
The location of ‘Krishnan’ crater and nearby features
| Photo Credit: Special arrangement
A 3.5 billion-old crater on Mars will henceforth be known after M.S. Krishnan, the pioneering Indian geologist. The International Astronomical Union (IAU) has approved it and several other names for Martian landforms proposed by two Kerala-based researchers.
Apart from ‘Krishnan,’ the IAU has also accepted several Kerala-based names for smaller landforms associated with the crater. These are ‘Valiamala,’ ‘Thumba,’ ‘Bekal,’ ‘Varkala’ and ‘Periyar’ for smaller craters and a vallis (valley). Which means, these places in Kerala now have counterparts on Mars!
The naming proposal was jointly submitted by Rajesh V.J. of the Department of Earth and Space Sciences, Indian Institute of Space Science and Technology, (IIST), and Asif Iqbal Kakkassery, formerly research scholar at IIST under the guidance of Dr. Rajesh and who currently works as Assistant Professor in Geology at Government College, Kasaragod.
Born in Thanjavur in what was then Madras Presidency in 1898, Dr. Krishnan was the first Indian to be director of the Geological Society of India. As for the other names, it is the first time that place names from Kerala are being adopted for Martian features, the team said.
While Valiamala is home to the IIST, Thumba is the place where the Indian space programme had its origins in the 1960s. Varkala is known for its geologically unique cliff formations and considered a potential Martian analogue site. Bekal in Kasaragod district was chosen for the historic Bekal Fort. Periyar is Kerala’s longest river, and is now commemorated through the naming of a Martian valley (Vallis).
“The plain inside Krishnan Crater has been officially named Krishnan Palus, and a channel cutting across it has been named Periyar Vallis,” Dr. Rajesh said.

Rajesh V.J. (left) and Asif Iqbal Kakkassery.
| Photo Credit:
Special arrangement
The findings have been published in the journal Meteoritics & Planetary Science.
Dr. Rajesh’s and Dr. Kakkassery’s research had identified signs of ancient glacial processes and fluvial activity on an unnamed crater in the Xanthe Terra region of Mars. It is this crater for which they proposed the name of Dr. Krishnan. It is in a region where evidence of ancient glaciation has been scientifically established. The features which henceforth will be known after places in Kerala are associated with this larger crater, Dr. Rajesh said.
Foundational contributions
IAU guidelines allow large, significant Martian craters to be named after deceased scientists who have made foundational contributions to planetary science. Smaller craters can be named after towns or villages with populations under 1,00,000, provided the names are easy to pronounce and have historical or cultural relevance, according to the team.

IAU had communicated the final list of approved names on Tuesday, IIST said.
As part of their work, which lasted about six years – inclusive of the COVID-19 pandemic period when work had to be halted – the team had proposed several Kerala-based names for Martian landforms. Many were initially rejected due to pronunciation and compliance issues related to IAU naming conventions. But persistent documentation and review had ultimately resulted in the approval of several of the names.
Published – November 26, 2025 03:05 pm IST



