Space News & Blog Articles

 A recently submitted study to The Astronomical Journal continues to search for the elusive Planet Nine (also called Planet X), which is a hypothetical planet that potentially orbits in the outer reaches of the solar system and well beyond the orbit of the dwarf planet, Pluto. The goal of this study was to narrow down the possible locations of Planet Nine and holds the potential to help researchers better understand the makeup of our solar system, along with its formation and evolutionary processes. So, what was the motivation behind this study regarding narrowing down the location of a potential Planet Nine?

Dr. Mike Brown, who is a Richard and Barbara Rosenberg Professor of Astronomy at Caltech and lead author of the study, tells Universe Today, “We are continuing to try to systematically cover all of the regions of the sky where we predict Planet Nine to be. Using data from Pan-STARRS allowed us to cover the largest region to date.”

Pan-STARRS, which stands for Panoramic Survey Telescope and Rapid Response System, is a collaborative astronomical observation system located at Haleakala Observatory and operated by the University of Hawai’I Institute of Astronomy with telescope construction being funded by the U.S. Air Force. For the study, the researchers used data from Data Release 2 (DR2) with the goal of narrowing down the possible location of Planet Nine based on findings from past studies.

In the end, the team narrowed down possible locations of Planet Nine by eliminating approximately 78 percent of possible locations that were calculated from previous studies. Additionally, the researchers also provided new estimates for the approximate semimajor axis (measured in astronomical units (AU)) and Earth-mass size of Planet Nine at 500 and 6.6, respectively. So, what are the most significant results from this study, and what follow-up studies are currently being conducted or planned?

“While I would love to say that the most significant result was finding Planet Nine, we didn’t,” Dr. Brown tells Universe Today. “So instead, it means that we have significantly narrowed the search area. We’ve now surveyed approximately 80% of the regions where we think Planet Nine might be.”

The China National Space Administration (CNSA) has put out a call for international and industry partners to contribute science payloads to its Chang’e-8 lunar lander, set for launch to the Moon in 2028. The mission, which will involve a lander, a rover, and a utility robot, will be China’s first attempt at in-situ resource utilization on the Moon, using lunar regolith to produce brick-like building materials.

Just like NASA’s Artemis plans, the CNSA’s plans for the Moon are targeted at the Lunar south pole, which is expected to be rich in useable resources, especially water. The presence of these resources will be vital for long-term human activity on the lunar surface.

Possible landing sites for Chang’e-8 include Leibnitz Beta, Amundsen crater, Cabeus crater, and the ridge connecting the Shackleton and de Gerlache craters, according to a presentation by Chang’e-8 chief deputy designer in October 2023.

Chang’e-8 will be the last CNSA robotic mission to be launched before construction begins on the International Lunar Research Station, China’s crewed moonbase being planned in collaboration with Russia’s Roscosmos. That makes Chang’e-8’s attempt to create building materials out of regolith a vital proof-of-concept for their lunar aspirations.

In order to make moon-bricks, the lander will carry an instrument that uses solar energy to melt lunar soil and turn it into useable parts at a speed of 40 cubic cm per hour.

During the 1970s, inventor/environmentalist James Lovelock and evolutionary biologist Lynn Margulis proposed the Gaia Hypothesis. This theory posits that Earth is a single, self-regulating system where the atmosphere, hydrosphere, all life, and their inorganic surroundings work together to maintain the conditions for life on the planet. This theory was largely inspired by Lovelock’s work with NASA during the 1960s, where the skilled inventor designed instruments for modeling the climate of Mars and other planets in the Solar System.

According to this theory, planets like Earth would slowly grow warmer and their oceans more acidic without a biosphere that regulates temperature and ensures climate stability. While the theory was readily accepted among environmentalists and climatologists, many in the scientific community have remained skeptical since it was proposed. Until now, it has been impossible to test this theory because it involves forces that work on a planetary scale. But in a recent paper, a team of Spanish scientists proposed an experimental system incorporating synthetic biology that could test the theory on a small scale.

The team included researchers from the Catalan Institution for Research and Advanced Studies (ICREA), the Universitat Pompeu Fabra’s Complex Systems Lab (UPE-CSL), the European Molecular Biology Laboratory (EMBL), and the Santa Fe Institute (SFI). Their paper, “A Synthetic Microbial Daisyworld: Planetary Regulation in the Test Tube,” recently appeared in the Journal of the Royal Society Interface. As they describe, their proposed test consists of two engineered micro-organisms in a self-contained system to see if they can achieve a stable equilibrium.

An image of Earth taken by the Galileo spacecraft in 1990. Credit: NASA/JPL

In response to challenges, Lovelock and British marine and atmospheric scientist Andrew Watson (a postgrad student of Lovelock’s) created a computer model named Daisyworld in 1983. The model consisted of an imaginary planet orbiting a star whose radiant energy slowly increases or decreases (aka. stellar flux). In the first (biological) case, the planet has a simple biosphere consisting of two species of daisies with different colors (black and white) that cause them to absorb different amounts of solar radiation.

Space-based solar power (SBSP) has been in the news recently, with the successful test of a solar power demonstrator in space taking place last summer. While the concept is fundamentally sound, there are plenty of hurdles to overcome if the technology is to be widely adopted – not the least of which is cost. NASA is no stranger to costly projects, though, and they recently commissioned a study from their internal Office of Technology, Policy, and Strategy that suggests how NASA could continue to support this budding idea. Most interestingly, if the technological cards are played right, SBSP could be the most carbon-efficient, lowest-cost power source for humanity by 2050.

To be clear, there are a lot of hurdles to overcome to get to that point, but first, let’s start with what the report looked at. Its primary concern was two-fold – how expensive the electricity from a power satellite is and how high its lifecycle carbon emissions are, including those introduced to the atmosphere to get it into space in the first place.

Those two data points were analyzed for two different systems, one modular one called the SPS-Alpha Mark-III suggested by prolific inventor John Mankins, which is a little more theoretical, and another by a group of Japanese researchers called the Tethered-SPS that uses a more traditional design. In most of the calculations the report provides, the SPS-Alpha Mark-III outperforms the more conventional system. Still, there are some technical hurdles to its implementation – though nothing so complicated as some of the others discussed therein.

The results report presents are not pretty for SBSP. Given their current levels of technical maturity, both solutions produce electricity that is more expensive than any existing technology. Not only that, even the more climate-friendly SPS-Alpha Mark-III is still comparable only to solar power in terms of climate impact and is beaten out by things like hydropower or even nuclear fission. So, some work needs to happen before there is any commercial incentive to adopt this technology.

Let’s tackle cost first – two big sources are the cost of getting the satellite into orbit and maintaining it when it’s up there, known as in-space assembly and maintenance (ISAM). The report even provides some allowances for the launch cost to be lower than it currently is (without fully functional Starships). But even with that lower cost, 863 launches to geosynchronous orbit for the smaller of the two systems will likely not allow any system to be cost-competitive with terrestrial alternatives.

Fire on a spacecraft can be catastrophic. It can spread quickly in a confined space, and for trapped astronauts, there may be no escape. It’s fading in time now, but Apollo 1, which was to be the first crewed Apollo mission, never got off the ground because of a fire that killed the crew. There’ve been other dangerous spacecraft fires too, like the one onboard the Russian Mir space station in 1997.

In an effort to understand how fire behaves in spacecraft, NASA began its Saffire (Spacecraft Fire Safety Experiment) in 2016. Saffire was an eight-year, six-mission effort to study how fire behaves in space. The final Saffire test was completed on January 9th.

Fire behaviour in buildings here on Earth is well-studied and well-understood. Fire prevention and suppression are important components in building design. It makes sense to bring that same level of understanding to space travel and even to surpass it.

“How big a fire does it take for things to get bad for a crew?” asked Dr. David Urban, Saffire principal investigator at NASA’s Glenn Research Centre. “This kind of work is done for every other inhabited structure here on Earth – buildings, planes, trains, automobiles, mines, submarines, ships – but we hadn’t done this research for spacecraft until Saffire.”

NASA has conducted six experiments under Saffire, and each one was conducted in an uncrewed Cygnus cargo vehicle after it completed its supply mission to the ISS. The vehicles are sent into the atmosphere to burn up, and the experiments are run prior to the vehicle’s destruction. Saffire 1 ran in 2016 inside an avionics bay with an airflow duct. The bay contained a cotton and fibreglass burn blend, which was ignited remotely with a hot wire.

On July 1, 2023, the Galileo Spacecraft launched with a clear mission: to map the dark and distant Universe. To achieve that goal, over the next 6 years, Galileo will make 40,000 observations of the sky beyond the Milky Way. From this data astronomers will be able to map the positions of billions of galaxies, allowing astronomers to observe the effects of dark matter.

There have been several galactic sky surveys before, but Galileo’s mission will take them to the next level. Galileo is equipped with a widefield imaging system. With each 70-minute exposure of the dark sky, it will capture the image and spectra of more than 50,000 galaxies. When it is complete, the Galileo survey will be the most detailed survey of galactic positions and distances. The mission will also make several deep sky observations, where it focuses on the most distant and dim galaxies.

One of the mysteries Galileo could answer is the nature of dark energy. The standard model of cosmology describes dark energy as a property of space and time. A cosmological constant that drives cosmic expansion. But some theories of dark energy argue that it’s an energy field within space and time, and that cosmic expansion isn’t constant. Galileo will study whether cosmic expansion varies, allowing astronomers to constrain or rule out certain models. The mission will also look at how dark matter distorts galaxies, allowing us to learn more about the properties of dark matter and how it interacts with regular matter.

The Euclid mission officially began its survey on Valentine’s Day and will complete about 15% of its survey this year. An initial deep sky data set will be released in Spring 2025, and data from the first year of the general survey will be released in Summer 2026.

You can read more about the Euclid Mission on ESA’s website.

After several months of meticulous, careful work, NASA has the final total for their haul of asteroidal material from the OSIRIS-REx mission to Bennu. The highly successful mission successfully collected 121.6 grams, or almost 4.3 ounces, of rock and dust. It won’t be long before scientists get their hands on these samples and start analyzing them.

These samples have been a long time coming. The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) was approved by NASA back in 2011 and launched in September 2016. It reached its target, the carbonaceous Apollo group asteroid 101955 Bennu, in December 2018. After spending months studying the asteroid and reconnoitring for a suitable sampling location, it selected one in December 2019. After two sampling rehearsals, the spacecraft gathered its sample on October 20th, 2020.

In September 2023, the sample finally returned to Earth.

There was some serendipity in the way the final total was reached. Some of it hitched a ride outside of the main sample container. There was some drama, too, as stubborn bolts on the TAGSAM head resisted removal and delayed access to the sample contained inside. Personnel from NASA’s Astromaterials Research and Exploration Science (ARES) had to design, build, and test new tools that they used to finally open the TAGSAM head and access the sample.

For OSIRIS-REx to be successful, it had to collect at least 60 grams of material. With a final total that is double that, it should open up more research opportunities and allow more of the material to be held untouched for future research. NASA says they will preserve 70% of the sample for the future, including for future generations.

Why would a young Sun-like star suddenly belch out a hugely bright flare? That’s what astronomers at Harvard Smithsonian Astrophysical Observatory want to know after they spotted such an outburst using a sensitive submillimeter-wave telescope. According to Joshua Bennett Lovell, leader of a team that observed the star’s activity, these kinds of flare events are rare in such young stars, particularly at millimeter wavelengths. So, what’s happening there?

Lovell and his team targeted the star, called HD 283572, in a search for circumstellar dust. It’s fairly young—about the same age the Sun was when our planets were first forming. It lies some 400 light-years away and is roughly 40 percent more massive than our star. During the outburst, it brightened up by about a factor of a hundred over 9 hours. The flare released about a million times more energy than any millimeter flares seen on any stars near the Sun.

The whole thing was pretty unusual because at first, it didn’t give any indication that it was about to flare, according to Lovell. “We were surprised to see an extraordinarily bright flare from an ordinary young star. Flares at these wavelengths are rare, and we had not anticipated seeing anything but the faint glow of planet-forming dust.”

Lovell and his team continued to observe the star using the submillimeter array on Mauna Kea in Hawai’i for several months. The hoped to see it flare again, but it remained quiet. “Our findings confirm that these flare events are rare at millimeter wavelengths, but that these can be extremely powerful for stars at this young age,” he said.

HD 283752 and the starfield it lies in, from optical and infrared DSS survey data. The insets show  Submillimeter Array (SMA) images centered on HD 283572 taken on January 14th and 17th, 2022 and March 27th, 2023. The red source in the middle panel shows the flare witnessed on January 17th. The star was not detected by the SMA on the other two days, nor in five other SMA observations not shown here. Credit: CfA/J. B. Lovell et al.

The future of space exploration includes some rather ambitious plans to send missions farther from Earth than ever before. Beyond the current proposals for building infrastructure in cis-lunar space and sending regular crewed missions to the Moon and Mars, there are also plans to send robotic missions to the outer Solar System, to the focal length of our Sun’s gravitational lens, and even to the nearest stars to explore exoplanets. Accomplishing these goals requires next-generation propulsion that can enable high thrust and consistent acceleration.

Focused arrays of lasers – or directed energy (DE) – and lightsails are a means that is being investigated extensively – such as Breakthrough Starshot and Swarming Proxima Centauri. Beyond these proposals, a team from McGill University in Montreal has proposed a new type of directed energy propulsion system for exploring the Solar System. In a recent paper, the team shared the early results of their Laser-Thermal Propulsion (LTP) thruster facility, which suggests that the technology has the potential to provide both high thrust and specific impulse for interstellar missions.

The research team was led by Gabriel R. Dube, an Undergraduate Research Trainee with the McGill Interstellar Flight Experimental Research Group (IFERG), and Associate Professor Andrew Higgins, the Principal Investigator of the IFERG. They were joined by Emmanuel Duplay, a graduate researcher from the Technische Universiteit Delft (TU Delft); Siera Riel, a Summer Research Assistant with the IFERG; and Jason Loiseau, an Associate Professor with the Royal Military College Of Canada. The team presented their results at the 2024 AIAA Science and Technology Forum and Exposition and in a paper that appeared in the AIAA journal Aerospace Research Central (ARC).

Artist’s concept of a Bimodal Nuclear Thermal Rocket in Low Earth Orbit. Credit: NASA

Higgins and his colleagues originally proposed this concept in a 2022 paper that appeared in Acta Astronautica – titled “Design of a rapid transit to Mars mission using laser-thermal propulsion.” As Universe Today reported at the time, the LTP was inspired by interstellar concepts like Starshot and Project Dragonfly. However, Higgins and his associates from McGill were interested in how the same technology could enable rapid transit missions to Mars in just 45 days and throughout the Solar System. This method, they argued, could also validate the technologies involved and act as a stepping stone toward interstellar missions.

For a long time, our understanding of the Universe’s first galaxies leaned heavily on theory. The light from that age only reached us after travelling for billions of years, and on the way, it was obscured and stretched into the infrared. Clues about the first galaxies are hidden in that messy light. Now that we have the James Webb Space Telescope and its powerful infrared capabilities, we’ve seen further into the past—and with more clarity—than ever before.

The JWST has imaged some of the very first galaxies, leading to a flood of new insights and challenging questions. But it can’t see individual stars.

How can astronomers detect their impact on the Universe’s first galaxies?

Stars are powerful, dynamic objects that wield a potent force. They can fuse atoms together into entirely new elements, an act called nucleosynthesis. Supernovae are especially effective at this, as their powerful explosions unleash a maelstrom of energy and matter and spread it back out into the Universe.

Supernovae have been around since the Universe’s early days. The first stars in the Universe are called Population III stars, and they were extremely massive stars. Massive stars are the ones that explode as supernovae, so there must have been an inordinately high number of supernovae among the Population III stars.

Fast radio bursts (FRBs) are strange events. They can last only milliseconds, but during that time can outshine a galaxy. Some FRBs are repeaters, meaning that they can occur more than once from the same location, while others seem to occur just once. We still aren’t entirely sure what causes them, or even if the two types have the same cause. But thanks to a collaboration of observations from ground-based radio telescopes and space-based X-ray observatories, we are starting to figure FRBs out.

Most FRBs happen well beyond our galaxy, so while we can pin down their locations, it’s difficult to observe any details about their cause. Then in 2020 we observed a fast radio burst in our galaxy. Subsequent observations found that it originated in the region of a highly magnetized neutron star known as a magnetar. This led to the idea that magnetars were the source of FRBs, possibly through magnetic flares similar to solar flares. But magnetars and Sun-like stars are very different. It still wasn’t clear how a magnetar could release such a tremendous amount of energy so quickly, even with their intense magnetic fields. Now a new study suggests the magnetar’s rotation plays a key role.

The study focuses on the 2020 FRB magnetar. Known as SGR 1935+2154, it is both a magnetar and a pulsar. This means it emits a regular radio pop as it rotates. Pulsars are incredibly regular and are used as a kind of cosmic clock for everything from studying gravitational waves to hypothetical navigation through the galaxy. But over time a pulsar’s rotation slows down as rotational energy radiates away thanks to its magnetic field. By observing this rate of decay, astronomers can better understand the structure of neutron stars and magnetars.

But sometimes the rate of rotation will shift suddenly. It’s known as a glitch if the rotation suddenly speeds up, and an anti-glitch if it suddenly slows down. These glitches are thought to occur when there’s some kind of sudden structural change in the neutron star, such as a starquake.

In 2022, NASA’s Nuclear Spectroscopic Telescope Array (NUSTAR) spacecraft and the Neutron Star Interior Composition Explorer (NICER) on the international space station both observed another fast radio burst from SGR 1935+2154. Together they had X-ray data on the magnetar before, during, and after the burst. The team then looked at radio observations during the same time and found a dip in the pulsar rotation rate during the burst. This implies a connection between rotation and burst.

There’s a problem with the Perseverance rover. One of its instruments, the laser-shooting SHERLOC, which is mounted on the end of the robotic arm, has a dust cover that is supposed to protect the instrument when it’s not in use. Unfortunately, the cover has been stuck open, and that can allow dust to collect on the sensitive optics. The cover is partially open, so the rover can’t use its laser on rock targets or collect mineral spectroscopy data. NASA engineers are investigating the problem and are hoping to devise a solution.

There are actually two dust covers on SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals), which protects the instrument’s cameras, a spectrometer, and the laser. SHERLOC’s mission is to search for organic compounds and minerals that have been altered in watery environments, which may be signs of past microbial life.

The cameras include a black-and-white context camera, along with WATSON (Wide Angle Topographic Sensor for Operations and eNgineering), a color camera for taking close-up images of rock grains and surface textures.

From images and data, engineers for Perseverance determined early this year that the one cover was stuck in a position where some of its operational modes couldn’t function. Right now, WATSON can still operate because it looks through a different aperture than the context camera, but the laser, spectrometer and context camera can’t work.

SHERLOC works by scanning a target from about 2 inches away using an internal fine-motion steering scanner mirror to raster the laser over a small (millimeter-sized) field of view. With deep ultraviolet Raman and fluorescence spectroscopy, the instrument can help differentiate types of organic materials in the object being scanned. During the course of the mission, the instrument has found a wealth of organic materials on Mars by scanning 34 rock targets, creating a total of 261 hyperspectral maps of those targets.

Now it’s Intuitive Machines’ turn to try making history with a robotic moon landing.

Today’s launch of the Houston-based company’s Odysseus lander marks the first step in an eight-day journey that could lead to the first-ever soft landing of a commercial spacecraft on the moon. Odysseus would also be the first U.S.-built spacecraft to touch down safely on the lunar surface since Apollo 17’s mission in 1972.

The lander — which is as big as an old-fashioned British phone booth, or the Tardis time portal from the “Doctor Who” TV series — was sent spaceward from Launch Complex 39A at NASA’s Kennedy Space Center atop a SpaceX Falcon 9 rocket at 1:05 a.m. ET (0605 UTC).

Liftoff was originally scheduled for the previous night, but was postponed due to concerns that arose while getting ready to load methane fuel onto the lander. The concerns were resolved, and tonight’s countdown proceeded smoothly.

After launching Intuitive Machines’ IM-1 mission, the Falcon 9’s first-stage booster flew itself back for a touchdown on SpaceX’s Landing Zone 1, not far from its Florida launch pad. Meanwhile, Odysseus separated from the rocket’s second stage and pressed onward to the next phase of its lunar odyssey.

Through the Artemis Program, NASA intends to send astronauts back to the Moon for the first time since the Apollo Era. But this time, they intend to stay and establish a lunar base and other infrastructure by the end of the decade that will allow for a “sustained program of lunar exploration and development.” To accomplish this, NASA is enlisting the help of fellow space agencies, commercial partners, and academic institutions to create the necessary mission elements – these range from the launch systems, spacecraft, and human landing systems to the delivery of payloads.

With NASA funding, a team of engineers from the University of Arizona College of Engineering (UA-CE) is developing autonomous robot networks to build sandbag shelters for NASA astronauts on the Moon. The designs are inspired by cathedral termite mounds, which are native to Africa and northern Australia’s desert regions. Their work was the subject of a paper presented at the American Astronautical Society Guidance, Navigation, and Control (AAS GNC) Conference, which took place from February 1st to 7th in Littleton and Breckinridge, Colorado.

The team was led by Associate Professor Jekan Thanga of the UA-CE Department of Aerospace and Mechanical Engineering, who is also the head of the Space and Terrestrial Robotic Exploration (SpaceTREx) Laboratory and the NASA-supported Asteroid Science, Technology and Exploration Research Organized by Inclusive eDucation Systems (ASTEROIDS) Laboratory. He and his team are partnering with NASA’s Jet Propulsion Laboratory and the Canadian space robotics company MDA to create the LUNAR-BRIC consortium, which is developing the technology for the Artemis Program.

Illustration of NASA astronauts and the elements of the Lunar Base Camp around the Moon’s south pole. Credit: NASA

Per the Artemis Program, NASA will land astronauts around the lunar south pole with the Artemis III mission, currently scheduled for 2026/27. By the end of the decade, they plan to build the infrastructure for long-duration stays, like the Lunar Gateway and the Artemis Base Camp. The latter element consists of a Foundation Lunar Habitat (FLH), the Lunar Terrain Vehicle (LTV), and a Habitation Mobility Platform (HMB). However, they will also need semi-permanent safe shelters while they search for optimal locations to build permanent habitats.

Planets orbit stars. That’s axiomatic. Or at least it was until astronomers started finding rogue planets, also called free-floating planets (FFPs). Some of these planets were torn from their stars’ gravitational grip and now drift through the cosmos, untethered to any star. Others formed in isolation.

Now, astronomers have discovered that some FFPs can orbit each other in binary relationships as if swapping their star for another rogue planet.

In 2023, astronomers working with the James Webb Space Telescope (JWST) detected 42 JuMBOs in the inner Orion Nebula and the Trapezium Cluster. JuMBOs are different than other free-floating planets. They’re Jupiter-Mass Binary ObjectS.

“The existence of these wide free-floating planetary-mass binaries was unexpected in our current theories of star and planet formation.”

In that research, the JWST performed a near-infrared survey of the region with its powerful NIRCam. It looked at powerful outflows and jets from young stars, ionized circumstellar disks, and other objects in the region. Among the findings were the 42 JuMBOs. “Further papers will examine those discoveries and others in more detail,” the authors of that paper wrote.

The orbit of Earth around the Sun is always changing. It doesn’t change significantly from year to year, but over time the gravitational tugs of the Moon and other planets cause Earth’s orbit to vary. This migration affects Earth’s climate. For example, the gradual shift of Earth’s orbit and the changing tilt of Earth’s axis leads to the Milankovitch climate cycles. So if you want to understand paleoclimate or the shift of Earth’s climate across geologic time, it helps to know what Earth’s orbit was in the distant past.

Fortunately, Newtonian mechanics and the law of gravity work backward in time as well as forward. We can use Newtonian dynamics to predict eclipses and the trajectories of spacecraft to the outer solar system, but we can also use it to turn back the clock and map Earth’s orbit into the deep past. Within limits.

Since there is no exact solution for the orbital motion of more than two bodies, we have to run our calculations computationally. A bit of chaos comes into the works, so any uncertainty we have in the current positions and motions of large solar system bodies decreases the accuracy of our retrodiction the further back in time we go. Fortunately with radar ranging and other measurements, our computations are so accurate we can trace Earth’s orbit back 100 million years into the past with some confidence. Or so we thought because a new paper demonstrates we’ve been overlooking the gravitational effect of passing stars.

The uncertainty of Earth’s orbit 54 million years ago. Credit: N. Kaib/PSI

Most stars are too distant to have any measurable effect on Earth’s orbit. They tug upon our world no more than the distant rocks of the Oort Cloud. But now and then a star will make a close approach. Not close enough to throw our solar system into chaos, but close enough to give the solar planets a gravitational nudge. The most recent close approach was HD 7977. Right now the star is about 250 light-years away, but 2.8 million years ago it passed within 30,000 AU or half a light-year of the Sun. It may have passed as close as 4,000 AU from the Sun. At the larger distance, the gravitational effect of HD 7977 would be negligible, but at the closer end of the range, it would be significant. When you add this into the computational mix, the uncertainties of Earth’s past orbit make it difficult to be confident more than 50 million years. And that has a significant impact on paleoclimate studies.

A recent study published in Nature presents a groundbreaking discovery that Saturn’s moon, Mimas, commonly known as the “Death Star” moon due to its similarities with the iconic Star Wars space station, possesses an internal ocean underneath its rocky crust. This study was conducted by an international team of researchers and holds the potential to help planetary geologists better understand the conditions for a planetary body to possess an internal ocean, which could also possess the conditions for life as we know it. While Mimas was photographed on several occasions by NASA’s Cassini spacecraft, including a close flyby in February 2010, what was the motivation behind this recent study regarding finding an internal ocean on Mimas?

Dr. Gabriel Tobie, who is a planetary scientist at Nantes Université in France and a co-author on the study, tells Universe Today, “One of the initial motivations to study Mimas was to understand why it is so different from the neighboring moon, Enceladus, which is characterized by a very active surface with direct communication with a global surface ocean. On Enceladus, we know that all the observed activity is controlled by tidal forces generated by Saturn. Mimas is closer to Saturn and should normally experience even more intense tidal forces. So why Mimas’ lack sign of activity?”

Discovered by William Herschel on September 17, 1789, Mimas is best known for its Death Star appearance due to Herschel Crater, which spans 139 kilometers (86 miles) in diameter, or just over one-third the diameter of Mimas at 396 kilometers (246 miles). Unlike other ocean worlds like Europa and Enceladus, whose surfaces are largely devoid of craters due to the frequent resurfacing from their respective internal oceans, the surface of Mimas possesses countless craters with no indications of resurfacing. Therefore, the debate for Mimas possessing an internal ocean has raged for years, including a 2014 study published in Science and a 2017 study published in JGR: Planets.

Dr. Tobie continues by telling Universe Today, “It was initially thought that Mimas remained frozen since its formation and that the conditions to initiate ice melting in its interior were never met. This new finding we report in this study shows that Mimas in fact is not that different than Enceladus. It also has a global ocean, but in contrast to Enceladus, such an ocean was formed very recently, explaining the lack of surface activity.”

After analyzing data from NASA’s Cassini, the researchers concluded that an internal ocean exists on the heavily cratered Mimas approximately 20-30 kilometers (12-18 miles) beneath its surface, forming less than 25 million years ago, which is young in geologic terms. Additionally, the team concluded the juncture where the internal ocean and ice interact reached less than 30 kilometers (18 miles) from the surface only 2-3 million years ago, indicating the ocean is potentially still developing and growing. Therefore, what implications does finding an ocean on Mimas have for other potential ocean worlds in our solar system?

It’s a classic statement shared at many public outreach events…’we are made of stardust’. It is true enough that the human body is mostly water with some other elelments like carbon which are formed inside stars just like the Sun. It’s not just common elements like carbon though for we also have slighly more rare elements like iodine and bromine. They don’t form in normal stars but instead are generated in collisions between neutron stars!  It poses an interesting question, without the neutron star merger event; ‘would we exist?’

Among the plethora of elements in the human body, Iodine – which is part of the thyroid hormone system and various physiological functions such as grown, development, body temperature regulation and heart rate and bromine which is responsible for tissue development and structural integrity. These elements are formed in systems where two neutron stars are orbiting each other but lose energy through the emission of gravity waves. As the system loses energy, the neutron stars spiral closer and closer to each other culminating in a collision and the creation of iodine and bromine. 

Neutron stars are formed when a massive star runs out of its fuel and undergoes collapse. As the core of the star collapses, the pressure and temperatures increase compressing all the protons and electrons into a neutron. If the mass falls within about 1 to 2 times the mass of the Sun then the collapse halts and a neutron star is formed. These objects can result in a stellar corpse the size of a city- approximately 20 km across. A sugar cube sized piece of neutron star material would weight in at 1 trillion kilograms here on Earth. that’s equivalent to the mass of a mountain! For those stars with more mass then the collapse continues to become a stellar mass blackhole. 

When neutron stars collide as described earlier in this article, the event is known as a kilonovae. Certainly if Earth happened to live in the blast zone then it would most definitely not be conduscive to live but, the elements synthesized are key elements supporting our very existience. The process is known as the rapid neutron-capture, or the r-process for short. Seed nuclei capture a series of neutrons just in time to avoid radioactive decay before another neutron is captured. 

The paper that was written by John Ellisa, Brian D. Fields and Rebecca Surman was published recently and it articulates the importants of the elemtns to human physiology. It also explores the possibility of searching for samples in the lunar surface that may have been depsotied by a recent kilonova explosion. 

When the interstellar object (ISO) Oumuamua appeared in our Solar System in 2017, it generated a ton of interest. The urge to learn more about it was fierce, but unfortunately, there was no way to really do so. It came and went, and we were left to ponder what it was made of and where it came from. Then, in 2019, the ISO comet Borisov came for a brief visit, and again, we were left to wonder about it.

There’s bound to be more of these ISOs traversing our Solar System. There’s been talk of having missions ready to go to visit one of these interstellar visitors in the future, but for that to happen, we need advance notice of its arrival. Could the Vera Rubin Observatory tell us far enough in advance?

No mission leaves the launch pad without detailed planning, and detailed planning depends on observations. Ground-based observations laid the foundation for our forays into the Solar System. NASA missions like OSIRIS-REx, Lucy, and Psyche are simply impossible without detailed ground observations preparing the way.

Soon, one of our most powerful and unique observatories will begin operations, the Vera Rubin Observatory. Its main activity will be the Legacy Survey of Space and Time (LSST.) The LSST will image our Solar System in far more detail than ever before, and it’ll do it continuously for a decade. The wealth of data that flows from those observations will be a massive benefit to mission planning and will probably inspire missions that we haven’t dreamed of yet.

The VRO’s Legacy Survey of Space and Time is based on the observatory’s 8.4 meter, wide-angle primary mirror and its ability to change targets in only five seconds. Attached to it is the world’s largest digital camera, a 3.2 gigapixel behemoth. The VRO will image the entire available night-time sky every few nights.

It was a $325 million dollar project that was intentionally smashed to smithereens in the interest of one day, saving humanity. The DART mission (Double Asteroid Redirection Test) launched in November 2021 on route to asteroid Dimorphos. Its mission was simple, to smash into Dimorphos to see if it may be possible to redirect it from its path. On impact, it created a trail of debris from micron to meter sized objects. A new paper analyses the debris field to predict where they might end up. 

Asteroid Dimorphos orbits around its host asteroid, Didymos and together they form a binary asteroid system. Neither asteroid poses a threat to Earth but their gave a fabulous opportunity to test technology for defending Earth from potential impactors. On 11 October NASA announced that DART successfully altered the orbit of Dimorphos showing that the kinetic energy of a spacecraft could indeed alter the trajectory of a potential threat. 

DART hit Dimorphos in an almost head on collision and the resulting ejecta plume travelled at approximately 2km/s. The plume had been observed by the Les Makes Observatory and with the Hubble Space Telescope. The debris contained material from dust sized particles to meteor and even boulder sized objects. Just before the impact, the CubeSat LICIACube was released from DART so that it could offer some long term monitoring of the debris field. 

Observations that followed showed delicate structures within the ejecta with a diffuse cloud that quickly transformed into a cone shaped formation with a tail. That tail, just like the tail of a comet was then pushed away from the asteroid system by the solar radiation pressure. Using ground based imagery, the mass and velocity of the ejected particles was established. 

The analysis of ejecta enabled modelling to be undertaken to estimate that approximately 3% of all ejected boulders would remain in orbit after 83 days (within the scope of the captured data). This estimation was in line with the pre-impact simulations over a 60 day period. By varying the parameters of the simulation they also revealed that 5% of 10cm sized particles escaping with a velocity of 0.12 and 0.18m/s would remain in orbit around the system after a 60 day period of time, similar again to the observations.