Could a new, fifth force of nature provide some answers to our biggest questions about dark matter and dark energy? We’re working on it.
The Standard Model is, for all intents and purposes, the supreme accomplishment of modern physics. It describes four forces of nature, a zoo of particles, and how they all interact. It is perhaps the most successful scientific theory of all time.
And it’s fantastically incomplete.
It turns out that the Standard Model is able to account for less than 5% of all the matter and energy in the cosmos. Another 25% or so is Dark Matter, an unknown kind of matter that is for all intents and purposes invisible. The rest is known as Dark Energy, a mysterious entity that is causing the expansion of the universe to accelerate.
One of the first things astronomers noticed when they first discovered dark matter and dark energy was their apparent similarity. Why in the world are the two dark components of our universe roughly the same strength? I know, 25% and 70% don’t sound very similar, but when it comes to astronomy – and especially cosmology – they’re basically the exact same number.
Maybe it’s just a coincidence that they have about the same strength, and we’re overthinking it.
Or maybe it’s something else. Clever physicists have proposed connections within the “dark sector” of the universe, where dark matter and dark energy talk to each other. This would allow them to follow each other’s evolution, ensuring that they have roughly equal contributions to the energy budget of the universe for long periods of time.
To make them talk to each other, you need a force. But this force can’t be any of the known ones, otherwise dark matter and/or dark energy must also interact with normal matter, and we would have seen more directly evidence of them already.
So it has to be a new force, a fifth force of nature, completely different from electromagnetism, gravity, strong nuclear, and weak nuclear. While ideas like this remain only in the realm of hypothesis, some of the ideas already have names.
One name is quintessence, the fifth essence of the universe. Another is dark photons, a particle that travels the cosmos like a photon but is, as its name suggests, dark.
To test these ideas we have to turn to the cosmos for answers. If a fifth force exists, it must be very subtle. Stronger manifestations of the fifth force have already been ruled out by observations of galaxy clusters, the expansion of the universe, and even the behaviors of neutron stars. So we have our work cut out for us – it will take a truly massive amount of data to tease out some signal that differs from expectations.
In 2015, the United Nations adopted the 2030 Agenda for Sustainable Development—the Sustainable Development Goals (SDGs)—a universal call to action to protect the planet for future generations and ensure that all people will enjoy peace and prosperity. These 17 goals included the elimination of poverty, hunger, and inequalities, the promotion of education, and the promotion of sustainable development worldwide. With the rapid development in Low Earth Orbit (LEO), there are growing concerns that an 18th SDG should be adopted for space.
This goal calls for the sustainable use of Earth’s orbit by space agencies and commercial industry and the prevention of the accumulation of space junk. This has become a growing problem in recent years thanks to the deployment of satellite mega-constellations and the “commercialization of LEO.” In a recent study led by the University of Plymouth, a team of experts outlined how the lessons learned from marine debris mitigation could be applied to space so that future generations can live in a world where space truly is “for all humanity.”
Graph showing how the number of unregistered objects (red) in space has increased in recent years. Credit: ESA/UNOOSA
According to the ESA’s Space Debris Office (SDO), there have been 6,740 rocket launches since the beginning of the Space Age in 1957. The number of satellites these rockets deployed close to 20,000 satellites in orbit, about 13,230 are still in space while about 10,200 are still operational. These satellites have immensely benefited society, providing global communications, high-bandwidth internet, and other services used by billions of people worldwide. They’ve also enabled Earth observation science, allowing scientists to monitor ecological systems, forest fires, natural disasters, and climate change.
However, these launches have also left LEO littered with spent rocket stages, inoperable satellites, and debris from explosions or collisions. According to the SDO, there are currently 40,500 space debris objects greater than 10 cm (~4 inches) in LEO, and over 100 million measuring from 1 mm to 10 cm (~0.04 to 4 inches). This could lead to a scenario known as Kessler Syndrome, where the accumulation of debris increases the likelihood of more collisions, creating a vicious cycle that poses a significant hazard to active satellites and operations in space.
“It’s important because space is a finite resource in dire need of environmental protection, and it’s been neglected thus far because it hasn’t been universally accepted as such. Our collective actions are leading us to a tragedy of the commons,” said co-author Moriba Jah, a Professor of Aerospace Engineering & Engineering Mechanics at the University of Texas at Austin.
In 2009, Kessler wrote that attempts to model the orbital debris problem indicated the debris environment had already become unstable. With the number of launches dramatically increasing annually, it is clear to many that the time for action is now. Dr. Imogen Ellen Napper, a Visiting Research Fellow with the IMRLU, led the study that recently appeared in One Earth. As she said in a University of Plymouth press release:
“The need to protect and connect our natural environments, from the ocean to Earth’s orbit, has never been more urgent. Both are vital to the health of our planet, yet increasingly under threat from the pressures we place on them. There is growing recognition that marine litter knows no international boundaries, and the same applies to space debris. A UN-backed agreement would be a crucial step in safeguarding Earth’s orbit for the future.”
Their work builds on a previous article titled “Protect Earth’s orbit: Avoid high seas mistakes,” authored by Dr. Napper and many of her colleagues who contributed to this latest paper. In the article, the team cited how insubstantial maritime governance has led to overfishing, habitat destruction, deep-sea mining, and plastic pollution. They further called for a legally binding treaty to ensure that the future expansion of the global industry does not irreparably harm Earth’s orbit. Said co-author Dr. Thomas Dowling, a lecturer in Remote Sensing & Geospatial Science at the University of Auckland:
“Not so long ago, our oceans were regarded as infinite resources to plunder and infinite sinks for our waste. We now know that view was grossly mistaken – many marine environments are now barren wastelands and more than eight million tonnes of plastic debris is estimated to enter the ocean every year. Earth’s orbit is a similar finite environment to the ocean, and mindlessly exploiting the orbital environment is repeating the mistakes of the past.
“It’s time to create policies to regulate what we’re putting in space, and we need to ensure objects entering orbit are safe, sustainable, and serving essential – or at least important – purposes for significant numbers of people around the world.”
“Just like plastic pollution and climate change, space junk is an issue that transcends borders,” added co-author Professor Heather Koldewey, the ZSL’s Head of Ocean and FAIRER Conservation. “Our ongoing efforts to protect the ocean highlight how important UN-backed agreements are for managing this crisis. It’s key we learn from the challenges and solutions in tackling marine debris and act now to protect our planet’s orbit.”
In their article and study paper, the team argues that SDG18 should draw direct inspiration from an existing goal—SDG14: Life Below Water, which calls for a commitment to “conserve and sustainably use the oceans, seas and marine resources for sustainable development.” While several organizations have begun to recognize the need for action, the authors say an additional SDG could be the means through which a global call to action could be made. The necessary mechanisms could be developed and enforced.
They also argue that SDG18 would complement the existing SDGs that emphasize how space technology will support an improved understanding of global issues. This includes Earth Observation (EO) satellites for tracking climate change, organizing disaster relief, and providing geolocation through the Global Navigation Satellite Systems (GNSS). However, the UN acknowledges that space-based research contributes to economic growth, increased food production, medical advances, access to research facilities, and connecting remote and isolated communities to services.
If this study emphasizes one thing above all, it is the interconnected nature of humanity’s efforts in space and life here on Earth. At the same time, it highlights the need for proactive measures and legal frameworks to address issues of global importance before they become unmanageable. Lastly, it reminds us that if humanity is to achieve the “Great Migration” and become an interplanetary species, we need to avoid making the same mistakes in space that we have on Earth.
Astronomers have been battling threats to their clear skies on all fronts lately. One of the most notable battles, which we have reported on repeatedly, is the one against Starlink and other mega-constellations of satellites, which, while they offer high-speed internet in the most far-flung places, also disrupt observations by sensitive telescopes due to their reflectivity and fast movement speed. They also pose a global problem, whereas a more down-to-earth issue is cropping up at one very special observatory. A vast industrial plant threatens the European Southern Observatory’s Paranal telescope planned only a few kilometers from the site.
The ESO recently released a statement calling on the government of Chile, where Paranal is located, to consider moving the project elsewhere. Currently, AES Andes, a subsidiary of AES Corporation, an American power utility, recently submitted a proposal for the environmental review of a 3000-hectare industrial area that includes hydrogen and ammonium factories, electricity-generating machinery, and, importantly, a lot of lights.
Lights are part and parcel of any large industrial project, but they pose a particular threat to Paranal. In a recent study, it was found to be the observational site with the least amount of light pollution. Any significant increase to that baseline over only about .1% of the generic background level could have a massive negative impact on the capabilities of the telescope located there.
Levels of light pollution at observatories around the world.
Credit – ESO, modified from Falchi et al
That telescope has been an essential part of the astronomical community and contributed to research such as the Nobel Prize-winning 2020 studies into the Sgr A*, the supermassive black hole at the center of our galaxy. It also represents billions of dollars of investment from the European Southern Observatory member states.
When thinking about natural resources, a clear sky might not come to someone’s mind, but it certainly is for Chile. In addition to Paranal, two other Chilean observatories are in the top three least light-polluted major astronomical observatories – Armazones and Tokyo Atacama. It also has four more in the top 15, making it one of the best contributors in the world to this type of astronomy.
That contribution is planned to grow with the ESO’s ongoing development of the Extremely Large Telescope not far from the Paranal site. While the light pollution from the planned industrial facility might not reach as far as what will be the biggest telescope of its kind in the world, any precedent by the Chilean government to approve projects that would undercut investment by ESO and other astronomical bodies would be detrimental to the long-term outlook of observations in the country.
The night sky over Paranal.
Credit – ESO YouTube Channel
Since the AES Andes proposal is still in the environmental impact assessment phase, it’s still early enough to provide feedback for a potential alternative. ESO’s letter shows support for the project in concept but suggests moving it to a different location so as not to negatively affect the telescope. Whether or not that is feasible and whether or not the Chilean government will support it at all remains to be seen. But this threat to one of the world’s great observatories shouldn’t be ignored.
If you were Captain of the first USS Enterprise, where would you go!? Humanity is on the cusp of reaching out among the stars, maybe not just yet, nor in our lifetimes but it is just around the corner cosmologically speaking. A new paper explores the new technology that could make it a reality but also carefully considers the ethical aspects. Before we make the first journeys we need to be clear about the ethical considerations too so that our exploration is sustainable and responsible.
In 1961 Yuri Gagarin completed the first human spaceflight. In the decades that followed human visitors arrived on the Moon and countless probes have visited the planets. Exploring the stars is a challenge of another level but with theoretical concepts like nuclear propulsion and even warp drive it may not be so far away. Project Orion proposed nuclear powered spacecraft while Project Breakthrough Starshot proposed sending small spacecraft to the stars. The challenges are still vast but no longer insurmountable.
Yury Gagarin before a space flight aboard the Vostok spacecraft. April 12, 1961 Credit: RIA Novosti
The human drive for exploration has meant the prospect of interstellar travel has always been the obvious next step. As the desire and technology finally start to make this a reality, the ethical debate must also begin as we consider the complex moral implications as we step out among the stars.
In a fascinating paper authored by Florian Neukart, Professor of Quantum Computing from the Institute of Computer Science in the Netherlands, the focus is to explore the multitude of different elements to interstellar travel. This includes factual elements such as propulsion systems, habitat construction and life support and also sociological, ethical and philosophical issues too. Humans travelling to and exploring planets in our Solar System is one thing but just imagine travelling to and arriving at a world with alien inhabitants. Seems perhaps the stuff of science fiction but once we start travelling across the gulf between the stars, it becomes a real possibility. The paper underlines the deep need to consider all facets of interstellar travel.
This artist’s impression depicts the exomoon candidate Kepler-1625b-i, the planet it is orbiting and the star in the centre of the star system. Kepler-1625b-i is the first exomoon candidate and, if confirmed, the first moon to be found outside the Solar System. Like many exoplanets, Kepler-1625b-i was discovered using the transit method. Exomoons are difficult to find because they are smaller than their companion planets, so their transit signal is weak, and their position in the system changes with each transit because of their orbit. This requires extensive modelling and data analysis.
Among the questions posed by the paper is the deeply emotive; Should we pursue interstellar travel given the unknowns, or might our resources be better spent addressing urgent Earth-bound challenges? To answer questions like this demands insights from physics, engineering, biology, ethics and social sciences.
The paper includes insight into the current technological capabilities in consideration of the current theoretical frameworks of interstellar travel. It discusses multiple possible technologies such as the Magnetic Fusion Plasma Drive, nuclear thermal propulsion, ion drives and even warp drives. Life support systems and habitat protection technology are also considered and discussed.
Artist impression of a starship with warp drive (Credit : Alorin)
I feel however that, whilst the technology will undoubtedly get us to the stars, the debates about whether we should will continue for some time. One thing is for sure, the many different aspects of interstellar travel must be carefully weighed up and considered with suitable frameworks being established. Not only will this protect us as we extend our travels into deep space but it will protect environments and life that we come across along the way.
January has an amazing parade of evening planets, well worth braving the cold for. We have brilliant Venus, high to the west after sunset, reaching greatest elongation on January 10th. Fainter Saturn sits just above Venus as the two meet on January 19th. Meanwhile, Jupiter dominates the eastern sky, fresh off of opposition in December. But stay awake just a bit longer after dusk, and you can see Mars rising in the east.
As a special treat, observers in most of North America will also see the nearly Full Moon pass in front of Mars Monday night.
Mars Opposition 2025
This works because Mars reaches opposition in January 2025, rising ‘opposite’ to the setting Sun. Think of the Red Planet as a slower runner on the outside track of the solar system, with the faster Earth approaching on the inside lane.
This also marks the center season to observe Mars. As Earth approaches the Red Planet, the apparent disk swells in the view of a telescope from a tiny dot to a larger globe where features can be discerned.
Dates to watch for involving Mars in 2025 include:
-Sunday, January 12th: Mars is closest to the Earth at 0.642 AU (96 million kilometers) distant;
-Wednesday, January 15th: Mars is brightest, shining at magnitude -1.5
-Thursday, January 16th: The planet Mars reaches opposition for 2025
-Monday, February 10th: Mars reaches its northernmost point at declination 26 degrees, 14’ north
-Wednesday, April 16th: Mars reaches aphelion at 1.6 AU from the Sun
-Monday, April 21st: Reaches eastern quadrature, 90 degrees from the Sun.
This serves as a prelude to checking out all naked eye planets in the evening sky in 2025, once Mercury joins the evening scene in late March.
Mars and Jupiter, rising to the east at dusk. Credit: Stellarium.
Mars Spends late January near Pollux, and then heads to Cancer and transits the open cluster Messier 44 on May 4th. On June 16th the planet passes just over a degree from Regulus, and the planet loiters in the evening for the remainder of 2025, until reaching solar conjunction on January 9th, 2026.
An Aphelion Opposition
Not all oppositions are created equal. This is because the orbits of both the Earth and Mars are elliptical, but its mainly the fault of the Red Planet: the planet can vary from 207 million kilometers from the Sun at perihelion, to 249 million kilometers away at aphelion. Oppositions for Mars occur every 26 months on average, roughly once every other calendar year. Perihelic oppositions are favorable with Mars reaching an apparent size of 25” across, while an opposition near aphelion sees the planet only reaching a measly 14” across. Moreover, these trend in cycles. 2003 saw an historic near-perihelion apparition of Mars, which then diminished on every pass to a paltry aphelion appearance in 2012. In 2025, we’re still headed towards unfavorable aphelic passes. Earth just reached perihelion in early January—while Mars reaches aphelion in mid-April. 2027 sees the nadir of the 15 year cycle, while 2033 sees us reaching favorable oppositions once again.
At its maximum, Mars will appear 15” across in 2025. The planet reaches -1.5 magnitude at opposition this year, rivaling nearby Jupiter in brightness.
Mars reappears from behind the Moon Monday night. Credit Stellarium.
The ‘Great North American Occultation’
North American observers are in for a treat on the night of January 13th when the near Full Moon actually occults (passes in front of) Mars. This is the best lunar-planetary occultation for the region for 2025. This occurs just five hours after Full, and two days prior to opposition. The Moon will take about 30 seconds to fully cover and then later reveal the Red Planet, in what promises to be a fine event.
The visiblity footprint for Monday night’s occultation. Credit: Occult 4.2
Note that, contrary to the old internet meme, Mars will not appear ‘as large as a Full Moon’ on this—or any other—year. This does, however, give you the rare chance to see the planet in the daytime just before sunset or immediately after sunrise on January 13-14th, using the nearby Full Moon as a guide.
The Moon occults Mars in 2022. Credit: Roger Hutchison.
The Moon occults Mars three more times in 2025: Once for northern Asia and Scandinavia on February 9th, again for the eastern Pacific and the west coast of South America on June 30th, and one last time for the remote Antarctic on July 28th.
Check or the IOTA’s dedicated site for ingress/egress times for select locations.
Mars on January 2nd. Credit: Thad Szabo.
Observing Mars Near Opposition
It’s fascinating to examine Mars near opposition… it’s the one planet that presents an actual surface to explore at the eyepiece. The white northern polar cap (currently tipped into view) is the most prominent feature. Settling in, darker swathes of terrain such as Syrtis Major may become apparent.
Fun fact: if you’re watching Mars at the same time every evening, you’re seeing nearly the same swatch of the planet turned Earthward, just rotated slightly in longitude from one night to the next. This happens because Mars rotates somewhat slower than the Earth, once every 24 hours and 38 minutes.
The ever-present possibility of a global dust storms can always make opposition season interesting. You can actually notice that something is afoot on Mars in terms of global dust storms, simply by noting the color of the planet, as a sickly yellow versus the healthy traditional red.
Finding Phobos and Deimos
Phobos and Deimos in the glare of Mars. Credit: Shahrin Ahmad.
Opposition is also a good time to try and cross the Martian moons of Phobos and Deimos off of your observing ‘life list.’ Discovered by astronomer Asaph Hall using the U.S. Naval Observatory’s then-new 26” refractor in 1877, the faint moons never stray far from dazzling Mars. +11.5th magnitude Phobos orbits the planet once every 7.7 hours and reaches a max separation of 14”, while outer 12.4th magnitude Deimos orbits once every 30.3 hours and reaches 45” away. Use an occulting bar eyepiece or nudge the planet just out of view to help you in your quest. Use a planetarium program such as Stellarium to see if a moon is currently visible.
The U.S. Naval Observatory refractor. USNO/Public Domain Image
Rovers on Mars actually catch sight of the Martian moons on occasion, including this fine transit of Phobos in front of the Sun from late 2024:
These transits actually help to refine the orbits of the two moons.
If skies are clear, be sure to check out Mars while you can, and don’t miss the best occultation of the year.
Scheduled for launch in 2027, the Nancy Grace Roman Telescope is slowly being readied for operation. This week, NASA announced that they have started to joined the mission’s telescope, instrument carrier and instruments onto the spacecraft. Having completed the construction, they will now move to the testing phase where the instrument will be subjected to more tests. These will include exposure to electromagnetic radiation expected during launch along with vibration and thermal changes too. If it passes these tests, the new space telescope will be on the home straight.
The Nancy Grace Roman Space Telescope is often referred to as the Roman Space Telescope. It’s been developed by NASA and was named after former chief astronomer Nance Grace Telescope. It has a mirror 2.4m in diameter so is similar in size to the Hubble Space Telescope but has a wider field of view. On board are instruments that enable it to explore exoplanets and the large scale structure of the universe. It will also investigate the nature of dark energy and try to understand more about the accelerated expansion of the universe through the study of gravitational lenses.
NASA’s Wide Field Infrared Survey Telescope (WFIRST) is now named the Nancy Grace Roman Space Telescope, after NASA’s first Chief of Astronomy. Credits: NASA
It’s fitting that the telescope has been named after Roman who was a leading American astronomer and astrophysicist. She was instrumental in the development of the Hubble Space Telescope so has often been called the ‘Mother of Hubble.’ She was born on 16 May 1925 and became one of the first female executives of NASA, including a role as Chief of Astronomy.
In a recent press release, NASA confirmed that a team of technicians have successfully integrated the telescope with instrument carrier, known as the Instrument Payload Assembly. Two instruments have been installed, the Coronagraph Instrument which will be used to block starlight to reveal and study exoplanets, the Optical Telescope Assembly and the Wide Field Instrument. The Wide Field Instrument is made up of 18 detectors that will give the telescope images with a field 100 times larger than Hubble’s but with the same resolution. I really can’t wait to see the images it produces. The whole assemble is now safely connected to the spacecraft that will take the observatory into its orbit.
This image of NASA’s Hubble Space Telescope was taken on May 19, 2009 after deployment during Servicing Mission 4. NASA
Mark Clampin, acting Deputy Associate Administrator for NASA’s Science Mission Directorate said “With this incredible milestone, Roman remains on track for launch and we’re a big step closer to unveiling the comos as never before.”
Launch is a little way off but before then, the instrumentation will under its next testing phase. There has been a significant amount of testing so far but this next test phase is designed to to ensure the individual components operate when integrated. By subjecting it to simulated launch conditions, the tests will check that the vibrations will not cause problems, that the communications equipment won’t create electromagnetic interference and to check, across a range of conditions, that the optics and instrumentation can cope with the predicted thermal variations.
NASA engineers and technicians position the James Webb Space Telescope (inside a large tent) onto the shaker table used for vibration testing. Credits: NASA/Chris Gunn
On completion of these tests, which are expected to last a few months, the aperture cover will be added to the outer barrel assembly with the solar panels soon after. Once this has been completed, the structure will be added to the spacecraft during autumn. To date though, all is going well with the testing and all is on track for launch no later than May 2027.
Few places in the solar system are better suited to a balloon than Titan. The combination of low gravity and high atmospheric density makes Saturn’s largest moon ideal for a lighter than “air” vehicle, and the idea to put one there has been around for at least two decades. So why haven’t we yet? The simple answer is the size of the necessary balloon is too large for the existing launch platforms. But a team from Boeing, the prime contractor on the Space Launch System (SLS), believes their new launch platform will be capable of getting a large balloon into orbit, along with its necessary scientific payload – and start unlocking the mysteries of this intriguing moon.
We’ve reported various balloon missions to Titan, including some that would “walk,” but Boeing’s design is more akin to a traditional blimp. It would have a balloon filled with helium and two ballast tanks that, combined with a cruciform tail, would allow the balloon to control its roll, pitch, and yaw.
The balloon would intake local atmospheric gases to descend or expel them to rise to control its altitude. The Boeing engineers offered two different altitude configurations: a 150m3 balloon for a 5km altitude or a 400m3 balloon for a 20km altitude orbit. When compressed, both balloon sizes can fit into an SLS payload fairing.
Fraser discusses why a mission to Titan would be interesting.
The gondola is where the real magic happens, and the paper the authors released was scant on details of what precisely this science would be. They mention various tools, including RADAR and LIDAR systems to scan the surface of Titan and, in particular, keep track of any changes from geological activity. There could also be atmospheric sensors that could detect whether there were any organic molecules in the area that would give an indication of what kind of liquid methane cycle there is, if any.
Another important point about the mission design is that it would last a long time—the team expects such a balloon to last in Titan’s atmosphere for years. During that time, it would be able to notice long-term trends, like seasonal variability, and possibly why the night side of Titan appears to be warmer than the day side.
The mission was designed for a launch in the 2034-2036 time frame, with several different windows of opportunity during those years that would take advantage of a lower delta-v requirement to get to the Saturnian system. However, the SLS has had its own difficulties that could delay that timeline. While it has launched once, in 2022, its second launch is not planned until 2026 – almost four years later. It is also not reusable, and given the requirements it has to meet NASA’s demand for Artemis launches to the Moon, it is unlikely that any additional SLS launches will be available in that time frame.
There are plenty of ideas for missions to Titan, as Fraser explains here.
That’s not to mention the cost, which is estimated at $2.5bn per launch at the time of writing. While that might eventually come down in price, it still has to compete with Starship, which has a higher launch capacity and has flown four times since the SLS took its first trip to the sky over two years ago.
Dragonfly, NASA’s helicopter mission to Titan, is already using a Falcon Heavy to launch in 2028. While the Falcon Heavy doesn’t have as much payload capacity as the SLS, it could still potentially get a smaller version of the same mission to Titan. Ultimately, as access to space gets cheaper, and there are more and more launch platforms capable of sending a balloon to this unique world, someday, a mission will likely be approved – it remains to be seen how it will get there.
We reported before about a NIAC-funded project known as the Lofted Environment and Atmospheric Venues Sensors (LEAVES) mission to study Venus’ atmosphere. While the technology behind the idea is still under development, it has already inspired a team of Worcester Polytechnic Institute (WPI) undergraduates to develop a supporting satellite mission to launch and communicate with the leaves. Their paper, part of their B.S. Thesis, details how to use these new sensors and the challenges ahead.
As a refresher – the main unique selling point of LEAVES is that they are inexpensive ways to collect data about Venus’ atmosphere – at least from the height of about 100km down to 30km, where a lot of interesting atmospheric physics is taking place. They are designed without a propulsion system and, as such, glide down on their own accord, sending back data about the local pressure, temperature, atmospheric composition, and the probe’s orientation via an inertial measurement unit like those used on drones.
They aren’t intended to last long, but the short time they will be present in the atmosphere could provide insights into several outstanding questions about Venus, such as what compound is absorbing near-ultraviolet light in the upper atmosphere or the local carbon monoxide concentration. However, their distribution over the planetary surface is a critical part of any such effort – which is where the mission design from the team at WPI comes in.
Venus’ environment is harsh on technology, as Fraser discusses in this video.
Their mission design revolves around two spacecraft joined together for launch and approach to Venus but then breaking apart into wildly different orbits. One of them, Demeter, is responsible for launching the LEAVES. The other, Persephone, is named after Demeter’s daughter, whom Venus’ Greek equivalent had taken away to the underworld. It is left at a higher orbit and responsible for transmitting the data collected by the LEAVES back to Earth.
Demeter had two important design decisions—one was where to deploy the LEAVES, and the second was how to. The team came up with a deployment strategy of eight LEAVES every 20 meters of latitude the entire way around the planet, for a total of 144 probes. Importantly, these would be deployed on the day/night light to examine how the difference between day and night might play a role in the sulfur dioxide cycle on Venus.
How to deploy them offered a different challenge – the team settled on 18 miniature housings, each attached to a small solid rocket booster using hydrazine. Demeter would orbit around the planet at an altitude of about 235km and would launch eight LEAVES every 20 degrees around the planet. Those LEAVES would descend through the atmosphere – some around the equator, some around the poles – and would deploy their glide form at about 150km from the surface. At around 100 km, they would start sending back data to Persephone, waiting overhead. After its deployment mission was complete, Demeter itself would deorbit and start burning up in Venus’ atmosphere.
Persephone has a much simpler job—it uses a rocket booster to reach a 2000km orbit and patiently waits until the LEAVES are deployed. It then uses a high-gain antenna to pick up signals from the LEAVES’ relatively weak communications systems and stores them on its local hard drive. Once all the data has been gathered, Persephone transmits it back to Earth.
All the components except one on both satellites have very high Technology Readiness Levels (TRL-9). The single exception is the deployment tubes for the LEAVES, which have an expected TRL of 1-2, meaning they would require more development and testing before being ready for prime time.
There is no deadline for that development and testing for now as LEAVES is still just a NIAC project and has not been selected for a mission opportunity to Venus. Given the increasing interest in exploring our sister planet, it seems likely that a similar mission will someday launch – and maybe some of the team that spent so much of their senior year working on this project will have a hand in working on the version that finally does make it there.
The InSight Lander arrived on Mars in 2018 to study the planet’s interior. Its mission ended prematurely in December 2022 after its solar panels were covered in the planet’s ubiquitous dust. NASA’s Mars Reconnaissance Orbiter captured an image of InSight recently and will continue to do so as the Martian dust slowly and inexorably reclaims the lander.
NASA and the DLR sent the InSight lander to Mars to study the planet’s interior. Though the lander’s mole instrument wasn’t able to complete its work, the mission is still considered a success. It detected more than 1,000 Marsquakes, which helped scientists understand Mars’ crust, mantle, and core. It also measured the frequency of meteoroid impacts and uncovered some information on the planet’s thermal evolution.
While the mission was pronounced finished in December 2022, mission personnel continued listening for signals from InSight in case the wind cleared dust from its panels. That effort will also soon end.
Now, the 358-kilogram (789 lb) spacecraft sits in its final resting place in Elysium Planitia. Barring some hyper-futuristic, impossible-to-foresee archaeological rescue expedition, the lander will never move. It’s stranded there, waiting to be imaged repeatedly by the Mars Reconnaissance Orbiter (MRO) and its HiRISE camera.
However, perhaps unexpectedly, InSight still has more to offer. Researchers say that by monitoring the way dust collects on the lander and moves around it, they can learn about Mars’ ubiquitous dust. That will help researchers better understand the planet and prepare more thoroughly for future missions.
“It feels a little bittersweet to look at InSight now.”
Ingrid Daubar, InSight Science Team Member, Brown University
This image was taken shortly before the end of the mission. It shows InSight’s landing spot and its SEIS instrument, covered with its protective windshield. Note the layer of dust accumulating on SEIS’s shield. Image Credit: NASA/JPL
“Even though we’re no longer hearing from InSight, it’s still teaching us about Mars,” said science team member Ingrid Daubar of Brown University in Providence, Rhode Island. “By monitoring how much dust collects on the surface — and how much gets vacuumed away by wind and dust devils — we learn more about the wind, dust cycle, and other processes that shape the planet.”
Martian dust is full of iron oxides, which give the planet its red appearance. It’s very fine and can be lifted high into the atmosphere during Mars’ global dust storms. It affects the planet’s weather and climate.
It’s a hazard for landers and rovers. InSight isn’t the only mission to succumb to it. Spirit and Opportunity also struggled with Martian dust before being defeated by it. Landers and rovers need to be protected from it. It can cover solar panels, rendering them ineffective. It can foul unprotected moving parts, contaminate science instruments, and cause problems with electronics and thermal control.
Martian dust is slightly magnetic due to its iron content, making it quite different from Earth dust. Scientists are concerned that its electrostatic properties might make it stick to surfaces and be difficult to remove. It could cling to some components in unanticipated ways.
There are unanswered questions about Mars’ dust. For instance, scientists don’t know exactly how it all formed or when. Are we seeing only ancient dust? Or is some of it newly created? Scientists aren’t certain how it becomes electrically charged during storms, whether it’s toxic and to what degree, or how exactly it’s transported around the planet during storms.
While monitoring InSight from space likely won’t answer all these questions, it can still teach scientists some things. One of the things they can observe is dust devil tracks. Back when the lander was still active, scientists matched MRO images of dust tracks near the lander with its wind data. They found that the whirling wind patterns that produce the dust devils subside in the winter and pick up again in the summer.
InSight is also helping scientists understand how quickly surface craters can be obscured by dust. When the lander touched down in 2018, its retrorockets left marks on the surface akin to craters. By knowing exactly when they were created and watching from orbit as they’re obscured by dust, researchers can learn how quickly impact craters can be erased.
These HiRISE images from MRO show the InSight lander after it landed with obvious rocket blast marks (L). The blast marks are becoming obscured in the image on the right, taken in 2022. Image Credit: NASA/JPL-Caltech/UArizona
The people behind missions like InSight put a lot of time and energy into them. They’re not only career-defining; each mission advances our collective understanding of nature, including other planets in our Solar System. InSight ended because of dust, not because we had learned all we could from it. So even though watching it from orbit and learning what they can is somewhat satisfying, it no doubt reminds the mission personnel of what went left undiscovered.
“It feels a little bittersweet to look at InSight now. It was a successful mission that produced lots of great science. Of course, it would have been nice if it kept going forever, but we knew that wouldn’t happen,” Daubar said.
It has been thought that the existence of plate tectonics has been a significant factor in the shaping of our planet and the evolution of life. Mars and Venus don’t experience such movements of crustal plates but then the differences between the worlds is evident. The exploration of exoplanets too finds many varied environments. Many of these new alien worlds seem to have significant internal heating and so lack plate movements too. Instead a new study reveals that these ‘Ignan Earths’ are more likely to have heat pipes that channel magma to she surface. The likely result is a surface temperature similar to Earth in its hottest period when liquid water started forming.
Plate tectonics explains the movement and interaction of the Earth’s upper layers. More accurately, the lithosphere which is composed of the crust and upper layer of the mantle. It is divided into a number of pieces known as tectonic plates which float around on the semi-fluid layer below called the asthenosphere. Where the plates meet, various geological features form such as mountains, volcanoes and trenches.
Location of the Mariana Trench. Credit: Wikipedia Commons/Kmusser
The process has been a crucial factor in the evolution of life on our planet. The shifting of landmasses has created new habitats and caused populations to become isolated allowing for individual ecosystems to form. Collisions of plates led to mountain range development which influenced the weather patterns and climate. Volcanic activity driven by plate movement led to soils becoming fertile, plant life to flourish and the release of gasses like carbon dioxide into the atmosphere that helped the planet regulate its climate. It really has been a crucial process in the evolution of our planet.
A typical “black smoker” volcanic vent here on E
In some respects the process also stops a planet’s internal environment from overheating. There is a train of thought that if Earth didn’t have such plate movement then it may be too hot internally for a stable environment to evolve. This was the subject of the paper by Matthew Reinhold and Laura Schaefer that was published in Advancing Earth and Space Sciences.
They explored the liklihood that such a world might have so much internal heating that instead, it would resemble bodies like Jupiter’s moon Io. Here we see intense levels of volcanism where laval violently erupts hundreds of kilometres into the atmosphere which is full of toxic gasses. It’s not just a lack of plate tectonics that can lead to high levels of internal heating. Tidal effects can cause worlds to have one face constantly pointing to the Sun giving a wide range of surface temperatures.
These are JunoCam images of Jupiter’s moon Io from its 3 February 2024 encounter. The first two images show Io illuminated by Jupiter-shine, and the rest are lit up by sunlight. The new volcano was captured in the second image in the sequence. Credit: NASA/JPL-Caltech/SwRI/MSSS.
Collectively these worlds are known casually as Ignan Earth’s and they are the target of the paper, to explore whether they are habitable. Exploring the geology of the bodies in our Solar System gives great insight. The team demonstrate that it is likely that worlds with high internal temperatures will develp a solid mantle. The crust will remain largely stable as a result with the only likely activity, heat-pipe tectonics – where some of the internal heat is transferred to the surface for example from volcanic activity.
The team were able to model the the likely surface temperature range based upon a number of different types of world and found that, contrary to previous expectations, a wide range of internal heating rates may well lead to worlds where the environment is conducive to habitability.
Of all the unanswered questions in modern science, perhaps the most talked about is whether we are alone in the Universe. A new paper looks at another way we might be able to detect advanced civilisations and at its centre is the need for energy! The more advanced a civilisation becomes, the greater their need for energy and one of the most efficient ways, according to current theories, is to harness the energy from an actively feeding black hole. The paper suggests a civilisation feeding matter into a black hole could harvest energy from it, more excitingly perhaps, the process could be detectable within 17,000 light years!
The search for intelligent life beyond Earth has been of fascination to scientists, philosophers and even inspired artists over the centuries. With hundreds of millions of stars in our Galaxy and billions of other galaxies across the cosmos, it seems the odds are in our favour of finding some other civilisations out there.
Planets everywhere. So where are all the aliens? Credit: ESO/M. Kornmesser
The discovery of thousands of exoplanets in recent decades adds to the excitement so, researchers have directed radio telescopes and space probes on the search for aliens. Projects like SETI, the Search for Extraterrestrial Intelligence has been scanning the sky looking for unusual patterns or messages that could reveal an advanced civilisation but despite the effort, there is a distinct lack of success, yet.
A different approach is to search for advanced civilisations based upon their energy signatures. It’s an innovative idea that seeks to identify civilisations based upon artificial patterns in the electromagnetic spectrum. We have certainly seen how human energy demand has increased as we have become more advanced and so theoretically any more advanced civilisations would need to harness energy on a scale far in excess of what we currently use. It may be that civilisations use giant megastructures like Dyson spheres to harness energy from stars and it’s the output from these or their impact on the light from a star that may be detectable.
Artist’s impression of a Dyson Sphere, an proposed alien megastructure that is the target of SETI surveys. Finding one of these qualifies in a “first contact” scenario. Credit: Breakthrough Listen / Danielle Futselaar
In a paper authored by Shant Baghram and published in the Astrophysical Journal, the team begin by categorising civilisations on the Kardashev Scale. It categorises advanced civilisations by measuring their technological advancement based upon the amount of energy they are capable of harnessing and using. They also propose an alternate scale based upon the Kardashev scale and the distance a civilisation is able to explore space, suggesting more advanced can explore further from host planet.
The Atacama Large Millimeter/submillimeter Array (ALMA). Credit: C. Padilla, NRAO/AUI/NSF
As a paper based purely on a theoretical model, they take the advanced civilisation’s category and explore the idea that they may use Dyson sphere’s around primordial black holes as an energy source. The team also propose observational techniques that may be employed to detect such structures using infrared and sub-millimetre signatures. They do assert however that telescopes like ALMA (the Atacama Large Millimetre/Sub-millimetre Array) is well placed to make observations and even to detect signatures and maybe even megastructures at distances of approximately 5.4 kiloparsecs (178 light years.)
On July 14th, 2015, the New Horizons probe made history by accomplishing the first flyby of Pluto and its largest satellite, Charon. The stunning images this mission took of these icy worlds have helped scientists address some of the key questions about Pluto and its massive moon, which have been shrouded in mystery for decades (owing to their great distance from Earth). One of the biggest mysteries that scientists have contemplated since Charon was first discovered in 1978 is how it came together with Pluto in the first place.
For decades, astronomers suspected that Pluto and Charon formed through a process similar to Earth and the Moon. This theory, known as the Giant Impact Hypothesis, states that roughly 4.5 billion years ago, primordial Earth was struck by a Mars-sized body named Theia. In a new study, a team of researchers from the University of Arizona challenged this assumption and offered an alternate theory known as “kiss and capture.” Their findings could help scientists better understand how planetary bodies in the outer Solar System form and evolve.
Previously, scientists believed that Pluto and Charon formed from a massive collision, similar to the Giant Impact Hypothesis. According to this theory, a Mars-sized planet named Theia collided with a primordial Earth roughly 4.5 billion years ago. This impact turned both bodies into molten debris that eventually coalesced to form the Earth and Moon, eventually settling into the Earth-Moon system. According to the team’s study, this theory does not fit when it comes to Pluto and Charon because it fails to take into account the structural strength of cold, icy worlds.
Using the University of Arizona’s high-performance computing cluster, the team conducted advanced impact simulations. This showed that when Pluto and a proto-Charon collided, they became temporarily stuck together and formed a single snowman-shaped object – not unlike Arrokoth, the first Kuiper Belt Object (KBO) that New Horizons surveyed on December 31st, 2018. Over time, they separated to become the binary system we observe there today. Said Denton in a U of A News story:
“Pluto and Charon are different – they’re smaller, colder and made primarily of rock and ice. When we accounted for the actual strength of these materials, we discovered something completely unexpected. Most planetary collision scenarios are classified as ‘hit and run’ or ‘graze and merge.’ What we’ve discovered is something entirely different – a ‘kiss and capture’ scenario where the bodies collide, stick together briefly, and then separate while remaining gravitationally bound.”
Their results also suggest that Pluto and Charon remained largely intact during their collision and retained much of their original composition. This challenges previous models that suggest that colliding bodies will exchange material during the impact. This is based on studies of the Apollo moonrocks, which indicated that the Earth and Moon are similar in composition, a finding that led scientists to conclude that the Earth-Moon system formed together. What’s more, their research offers a potential explanation for how Pluto may have developed an internal ocean.
View from the surface of Pluto, showing its large moon Charon in the distance. Credit: New York Times
The collision process, they state, combined with the tidal friction caused by the separation of Pluto and Charon, would have caused considerable internal heating for both bodies. This could have provided the necessary mechanism for creating a subsurface ocean, contrary to a previous theory where scientists have argued that Pluto formed during the very early Solar System when there were far more radioactive elements. However, scientists have expressed doubts about this theory because of the timing constraints it imposes.
Denton and her colleagues are now planning follow-up studies to explore several related questions about this system of icy bodies. This includes how tidal forces influenced Pluto and Charon’s early evolution when they were much closer together, how this formation scenario aligns with Pluto’s current geological features, and whether similar processes could explain the formation of other binary systems. Said Denton:
“We’re particularly interested in understanding how this initial configuration affects Pluto’s geological evolution. The heat from the impact and subsequent tidal forces could have played a crucial role in shaping the features we see on Pluto’s surface today.”
Months after deciding that its previous plan for bringing samples back from Mars wasn’t going to work, NASA says it’s working out the details for two new sample return scenarios, with the aim of bringing 30 titanium tubes filled with rocks and soil back to Earth in the 2030s.
One scenario calls for using a beefed-up version of NASA’s sky crane to drop the required hardware onto the Martian surface, while the other would use heavy-lift commercial capabilities provided by the likes of SpaceX or Blue Origin.
NASA Administrator Bill Nelson said the space agency plans to flesh out the engineering details for each option over the course of the next year and make its choice in 2026. But that all depends on what Congress and President-elect Donald Trump’s administration want to do.
An artist’s conception shows NASA’s sky crane system lowering a rover onto the Martian surface. One option calls for a similar system to be used to put a sample retrieval platform on Mars. (NASA Illustration / Ashwin R. Vasavada)
“I don’t think we want the only sample return coming back on the Chinese spacecraft, and that’s just simply a grab-and-go kind of mission, whereas ours has been a very methodical process. … I think that the administration will certainly conclude that they want to proceed, so what we wanted to do was to give them the best possible options so that they can go from here,” he told reporters.
For years, NASA has been working on a plan that started out with the collection and caching of samples by the Perseverance rover in Mars’ Jezero Crater, which is considered prime territory for harboring potential evidence of ancient life. Those samples would have been gathered up and brought to a sample retrieval platform, where they would have been sent into Martian orbit on a rocket known as the Mars Ascent Vehicle. The samples would be transferred to a Mars orbiter built by the European Space Agency. That orbiter would then deliver the samples back to Earth for laboratory study.
It was a complex plan, and last year, NASA determined that the operation would have taken until 2040 to get the samples back, with a price tag of $11 billion. “That was just simply unacceptable,” Nelson said.
NASA asked its experts as well as commercial space ventures to come up with ideas for lowering the cost and speeding up the schedule, which resulted in the two options presented today.
The sky crane option would build upon the technology that used a rocket-powered, free-flying platform to lower NASA’s Curiosity and Perseverance rovers to the Martian surface. “You’re looking at cost in the range of $6.6 billion to $7.7 billion,” Nelson said.
The estimated price tag for the commercial heavy-lift option is in the range of $5.8 billion to $7.1 billion. “You all know that SpaceX and Blue Origin have already been ones that have expressed an interest, but it could be others as well, and a team is evaluating and researching all industry capability to include the schedule and the budget to determine the best strategy going forward,” Nelson said.
Both options would use many of the same elements proposed under the previous plan, but would trim costs by using a smaller Mars Ascent Vehicle as well as simpler design for the sample retrieval platform, powered by a radioisotope thermoelectric generator rather than solar panels. The samples would be brought back from Mars and sent down to Earth by ESA’s Earth Return Orbiter. NASA said ESA is currently evaluating the options proposed by NASA.
The newly proposed schedule could lead to launches in the 2030-31 time frame, and delivery of the samples by as early as 2035. “But it could go out to 2039,” Nelson said. “Now, a good reason for why it could get extended out is if the Congress and the new administration do not respond.”
Nelson said Congress would have to commit at least $300 million during the current fiscal year to keep the Mars sample return campaign on track. “If they want to get this thing back on a direct return earlier, they’re going to have to put more money into it, even more than $300 million in fiscal year ’25, and that would be the case every year going forward,” he said.
Trump has been bullish on Mars exploration, in part due to the influence of SpaceX founder Elon Musk. So bullish, in fact, that he wants to have astronauts on the Red Planet by 2028, potentially forcing another overhaul of the Mars sample return campaign.
“We will reach Mars before the end of my term,” Trump said during a campaign rally last October. “Elon promised me he was going to do that. … He told me that we’re going to win, and he’s going to reach Mars by the end of our term, which is a big thing. Before China, before anybody.”
