News Feeds

Neptune’s largest moon, Triton, is one of the most biologically interesting places in the solar system. Despite being hard to reach, it appears to have active volcanoes, a thin atmosphere, and even some organic molecules called tholins on its surface. However, Voyager only visited it once, in passing, 35 years ago. Technology has advanced a lot in the intervening decades, and a new push for a lander on Triton specifically has been garnering attention. One such mission was described by Steve Oleson and Geoffrey Landis of NASA’s Glenn Research Center. Their concept mission, known as Triton Hopper, was funded by NASA’s Institute for Advanced Concepts (NIAC) back in 2018 and utilized a cryogenic pump to extract propellant from Triton’s surface to power a “hopper” that could travel up to 5 km a month, and do some fascinating science along the way.

The first challenge to any mission on Triton is getting there. As part of the NIAC final report for the Triton Hopper, the authors performed a preliminary study examining different propulsion methods. Solar electric propulsion and aerobraking in Neptune’s larger atmosphere came out on top. The Hopper would have to hitch a ride with a larger orbital spacecraft responsible for trajectory planning of the “hops” and communicating with Earth.

Once safely deposited on Triton’s surface, a hopper could do lots of exciting science. The instrument payload described in the mission brief included ground-penetrating radar, spectroscopy equipment, a microscope, and even a seismometer. In total, the whole system weighed just under 300 kg—relatively light for an interplanetary mission.

Video describing the Triton Hopper mission in detail.
Credit – Dreksler Astral YouTube Channel

But most of that weight wouldn’t be in the instrumentation—it would be in the Hopper’s unique propulsion system. The concept behind the propulsion system is simple enough: Get some propellant material into the spacecraft, then heat that material to a point where it is pressurized. Once enough pressure is built up, release it as a jet stream that would allow the 300 kg spacecraft to overcome the relatively weak gravity of Titan, which is only ½ the gravity of our own Moon.

The study focused on two main ways to get material into the Hopper – a shovel and a cryogenic pump. Each has its advantages, though the pump was more effective, at least in the theoretical simulations run as part of the Phase I project. The shovel suffered from potential contamination by other material being loaded into the propellant collection hopper and either blocking the nitrogen-rich ice and snow from entering it or itself being absorbed into the thermal chamber and sucking up some of the heat intended to melt the propellant.

On the other hand, a cryopump could use waste heat from the rover’s normal power-generating operations to directly melt the ice and snow the Hopper landed on and absorb that into a heating chamber, where it would be further heated before being used as a propellant. This methodology can be effective at gathering the best propellant options and providing an outlet for the lander’s waste heat that doesn’t just radiate into Triton’s thin atmosphere.

Fraser discusses why Triton is so interesting with Dr. Jason Hofgartner

Once enough pressure is built up by heating the propellant, the Hopper can take off from the moon’s surface and “hop” a short distance using its six power and four steering thrusters. The authors estimate about 50 seconds of specific impulse once a month. While that might not seem like a lot, it would allow the Hopper to cover about 150 kilometers over the course of a two-year mission.

It could find plenty of interesting scientific spots in those two years. However, the mission, which is also competing for resources with plenty of other mission concepts for Triton landers, appears to be on hold. It hasn’t received a Phase II, and there haven’t been any development updates in the last few years. But given the general popularity of the hopper concept even on other worlds in our solar system and the desirability of Triton as an exploration destination, it seems likely that someday some form of this mission will soar above the ice surface of Neptune’s biggest moon. It might just be a while before it does.

Learn More:
Oleson & Landis – Triton Hopper: Exploring Neptune’s Captured Kuiper Belt Object
UT – NASA Wants to Send a Low-Cost Mission to Explore Neptune’s Moon Triton
UT – Will Triton finally answer, ‘Are we alone?’
UT – Want to Explore Neptune? Use Triton’s Atmosphere to Put on the Brakes

Lead Image:
Artist’s conception of the Triton Hopper mission.
Credit – S. Oleson

The post A Hopper Could Explore Over 150km of Triton’s Surface In Two Years appeared first on Universe Today.

We’ve all read the advice, during a meteor shower there is no equipment needed. All you need to do is lay back and wonder at one of the most spectacular sights the universe has to offer. That’s about it though and while you lay back on a lounger and watch it really can be a wonderfully grounding and relaxing experience. Unless you happen to be on National TV and miss a meteor behind your head and just tell the world there’s nothing to see. Not that I’m bitter about that of course!

It’s quite easy to get confused; a meteor is a piece of rock that has fallen through the Earth’s atmosphere and been destroyed on its way down, a meteorite survives the plunge and a meteoroid is a piece of space rock floating through space before it encounters the atmosphere. We can see meteors any night of the year and these are called sporadic meteors however around 20 times a year we can enjoy a burst of meteor activity in events known as meteor showers. There are other showers but these are often faint and barely even noticeable. 

A brilliant Geminid meteor shower photographed from Mt. Balang, China. Credit: NASA/Kevin Wu

Individual meteors are seen as they plummet to Earth. Their passage through the atmosphere causes the gas to heat and emit light which we see as the familiar streak of light. The atmosphere is of great importance to us because it protects us from countless meteoric visitors that would otherwise strike the surface. Instead, only the largest get through but thankfully they are few and far between. Spacecraft and satellites of course orbit above the protective shield of the atmosphere and so are far more susceptible to damage. 

Organisations like NASA take the risk of meteoroid impact very seriously and their greater concern is the sporadic meteors. The showers that we all enjoy only raise the risk for a short time and their characteristics are well understand. This means that their risk profile can be very well calculated with NASA’s Meteoroid Environment Office issuing regular forecasts. The real risk though comes from outbursts, one off unexpected meteoroids or from the countless minor showers that are not yet well documented or understood. 

This isn’t just a paper based exercise though. The International Space Station has been in orbit since 1998 and in that time has had to adjust its course numerous times. There have been occasions when the occupants have had to get into an escape module and distance themselves from the Station due to possible meteoroid impact. To date though, there has been no major damage. There are thousands of satellites in orbit to and damage has been sustained by some. 

International Space Station. Credit: NASA

A paper recently published by Althea V. Moorhead and a small multi-discipline team from NASA’s Meteoroid Environment Office and the University of Western Ontraio looks at quantifying potentially hazardous meteor showers and looks at existing showers to determine which are high risk and of concern. 

The team conclude that for a shower to be classed as hazardous, the number of meteoroids of a certain mass or larger that impact upon an exposed spacecraft surface in low Earth orbit over a unit of time (known as the meteoroid flux) must raise by 5% over the sporadic rate. This would contribute 105 Joules of energy, sufficient to damage relatively delicate spacecraft components. The team are clear that they do not recommend spacecraft should mitigate for this level but instead, at least highlight for investigations from meteoroid forecast reports. 

Having identified the criteria, the team then assessed 74 of the established 110 meteor showers listed in the IAU Meteor Data Centre catalogue. They found that six showers would meet the criteria for being categorised as hazardous, indeed they exceeded the threshold by a factor of two! The showers of note are the daytime Arietids, Geminids, Perseids, Quadrantids, Southern Delta Aquariids and the daytime Xi Sagittariids. There are a further 11 showers that meet the threshold but do not exceed by a factor of two. 

Clearly as the study shows spacecraft operators need to be very conscious of meteoroid activity not just in their orbital operations but also in design and planning. To those of us on the ground we can still of course, sit back and relax to enjoy the spectacle but it adds an interesting context that, as we step out into the universe, those wonderful showers pose a very real risk to the safety of our explorers. 

Source : The threshold at which a meteor shower becomes hazardous to spacecraft

The post Can Meteor Showers Be Dangerous to Spacecraft? appeared first on Universe Today.

Meanwhile, in Dobrzyn, Hili is a tardy meteorologist:

Hili: The wind caused terrible damage.
A: But that was over two weeks ago.
Hili: But I noticed it first now.

Hili: Wiatr narobił strasznych szkód.
Ja: To już ponad dwa tygodnie temu.
Hili: Ale ja dopiero teraz to zauważyłam.

Does a mythical place where the elephants go to die actually exist?

The Maugean skate (Zearaja maugeana) is only found in one habitat in Australia, which is under threat from human activity. Now the species has been saved from extinction by hatching in captivity

We know that modern humans took one of two routes to first reach Australia, and now an ancient chunk of plant resin has tipped the evidence towards the northern option

New findings document fewer ship tracks, reduced cloud cover, and boosted warming after ship emissions regulations took effect in 2020.

Space exploration has led the world in that wonderful human ability to co-operate, alas history shows we don’t do it quite as much as we should! Recently NASA has put a request out to the wider community for ideas for their VIPER rover which was designed for lunar exploration. The exact purpose of VIPER was to hunt for volatile minerals in the polar regions of the Moon. The big question, will NASA get any takers?

Lunar exploration has really kicked up a gear again in recent years. NASA have developed a new rover known as VIPER standing for Volatiles Investigating Polar Exploration Rover. The 430 kilogram vehicle planned to explore the southern polar region on the Moon and had been scheduled for launch toward the end of 2024. The main purpose of VIPER was to try and locate water ice and other resources crucial for human lunar exploration. It has a suite of scientific instruments including a drill and will explore the polar region, mapping volatile elements on route. 

An artist’s concept of the completed design of NASA’s Volatiles Investigating Polar Exploration Rover, or VIPER. VIPER will get a close-up view of the location and concentration of ice and other resources at the Moon’s South Pole, bringing us a significant step closer to NASA’s ultimate goal of a long-term presence on the Moon – making it possible to eventually explore Mars and beyond. Credits: NASA/Daniel Rutter

Discovering the location of water deposits and other volatile, essential substances on the Moon is crucial to future human exploration. Water can not only sustain life through providing drinking water and oxygen through electrolysis but can be separated into hydrogen and oxygen to produce rocket fuel. Suitably located reserves will drive down exploration costs and make long term habitation on the Moon far more sustainable. 

On 17th July however NASA announced its intention to discontinue VIPER and to identify different methods for locating water and other volatiles at the lunar south pole. Claiming budgetary issues, it seemed VIPER was doomed however they are still committing to getting it to the Moon. As part of the announcement NASA requested for interested American companies and institutions to come forward if they would like to use VIPER for lunar exploration. The move supported NASA’s intent to support sustainable lunar exploration for the benefit of all. 

Between 17 July and the 1 August, NASA have been accepting expressions of interest to use the VIPER rover. They now have the challenge of working through the information to see how the interested groups and organisations would use VIPER and how the proposal would come at no cost to the US Government. It is not just American organisations though, NASA are going to be looking at any proposals from international groups to although this will be through a separate channel. 

The window is now closed for accepting proposals and NASA will see just how potential partners will look to achieve NASA science and exploration goals using VIPER. NASA has of course built up technological and science expertise and wants to build upon this with future projects as we further our knowledge of lunar exploration. 

Source : NASA Explores Industry, Partner Interest in Using VIPER Moon Rover

The post NASA is Looking for a Commercial Partner to Save VIPER appeared first on Universe Today.

New research explains the mathematics behind how initial predispositions and additional information affect decision making.

On 19 and 20 August, the JUICE mission will make the first ever attempt to get a gravitational boost from both Earth and the moon on its way to Jupiter

New research shows that programming robots to create their own teams and voluntarily wait for their teammates results in faster task completion, with the potential to improve manufacturing, agriculture and warehouse automation.

New research shows that programming robots to create their own teams and voluntarily wait for their teammates results in faster task completion, with the potential to improve manufacturing, agriculture and warehouse automation.

Common push puppet toys in the shapes of animals and popular figures can move or collapse with the push of a button at the bottom of the toys' base. Now, a team of engineers has created a new class of tunable dynamic material that mimics the inner workings of push puppets, with applications for soft robotics, reconfigurable architectures and space engineering.

Common push puppet toys in the shapes of animals and popular figures can move or collapse with the push of a button at the bottom of the toys' base. Now, a team of engineers has created a new class of tunable dynamic material that mimics the inner workings of push puppets, with applications for soft robotics, reconfigurable architectures and space engineering.

Common push puppet toys in the shapes of animals and popular figures can move or collapse with the push of a button at the bottom of the toys' base. Now, a team of engineers has created a new class of tunable dynamic material that mimics the inner workings of push puppets, with applications for soft robotics, reconfigurable architectures and space engineering.

Large Language Models (LLMs) are entirely controllable through human prompts and lack 'emergent abilities'; that is, the means to form their own insights or conclusions. Increasing model size does not lead LLMs to gain emergent reasoning abilities, meaning they will not develop hazardous abilities and therefore do not pose an existential threat. A new study sheds light on the (until now unexplained) capabilities and shortcomings of LLMs, including the need for carefully engineered prompts to exhibit good performance.

Quakes and meteor impacts on Mars generate seismic waves that can help map the interior. A new study analyzed seismic waves detected by the Insight lander and concludes that 11-20 kilometers beneath the surface, a zone of pores and fractures is filled with liquid water -- more than was thought to fill Mars' surface oceans before they disappeared 3 billion years ago. Though too deep to drill, the reservoir is a possible refuge for life.

If we want to reduce the greenhouse gas emissions from food production, we have to make it more efficient as the global population grows – and that isn't happening

Wastewater, which is full of pollutants that contain nitrogen, can be directly fed into a new chemical reactor that converts it into ammonia, with purified water and oxygen as by-products

Nanotubes can serve as biosensors. They change their fluorescence when they bind to certain molecules. Until now, it was unclear why. Researchers have gained new insights into the cause of the fluorescence.