Alex McColgan

This would have been an appropriate name, as any planet closer to the sun than Mercury would have been exceptionally hot. Mercury already experienced temperatures of 427 degrees Celsius. Vulcan would have been even hotter. And yet, for all these sightings, confirmation of the planet remained elusive. But what made Le Verrier's claim stand out was the way he had come to make it.

This would have been an appropriate name, as any planet closer to the sun than Mercury would have been exceptionally hot. Mercury already experienced temperatures of 427 degrees Celsius. Vulcan would have been even hotter. And yet, for all these sightings, confirmation of the planet remained elusive. But what made Le Verrier's claim stand out was the way he had come to make it.

This would have been an appropriate name, as any planet closer to the sun than Mercury would have been exceptionally hot. Mercury already experienced temperatures of 427 degrees Celsius. Vulcan would have been even hotter. And yet, for all these sightings, confirmation of the planet remained elusive. But what made Le Verrier's claim stand out was the way he had come to make it.

In 1845, before his discovery of Neptune, Le Verrier had been asked by the director of the Paris Observatory to apply Newton's laws of physics to the orbit of the planet Mercury, to see if the two lined up. Le Verrier did so, laying out a theoretical orbit that Mercury would take around the Sun based on Newtonian physics.

In 1845, before his discovery of Neptune, Le Verrier had been asked by the director of the Paris Observatory to apply Newton's laws of physics to the orbit of the planet Mercury, to see if the two lined up. Le Verrier did so, laying out a theoretical orbit that Mercury would take around the Sun based on Newtonian physics.

In 1845, before his discovery of Neptune, Le Verrier had been asked by the director of the Paris Observatory to apply Newton's laws of physics to the orbit of the planet Mercury, to see if the two lined up. Le Verrier did so, laying out a theoretical orbit that Mercury would take around the Sun based on Newtonian physics.

Once his prediction was made, astronomers observed Mercury to see how well it matched up. Only, it did not. Le Verrier tried again. Reasoning that it was possible his maths had been out, he did a much more thorough study in 1859. Using multiple observed sightings of Mercury as his baseline, he once again mapped out Mercury's orbit. But once again, his predictions were out.

Once his prediction was made, astronomers observed Mercury to see how well it matched up. Only, it did not. Le Verrier tried again. Reasoning that it was possible his maths had been out, he did a much more thorough study in 1859. Using multiple observed sightings of Mercury as his baseline, he once again mapped out Mercury's orbit. But once again, his predictions were out.

Once his prediction was made, astronomers observed Mercury to see how well it matched up. Only, it did not. Le Verrier tried again. Reasoning that it was possible his maths had been out, he did a much more thorough study in 1859. Using multiple observed sightings of Mercury as his baseline, he once again mapped out Mercury's orbit. But once again, his predictions were out.

Not by much, only 45 arcseconds per century, but enough that there was conclusively something weird going on. Confident of his maths this time, Le Verrier reached the conclusion that there must be some mass pulling Mercury out from the idealised orbit, either a planet or a series of asteroids. Given his success by now at locating Neptune, many astronomers believed him.

Not by much, only 45 arcseconds per century, but enough that there was conclusively something weird going on. Confident of his maths this time, Le Verrier reached the conclusion that there must be some mass pulling Mercury out from the idealised orbit, either a planet or a series of asteroids. Given his success by now at locating Neptune, many astronomers believed him.

Not by much, only 45 arcseconds per century, but enough that there was conclusively something weird going on. Confident of his maths this time, Le Verrier reached the conclusion that there must be some mass pulling Mercury out from the idealised orbit, either a planet or a series of asteroids. Given his success by now at locating Neptune, many astronomers believed him.

Scientists rushed to telescopes to try and spot the alleged planet, and it wasn't long before results began to come in. Spotting a planet so close to the Sun was inherently difficult. The glare of the Sun would completely obliterate the reflected shine of a tiny planet. As such, the most effective method of spotting such an object was to see the darkening it caused as it travelled across the Sun.

Scientists rushed to telescopes to try and spot the alleged planet, and it wasn't long before results began to come in. Spotting a planet so close to the Sun was inherently difficult. The glare of the Sun would completely obliterate the reflected shine of a tiny planet. As such, the most effective method of spotting such an object was to see the darkening it caused as it travelled across the Sun.

Scientists rushed to telescopes to try and spot the alleged planet, and it wasn't long before results began to come in. Spotting a planet so close to the Sun was inherently difficult. The glare of the Sun would completely obliterate the reflected shine of a tiny planet. As such, the most effective method of spotting such an object was to see the darkening it caused as it travelled across the Sun.

And in 1859, Edmond Modeste Lescarbol claimed to have seen just that. Lescarbol was a French amateur astronomer and physician who, using basic tools in a homemade observatory, claimed to have spotted a small black object passing by the Sun on the 22nd of December. He wrote to Le Verrier, who was so taken by his claim that he travelled by train to the man's home unannounced to verify it.

And in 1859, Edmond Modeste Lescarbol claimed to have seen just that. Lescarbol was a French amateur astronomer and physician who, using basic tools in a homemade observatory, claimed to have spotted a small black object passing by the Sun on the 22nd of December. He wrote to Le Verrier, who was so taken by his claim that he travelled by train to the man's home unannounced to verify it.

And in 1859, Edmond Modeste Lescarbol claimed to have seen just that. Lescarbol was a French amateur astronomer and physician who, using basic tools in a homemade observatory, claimed to have spotted a small black object passing by the Sun on the 22nd of December. He wrote to Le Verrier, who was so taken by his claim that he travelled by train to the man's home unannounced to verify it.

He questioned Lescarbol, heard his observations, and came to the conclusion that the man was telling the truth. So, the two of them announced to the scientific community Les Carbol's discovery. They named the planet Vulcan. The scientific community was once again very impressed. Lescarbol was given the Légion d'honneur, the highest order of merit in France.

He questioned Lescarbol, heard his observations, and came to the conclusion that the man was telling the truth. So, the two of them announced to the scientific community Les Carbol's discovery. They named the planet Vulcan. The scientific community was once again very impressed. Lescarbol was given the Légion d'honneur, the highest order of merit in France.