A world famous astrophotographer risked his own eyesight in a bid to capture a stunning image of Venus as it passed perilously close to the sun.
Andrew McCarthy, from Arizona, US, takes some of the most striking and detailed images of astronomical objects, and shares them on social media as @Cosmic_Background.
When producing his latest creation, a sensational view of Venus just five degrees from the sun, he put his own eyesight on the line to get the shot.
He had no way of seeing his target, Earth’s ‘evil twin’ world, until it was in the viewfinder, so made use of a filter to plan the precise moment to expose the lens of his camera, and avoid ruining both his vision and the telescope with sunlight.
‘This is the most dangerous shot I’ve ever attempted,’ McCarthy said, adding that if he had attempted to see the shot visually he ‘could have easily blinded’ himself.
A world famous astrophotographer risked his own eyesight in a bid to capture a stunning image of Venus as it passed perilously close to the sun
Andrew McCarthy, from Arizona, US, takes some of the most striking and detailed images of astronomical objects, and shares them online as CosmicBackground
VENUS: THE BASICS
Venus, the second planet from the sun, is a rocky world about the same size and mass as the Earth.
However, its atmosphere is radically different to ours – being 96 per cent carbon dioxide and having a surface temperature of 867°F (464°C) and pressure 92 times that of on the Earth.
The inhospitable planet is swaddled in clouds of sulphuric acid that make the surface impossible to glimpse.
In the past, it has been suggested that Venus likely had oceans similar to Earth’s – but these would have vaporised as it underwent a runaway greenhouse effect.
The surface of Venus is a dry desertscape, which is periodically changed by volcanic activity.
Facts and Figures
Orbital period: 225 days
Surface area: 460.2 million km²
Distance from Sun: 108.2 million km
Length of day: 116d 18h 0m
Radius: 6,051.8 km
Mass: 4.867 × 10^24 kg (0.815 M⊕)
For the latest image, McCarthy wanted to capture Venus as it was bathed in the light from the nearby sun — but this is a tricky picture to get.
‘Venus was so close to the sun I had to stand in front of my telescope during capture to use my body’s shadow to protect the focused light from the sun from entering it as I captured,’ the astrophotographer explained.
‘Any wrong move while attempting to find Venus could result in inadvertently letting the sun’s light into the scope, which would instantly ruin the camera I was using.’
Due to the planet’s position almost right in front of the sun, the light appears as a ring around Venus, highlighting the hot world’s surface, with the sun scattering in the atmosphere, creating a silhouette of the shaded surface.
‘Ordinarily, photographing Venus is no more dangerous than photographing any of the other planets. It’s not dangerous at all,’ McCarthy explained.
‘But on this particular day, Venus was less than 5 degrees away from the sun, which meant the slightest mistake and the sun’s light could reach focus within the telescope, which would be a disaster.
‘My telescope was unfiltered and pointed dangerously close to the sun, at a target I was unable to see until it was in frame.’
To mitigate the risks involved, McCarthy spent time planning a careful approach to taking the incredibly dangerous photograph.
He said: ‘I started by pointing the telescope at the sun using a filter, which allowed me to precisely sync my telescope’s position with the computer in the mount that controlled it.
‘By then telling it to slew to Venus’s position, I was able to ensure I wouldn’t need to slew around hunting for the planet and accidentally have the sun’s light fry my camera.
‘Once I was sure the sun’s light wasn’t in frame, I removed the filter to observe the planet.’
The astrophotographer even made a video showing the effects of direct sunlight into a telescope – by scorching a piece of wood in just a few seconds
The planet wasn’t visible with the filter attached, but the filter was needed during positioning to reduce the risk of harming the camera or his eyesight
The planet wasn’t visible with the filter attached, but the filter was needed during positioning to reduce the risk of harming the camera or his eyesight.
‘It wasn’t without its own challenges, and it took me a few tries before I was able to get the planet centred in the field of view, but it felt like the safest way to do this.’
The astrophotographer even made a video showing the effects of direct sunlight into a telescope – by scorching a piece of wood in just a few seconds.
Sharing images on social media as @Cosmic_Background, McCarthy has become world famous for his amazing images of the solar system and beyond.
From comets at their closest passing of the Earth, to the most detailed images of the surfaces of the moon and the sun, the dedicated astrophotographer spends hours upon hours gazing through his telescope
Some of the images he captures, including a recent detailed view of the surface of the sun, are made up of tens of thousands of photographs to gather lots of data.