Signs of Life on the ‘Morning Star’

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Illustration of the surface of Venus protected by a thick atmosphere. The presence of sulfuric acid on the planet allows lightning to occur.

“I look at the sky full of scattered stars. They twinkle simply like diamonds. One of them appears with brightest light. That\'s my star, the beautiful Morning Star.”

Indonesian children are likely to be familiar with the song "Bintang Kejora" (Morning Star) by A.T. Mahmud. At dawn Tuesday (15/9/2020), the Kejora was seen on the eastern horizon. Its light is very bright and its presence that always accompanies the sun makes this object easy to recognize.

Although the archipelago’s people call it a star, as in “Lintang Panjer Isuk” or “Lintang Panjer Sore” (Javanese) or “Bintoeng Bawi” (Buginese), “Bintang Kejora” is actually a planet, Venus. In the past, all bright objects in the sky were called stars, and no distinction was made between stars, planets, meteors or comets as modern astronomy does.

Venus is a planet that is closer to the Sun than the Earth, and is only visible shortly before sunrise or just after sunset. The planet is positioned near the horizon when viewed on Earth, and will never be visible high overhead or at midnight.

Over the last few decades, astronomers had hoped to find life on Earth’s closest neighboring planet. However, the extreme atmospheric conditions on Venus do not put the planet at the top of the list of places in the solar system that could potentially sustain life from Earth.

Although it is considered Earth\'s twin because of its similarity in size, mass and geological processes, the condition on Venus is often referred to as “hell”. With an atmosphere containing 96 percent carbon dioxide, an average surface temperature of 464 degrees Celsius and a surface pressure 90 times Earth’s, many experts are pessimistic that the planet can support life.

In the past, all bright objects in the sky were called stars, and no distinction was made between stars, planets, meteors or comets as modern astronomy does.

KOMPAS/STELLARIUM

The position of the planet Venus as seen from Jakarta on Monday (27/4/2020) at 18.30 WIB. Venus is visible below the west-northwest direction. Above Venus there is the Moon and the upper left is the constellation Orion or Lintang Waluku.

However, a study led by Jane S. Greaves of Cardiff University in the United Kingdom and published on Monday (14/9) in the journal Nature Astronomy, has found phosphine gas in the Venusian atmosphere. This gas is found at an altitude 50-60 kilometers above the planet’s surface, where the temperature drops to 20-30 degrees Celsius.

Phosphine is a gaseous chemical compound containing one phosphorus atom and three hydrogen atoms. The gas’s existence is often referred to as a sign of life on other planets or satellites in the solar system.

The research team first detected the presence of phosphine on Venus in June 2017 a using the James Clerk Maxwell radio telescope in Hawaii, the United States. To confirm the finding, the team reexamined the planet in March 2019 using the Atacama Large Millimeter Array (ALMA) radio telescope in Chile.

The ALMA research found that a layer of the Venusian atmosphere contains 20 parts per billion (ppb) of phosphine. This means that 20 molecules of phosphine are present in 1 billion atmospheric molecules on Venus. This is equivalent to the phosphine detected on Jupiter and Saturn, and much greater than the phosphine on Earth.

As reported in the BBC, the phosphine on Earth is produced by intestinal microbes in animals like penguins, or in oxygen-poor environments like swamps. The gas is also produced through industrial processes, as well as abiotic, or nonbiological, processes like volcanic activity, lightning and falling meteorite.

KOMPAS/Planet-C Project Team/JAXA

Image of the planet Venus taken by the Japanese Akatsuki spacecraft. During March-May 2020, Venus will be visible in the western sky, shortly after sunset and will set around 7 pm.

From long ago, experts suspected that even if there were life on Venus, it would not be on the planet’s surface, but in the upper atmosphere.

Factories and various abiotic processes produce 10,000 times less phosphine than what has been detected on Venus. Thus, the main theory for the gas’s existence on the planet is that certain microbes exist there.

"From long ago, experts suspected that even if there were life on Venus, it would not be on the planet’s surface, but in the upper atmosphere," said an astrobiological researcher and astronomy professor Taufiq Hidayat of the Bandung Institute of Technology.

Just a sign

Even with this discovery of a sign of potential life, experts cautioned that it was too early to conclude that there was life on Venus.

"This discovery especially is just another reminder of how much more we have yet to learn about Venus," said astrobiologist Victoria Meadows of the University of Washington, in the US, as quoted on Space.com.

Skepticism is necessary in light of the extreme Venusian environment. The clouds on Venus are very thick and contain 75-95 percent sulfuric acid, which can destroy the cellular structure of organisms on Earth.

To survive in this environment with high sulfuric acid content, biochemist William Bains, who is affiliated with the Massachusetts Institute of Technology (MIT) in the US and was involved in the research, said that the microbes in Venus\' air could have a biochemical system that was different from organisms on Earth. At the very least, they must have some kind of “armor” or a protective system.

KOMPAS/STELLARIUM

Planet Venus or Morning Star from the Jakarta sky which is seen on May 4, 2019 at around 05.00 WIB.

In addition, experts have challenged the idea of phosphine as an indication of organic life. Moreover, that the research team found 1,000 times more phosphine on Venus than on Earth was also odd. Matthew Pasek, an astrobiologist and geochemist at the University of South Florida who was not involved in the research, noted that Earth, with its myriad biological activities, should have a greater amount of phosphine than Venus.

Some scientists have also warned that phosphine was not always produced through biological activity, and that more laboratory research was needed to support this hypothesis.

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It will take many more missions to Venus to confirm any potential life on the planet. In the 1960s to 1990s, the Soviet Union’s Venera missions collected a great deal of information about Venus, including the first photographs of the surface of Venus taken during the Venera 9 mission in 1975.

Most recentky, the European Union launched its Venus Express mission to the planet in 2005 and Japan launched the Akatsuki Venus Climate Orbiter in 2010.

The answer to the mystery of life on Venus is entirely dependent on future space missions. "Ideally, a lander should again be sent to Venus," said Taufiq.