Venus mission could indicate Earth’s long-term future: Dr Mylswamy Annadurai

Interview/ Mylswamy Annadurai, project director, Chandrayaan 1 & 2, and programme director, Mangalyaan

Mylswamy Annadurai was the project director of Chandrayaan 1 & 2, and programme director, Mangalyaan. In an exclusive interview with THE WEEK, he talks about why the Venus and Mars missions matter for the scientific community across the world. Excerpts:

Q/ What is your view on the Venus missions of India and others?

Missions to Venus were primarily driven by the basic curiosity of why the twin planets of earth and Venus evolved in two different ways. Many missions were sent in the 1960s and 1970s, but the answer was elusive. It led to almost no missions in the past four decades. But the advent of new instruments rekindles [interest].

Q/ How would a trip to Venus help us understand earth’s evolution?

Some planetary models suggest that early Venus may have had a global ocean of liquid water that covered much of its surface. This ocean would have been similar in size to earth’s oceans and may have persisted for hundreds of millions or even billions of years. During this time, earth and Venus would have been much more obvious twins. However... one became habitable, the other a runaway greenhouse world. The exact causes for this diverse dramatic evolution still aren’t known. To find out what happened, we need to send more missions. Venus sits at what planetary scientists say is the ‘inner edge of the habitable zone’, making it a natural laboratory for studying planetary habitability limits. In other words, this may possibly indicate earth’s long-term future, too.

Q/ What additional information can we get from newer Venus missions?

Technically speaking, earlier missions—Venera, Pioneer Venus, Magellan—gave us first‑generation data. Basic atmospheric composition, coarse radar maps and short‑lived lander measurements.

The new missions—Shukrayaan, DAVINCI, VERITAS, EnVision—bring 21st‑century sensors, far superior resolution and entirely new scientific capabilities. Earlier missions provided atmospheric composition and radar maps at 100m–300m resolution. They revealed volcanoes, plains and tesserae—but not fine details.

ISRO’s Shukrayaan carries instruments to study surface emissivity and subsurface thermal signatures. This will reveal buried lava channels, ancient crystal blocks, evidence of past oceans, subsurface water‑bearing minerals. This will be the first‑time there is access to Venus’s hidden geological history.

Upcoming missions such as Shukrayaan will help explain aspects such as how Venus lost its water, how atmospheres evolve without magnetic fields, etc.

VERITAS and EnVision, for instance, will operate for years, enabling time‑series monitoring, seasonal atmospheric studies, detection of active geological changes, leading to a new era of continuous Venus observation.

Q/ Why has Venus always puzzled scientists?

Despite decades of study, Venus still defies easy understanding because its dense clouds hide the surface from optical observation, its extreme greenhouse climate is unlike any other planet, its geological history is unresolved, its super‑rotating atmosphere (winds 60x faster than the planet’s rotation) remains unexplained. Possible active volcanism on Venus is suspected but not yet confirmed.

Q/ What are the possible challenges in the Venus mission?

Venus has the most hostile planetary environment in the solar system. The surface temperature is around 460 degrees Celsius (hotter than Mercury), pressure 92 bar and the atmosphere is corrosive with sulphuric acid clouds. It also has [the] potential [for a] communication blackout because of its thick atmosphere, which disrupts radio signals. Such an environment leads to rapid degradation of spacecraft hardware.

Q/ What about the upcoming Mars missions?

India’s second mission to Mars will target a soft lander and rover. An instrument suite for in situ mineral, chemical and atmospheric, could be the added science element. On the other hand, missions from NASA-ESA (National Aeronautics and Space Administration-European Space Agency) and China will move towards sample return missions from Mars.

Q/ How will Mangalyaan 2 differ from Mangalyaan 1?

India’s first mission was a technical demonstrator that a low-cost mission to Mars is possible. Mangalyaan 2 will be a full-fledged science mission carrying an orbiter, a lander or a rover. This is similar to how India approached its moon missions.

Q/ What kind of add-ons will be part of Mangalyaan 2?

Mangalyaan 2 will carry almost a new suite of scientific instruments far more advanced and diverse than Mangalyaan 1, which will directly enable deeper, multi‑layered exploration of Mars’s dust environment, atmosphere, plasma and solar‑wind interactions.

Q/ What new aspects of Mars can be explored?

Even after 60 years of missions, humanity has touched only the martian surface, literally and figuratively. No rover or lander has gone deeper than 5–7cm. We have never searched for active biological processes. Humans are naturally drawn to the question: “Are we alone?” Mars is the closest place where we might find an answer. It is a planetary time capsule and preserves four‑billion‑year‑old riverbeds, ancient volcanic plains, impact craters untouched for aeons. Studying Mars is like reading the early chapters of earth’s own story, preserved in stone.

Q/ Why has the red planet been so fascinating for humans?

Mars has fascinated humans because it sits at the intersection of science, imagination, culture and existential curiosity. It is the one planet that feels close enough to touch yet mysterious enough to provoke wonder. It has mountains, valleys, polar caps, seasons, sunsets, dust storms and a 24.6‑hour day. Its past includes flowing rivers, lakes and possibly oceans. It is the only planet where life could have evolved independently. All these make Mars feel like a “younger cousin” of earth.