I want to be remembered as someone who used whatever talent she had to do her work to the best of her ability.
Ruth Bader Ginsburg (1933-2020), associate justice of the Supreme Court of the United States
On 14th September 2020 the Royal Astronomical Society announced the discovery of a rare molecule, phosphine – PH3, the phosphorous equivalent of ammonia – in the clouds of Venus (Note: on the 16th of October 2020 the news was corrected and declared invalid). On Earth this gas is either made industrially, or produced by microbes living in oxygen-free environments.
Phosphine could indicate the presence of aerobic bacteria living in the upper Venusian atmosphere, which has a more tolerable temperature (30o C) compared to surface temperatures of over 400o C. The article reported the presence of 20 ppb (parts per billion) of phosphine by volume in the atmosphere, equivalent roughly to the volume of a single rice grain in 1000 kg of rice. The authors are rightly cautious about the origins and warn against over interpretations. Professor Jane Greaves of Cardiff University, the leading author of this study published in Nature Astronomy, says that at the moment it is still difficult to understand how these bacteria, if they are present at all, can survive in the highly acidic atmosphere of Venus. The bacteria responsible for phosphine production on Earth can only tolerate 5% of the acidity present in the Venusian clouds.
Around 3600 years ago – the tables of Venus of Ammisaduqa
The Assyro-Babylonians arrived first, compiling a 21-year-long astronomical record of the rising and setting of Venus. They were also the first to understand that the morning star and the evening star were the same thing (which initially deceived the Egyptians and the Greeks, who believed they were two different celestial bodies).
Around 2300 years ago – Aphrodite
The Greeks eventually understood that the first star of the morning and the first star of the evening were the same thing, and they named this “star” Aphrodite, in honor of the goddess of love.
Around 1200 – The Code of Dresden
The Maya produced an almanac showing the complete cycle of Venus, and developed a religious calendar based on the movements of the planet, which they call Noh Ek, the great star.
1610 – Galileo
In 1610 Galileo Galilei confirmed that Venus was a planet and not a star, also confirming Copernicus’ theories about the motion of the planets around the sun.
1627 – The first scientific forecast
Kepler predicted the 1631 transit of Venus across the face of the sun, but, despite not being what we would call an amateur in the subject matter, made an error in calculating the elliptical orbits of the planets. This didn’t allow him to predict that this transit would have occurred after the sun had set (and would thus be invisible) in almost all of Europe.
1639 – The first scientific observation
The first direct observation of a transit of Venus was made by Jeremiah Horrocks, aged only 21, from his home in England on 4th December 1639, using a telescope not much more powerful than the one used by Galilei, his spectacles and a piece of paper attached to a wall. Horrocks, an amateur astrophile who attended Cambridge University between the ages of 14-17, but never graduated, was able to predict the transit by understanding and correcting the calculation error made by Kepler. The transit of 1639, had not been predicted by Kepler, and was seen, in all probability, only by Horrocks and his friend William Crabtree, from their country homes.
1761 – What color is the sky of Venus?
Mikhail Lomonosov, a Russian polymath, theorizes that Venus had an atmosphere using a two-lens achromatic refractor and a sun filter. Lomonosov saw a halo around the planet when Venus entered and exited the sun, and interpreted this effect as the refraction of sunlight through an atmosphere. But don’t be fooled: sky on Venus is not blue. Due to the dense clouds the sky on Venus is not blue, but more of a gloomy orangy-grey.
1961-1964 – Retrograde rotation
Until the 19th century it was believed that the Venusian day lasted, like Earth, 24 hours. It was Giovanni Schiaparelli, around 1860, who first proposed a much slower rotation of Venus. The rotation of Venus was measured for the first time in 1961, and in 1964 was confirmed that it was retrograde (if you could see it through the clouds, the sun would rise in the west) and that one rotation of the planet takes 243 Earth days, longer than it takes Venus to orbit the sun (225 Earth days). The combination of slow retrograde rotation and fairly rapid orbit gives just less than 2 Venusian solar days per Venus year!
1961 – Sputnik 7 and Venera 1 – the first attempt
At the start of the space race, the Russians are the first to try to reach Venus, launching the Sputnik 7 rocket loaded with the Venera 1 probe. Once in Earth orbit, the launch engines on the rocket bound for Venus failed, it appears no one thought about how to engineer a transformer to work in vacuum! Sputnik re-entered our atmosphere after a 22-day tour around the Earth, but lessons had been learned about launching such large and ambitious space-craft.
1962- Mariner 2 – the first probe
The first probe that reached Venus was the American Mariner 2, which flew past the planet on 14th December 1962 and accurately measured the atmospheric temperature of Venus (around 500o C). “It’s rather hot” said the understated official press release.
1966 – Venera 3 – the first arrival
On 1st March 1966 the Soviet probe Venera 3 was the first probe to enter the atmosphere of Venus. Radio transmissions failed (due to the extreme heat) before being able to tell us if or how the landing went.
1967 – Venera 4 – the first probe to actually transmit
Venera 4 enters the Venusian atmosphere on 18th October 1967, confirming that the air on Venus is not the finest: the atmosphere is made up of 95% CO2 and the pressure on the ground was calculated to be up to 100 times atmospheric pressure on Earth, which is like being 1 km under the sea. Venera 4 fell victim to the increasing pressure and temperature at an altitude of 25 km while crossing through the thick cloud blanket.
1970 – Venera 7 and its 23 minutes of glory
Venera 7 was the first robot to land on the surface of Venus on 15th December 1970. During descent, the probe’s parachute broke and Venus 7 started a long free-fall, ending with a 16 m/s (37 mph) “landing” on something hard. Venera 7 did not last long, but from the surface, with damaged antennas, transmitted for 23 minutes, confirming there was no water on Venus, that the temperature is not ideal for growing roses, reaching 475o C and the surface is entirely covered by 35 km thick clouds, giving Venus only 3% of the sunlight that there is on Earth, albeit much closer to the sun.
1989 – Magellan – what’s hidden under those clouds
The Magellan orbiter, also called Venus Radar Mapper, was a spacecraft launched by NASA on 4th May 1989 to map Venus’ surface. Magellan was the fifth successful mission NASA launched to our neighbor. For the first time we could see through the cloud to observe the actual terrain of this planet: a contorted, rocky world, covered by lava flows and volcanic edifices, with only a few areas that look like our continents emerging from what might have been a now dried up ocean. The surface of Venus appears geologically young, testament perhaps to planet wide volcanic convulsions reshaping the surface. All in all, not much of a divine twin sister for Earth.
Odd curiosity: NASA maintains the original webpage of the Magellan mission as “historical document” of the primordial Internet era. You can check it out here.
2005 – The first time for Europe
The Venus Express was the first mission of the European Space Agency (ESA) aimed exclusively at Venus. Launched in 2005, for 8 years the Venus Express satellite transmitted data about the Venusian atmosphere, its winds and its circulation.
The Japanese mission, also called the Venus Climate Orbiter (VCO), is a space probe built to study Venus’ atmosphere, in particular its stratification (if you want to know why atmospheric stratification on Venus is important check out the documentary we recommend at the end).
2030 – NASA returns to Venus after forty years of absence – On June 2nd 2021, NASA announced its return to Venus with two missions, DAVINCI+ and VERITAS, which will respectively study the evolution of the Venusian atmosphere and its geological history (it is still unclear whether Venus has plate tectonics or not). Both are scheduled for launch between 2028 and 2030.
Botticellian Amazons | Science fiction set on Venus dates back to the late 19th century, when it became public knowledge that Venus was similar to the Earth and had an atmosphere. The fact that it was closer to the sun automatically led to the idea of a warmer planet, and this, to 19th and 20th century authors, meant only one thing: scantily clad women. The 1950s and 1960s treated us to Zsa Zsa Gabor as the cruel queen Yllana in “Queen of Outer Space“; the Russian “Voyage to the Planet of Prehistoric Women” where, thanks to a fine Botticellian cross-over, women not only wore bikinis, but they were made of shells; to the Planet Stories comic books in which Venus was inhabited by Amazons in golden bras (because it was very hot, of course). The genre flourished and proliferated until the discoveries of the late 60s and 70s made it clear that it was too hot even for the golden bras to survive. Reality killed the genre, which never actually recovered.
Venus – Death of A planet | This documentary can be found streaming on Magellan TV. If you do not have a subscription, but have never used Magellan TV, you can still watch it for free. It talks about a possible colony on Venus with space bases floating in the upper part of the atmosphere. Very sci-fi, a bit over-dramatized, and with a mildly irritating overuse of the words “tormented”, “hellish” and “terrible”, nonetheless it is quite rigorous in its background, with some interviews with top scientists, and is still engaging.
Tori Amos “To Venus and Back” | Electronic experimentation and unpredictable musical structures from Neil Gaiman’s muse’s fifth studio album (Gaiman’s “Delirium” character in Sandman is inspired by her). Not for everyone.
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