Astronomy

An AI program can learn from smartphone users' behaviours in order to send timely pop-up reminders about when to close attention-grabbing apps. The system effectively reduced how often people opened apps such as TikTok

An AI program can learn from smartphone users' behaviours in order to send timely pop-up reminders about when to close attention-grabbing apps. The system effectively reduced how often people opened apps such as TikTok

It's total solar eclipse day, April 8, and we're rounding up the best images of the phenomenon on social media.

Missions to asteroids have been on a tear recently. Visits by Rosetta, Osirix-REX, and Hayabusa2 have all visited small bodies and, in some cases, successfully returned samples to the Earth. But as humanity starts reaching out to asteroids, it will run into a significant technical problem – bandwidth. There are tens of thousands of asteroids in our vicinity, some of which could potentially be dangerous. If we launched a mission to collect necessary data about each of them, our interplanetary communication and control infrastructure would be quickly overwhelmed. So why not let our robotic ambassadors do it for themselves – that’s the idea behind a new paper from researchers at the Federal University of São Paulo and Brazil’s National Institute for Space Research.

The paper primarily focuses on the control problem of what to do when a spacecraft is approaching a new asteroid. Current missions take months to approach and require consistent feedback from ground teams to ensure the spacecraft understands the parameters of the asteroid it’s approaching – especially the gravitational constant.

Some missions have seen more success with that than others – for example, Philase, the lander that went along with Rosetta, had trouble when it bounced off the surface of comet 67P/Churyumov-Gerasimenko. As the authors pointed out, part of that difference was a massive discrepancy between the actual shape of the comet and the observed shape that telescopes had seen before Rosetta arrived there. 

Fraser discusses the possibility of capturing an asteroid.

Even more successful missions, such as OSIRIS-Rex, take months of lead-up time to complete relatively trivial maneuvers in the context of millions of kilometers their overall journey takes them. For example, it took 20 days for OSIRIX-Rex to perform multiple flybys at 7 km above the asteroid’s surface before its mission control deemed it safe to enter a stable orbit.

One of the significant constraints the mission controllers were looking at was whether they could accurately calculate the gravitational constant of the asteroid they were visiting. Gravity is notoriously difficult to determine from far away, and its miscalculation led to the problems with Philae. So, can a control scheme do to solve all of these problems?

Simply put, it can allow the spacecraft to decide what to do when approaching their target. With a well-defined control scheme, the likelihood of a spacecraft failure due to some unforeseen consequence is relatively minimal. It could dramatically decrease the time missions spend on approach and limit the communication bandwidth back toward mission control on Earth. 

One use case for quick asteroid mission – mining them, as Fraser discusses here.

Such a scheme would also require only four relatively ubiquitous, inexpensive sensors to operate effectively – a LiDAR (similar to those found on autonomous cars), two optical cameras for depth perception, and an inertial measurement unit (IMU) that measures parameters like orientation, acceleration, and magnetic field. 

The paper spends plenty of time detailing the complex math that would go into the control schema – some of which involve statistical calculations similar to basic learning models. The authors also run trials on two potential asteroid targets of interest to see how the system would perform.

One is already well understood. Bennu was the target of the OSIRIX-Rex mission and, therefore, is well-characterized as asteroids go. According to the paper, with the new control system, a spacecraft could enter a 2000 m orbit within a day of approaching from hundreds of kilometers away, then enter an 800 m orbit the next day. This is compared to the months of preparatory work the actual OSIRIS-Rex mission had to accomplish. And it can be completed with minimal thrust and, more importantly, fuel – a precious commodity on deep-space missions.

Asteroid defense is another important use case for quick asteroid missions – as Isaac Arthus discusses in this video.
Credit – Isaac Arthur

Another demonstration mission is one to Eros, the second-largest asteroid near Earth. It has a unique shape for an asteroid, as it is relatively elongated, which could pose an exciting challenge for automated systems like those described in the paper. Controlling a spacecraft with the new schema for a rendezvous with Eros doesn’t have all the same advantages of a more traditional asteroid like Bennu. For example, it has a much higher thrust requirement and fuel consumption. However, it still shortens the mission time and bandwidth required to operate it.

Autonomous systems are becoming increasingly popular on Earth and in space. Papers like this one push the thinking about what is possible forward. Suppose all that’s required to eliminate months of painstaking manual technical work is to slap a few sensors and implement a new control algorithm. In that case, it’s likely that one of the various agencies and companies planning to rendezvous with an asteroid shortly will adopt that plan.

Learn More:
Negri et al. – Autonomous Rapid Exploration in Close-Proximity of an Asteroid
UT – Miniaturized Jumping Robots Could Study An Asteroid’s Gravity
UT – How to Make Asteroid Landings Safer
UT – A Spacecraft Could use Gravity to Prevent a Dangerous Asteroid Impact

Lead Image:
Artist’s conception of the Lucy mission to the Trojan asteroids.
Credit – NASA

The post If We Want to Visit More Asteroids, We Need to Let the Spacecraft Think for Themselves appeared first on Universe Today.

I remember reading about an audacious mission to endeavour to drill through the surface ice of Europa, drop in a submersible and explore the depths below. Now that concept may be taking a step closer to reality with researchers working on technology to do just that. Worlds like Europa are high on the list for exploration due to their potential to harbour life. If technology like the SLUSH probe (Search for Life Using Submersible Head) work then we are well on the way to realising that dream. 

The search for life has always been something to captivate the mind. Think about the diversity of life on Earth and it is easy to see why we typically envisage creatures that rely upon sunlight, food and drink. But on Earth, life has found a way in the most inhospitable of environments, even at the very bottom of the ocean. The Mariana’s Trench is deeper than Mount Everest is tall and anything that lives there has to cope with cold water, crushingly high pressure and no sunlight. Seems quite alien but even here, life thrives such as the deep-sea crustacean Hirondellea Gigas – catchy name. 

Location of the Mariana Trench. Credit: Wikipedia Commons/Kmusser

Europa, one of the moon’s of Jupiter has an ice crust but this covers over a global ocean of liquid water.  The conditions deep down in the ocean of Europa might not be so very different from those at the bottom of the Mariana’s Trench so it is here that a glimmer of hope exists to find other life in the Solar System. Should it exist, getting to it is the tricky bit. It’s not just on Europa but Enceladus and even Mars may have water underneath ice shelves. Layers of ice up to a kilometre thick might exist so technology like SLUSH has been developed to overcome. 

Natural color image of Europa obtained by NASA’s Juno spacecraft. (Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)

The technology is not too new though since melt probes like SLUSH have been tested before. The idea is beautifully simple.  The thermo-mechanical probe uses a drilling mechanism to break through the ice and then the heat probe to partially melt the ice chips, forming slush to enable their transportation to behind the probe as it descends. 

The probe, which looks rather like a light sabre, is then able to transmit data from the subsurface water back to the lander. A tether system is used for the data transmission using conductive microfilaments and an optical fibre cable. Intriguingly and perhaps even cunningly, should the fibre cable break (which is a possibility due to tidal stresses from the ice) then the microfilaments will work as an antenna.  They can then be tuned into by the lander to resume data transmission. The tether is coiled up and housed inside spools which are left behind in the ice as the spool is emptied. I must confess my immediate thought here was ‘litter’! I accept we have to leave probes in order to explore but surely we can do it without leaving litter behind! However there is a reason for this too. As the spools are deployed, they act as receivers and transmitters to allow the radio frequencies to travel through the ice. 

The company working on the device is Honeybee Robotics have created prototypes. The first was stand alone, had no data transmission capability and demonstrated the drilling and slushing technology in an ice tower in Honeybee’s walk in freezer. While this was underway, the tether communication technology was being tested too with the first version called the Salmon Probe. This was taken to Devon Island in the Arctic where the unspooling method is being put through its paces. The first attempts back in 2022 saw the probe achieving depths of 1.8m! 

A further probe was developed called the Dolphin probe and this was capable of getting to depths of about 100m but sea ice limitations meant it could only get to a depth of 2m! Thus far, all probes have performed well. Honeybee are now working on the Narwhal Probe which will have more measuring equipment on board, a deployable tether and spool and will be far more like the finished product. If all goes to plan it will profile the ice on Devon Island to a depth of 100m.  This is still quite short of the kilometre thick ice expected but it is most definitely fantastic progress toward exploring the cold watery depths of alien worlds. 

Source : SLUSH: AN ICE DRILLING PROBE TO ACCESS OCEAN WORLDS

The post Testing a Probe that Could Drill into an Ice World appeared first on Universe Today.

People with long covid after a serious covid-19 infection have raised levels of many immune molecules in their blood. Better understanding how these molecules can vary could lead to more targeted treatments

People with long covid after a serious covid-19 infection have raised levels of many immune molecules in their blood. Better understanding how these molecules can vary could lead to more targeted treatments

One in three adults have non-alcoholic fatty liver disease – often without knowing. Now we understand what causes this stealthy condition and how to reverse it

One in three adults have non-alcoholic fatty liver disease – often without knowing. Now we understand what causes this stealthy condition and how to reverse it

It has often been likened to talcum powder. The ultra fine lunar surface material known as the regolith is crushed volcanic rock. For visitors to the surface of the Moon it can be a health hazard, causing wear and tear on astronauts and their equipment, but it has potential. The fine material may be suitable for building roads, landing pads and shelters. Researchers are now working to analyse its suitability for a number of different applications.

Back in the summer of 1969, Armstrong and Aldrin became the first visitors from Earth to set foot on the Moon. Now, 55 years on and their footprints are still there. The lack of weathering effects and the fine powdery material have held the footprints in perfect shape since the day they were formed. Once we – and I believe this will happen – establish lunar bases and even holidays to the Moon those footprints are likely still going to be there. 

There are many challenges to setting up permanent basis on the Moon, least of which is getting all the material there. I’ve been embarking on a fairly substantial home renovation over recent years and even getting bags of cement and blocks to site has proved a challenge. Whilst I live in South Norfolk in UK (which isn’t the easiest place to get to I accept) the Moon is even harder to get to. Transporting all the necessary materials over a quarter of a million kilometres of empty space is not going to be easy. Teams of engineers and scientists are looking at what materials can be acquired on site instead of transporting from Earth. 

The fine regolith has been getting a lot of attention for this very purpose and to that end, mineralogist Steven Jacobsen from the Northwestern University has been funded by NASAs Marshall Space Flight Centre to see what it back be used for. In addition NASA has partnered with ICON Technology, a robotics firm to explore lunar building technologies using resources found on the Moon. A key challenge with the lunar regolith though is that samples can vary considerably depending on where they are collected from. Jacobsen is trying to understand this to maximise construction potential. 

ICON were awarded the $57.2 million grant back in November 2022 to develop lunar construction methods. Work had already begun on space based construction, again from ICON in their Project Olympus. This didn’t just focus on the Moon though, Mars was also part of the vision to create construction techniques that could work wherever they were employed. 

Artist’s concept for a lunar base using construction robots and a form of 3D printing contour-crafitng.

3D printing may play a part in the lunar construction approach. It is already being used by ICON and others like them to build houses here on Earth. Employing 3D technology on the Moon using raw lunar material could be one solution. 

One of the first priorities would be to establish a suitable permanent landing area on the Moon. Without it, every time a lander arrives, the fine regolith will get kicked up and disturbed and may very well play havoc with other equipment in the vicinity. The particles can be quite sharp too so it may be quite abrasive on equipment. 

Source : Examining lunar soil for moon-based construction

The post What Could We Build With Lunar Regolith? appeared first on Universe Today.

The atmosphere of exoplanet WASP-76b may rain iron and form a strange, rainbow-like phenomenon called a “glory” never yet seen outside the solar system

An elite athlete’s metabolism mostly looks different from that of a person with COVID—but their occasional similarities can reveal important insights into health and disease

Look for these astronomical and Earthbound phenomena during the total solar eclipse on April 8, 2024.

The post What to Look For & When During a Total Solar Eclipse appeared first on Sky & Telescope.

Indiana is in the path of totality for the 2024 solar eclipse, and the state's residents have different ideas about the best spot to watch the event unfold.

When anger strikes, decreasing arousal is more likely to reduce aggression than venting is, according to a massive review of 154 studies

A modern butchery experiment using replicas of Stone Age tools raises new questions about how often prehistoric peoples hunted large animals such as bison or mammoths

A modern butchery experiment using replicas of Stone Age tools raises new questions about how often prehistoric peoples hunted large animals such as bison or mammoths

Kate Russo has seen 13 total solar eclipses, and even she isn't ready for this one.

Astronomical simulations and ancient Egyptian texts show the Milky Way was linked to the ancient Egyptian sky goddess Nut. This fits within multicultural myths about our home galaxy

The eclipse is about to begin. Totality will arrive at Mexico’s west coast around 11.07am local time, moving east until it leaves Newfoundland, Canada, around 5.16pm there