength of the light. Short wavelengths, such as blue and green are strongly scattered, red much less so. Infrared light has a longer wavelength than red light and is scattered even less, ideal for looking inside stellar birth clouds, except that those wavelengths are absorbed by our atmosphere.

We need to observe cosmic infrared light from above the atmosphere, in space. That is where the James Webb Space Telescope (JWST) comes in. It is designed to observe at infrared wavelengths that do not reach the ground. This makes it ideal for studying the birth and extreme youth of stars.

One of the most recent JWST images shows a sun-like star that has been shining for no more than 50,000 years. The object, poetically named HH212, lies in the constellation of Orion. This constellation, named after a mythical hunter, is the most spectacular star grouping in our winter skies.

The most easy-to-spot feature is a line of three stars, representing the hunter's belt. HH212 is close to these stars, and lies at a distance of about 1,300 light years from us. The JWST image shows two pink jets shooting out in opposite directions. That pink colour is produced by hydrogen. Since clouds take around a million years to produce stars, and sun-like stars shine for maybe 10 billion years, that star is very young. It has probably achieved nuclear fusion, but still growing by pulling in material from its birth cloud.

Any random cloud of gas and dust in space is generally travelling in some direction, and is also rotating. Just as in the case of a twirling skater or ballerina pulling in her arms, the rotation accelerates as the cloud shrinks.

Part of the material forms a rapidly rotating protostar (star to be). The rest forms a disc, some of which is rotating too quickly to collapse onto the star. This will form planets, asteroids and other bodies.

There are magnetic fields in the cloud, which also get concentrated in the disc and in the young star. These combine with very hot gas to form a material rather like putty. This resists being compressed by infalling material from the disc and squeezes out from the pole regions of the star as two jets, more or less at right angles to the disc.

This young star has not yet settled down to steady shining and is producing lots of little burps and explosions, which launch shock waves outward. These make the hydrogen in those jets glow with that characteristic pink colour.

If we could see back 4.5 billion years to the birth of our sun, we would probably see something like this.

•••

• Saturn lies in the south after sunset, with Jupiter in the east.

• Venus will rises in the early hours.

• The Moon will reach its first quarter on Nov. 20.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

In a galaxy far away and long ago

Pulse that created it all

Photo: Pixabay

A colossal energy release in a distant galaxy eight billion years ago is believed to have led to the creation of Earth, the Sun and other planets 4.5 billion years later.

It happened eight billion years ago.

The birth of our planet, the Sun and the other bodies of the Solar System lay some 3.5 billion years in the future. There was a colossal energy release in a distant galaxy. One of the things it caused was a pulse of radio energy of enormous power, but only about a millisecond long. That pulse was radiated into space in all directions, including the one in which, billions of years later, our world would form.

As that pulse of radio energy travelled through intergalactic space, the Solar System was born, and soon after, life appeared on the Earth. The dinosaurs came and went, our ancestors came down out of the trees and gradually developed a high-tech society. They became interested in astronomy and eventually built highly sensitive optical and radio telescopes.

When it arrived at Earth, the pulse, now extremely weak, was detected by the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, a development prototype for the Square Kilometre Array, an international project to build the largest radio telescope in the world. Australia is a participant and so is Canada.

These short radio pulses have been known for some years, and have come to be called “fast radio bursts.”

Many have been detected, mainly by the ASKAP radio telescope in the Southern Hemisphere, and in the Northern Hemisphere by the CHIME radio telescope, located at our observatory.

This particular pulse is especially interesting because it is the most intense yet detected, and comes from the farthest away.

To be detectable after travelling eight billion light years, that pulse of radio emission must have been unbelievably strong. Moreover, if it was a mere millisecond in duration, the source could not be larger than the distance it takes light and radio waves to travel in a millisecond, meaning the source has to be smaller than 300 kilometres.

For comparison, the Moon has a diameter of 3,475 km, more than eleven times larger. Yet, that tiny object managed to emit, in that pulse, the total amount of energy produced by the Sun over 30 years. There are three objects that are extremely compact which can generate huge energy releases—black holes, neutron stars and magnetars.

Black holes are the ultimate energy machine—drop stuff in. You get almost total conversion of mass into energy. However, black holes are not good at producing short, sharp pulses of radio energy.

Neutron stars, the collapsed cores of dead stars shrunken down to a few kilometres in diameter, can produce pulses of radio waves, but not strong enough to explain fast radio bursts.

The most popular candidate at the moment is the magnetar. These are neutron stars with exceptionally strong magnetic fields. These are so strong that if we were miraculously transported to the surface of a magnetar, and were not instantly killed by the heat, radiation and enormous gravitational attraction, we would be killed by the magnetic fields disrupting our life processes.

If by some further miracle we could walk on that surface and survive, we would find it easy to walk in the direction of the magnetic fields and almost impossible to walk across them.

One way magnetars produce intense energy releases is through stressing their intense magnetic fields. As magnetars spin, these magnetic fields can get increasingly wound up and distorted, storing enormous amounts of energy, like an unimaginably huge, stretched elastic. Eventually, just as in the case of an over-stretched elastic band, the stresses in the distorted magnetic fields get too much and they snap, releasing pulses of energy strong enough to detect billions of light years away.

That is something to ponder.

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• Saturn lies in the south after sunset, with Jupiter shining in the east.

• Venus rises in the early hours.

• The Moon will be new on Nov. 13.

Ken Tapping is an astronomer with the National Research Council's Dominion Radio Astrophysical Observatory near Penticton.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.