On 23rd August last year, India’s Chandrayaan-3 made history being the first to soft-land on the moon’s south polar region. The landing marked the end of the high-octane phase of the mission. But its next phase was a slow-burner.

Pragyan, the suitcase-sized rover, that hitched a ride to the moon aboard the lander, Vikram, rolled off a ramp onto the lunar surface. It traversed along the dusty lunar surface slowly, at a pace even a snail could beat. Handlers at the Indian Space Research Organization (ISRO) didn’t want the suitcase-sized rover to risk stumbling over a rock or near a ridge, and jeopardize the mission.

The whitish spots are material excavated from the moon’s interior.

Nevertheless, the rover had a busy schedule to stick to. It was to probe the lunar soil, and relay that scientific data back to earth. Pragyan covered 100 meters in two weeks, before it stopped to take a nap ahead of a long lunar night. At the time, the rover’s battery pack was fully charged, thanks to the on-board solar panels soaking up sunlight during the day.

But lunar weather is harsh, especially at the south pole, where Pragyan napped, temperatures can reach as low as -250 degrees centigrade during the night. Added to that, a lunar night lasts two weeks. ISRO deemed Pragyan had only a 1% chance to survive.

Later, the expected happened, when the rover went unresponsive to ISRO’s pings to wake up.

But ISRO said the rover achieved what it was tasked to do. It relayed data all along for two weeks, examining soil from some 23 locations around the mission’s landing point, Statio Shiv Shakti. As months passed by, a slew of discoveries were made. Sulphur was discovered at the south pole, early on while the mission was ongoing. And only a few months ago, Pragyan found evidence of past weathering activity at the south pole.

But since August this year, research teams from ISRO and the Physical Research Laboratory in Ahmedabad, India, reported Pragyan’s most important findings yet – one of which sheds light onto the moon’s origins.

Chandrayaan-3’s Vikram lander, seen from the Pragyan rover’s camera

Moon and the Early Earth

Chandrayaan-3 had carried a radioactive passenger to the moon’s surface – curium-244.

The radioactive curium helps lase the surface: firing alpha particles (which are helium nuclei) at the dusty terrain. Some of these alpha particles bounce off the dust, whereas others evict electrons from the lunar soil, thereby producing x-ray emissions. Keeping watch is the Alpha Particle X-ray Spectrometer (APXS) on-board the Pragyan rover. In August, PRL scientists published findings in the journal, Nature, based on APXS data, reporting discovery of ferroan anorthosite.

It wasn’t the first ever detection per se of ferroan anorthosite. In fact, Apollo 11 had brought back anorthosite rocks to earth, where they were identified as such. That was in 1969, and Apollo sampled them from the equator. Successive missions by the Soviet Union and most recently China affirmed likewise from mid-latitude – equatorial regions as well. But Pragyan’s detection of the rock type was the first ever from the polar region.

The Pragyan rover’s payload.

Anorthosites are common on earth. In fact, just a year after the Apollo 11 sampled the rock, scientists had evidence of the earth and the moon’s entangled history. The authors noted the similar composition between these rocks, that are geographically widespread. Furthermore, ferroan anorthosite is an igneous rock that forms on earth when hot lava produced in volcanic eruptions cools down.

And scientists had piled up evidence in support of a similar process that underwent on the moon. The anorthosite rocks on the moon are old, in fact, more than 4 billion years ago – a figure close to the earth’s inception with rest of the solar system – around 4.5 billion years. Scientific consensus has been that the moon was formed from remnants of a collision between the early earth and a rogue Mars-sized planetary body.

But the collision energy would have yielded a moon that was molten. A lava blanketing the surface – aka a global magma ocean. As this ocean cooled, minerals amongst which is plagioclase (a class of feldspar) crystallized and formed the anorthosite rocks on the moon. It’s commonly called the lunar magma ocean hypothesis.

When Pragyan treaded over the dusty lunar terrain, it didn’t register the anorthosite as a physical rock per se. Instead, it observed remnants of the rock, as fine powder.

Meteorites beat down rocks to fine powder, as they slam into the moon from space with regular impunity. On earth, the ground is saved by the presence of an atmosphere. But the moon virtually has no atmosphere. Nor does it have water to wear down the rocks. The surface is extremely hot during the lunar day – in fact, when Chandrayaan-3 landed on the moon, the surface temperature was some 50 degrees centigrade. Just a few months ago, Pragyan revealed possible signs of rock degradation from the rims of a crater.

Moon dust opens doors to the past

The fact the moon doesn’t (and can’t) sustain an atmosphere helps it make an attractive destination to learn more about our planet and the satellite’s shared origins. There’s no chemistry to remove traces of the moon’s early evolution from the lunar dust. As such, the dust opens doors to the past.

Space explorations missions soft-landing on the surface study this dust – or sample and shuttle them to earth for scientists to study them in detail.

In fact, Pragyan revealed a crater that’s amongst the oldest ever discovered on the moon. The findings were published in the journal, Icarus, in September. Hidden in plain sight, the rover’s navigation camera, NavCam, spotted subtle stretch marks on the surface, that were confirmed later with the Chandrayaan-2 orbiter (which has been orbiting the moon since 2019). In fact, this crater was found buried under nearby craters, most notably the South Pole-Aitkin basin located 350 km away. The basin is the largest impact crater in the entire solar system (some 2,500 km wide and 8 km deep) touted to have formed millions of years ago.

And this became subject to an earlier paper that PRL scientists authored, and was published in August. Pragyan identified material thought to have emerged from the moon’s interior. The APXS instrument picked up unusually high magnesium content in the vicinity. The authors speculate the meteorite that created the basin probably dug up magnesium from deep inside the moon’s upper mantle, and spewed them into Pragyan’s vicinity. 

But some experts believe in an alternate explanation. They believe the magnesium might have come from surface rocks in the vicinity, and not from the upper mantle. In fact, the authors acknowledged this amongst other possible alternatives. Nonetheless, the Chandrayaan-3’s findings doesn’t dispute the lunar magma ocean hypothesis either, if not backing it outright. Saying that, the theory lives on to fight another day.

On October 26, 2024, the prestigious Sardar Patel Memorial Lecture at Rang Bhawan in New Delhi, India’s capital, brought together students, scientists, and space enthusiasts to explore the future of India’s space ambitions. The event, hosted by Akashvani, Indian state-owned public radio broadcaster, featured a compelling lecture by Dr. S. Somanath, Chairman of India’s space agency ISRO and the Space Commission. His address, titled “Indian Space Odyssey: In Search of New Frontiers,” was not just a presentation of current achievements, but a bold declaration of India’s aspirations in the vast expanse of space.

India’s Space Vision 2047

Dr. Somanath captivated the audience with a glimpse into India’s Space Vision 2047, particularly the ambition to achieve a human landing on the Moon. He introduced the innovative concept of a The Bharatiya Antariksha Station (Indian Space Station), envisioned as a launchpad for lunar missions. This ambitious plan reflects a paradigm shift in India’s approach to space exploration, emphasizing not just technology but also strategic vision.

A highlight of Dr. Somanath’s lecture was his discussion on the advancements in lander technology. He underscored ISRO’s commitment to developing reusable rockets, an initiative that promises to reduce costs and increase the frequency of missions. This technological evolution is crucial for India’s future missions, including a proposed exploration of Venus—where scientists aim to study its mysterious surface and atmosphere.

Dr. Somanath articulated a compelling narrative about harnessing space technology for national development

A Drive for National Development

Dr. Somanath articulated a compelling narrative about harnessing space technology for national development. Underlining ISRO’s mission, he emphasized the organization’s focus on addressing India’s needs in natural resource management, satellite communication, and navigation. Moreover, he expressed a profound commitment to inspiring the next generation of scientists and engineers, which is vital for sustaining India’s growth in the space sector.

The Chairman highlighted that ISRO’s achievements are not merely technological milestones but also reflections of India’s indomitable spirit. He conveyed a vision where space technology serves to enhance the quality of life on Earth, addressing global challenges and fostering international cooperation.

A recent image captured by the NASA/ESA Hubble Space Telescope showcases the captivating spiral galaxy Messier 90 (M90), situated in the Virgo constellation. This latest visualization is a significant enhancement over previous images, offering an expansive view of M90’s dusty disk, gaseous halo, and vibrant core.

Hubble first photographed M90 in 1994 using the Wide Field and Planetary Camera 2 (WFPC2), which produced a distinctive stair-step pattern due to its sensor layout. However, following the installation of Wide Field Camera 3 (WFC3) in 2009, Hubble revisited M90 in both 2019 and 2023, leading to the creation of this new, breathtaking image.

In the inner regions of M90’s disk, bright red areas indicate sites of active star formation, illuminated by H-alpha light from nebulae. M90 resides among other galaxies in the relatively nearby Virgo Cluster, having taken a path near the cluster’s center approximately 300 million years ago. The high density of gas in the inner cluster exerted significant pressure on M90, stripping away vast amounts of gas and creating the diffuse halo observed in the latest image. This loss of gas will hinder new star formation, ultimately leading to a gradual fading of the galaxy.

Located 55 million light-years from Earth, M90 is one of the few galaxies on a trajectory toward us. Its accelerated orbit within the Virgo Cluster indicates that M90 is in the process of escaping the cluster entirely, marking a unique phase in its cosmic journey.