The crescent Earth rises above the lunar horizon in this undated NASA handout photograph taken from the Apollo 17 spacecraft in lunar orbit during the final lunar landing mission in the Apollo program in 1972.
| Photo Credit: Reuters

During the Apollo 17 mission in 1972 – the last time people walked on the moon – U.S. astronauts Harrison Schmitt and Eugene Cernan collected about 243 pounds (110.4 kg) of soil and rock samples that were returned to Earth for further study.

A half century later, crystals of the mineral zircon inside a coarse-grained igneous rock fragment collected by Schmitt are giving scientists a deeper understanding about the moon’s formation and the precise age of Earth’s celestial partner.

The moon is about 40 million years older than previously thought – forming more than 4.46 billion years ago, within 110 million years after the solar system’s birth, scientists said on Monday, based on analyses of the crystals.

Chandrayaan-3 | India lights up the dark side of the moon  

The leading hypothesis for lunar formation is that during the solar system’s chaotic early history a Mars-sized object called Theia slammed into primordial Earth. This blasted magma – molten rock – into space, forming a debris disk that orbited Earth and coalesced into the moon. But the exact timing of the moon’s formation has been hard to nail down.

Mineral crystals were able to form after the magma cooled and solidified. The researchers used a method called atom probe tomography to confirm the age of the oldest-known solids that formed after the giant impact, the zircon crystals inside the fragment of a type of rock called norite collected by Schmitt.

“I love the fact that this study was done on a sample that was collected and brought to Earth 51 years ago. At that time, atom probe tomography wasn’t developed yet and scientists wouldn’t have imagined the types of analyses we do today,” said cosmochemist Philipp Heck, senior director of research at the Field Museum in Chicago, a University of Chicago professor and senior author of the study published in the journal Geochemical Perspectives Letters.

Also Read | Why are space agencies racing to the moon’s south pole?

“Interestingly, all the oldest minerals found on Earth, Mars and the moon are zircon crystals. Zircon, not diamond, lasts forever,” UCLA planetary scientist and study co-author Bidong Zhang added.

The rock containing the zircon was collected in the Taurus-Littrow valley at the southeastern edge of the lunar Mare Serenitatis (Sea of Serenity) and stored at NASA’s Johnson Space Center in Houston.

“Zircons are very hard and tough and survive the breakdown of rocks during weathering,” Heck said.

A study led by Zhang published in 2021 used a technique called ion microprobe analysis to measure how many atoms of uranium and lead were in the crystals, calculating the age of the zircon based on the decay of radioactive uranium to lead over time. That age needed to be confirmed through another method because of a potential complication involving lead atoms if defects existed in the zircon crystal structure.

The new study used atom probe tomography to determine there were no complications involving the lead atoms, confirming the age of the crystals.

Also Read | One giant step: Moon race heats up

“I see this as a great example of what the nanoscale, or even atomic scale, can tell us about big-picture questions,” said study lead author Jennika Greer, a cosmochemist at the University of Glasgow in Scotland.

The moon, which orbits Earth at an average distance of about 239,000 miles (385,000 km), has a diameter of about 2,160 miles (3,475 km), a bit more than a quarter of our planet’s diameter.

“The giant impact that formed the moon was a cataclysmic event for Earth and changed Earth’s rotational speed. After that, the moon had an effect on stabilizing Earth’s rotational axis and slowing down Earth’s rotational speed,” Heck said. “The formation date of the moon is important as only after that Earth became a habitable planet.”

“The moon helps stabilize Earth’s axis for a stable climate,” Zhang added. “The moon’s gravitational pulls help shape the ocean’s ecosystem. The moon is inspirational to human cultures and explorations. And NASA and other space agencies see the moon as a steppingstone for future deep-space explorations.”

The Dark Side of the Moon, 23 August 2023: The portion of Chandrayaan-3’s landing site taken after by Vikram Lander after the successful landing.
| Photo Credit: ISRO/The Hindu

India’s space agency is attempting to land a spacecraft on the moon’s south pole, a mission that could advance India’s space ambitions and expand knowledge of lunar water ice, potentially one of the moon’s most valuable resources.

Here’s what’s known about the presence of frozen water on the moon – and why space agencies and private companies see it as a key to a moon colony, lunar mining and potential missions to Mars.

How did scientists find water on the moon?

As early as the 1960s, before the first Apollo landing, scientists had speculated that water could exist on the moon. Samples the Apollo crews returned for analysis in the late 1960s and early 1970s appeared to be dry.

In 2008, Brown University researchers revisited those lunar samples with new technology and found hydrogen inside tiny beads of volcanic glass. In 2009, a NASA instrument aboard the Indian Space Research Organisation’s Chandrayaan-1 probe detected water on the moon’s surface.

Also Read | With moon now in India’s orbit, focus shifts to Pragyan rover

In the same year, another NASA probe that hit the south pole found water ice below the moon’s surface. An earlier NASA mission, the 1998 Lunar Prospector, had found evidence that the highest concentration of water ice was in the south pole’s shadowed craters.

Why is water on the moon important?

Scientists are interested in pockets of ancient water ice because they could provide a record of lunar volcanoes, material that comets and asteroids delivered to Earth, and the origin of oceans.

If water ice exists in sufficient quantities, it could be a source of drinking water for moon exploration and could help cool equipment.

It could also be broken down to produce hydrogen for fuel and oxygen to breathe, supporting missions to Mars or lunar mining.

Also Read | Not just sons of Tamil Nadu but State’s soil itself contributed to Moon mission

The 1967 United Nations Outer Space Treaty prohibits any nation from claiming ownership of the moon. There is no provision that would stop commercial operations.

A U.S.-led effort to establish a set of principles for moon exploration and the use of its resources, the Artemis Accords, has 27 signatories. China and Russia have not signed.

What makes the south pole especially tricky?

Attempted landings on the moon have failed before. Russia’s Luna-25 craft had been scheduled to land on the South Pole this week but spun out of control on approach and crashed on Sunday. The south pole – far from the equatorial region targeted by previous missions, including the crewed Apollo landings – is full of craters and deep trenches.

ISRO’s Chandrayaan-3 mission is on track for an attempted landing on Wednesday, the space agency has said. A previous Indian mission failed in 2019 to safely land near the area targeted by Chandrayaan-3.

Both the United States and China have planned missions to the south pole.

Sonia Gandhi. File
| Photo Credit: PTI

Congress on Thursday accused Prime Minister Narendra Modi of hogging the limelight after the success of Chandrayaan-3.

In a letter to the ISRO Chairman, Congress Parliamentary Party chairperson Sonia Gandhi said she was writing to him to let him know how thrilled she was by the ISRO’s magnificent achievement on Wednesday. “It is a matter of great pride and excitement to all Indians, particularly the younger generation,”Ms. Gandhi said, adding that the space research agency’s outstanding capabilities have been built up over decades.

Stating that the excitement and pride of the Chandrayaan-3 landing will “stay with us for a long time”, Congress general secretary K.C. Venugopal targeted the Prime Minister on X (formely Twitter) for “hogging the limelight”.

“However, the PM must answer some for his hypocrisy. You were quick to come on screen and take credit after the landing, but why has your government failed so terribly in supporting the scientists and the ISRO,” he said.

The Congress leader asked as to why the Heavy Engineering Corporation (HEC) engineers, who worked on Chandrayaan-3 launch pad, have not received their salaries for the last 17 months.

“Why did you cut the budget for such crucial missions by 32%? These are the heroes of our country, they run a world-class space research program, but you have no regard for their talent and hard work. To add insult to injury, you hogged the limelight when that moment was about the scientists’ achievements,” he added.

Congress leader Jairam Ramesh also shared several photographs of Jawaharlal Nehru and Indira Gandhi with doyens of India’s space programme such as Vikram Sarabhai to highlight the continuity in the country’s progress in the sector.

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July 14: LVM3 M4 vehicle successfully launches Chandrayaan-3 into orbit from Sriharikota in Andhra Pradesh. Chandrayaan-3 starts its journey into precise orbit.

July 15: First orbit-raising manoeuvre (Earthbound firing-1) successfully performed from ISTRAC/ISRO, Bengaluru. The spacecraft is in 41762 km x 173 km orbit.

July 17: Second orbit-raising manoeuvre performed. Spacecraft is in 41603 km x 226 km orbit.

July 22: Another orbit-raising manoeuvre completed using earth-bound perigee firing.

July 25: ISRO performs one more orbit-raising manoeuvre. Spacecraft is in 71351 km x 233 km orbit.

August 1: ISRO performs Translunar Injection successfully and inserts the spacecraft into translunar orbit. Orbit achieved is 288 km x 369328 km.

August 5: Lunar-Orbit Insertion of Chandrayaan-3 performed successfully. Orbit achieved is 164 km x 18074 km, as intended.

August 6: ISRO performs second Lunar Bound Phase (LBN). With this, the spacecraft is in a 170 km x 4313 km orbit around the Moon. The space agency releases video of the Moon as viewed by Chandrayaan-3 during lunar orbit insertion.

August 9: Chandrayaan-3’s orbit is reduced to 174 km x 1437 km after a manoeuvre is performed.

August 14: Mission is in orbit circularisation phase after another manoeuvre. The spacecraft is in 151 km x 179 km orbit.

August 16: Spacecraft brought down to an orbit of 153 km x 163 km after firing is completed.

August 17: Lander module is successfully separated from the propulsion module.

August 19: ISRO performs de-boosting of the lander module to reduce its orbit. The lander module is in 113 km x 157 km orbit around the Moon.

August 20: One more de-boosting or orbit reduction manoeuvre on the lander module is performed. The lander module is in 25 km x 134 km orbit.

August 21: Chandrayaan-2 orbiter formally welcomes Chandrayaan-3 lander module saying ‘Welcome, buddy!’. Two-way communication between the two is established. Mission Operations Complex (MOX) now has more ways to communicate with the lander module.

August 22: ISRO releases images of the Moon captured by the Lander Position Detection Camera (LPDC) of the Chandrayaan-3 mission from an altitude of about 70 km. Systems are undergoing regular checks. Smooth sailing is continuing.

August 23: Safe and soft landing of Chandrayaan-3’s lander module on the southern pole of lunar surface expected at 6.04 p.m. – PTI

An illustration showing the soft-landing of Chandrayaan-3 on the surface of the Moon. The spacecraft is set to land on August 23, 2023 around 6.04 p.m. IST.

The Indian Space Research Organisation (ISRO) has been able to successfully establish a two way communication between Chandrayaan-3’s Lander Module and its predecessor Chandrayaan-2’s orbiter.  

“‘Welcome, buddy!’ Ch-2 orbiter formally welcomed Ch-3 LM. Two-way communication between the two is established. MOX has now more routes to reach the LM,” the space agency posted on X (formerly Twitter).

Also read: Chandrayaan-3 | How NASA, ESA will support ISRO during the Moon landing on August 23

The Chandrayaan-2 mission launched on July 22, 2019 consisted of an Orbiter, Lander and Rover to explore the unexplored south pole of the Moon.

The Orbiter, which has been placed in its intended orbit around the Moon, objective is to enrich understanding of the moon’s evolution and mapping of the minerals and water molecules in the Polar Regions, using its eight state-of-the-art scientific instruments.

According to ISRO the Orbiter is healthy and all the payloads are operational.

The Orbiter payloads include : Terrain Mapping Camera – 2, Chandrayaan 2 Large Area Soft X-ray Spectrometer (CLASS), Solar X-Ray Monitor, Imaging IR Spectrometer, Dual Frequency Synthetic Aperture Radar, Chandra’s Atmospheric Composition Explorer – 2, Orbiter High Resolution Camera and Dual Frequency Radio Science Experiment.

“The Orbiter camera is the highest resolution camera (0.3m) in any lunar mission so far and shall provide high resolution images which will be immensely useful to the global scientific community. The precise launch and mission management has ensured a long life of almost 7 years instead of the planned one year,” states the Chandrayan-2 mission profile.