My Science School

Mars rover’s microphone captures ten seconds of rumbling noise created by dust devil on the Red Planet. It's the same microphone that provided the first sounds of Martian wind in 2021.

What does a dust devil sound like on Mars? A NASA rover by chance had its microphone on when a whirling tower of red dust passed directly overhead, recording the racket.

It's about 10 seconds of not only rumbling gusts of up to 40 kph, but the pinging of hundreds of dust particles against the rover Perseverance. Scientists released the first-of-its-kind audio. It sounds strikingly similar to dust devils on Earth, although quieter since Mars' thin atmosphere makes for more muted sounds and less forceful wind, according to the researchers.

The dust devil came and went over Perseverance quickly last year, thus the short length of the audio, said the University of Toulouse's Naomi Murdoch, lead author of the study appearing in Nature Communications.

At the same time, the navigation camera on the parked rover captured images, while its weather-monitoring instrument collected data.

"It was fully caught red-handed by Persy," said co-author German Martinez of the Lunar and Planetary Institute in Houston.

Photographed for decades at Mars but never heard until now, dust devils are common at the red planet.

This one was in the average range: at least 400 feet (118 metres) tall and 80 feet (25 metres) across, travelling at 16 feet (5 metres) per second.

The microphone picked up 308 dust pings as the dust devil whipped by, said Murdoch, who helped build it.

Given that the rover's SuperCam microphone is turned on for less than three minutes every few days, Murdoch said it was "definitely luck" that the dust devil appeared when it did on Sept. 27, 2021. She estimates there was just a 1-in-200 chance of capturing dust-devil audio. Of the 84 minutes collected in its first year, there's "only one dust devil recording," she wrote in an email from France.

WHAT IS A DUST DEVIL?

• Common across Mars, dust devils are short-lived whirlwinds loaded with dust that form when there is a major difference between ground and air temperatures.
• They are a common feature in the Jezero crater, where the Perseverance rover has been operational since February 2021 - but it had never before managed to record audio of one of them.
• By chance on September 27, 2021, a dust devil 118 metres high and 25 metres wide passed directly over the rover.
• This time, the microphone on the rover's SuperCam managed to catch the muffled, whirring sounds.

Sounds...so far

• The same microphone on Perseverance's mast provided the first sounds from Mars namely the Martian wind soon after the rover landed in February 2021.
• It followed up with audio of the rover driving around and its companion helicopter, little Ingenuity, flying nearby, as well as the crackle of the rover's rock-zapping lasers, the main reason for the microphone.

ROCK SAMPLES

On the prowl for rocks that might contain signs of ancient microbial life, Perseverance has collected 18 samples so far at Jezero Crater, once the scene of a river delta. NASA plans to return these samples to Earth a decade from now. Its helicopter Ingenuity has logged 36 flights, the longest lasting almost three minutes.

CAN ACOUSTIC DATA SOLVE THE MARTIAN MYSTERY?

• These recordings allow scientists to study the Martian wind, atmospheric turbulence and now dust movement as never before.
• The impact of the dust-made "tac tac tac sounds will let researchers count the number of particles to study the whirlwind's structure and behaviour.
• It could also help solve a mystery that has puzzled scientists. On some parts of Mars, whirlwinds pass by sucking up dust, cleaning the solar panels of rovers along the way.
• Understanding why this happens could help scientists build a model to predict where the whirlwinds might strike next.
• It could even shed light on the great dust storms that sweep across the planet, famously depicted in the 2015 science-fiction film "The Martian".

Picture Credit : Google 

Also called the "third zone" of the solar system, this large volume of space outside Neptune's orbit is home to thousands of icy, cold objects. This is where Pluto is also present.

In the cold, outermost area of our solar system lies one of the largest structures in our solar system. Also called the "third zone" of the solar system, this "donut-shaped" volume of space is called the Kuiper belt. This is where Pluto is also present.

The region encompasses hundreds of thousands of icy, cold objects and is outside Neptune's orbit.

The region is named so after astronomer Gerard Kuiper, who published a paper speculating objects beyond Pluto. This was also suggested by Astronomer Kenneth Edgeworth in the papers he published and sometimes this belt is called the Edgeworth-Kuiper Belt. Some researchers also refers to it as the Trans-Neptunian Region.

The icy bodies are called Kuiper Belt Objects (KBOS) or trans-Neptunian objects (TNOS). They are highly diverse in terms of size, shape, and colour. A significant number of KBOS have moons.

So how did the icy objects form? According to scientists, these icy objects are leftovers after the formation of our solar system. The region must have formed after these objects came together to form a planet but Neptune's gravity played spoilsport. The gravity shook up this region and these icy objects couldn't join to form a planet.

The Kuiper Belt volume is being lost nowadays. The amount of material which it carries now is much less when compared to what it contained earlier.

The objects in the belt collide and lead to fragmented, smaller objects. Sometimes the dust gets blown out of the solar system. We take a look at a few of the KBOS.

Haumea

This KBO is known for its strange shape and rotation style. According to NASA, the Haumea resembles a squashed American football. This was a result of the object's collision with another object half the size of it.

Eris

Smaller than Pluto, Eris takes 557 years to orbit the Sun. It has a moon called Dysnomia.

Arrokoth

Lying some billion miles past Pluto is the Arrokoth, a Kuiper Belt Object which means sky in the Native American language. This small snowman-shaped object is believed to hold clues about the origin of life on Earth and also about the planet's formation.

Picture credit : Google 

A mission conceived as one for preventive maintenance turned out to be more urgent after four of the six gyroscopes on board the Hubble space telescope failed.

The Hubble space telescope has changed our understanding of the universe A telescope that was launched into low Earth orbit in 1990, Hubble still remains operational and continues to be a vital research tool. Following NASA's most recent review of Hubble's operations, it has been announced that NASA would support the observatory through June 2026, with estimates suggesting that it might be able to continue operations until the mid-2030s and even beyond.

Designed to be visited

While the longevity of the telescope is testament to the vision of those who conceived the mission, there's another crucial factor that has made it possible. Hubble was the first telescope that was designed to be visited in space. This meant that astronauts could not only perform repairs and replace parts, but also upgrade its tech with newer instruments. There have been five such missions that have taken place from 1993 to 2009. One such servicing mission in December 1999 turned out to be a life saver for the telescope.

After the first servicing mission in 1993 and the second one in 1997, the third to carry out preventive repairs was scheduled for June 2000. Since Servicing Mission 2 in February 1997, however, three of the six gyroscopes aboard Hubble had failed. With at least three working gyroscopes necessary for Hubble's operation, it prompted the managers to split Servicing Mission 3 (SM3) into two parts, SM3A and SM3B, with the former scheduled for December 1999.

An unexpected failure

 On November 13, 1999, a fourth gyroscope failed unexpectedly. With SM3A planned for the following month, this triggered NASA to place Hubble into safe mode. The safe mode was a sort of protective hibernation that prevented the telescope from making any observation. Hubble was in this state for over a month, waiting for the crew of SM3A to make their way.

With servicing mission veterans Steven Smith and Michael Foale at the helm, the seven-member crew aboard the Discovery Space Shuttle (STS-103) left for space on December 19. Within a couple of days, they manoeuvred close enough to Hubble such that it could be grappled with Discovery's robotic arm.

All six gyroscopes replaced

 The first of the three scheduled spacewalks took place over 8 hours and 15 minutes spanning December 22-23 (Central European Time, CET). Smith, along with fellow crew member John Grunsfeld, managed to replace all six of Hubble's gyroscopes. The entire astronomical community heaved a collective sigh of relief on receiving this news. The duo also replaced kits to prevent Hubble's batteries from overcharging.

While Hubble's main computer was changed in the second spacewalk that spanned 8 hours 10 minutes through December 23-24 (CET), the final spacewalk spanning 8 hours 8 minutes through December 24-25 (CET) saw a faulty transmitter and data tape recorder being replaced. Preliminary tests were then conducted to ensure that all of Hubble's systems, be it old or new, were performing satisfactorily.

Backs away slowly

Minutes into December 26 (CET), the Hubble telescope was released. Discovery then backed away from Hubble slowly. Having successfully performed the major objectives of the mission, the astronauts on board used the time remaining to stow away equipment, apart from making preparations for landing.

After orbiting the Earth 119 times and travelling more than 5 million km, Discovery made its way back. It performed a smooth night-time landing, touching down on the runway at the Kennedy Space Center in the U.S. on December 27. Hubble was successfully back in operation, and has been for over two decades since then.

Picture Credit : google 

Discovered first on December 20, 1900, comet 21P/Giacobini-Zinner gets its name from two astronomers. From being one of the last comets to be discovered in the 19th Century, this comet is now best known for having the first encounter with a spacecraft.

Comets are popular for different reasons. There's Halley's comet, which is the most famous of them all. Regularly visible to the naked eye from the Earth, Halley's comet has been observed and recorded by astronomers for over 2,000 years. Then, there is comet Hyakutake. Discovered only in 1996, this comet's passage near the Earth in the same year was one of the closest cometary approaches in nearly 200 years. We will be turning our attention to comet 21P/Giacobini-Zinner, whose claim to fame now includes being the first comet to encounter a spacecraft. This comet was first discovered on December 20, 1900, making it one of the last comets to be discovered in the 19th Century. A discoverer of a number of comets, French astronomer Michel Giacobini found this comet while skygazing from Nice Observatory. It was followed for two months and orbital calculations revealed that the comet was a periodic object with an orbital period less than seven years.

Recovered in 1913

It wasn't recovered in 1907, when it was not placed favourably for viewing. Even though the comet was expected to be unfavourably placed in 1914 as well, German astronomer and renowned science historian Ernst Zinner accidentally rediscovered it on October 23, 1913.

Since both Giacobini and Zinner discovered and recovered this comet, it is named after them and is called comet 21P/Giacobini-Zinner. The letter "p" indicates that it is a periodic comet, which are comets with orbital periods less than 200 years. When orbital calculations were revised when the comet was recovered in 1913, its orbital period was found to be close to 6.6 years, and the comet has been observed on almost every return since then.

Draconid meteor shower

This comet had favourable returns in 1959, 1985, and 2018, when it was well observed as its perihelion (closest approach to sun) allowed it to pass close to the Earth. The nucleus of the Giacobini-Zinner sprays ice and rock into space every time it returns to the inner solar system. This makes the comet the parent comet of the Draconid meteor shower, which takes place in early October each year.

While this meteor shower is quite weak in most years, there have been Draconic meteor storms on record, meaning that over 1,000 meteors were seen per hour at the location of the observer. The 1933 and 1946 Draconid storms were particularly intense, with over 500 meteors observed per minute in Europe during the former and 50-100 per minute seen in the U.S. during the latter.

Farquhar's idea

Comet Giacobini-Zinner's current claim to fame was a result of its favourable return in 1985. When funding for a spacecraft mission to comet 1P/Halley, which was enroute to its 1986 perihelion passage, didn't materialise, planetary scientist Robert Farquhar came up with an idea. He suggested that the already existing International Sun-Earth Explorer 3 (ISEE-3) be placed on an alternate path that would take it towards Giacobini-Zinner.

Once the idea was approved, ISEE-3 was sent on a series of lunar flybys that would take it towards Giacobini-Zinner. Following the final lunar flyby in December 1983, ISEE-3 was renamed the International Cometary Explorer (ICE).

On September 11, 1985, ICE passed through the ion tail of Giacobini-Zinner, thereby completing the first encounter between a comet and a spacecraft. While ICE lacked cameras, it did carry scientific instruments that enabled it to record measurements of the electric environment around the comet and also as to how the comet interacted with the solar wind.

Even though an international fleet of spacecraft, including ICE, met Halley in 1986 from a number of vantage points for a study like never before, Giacobini-Zinner will forever hold the title of being the first comet to encounter a spacecraft. While its most recent return in 2018 might be comet 21P's most favourable return in the 21st Century, you can still look forward to its approach once in less than seven years, and maybe even try and track it.

Picture Credit : Google