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Science

NASA Perseverance Mars rover investigates ‘odd’ rock, zaps it with a laser

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NASA’s Perseverance rover snapped a view of this odd rock on March 28. If you look closely just to the right of center, you can see a series of tiny marks where the rover’s laser zapped it.


NASA/JPL-Caltech/ASU

Mars is a haven for meteorites, and it’s always notable when a rover comes across one of these emissaries from space. Scientists are currently scrutinizing a holey rock spotted by NASA’s Perseverance rover that bears a resemblance to meteorites seen elsewhere.

NASA hasn’t declared what the rock is just yet, but the Perseverance team tweeted on Wednesday, “While the helicopter is getting ready, I can’t help checking out nearby rocks. This odd one has my science team trading lots of hypotheses.”

The rover team said the rock is about 6 inches (15 centimeters) long and told space fans to look closely at the image to “spot the row of laser marks where I zapped it to learn more.”

Perseverance is equipped with a rock-zapping laser designed to help it collect data on Mars geology. You can listen to the laser in action as heard by a microphone. “Variations in the intensity of the zapping sounds will provide information on the physical structure of the targets, such as its relative hardness or the presence of weathering coatings,” NASA said when it shared the laser audio earlier in March.  

Researchers are already throwing around some ideas about the rock, including that it may be a weathered piece of bedrock, a little chunk of Mars from elsewhere that was flung by an impact event or a meteorite.

Perseverance is already hip to meteorites. There’s a tiny slice of a Martian meteorite built into a calibration target used by the rover’s Sherloc (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument. So NASA sent a piece of Mars back to Mars. 

The rover made time for the rock investigation while it’s in the process of unfolding the Ingenuity helicopter so it can set it down on the surface prior to what NASA hopes will be the first powered, controlled flight on another planet. 

Between rocks and choppers, it’s been an exciting week for the Perseverance mission.

Follow CNET’s 2021 Space Calendar to stay up to date with all the latest space news this year. You can even add it to your own Google Calendar.      



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Perseverance Has Officially Started Its Search For Signs of Life on Mars

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The bundle of instruments known as SuperCam on board the Perseverance Mars rover has collected its first samples in the hunt for past life on the red planet, mission scientists said Wednesday.

 

The return to Earth years from now of the rocks and soil it retrieves “will give scientists the Holy Grail of planetary exploration,” Jean-Yves le Gall, president of France’s National Centre for Space Studies (CNES), which mostly built the mobile observatory, commented via a YouTube broadcast.

These “pieces of Mars”, he said, may “finally answer this fascinating and fundamental question: was there ever life elsewhere than Earth?”

After seven months in space, NASA’s Perseverance rover gently set down on Martian soil last month and sent back black-and-white images revealing the rocky fields of Jezero Crater, just north of the Mars equator.

“The critical component of this astrobiology mission is SuperCam,” said Thomas Zurbuchen, deputy head of NASA’s Science Mission Directorate.

Mounted on the rover’s mast, the shoebox-sized gizmo is packed with spectrometers, a laser, and an audio recording device to analyse the chemistry, mineralogy and molecular composition of Mars’ famously red surface.

SuperCam’s laser can zap objects smaller than a pencil point from as far away as seven metres (20 feet), and enables the observation of spots beyond the reach of the rover’s robotic arm.

“The laser is uniquely capable of remotely clearing away surface dust, giving all of its instruments a clear view of the targets,” said Roger Wiens, an engineer at the Los Alamos National Laboratory (LANL) and SuperCam principal investigator.

 

The mission suffered a serious mishap before liftoff, revealed LANL’s Scott Robinson, who said more than 500 engineers and scientists contributed to the project.

“The mast unit optics were destroyed in a freak accident just four months before delivery,” he explained. “The team scrambled to pull together spare parts to rebuild the telescope from scratch.”

The accident turned out to be a blessing in disguise.

A ‘freak accident’

In reassembling the unit, engineers discovered what Robinson described as a “Hubble-like” flaw in the original mirror.

Shortly after the Hubble Space Telescope’s launch in 1990, operators realized that the observatory’s primary mirror had an aberration – later corrected – that affected the clarity of images.

Scientists believe that around 3.5 billion years ago the crater in which Perseverance landed was home to a river that flowed into a deep lake, depositing sediment in a fan-shaped delta.

The rover is tasked with collecting more than two dozen rock and soil samples in sealed tubes, to be sent back to Earth sometime in the 2030s for analysis.

SuperCam is also taking close-up shots of rock targets on Mars. (NASA/JPL-Caltech/LANL/CNES/CNRS/ASU/MSSS)

About the size and weight of an SUV, Perseverance is equipped with a two-meter (seven-foot) robotic arm, 19 cameras, two microphones, as well as other cutting-edge instruments.

A small helicopter drone tucked under its belly will attempt the first powered flight on another planet in a few weeks’ time.

One instrument on board is designed to make oxygen from Mars’s primarily carbon dioxide atmosphere, something that would greatly facilitate human habitation.

Perseverance is the fifth rover to set wheels down on Mars, all of them from NASA. The feat was first accomplished in 1997.

Its core mission lasts just over two years, but the rover could remain operational well beyond that.

© Agence France-Presse

 

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NASA releases audio recordings of first wind sounds, laser strikes captured on Mars

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NASA’s Jet Propulsion Laboratory (JPL) released two historic audio recordings from the surface of Mars on Wednesday.

In the first audio clip, recorded using the Perseverance Mars rover’s two microphones, listeners can hear wind. 

NASA’S CHANDRA OBSERVATORY LOOKING AT BARRED SPIRAL GALAXY 86 MILLION LIGHT-YEARS AWAY

In their post on SoundCloud, NASA described the sound as “listening to a seashell or having a hand cupped over the ear.” 

They obtained the audio from the instrument on Feb. 19, around 18 hours after landing on the planet’s Jezero Crater.

“The rover’s mast, holding the microphone, was still stowed on Perseverance’s deck, and so the sound is muffled,” they explained. 

In the second clip, listeners can hear laser impacts on a rock target in audio that was taken on March 2. 

“The sounds of 30 impacts are heard, some slightly louder than others. Variations in the intensity of the zapping sounds will provide information on the physical structure of the targets, such as its relative hardness or the presence of weathering coatings,” NASA wrote in a caption. “The target, Máaz (‘Mars’ in Navajo), was about 10 feet (3.1 m) away.”

Both recordings were taken using the rover’s SuperCam, which is a rock-vaporizing instrument mounted on the “head” of the rover’s mast that will help scientists hunt for fossils on the red planet.

In the clip with audible wind, the mast on which the microphone sits was still stowed, muffling the sound, which Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPERAO) researcher and planetary scientist Naomi Murdoch discussed during a joint news conference with Centre National D’Etudes Spatiales (CNES) and NASA on Wednesday.

“First of all, on the surface of Mars, we have a very low atmospheric pressure. It’s actually 150 times lower than on Earth. In addition, the atmosphere is made up of carbon dioxide,” Murdoch explained. “And, these two factors together mean that sound doesn’t propagate in the same way on the surface of Mars as it does on Earth.”

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“For that reason, the SuperCam microphone is particularly sensitive. And this allows us to record sounds despite the strong attenuation in the Martian atmosphere,” she said.

The Mars 2020 rover marks the third time the microphone was sent to Mars.

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Science

SpaceX adds laser links to Starlink satellites to serve Earth’s polar areas

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Enlarge / Starlink logo imposed on stylized image of the Earth.

SpaceX has begun launching Starlink satellites with laser links that will help provide broadband coverage in polar regions. As SpaceX CEO Elon Musk wrote on Twitter on Sunday, these satellites “have laser links between the satellites, so no ground stations are needed over the poles.”

Enlarge / Starlink satellites prior to launch. The black circles in the middle are laser links.

The laser links are included in 10 Starlink satellites just launched into polar orbits. The launch came two weeks after SpaceX received Federal Communications Commission approval to launch the 10 satellites into polar orbits at an altitude of 560km.

“All sats launched next year will have laser links,” Musk wrote in another tweet yesterday, indicating that the laser systems will become standard on Starlink satellites in 2022. For now, SpaceX is only including laser links on polar satellites. “Only our polar sats have lasers this year & are v0.9,” Musk wrote.

Alaskan residents will benefit from the polar satellites, SpaceX told the FCC in an application to change the orbit of some of its satellites in April 2020. The plan is to “ensure that all of the satellites in SpaceX’s system will provide the same low-latency services to all Americans, including those in places like Alaska that are served by satellites in polar orbits,” SpaceX said at the time. The satellites can serve both residential and US-government users “in otherwise impossible-to-reach polar areas,” SpaceX said.

Starlink satellites communicate with ground stations, of which about 20 are deployed in the United States so far. A SpaceNews article today described how the laser links reduce the need for ground stations and provide other benefits:

Inter-satellite links allow satellites to transfer communications from one satellite to another, either in the same orbital plane or an adjacent plane. Such links allow operators to minimize the number of ground stations, since a ground station no longer needs to be in the same satellite footprint as user terminals, and extend coverage to remote areas where ground stations are not available. They can also decrease latency, since the number of hops between satellites and ground stations are reduced.

The 10 satellites were originally authorized by the FCC for altitudes in the 1,100-1,300km range. The FCC approval allowing SpaceX to cut the altitude in half will help reduce latency.

With polar orbits, also known as Sun-synchronous orbits, satellites “travel past Earth from north to south rather than from west to east, passing roughly over Earth’s poles,” as the European Space Agency explains.

“Space lasers have exciting potential”

In December, during an interview with Ars’ Senior Space Editor Eric Berger, SpaceX President Gwynne Shotwell said demonstrating laser communications in space was among the company’s most significant achievements in 2020.

SpaceX had revealed a few months earlier that it was testing space lasers for transferring data between satellites. Starlink engineers provided more detail in a Reddit AMA in November; here’s an excerpt from our coverage at the time:

“The speed of light is faster in vacuum than in fiber, so the space lasers have exciting potential for low latency links,” the Starlink team said on Reddit in response to a question about the space-laser testing. “They will also allow us to serve users where the satellites can’t see a terrestrial gateway antenna—for example, over the ocean and in regions badly connected by fiber.”

Space lasers won’t play a major role in Starlink any time soon, though. “We did have an exciting flight test earlier this year with prototype space lasers on two Starlink satellites that managed to transmit gigabytes of data,” the engineering team wrote. “But bringing down the cost of the space lasers and producing a lot of them fast is a really hard problem that the team is still working on.”

SpaceX seeks FCC OK for more polar satellites

In November 2020, SpaceX urged the FCC for an expedited approval “to facilitate deployment of 348 Starlink satellites into Sun-synchronous polar orbits at the lower altitude,” the FCC said in its decision to approve 10 satellites. The FCC approved only those 10 because it is evaluating interference concerns raised by other satellite companies.

“We find that partial grant of ten satellites will facilitate continued development and testing of SpaceX’s broadband service in high latitude geographic areas in the immediate term pending later action to address arguments in the record as to both grant of the modification as a whole and the full subset of polar orbit satellites,” the FCC order said.

Amazon’s Project Kuiper, Viasat, Kepler Communications, and Pacific Dataport urged the FCC to reject even the partial grant of 10 satellites because of the potential for increased interference with other non-geostationary satellite systems. But the FCC order said that SpaceX committed to “operate these satellites on a non-harmful interference basis with respect to other licensed spectrum users until the Commission has ruled on its modification in full.” A battle between SpaceX and Amazon is brewing, with Musk accusing Amazon of trying “to hamstring Starlink today for an Amazon satellite system that is at best several years away from operation.”



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Science

Record-breaking laser link could provide test of Einstein’s theory

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UWA’s rooftop observatory. Credit: ICRAR

Scientists from the International Centre for Radio Astronomy Research (ICRAR) and the University of Western Australia (UWA) have set a world record for the most stable transmission of a laser signal through the atmosphere.

In a study published today in the journal Nature Communications, Australian researchers teamed up with researchers from the French National Centre for Space Studies (CNES) and the French metrology lab Systèmes de Référence Temps-Espace (SYRTE) at Paris Observatory.

The team set the world record for the most stable laser transmission by combining the Aussies’ phase stabilization technology with advanced self-guiding optical terminals. Together, these technologies allowed laser signals to be sent from one point to another without interference from the atmosphere.

Lead author Benjamin Dix-Matthews, a Ph.D. student at ICRAR and UWA, said the technique effectively eliminates atmospheric turbulence. “We can correct for atmospheric turbulence in 3-D, that is, left-right, up-down and, critically, along the line of flight,” he said. “It’s as if the moving atmosphere has been removed and doesn’t exist. It allows us to send highly stable laser signals through the atmosphere while retaining the quality of the original signal.”

The result is the world’s most precise method for comparing the flow of time between two separate locations using a laser system transmitted through the atmosphere.

One of the self-guiding optical terminals on its telescope mount on the roof of a building at the CNES campus in Toulouse. Credit: ICRAR/UWA

ICRAR-UWA senior researcher Dr. Sascha Schediwy said the research has exciting applications. “If you have one of these optical terminals on the ground and another on a satellite in space, then you can start to explore fundamental physics,” he said. “Everything from testing Einstein’s theory of general relativity more precisely than ever before, to discovering if fundamental physical constants change over time.”

The technology’s precise measurements also have practical uses in earth science and geophysics. “For instance, this technology could improve satellite-based studies of how the water table changes over time, or to look for ore deposits underground,” Dr. Schediwy said.

There are further potential benefits for optical communications, an emerging field that uses light to carry information. Optical communications can securely transmit data between satellites and Earth with much higher data rates than current radio communications.

“Our technology could help us increase the data rate from satellites to ground by orders of magnitude,” Dr. Schediwy said. “The next generation of big data-gathering satellites would be able to get critical information to the ground faster.”

The phase stabilization technology behind the record-breaking link was originally developed to synchronize incoming signals for the Square Kilometer Array telescope. The multi-billion-dollar telescope is set to be built in Western Australia and South Africa from 2021.

Moon to Earth: Western Australia to host space communications station

More information:
Benjamin P. Dix-Matthews et al. Point-to-point stabilized optical frequency transfer with active optics, Nature Communications (2021). DOI: 10.1038/s41467-020-20591-5

Provided by
International Centre for Radio Astronomy Research

Citation:
Record-breaking laser link could provide test of Einstein’s theory (2021, January 22)
retrieved 22 January 2021
from https://phys.org/news/2021-01-record-breaking-laser-link-einstein-theory.html

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Groundbreaking New Laser System Cuts Through Earth’s Atmosphere Like It’s Nothing

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To artists and romantics, the twinkling of stars is visual poetry; a dance of distant light as it twists and bends through a turbulent ocean of air above our heads.

Not everybody is so enamoured with our atmosphere’s distortions. To many scientists and engineers, a great deal of research and ground-to-satellite communication would be a whole lot easier if the air simply wasn’t there.

 

Losing our planet’s protective bubble of gases isn’t exactly a popular option. But Australian and French researchers have teamed up to design the next best thing – a system that guides light through the tempestuous currents of rippling air with the flick of a mirror.

The result is a laser link capable of holding its own through the atmosphere with unprecedented stability.

While astronomers have a few tricks up their sleeve to correct for the atmosphere’s distortions on incoming light, it’s been a challenge to emit a coherent beam of photons from the ground to a distant receiver so they keep together and on point.

Keeping transmissions on target and coherent – with their phases remaining neatly in line – through hundreds of kilometres of shifting air would allow us to link highly precise measurement tools and communications systems.

Satellites could probe for ores or evaluate water tables with improved precision. High-speed data transfer could require less power, and contain more information.

Lead author Ben Dix-Matthews, an electrical engineer with the International Centre for Radio Astronomy Research in Australia, explained the technology to ScienceAlert.

 

“The active terminal essentially uses a small four-pixel camera, which measures the sideways movement of the received beam,” says Dix-Matthews.

“This position measurement is then used to actively control a steerable mirror that keeps the received beam centred and removes the sideways movement caused by the atmosphere.”

In effect, the system can be used to compensate for the warping effects of the moving air in three dimensions – not just up and down, or left and right, but along the beam’s trajectory, keeping the link centred and its phases in order.

So far it’s only been tested across a relatively short distance of 265 metres (about 870 feet). About 715 metres (just under half a mile) of optical fibre cable was run underground between the transmitter and receiver to carry a beam for comparison.

The results were so stable they could be used to connect the kinds of optical atomic clocks used to test fundamental physics, such as Einstein’s theories of relativity.

With the proof of concept demonstrated, there’s no reason to think a similar technique won’t one day be aiming for the sky, and beyond. Though there are a few hurdles that need to be overcome first.

 

“During this experiment we had to do the initial alignment by hand, using a visible guide laser that was in line with the stabilised infrared beam,” Dix-Matthews told ScienceAlert.

“When making links between optical atomic clocks, it would be good to have a way of doing this coarse alignment more easily.”

Fortunately Dix-Matthews’ French collaborators are working on a device that will speed up the initial coarse alignment process, promising a second generation of laser link technology that won’t require such an involved set-up.

The team also found temperature variations in the equipment affected the phase’s stability, limiting the duration of the signal to around 100 seconds. This hurdle will also be the focus of future improvements.

We might not need to wait long. The researchers are already making headway on upgrades for their system.

“We have started using a high-power laser amplifier that should help us deal with the larger power losses expected over longer distances, such as to space,” says Dix-Matthews.

“We have also completely rebuilt our active terminal to make it more sensitive to low received powers and make it more effective at cancelling out the movement of the received beam.”

With orbiting technology rapidly becoming a major focus for many data providers, potentially filling our skies with satellites, innovations that make linking communications systems across our atmosphere will only become more sought after.

As useful as our atmosphere is for, well, keeping us all alive, there are certainly some downsides to being buried under a restless blanket of warm gas.

This research was published in Nature Communications.

 

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