ISRO

A Lunar Lander Found the First Seismic Activity on the Moon Since the ’70s

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What could the mysterious moonquake be?

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  • On August 23, the India Space Research Organization’s Vikram lunar lander, carrying the Pragyan rover, soft landed on the Moon’s southern polar region.
  • Onboard the Vikram lander is the Instrument for Lunar Seismic Activity (ISLA), which captured Pragyan’s first journey onto the surface as well as this unexpected “natural event”
  • This is likely the first recorded evidence of lunar seismic activity since the Apollo Missions more than 50 years ago

Just recently, the India Space Research Organization (ISRO) completed a years-long mission to be the fourth country to ever land on the Moon and the first to land in the southern lunar polar region. Now that the tricky part involving retro-rockets and orbital mechanics is over, the science can truly begin—and Chandrayaan-3’s Vikram lander isn’t wasting any time.

Onboard the Vikram lander, which is also carrying the lunar rover Pragyan, is the Instrument for Lunar Seismic Activity (ILSA) based on Micro Electro Mechanical Systems (MEMS) technology that’s already detecting minute rumblings on the Moon. The most obvious disruptions came from the Pragyan rover itself as it began its mission on the lunar surface, but on August 26, Vikram also “recorded an event, appearing to be a natural one,” according to an ISRO statement. The space agency says it’s investigating the seismic source.

This is the first time that humans have detected new seismic events on the Moon since the Apollo missions between 1969 and 1972, which were designed to discern the internal composition of the Moon.

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An image of the Vikram lander with the ISLA experiment clearly marked along with ChaSTE (Chandra’s Surface Thermophysical Experiment), which measures the temperature profile of the lunar topsoil.

Because of the experimental nature of the Apollo 11 mission, it arrived on the Moon carrying an Early Apollo Surface Experiments Package (EASEP) with only two experiments packed inside. Future Apollo missions (excluding Apollo 13 for obvious reasons) arrived at the Moon with a more robust Apollo Lunar Surface Experiments Package (​​ALSEP), which contained geophysical instruments engineered to monitor the lunar surface for one year after the astronauts’ departure. Instead, the instruments operated for 8 years, with the last of the experiments shutting down on September 30, 1977.

Amazingly, the ALSEP seismometers could magnify lunar vibrations by 10 million times, a feat completely made impossible on Earth due to weather and human-induced noise. While most Apollo missions included a passive scientific experiment designed to monitor the entire Moon, Apollo 14 and 16 included active seismic experiments to monitor the local area. Apollo 17, the last of the crewed lunar missions, contained a Lunar Seismic Profiling Experiment designed to dig up data on the physical properties of lunar material near the surface

Although a robust data set, scientists have been hungry for more in the 50 years since the Apollo missions. And Vikram’s data is doubly valuable, as no lunar lander has ever visited the Moon’s southern polar region. This area of the Moon is of particular interest because of its deposits of ice—a vital resource for anyone thinking of setting up shop on the lunar surface. In fact, the lunar south pole is so enticing that the U.S. and China both have future missions planned for the region.

For now, ISRO has placed the solar-powered Vikram and Pragyan into sleep mode during the 14-day-long lunar night. But they should reawaken around September 22, ready to uncover more seismic secrets of Earth’s only natural satellite.

NASA’s Found a Lost Spacecraft Orbiting Our Moon

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Lost in space.

 
An Indian spacecraft that lost contact with Earth eight years ago has been rediscovered orbiting the Moon.

NASA’s Earth-based radars have detected the signal of the Indian Space Research Organisation’s (ISRO) tiny Chandrayaan-1 spacecraft, which left Earth for the Moon’s orbit back in 2008, and was last heard from in August 2009.

You’d think it wouldn’t be that hard to find a spacecraft that we know is in orbit around our closest satellite, but it’s a lot trickier than it sounds.

It’s tough enough to accurately find space debris in Earth’s own orbit, and thanks to the lunar glare, optical telescopes are out when it comes to looking for lost objects around the Moon.

Not to mention that Chandrayaan-1 is only around 1.5 metres (5 feet) on each side, so from Earth it would be less than a tiny speck around the Moon.

There’s also the fact that our Moon is covered in regions called mascons, or mass concentrations, which have higher-than-average gravitational pull and have been known to tug a spacecraft out of orbit over time – sometimes even causing them to crash into the lunar surface.

So despite the fact that we last heard from Chandrayaan-1 while it was circling the Moon, after eight years of radio silence, there were no guarantees it was still there, and the orbiter had been classified as ‘lost’.

But NASA has used a new radar technique to discover the missing spacecraft, as well as showing that it could accurately pinpoint the location of NASA’s still-active Lunar Reconnaissance Orbiter (LRO).

 “Finding LRO was relatively easy, as we were working with the mission’s navigators and had precise orbit data where it was located,” said Marina Brozovic, a radar scientist at NASA’s Jet Propulsion Laboratory (JPL).

“Finding India’s Chandrayaan-1 required a bit more detective work because the last contact with the spacecraft was in August of 2009.”

To figure it out, the team first came up with the best predictions of where Chandrayaan-1 might have ended up. According to where it was last heard from, their best guess was that it would be some 200 km (124 miles) above the Moon, in a polar orbit.

Based on that estimate, they then beamed microwaves towards the Moon’s north pole, around 380,000 km (237,000 miles) away, using a huge antenna at NASA’s Goldstone Deep Space Communications Complex in California, and waited for them to bounce back.

The idea was that if any small spacecraft crossed the paths of these microwaves, they’d be able to detect them – similar to the way we can map the bottom of Earth’s oceans with radars.

And that’s exactly what happened – the team detected a small spacecraft crossing the path of the microwaves twice in around four hours, the same orbital period that Chandrayaan-1 was predicted to have.

They continued to listen in to the radars bouncing back from the spacecraft in order to get a better idea of its new orbit and position. Impressively, they found it had barely shifted course in the almost eight years it had been adrift by itself.

“It turns out that we needed to shift the location of Chandrayaan-1 by about 180 degrees, or half a cycle from the old orbital estimates from 2009,” said Ryan Park, manager of JPL’s Solar System Dynamics group.

“But otherwise, Chandrayaan-1’s orbit still had the shape and alignment that we expected.”

Chandrayaan-1 was India’s first mission to the Moon, and its job was to perform chemical and geological mapping.

Most famously, it had an impactor attached to it that was released in November 2008 and deliberately crashed into the Moon, blasting up huge amounts of lunar dust for scientists to examine – providing the first solid evidence of water ice on the lunar surface.

After 10 months, Chandrayaan-1 completed its mission, and lost contact with Earth as planned.

No one knows what shape it’s in now or what it’s been doing out there in the cold depths of space all this time, but it’s slightly comforting to know it’s still there.

India is now planning its second moon mission, Chandrayaan-2, which will consist of an orbiter, lander, and rover, for early 2018.

In the case of Chandrayaan-1, there’s not a whole lot we can do with this information. But the accurate discovery of the spacecraft, as well as NASA’s LRO, is a proof-of-concept for this new technique, which will be hugely useful in years to come as we continue to send humans and technology out into space.

Not only does it mean we can keep better track of any spacecraft or people we have in space, but it also means we can better monitor for any hazards heading their way.

Plus, it’s always nice to know in the cold expanse of space that someone back home can figure out where you are.

How the world’s lightest material produced by ISRO will help our jawans in Siachen.

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To keep our soldiers warm, in freezing temperatures at Siachen, the Vikram Sarabhai Space Centre in Thiruvananthapuram (ISRO’s research arm) has manufactured the world’s lightest material called silica aerogel or ‘blue air’. This material can be used on earth as well as in outer space. The material has an outstanding thermal resistance that can be used in soldier uniforms to help them stay warm. The initiative comes following the death of Lance Naik Hanumanthappa and many other soldiers who lost their lives at Siachen recently, reported India Today.

Image: The Indian Express

In a report by India Times, the indigenous creation can also hopefully be used in rocket engines for insulation. For our soldiers, the material can be used for insoles, thermal jackets, and even have purposes for window glazing.

Points on Blue Air:

  • Silica aerogel or Blue Air has a density of 1,000 gram per cubic metre, which makes it even lighter than air, which weighs 1,200 gram per cubic metre (at 20 degree Celsius, sea level)
  • Silica aerogel had 15 Guiness World Records entries as the lowest-density solid and the best insulator till 2011
    • Although, it was ousted by aerographite in 2012 and aeroghraphene in 2013, silica aerogel is the lightest material with a commercial value
    • 97 percent of the volume of silica aerogel contains air, which makes it extremely light and gives it supreme thermal insulative qualities
    • Silica aergel is also known as ‘frozen smoke’ for its lightness
    • ISRO has manufactured the product to make uniforms for the Indian Army soldiers at Siachen and other places with extreme conditions
    • This product can also be used in rocket engines for insulation.