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The Skeptics Guide #1017 - Jan 4 2025

Skeptics Guide to the Universe Feed - Sat, 01/04/2025 - 6:00am
Psychic Predictions 2024; News Items: Space Exploration in 2025, Emerging Diseases, Dark Energy May Not Exist, Bigfoot Deaths; Who's That Noisy; Your Questions and E-mails: Fusion Energy, In Memoriam Addendum; Science or Fiction
Categories: Skeptic

There Were Over 260 Orbital Launches in 2024. A New Record

Universe Today Feed - Sat, 01/04/2025 - 2:43am

The launch of a rocket into orbit should never become routine. There was a time, probably around the 50’s and 60’s that a rocket launch hit the headlines. Now its just another launch. Last year (2024) saw a record breaking 263 launches. The US launched 158, China launched 68 and other countries/regions like Europe, Russian and Japan. Last year just 224 launches were completed and two years ago in 2022, 168 launches were completed. Surprisingly perhaps, prior to 2020 the record was set at 141 back in 1967, the future of rocket flight still seems quite alive! 

Surprisingly perhaps, rocket flight in its purest form dates back centuries with its origins in ancient China. The 9th century Chinese were recorded to have fired gunpowder propelled bamboo tubes at their enemies in the first examples of rocket flight. Modern rocketry only began to take shape in the 20th century thanks to the work from engineers and scientists like Konstantin Tsiolkovsky and Robert Goddard. 

Tsiolkovsky’s theoretical work laid the foundations for rocketry, while Goddard successfully launched the first liquid-fuelled rocket in 1926 in the United States. During World War II, rocket technology advanced rapidly driven sadly for the search for weaponry not exploration. The development of the V-2 rocket by Germany marked the first long-range ballistic missile while the Cold War rivalry between the United States and the Soviet Union further accelerated rocket development. Eventually this lead to the launch of Sputnik 1 in 1957 and the Apollo 11 Moon landing in 1969 and in the years that followed rocket launches for missions to explore distant planets and the establishment of space stations.

The Sputnik spacecraft stunned the world when it was launched into orbit on Oct. 4th, 1954. Credit: NASA

Perhaps one of the most spectacular developments over recent years and 2024 saw this demonstrated beautifully, spacecraft landing back successfully under rocket control. SpaceX have been driving this technology forward at pace firstly with the landing of their Falcon rockets on drone ships but last year saw a real milestone. 

A SpaceX Falcon 9 reusable first stage lands on the drone ship before being transported to Port Canaveral. Image: SpaceX

October saw the 5th test flight of the SpaceX Starship launch vehicle. Its the tallest launch vehicle to have flown, beating the Apollo Saturn V rocket by 11 metres. After its launch on 13 October and the upper stage being delivered into a suborbital trajectory (reached space but didn’t complete an orbit before returning) the booster returned! It didn’t just disintegrate or flat down attached to parachutes, it used the powerful Raptor engines to return to the launch pad. After descent, it slowed, almost hovering in mid air, before manoeuvring sideways to line up with launch pad before touching back down. As it returned to the arms of the launch tower, the arms grabbed the rocket and the engines shut down! 

SpaceX’s Starship Super Heavy booster settles back into the arms of its launch-pad cradle in Texas. (Credit: SpaceX)

It is no doubt that 2024 saw some amazing developments in rocket flight including but not limited to the SpaceX booster landings. What of 2025? What can we look forward to in the year ahead? Well I’m not sure we are going to see any pure rocket launch landmarks this year but there are some exciting missions ahead; NASA launching SPHEREx (new space observatory to map the sky in optical and near-infrared,) SpaceX launching to missions to surface of Moon (Texas built Blue Ghost and a Japanese lander,) a new commercial space station called Haven-1 and if all goes to plan we may finally see the return to Earth of Suni Williams and Butch Wilmore who have been stuck on the ISS since June after their planned 1 week mission!

This artist’s illustration shows NASA’s SPHEREx observatory in orbit. The mission will launch in 2025. Image Credit: By NASA/JPL – https://www.jpl.nasa.gov/missions/spherex, Public Domain, https://commons.wikimedia.org/w/index.php?curid=143819030

Source : Space Stats

The post There Were Over 260 Orbital Launches in 2024. A New Record appeared first on Universe Today.

Categories: Science

New Study Explains How Mars Dust Storms Can Engulf the Planet

Universe Today Feed - Fri, 01/03/2025 - 12:31pm

Mars is well-known for its dust storms, which occur every Martian year during summer in the southern hemisphere. Every three Martian years (five and a half Earth years), these storms grow so large that they are visible from Earth and will engulf the entire planet for months. These storms pose a significant threat to robotic missions, generating electrostatic charges that can interfere with their electronics or cause dust to build up on their solar panels, preventing them from drawing enough power to remain operational.

While scientists have studied these storms for decades, the precise mechanisms that trigger them have remained the subject of debate. In a new study, a team of planetary scientists at the University of Colorado Boulder (CU Boulder) has provided new insight into the factors involved. According to their findings, relatively warm and sunny days may kick off the largest storms every few years. These could be the first step toward forecasting extreme weather on Mars, which is vital for future crewed missions to Mars.

The study was led by Heshani Pieris, a graduate student at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. She was joined by Paul Hayne, a researcher at LASP and an associate professor at the Department of Astrophysical and Planetary Sciences at CU Boulder. Their findings were presented at the 2024 meeting of the American Geophysical Union, which took place from December 9th to 13th in Washington, D.C.

Mars seen before, left, and during, right, a global dust storm in 2001. Credit: NASA/JPL/MSSS

Mars experiences dust storms regularly, which often begin as smaller storms that form around the polar regions, usually during the second half of the Martian year. These storms can grow rapidly as they move towards the equator until they cover millions of square kilometers. While these dust storms are not very powerful due to Mars’ thin atmosphere (roughly 0.5% as dense as Earth’s), they can still pose a significant hazard. In fact, global dust storms were responsible for the loss of the Opportunity rover in 2018 and the InSight lander last year.

“Dust storms have a significant effect on rovers and landers on Mars, not to mention what will happen during future crewed missions to Mars. This dust is very light and sticks to everything,” said Pieris in a recent NASA press release. “Even though the wind pressure may not be enough to knock over equipment, these dust grains can build up a lot of speed and pelt astronauts and their equipment,” added Hayne. “We need to understand what causes some of the smaller or regional storms to grow into global-scale storms. We don’t even fully understand the basic physics of how dust storms start at the surface.”

For their study, Pieris and Hayne focused on “A” and “C” storms, two weather patterns that tend to occur every year on Mars. This consisted of analyzing data gathered by the Mars Climate Sounder instrument aboard NASA’s Mars Reconnaissance Orbiter (MRO) over the course of 15 years (eight Mars years). Specifically, they searched for periods of unusual warmth, when more sunlight filtered through Mars’ thin atmosphere to heat the planet’s surface. They discovered that roughly 68% of major storms on the planet were preceded by a sharp rise in temperatures at the surface, which led to dust being kicked up.

Artist’s depiction of a dust storm on Mars. Credit: NASA

While these results don’t definitively prove that warmer conditions cause dust storms, they indicate that the same phenomena that trigger storms on Earth may be at work on Mars. During hot summers in dry regions, warm air near the surface can rise through the atmosphere, leading to large gray clouds that signal rain. Said Pieris:

“When you heat up the surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it. This study is not the end all be all of predicting storms on Mars. But we hope it’s a step in the right direction.”

Pieris and Hayne are now gathering more recent observations of Mars to continue investigating these explosive weather patterns. Eventually, they hope that scientists will be able to predict weather patterns on Mars based on live data from the planet.

Further Reading: UC Boulder, AGU24

The post New Study Explains How Mars Dust Storms Can Engulf the Planet appeared first on Universe Today.

Categories: Science

Research may boost next-generation space rockets

Matter and energy from Science Daily Feed - Fri, 01/03/2025 - 12:09pm
Hidden patterns in electric propulsion plasma beams could help ensure the success of long-term space missions.
Categories: Science

Research may boost next-generation space rockets

Space and time from Science Daily Feed - Fri, 01/03/2025 - 12:09pm
Hidden patterns in electric propulsion plasma beams could help ensure the success of long-term space missions.
Categories: Science

The carbon in our bodies probably left the galaxy and came back on cosmic 'conveyer belt'

Matter and energy from Science Daily Feed - Fri, 01/03/2025 - 12:09pm
Scientists recently discovered that the giant 'conveyer belt' currents that push star-forged material out of our galaxy and pull it back in can also transport carbon atoms. That means that a good deal of the carbon here on Earth, including the carbon in our bodies, likely left the galaxy at some point!
Categories: Science

The carbon in our bodies probably left the galaxy and came back on cosmic 'conveyer belt'

Space and time from Science Daily Feed - Fri, 01/03/2025 - 12:09pm
Scientists recently discovered that the giant 'conveyer belt' currents that push star-forged material out of our galaxy and pull it back in can also transport carbon atoms. That means that a good deal of the carbon here on Earth, including the carbon in our bodies, likely left the galaxy at some point!
Categories: Science

New nanocrystal material a key step toward faster, more energy-efficient computing

Matter and energy from Science Daily Feed - Fri, 01/03/2025 - 9:50am
Chemistry researchers have taken a key step toward next-generation optical computing and memory with the discovery of luminescent nanocrystals that can be quickly toggled from light to dark and back again.
Categories: Science

Breakthrough for 'smart cell' design

Matter and energy from Science Daily Feed - Fri, 01/03/2025 - 9:49am
Bioengineers have developed a new construction kit for building custom sense-and-respond circuits in human cells. The research could revolutionize therapies for complex conditions like autoimmune disease and cancer.
Categories: Science

Student Team Designs 2U CubeSat with Big Ambitions

Universe Today Feed - Fri, 01/03/2025 - 9:23am

CubeSats can be used in many different scenarios, and one of their most important uses is providing an easy path to understanding how to design, plan, and launch a mission. That was the idea behind AlbaSat, a 2U CubeSat currently under development by a team at the University of Padova with an impressive four different functional sensors packed into its tiny frame.

AlbaSat was initially developed as a student project at the University of Padova as part of ESA’s Fly Your Satellite (FYS) program, which, through its two iterations, has helped students get their CubeSat ideas off the ground – literally. AlbaSat was one of the more ambitious projects in the program, with four different key scientific objectives.

First was a study of the prevalence of space debris, which is becoming a growing problem, as the team noted in their paper describing the mission’s feasibility when they discussed Kessler Syndrome. Tracking small debris floating in orbit is a challenge from the ground, but a satellite in orbit itself could do better. To do so, the team developed the Impact Sensor, which would detect debris hitting AlbaSat itself. It consists of a resistive sensing element placed on top of some PTFE, which was prototyped in a project called DRAGONS by researchers at the Fraunhofer Institute for High-Speed Dynamics.

Video describing ESA’s Fly Your Satellite program, which AlbaSat is taking advantage of.
Credit – ESA YouTube Channel

AlbaSat will also carry a tri-axial MEMS accelerometer to complement that instrument to detect any micro-vibrations the satellite experiences in its orbit. It is important to understand what impact, if any, those vibrations might have on either satellite performance or orbital decay.

Another complementary payload is the laser rangefinder. This is intended to keep precise track of the satellite’s orbit by reflecting a laser from a ground station off of a series of “Corner Cube Retroreflectors” that can reflect the laser to the transmitting station. Understanding the orbital path is key to ensuring the other payloads onboard the tiny CubeSat work properly.

The final functional payload is a test rig for optical receivers that might someday be useful in proving novel communications technology. Known as the “QPL,” this subsystem consists of an active reflectometer that can receive signals intended for use in quantum communications systems. 

A NanoMind A3200 central computer, a NanoCom AX100 communication system, the necessary electrical subsystems, solar panels, and the functional payloads for energy collection. The mission is designed to last as long as possible, but its orbit will decay in less than 12 years, per ESA debris mitigation guidelines.

Fraser talks about the danger posed by Kessler Syndrome, one of the primary study areas of the AlbaSat mission.

Students from the University of Padova have been diligently working on the system. In February, they passed environmental testing of the impact sensor, which garnered them a press release from ESA itself. More recently, Space Voyaging published a detailed profile that tracked the team as they interfaced with ESA experts, helping them get their satellite into space.

When they do, it will be the University of Padova’s first foray into the CubeSat space. Hopefully, it will be a worthy addition to the stable of student-designed CubeSats that contribute valuable scientific data. It hopes to launch sometime this year, and it will carry many students’ hopes.

Learn More:
Mozzato et al – Concept and Feasibility Analysis of the Alba Cubesat Mission
ESA – AlbaSat Impact Sensor completes the environmental test campaign
Space Voyaging – AlbaSat: the First CubeSat of the University of Padua
UT – CubeSat Propulsion Technologies are Taking Off

Lead Image:
3D Mockup of AlbaSat
Credit – AlbaSat CubeSat / University of Padova

The post Student Team Designs 2U CubeSat with Big Ambitions appeared first on Universe Today.

Categories: Science

This Fast Radio Burst Definitely Came From a Neutron Star

Universe Today Feed - Fri, 01/03/2025 - 8:28am

Fast radio bursts (FRBs) are notoriously difficult to study. They are flashes of radio light that can outshine a galaxy but often last for only a fraction of a second. For years, all we could do was observe them by random chance and wonder about their origins. Now, thanks to wide-field radio telescopes such as CHIME, we have some general understanding as to their cause. They seem to originate from highly magnetic neutron stars known as magnetars, but the details are still a matter of some debate. Now a team has used a method known as scintillation to reveal more clues about this mysterious phenomenon.

Most FRBs occur in distant galaxies, meaning that their light must travel through the intergalactic medium and through the interstellar medium of the Milky Way to reach us. As a result, the light can be affected by gas and dust, causing it to distort a bit in frequency and polarization. Since different media affect different wavelengths of radio light, this can help us understand the origins of an FRB.

In this study, the team focused on an FRB named 20221022A, which originated in a galaxy 200 million light-years away. As the light traveled to us, interaction with the intergalactic medium caused the burst to flicker in brightness, known as scintillation. It’s similar to the way stars twinkle because their light passes through turbulent layers of Earth’s upper atmosphere.

One of the classic ways to distinguish a star from a planet in the night sky is that stars twinkle, but planets don’t. The light of both passes through the atmosphere, but since planets appear as a small disk of light, we don’t see them flicker. Stars appear as points of light, so we can see the flicker. The apparent size of a light source is the key factor.

In the same way, by looking at the scintillation of the FRB, the team was able to determine the size and location of the FRB light source. In this case, they found that FRB 20221022A had to have happened within 10,000 kilometers of a highly magnetic pulsar. This means the FRB must have originated within the magnetosphere of the pulsar, which confirms magnetars as the source of this particular FRB.

This study not only confirms magnetars as the source of FRBs; it proves that it is specifically an effect of their intense magnetic fields. Further observations such as this should allow us to understand how these magnetic fields can generate such intense radio light so quickly.

Reference: Nimmo, Kenzie, et al. “Magnetospheric origin of a fast radio burst constrained using scintillation.” Nature 637.8044 (2025): 48-51.

The post This Fast Radio Burst Definitely Came From a Neutron Star appeared first on Universe Today.

Categories: Science

Global treaty is failing to curb ultra-potent greenhouse gas emissions

New Scientist Feed - Fri, 01/03/2025 - 8:00am
Countries have pledged to phase out HFC-23, a powerful greenhouse gas, but atmospheric data shows that emissions are five times higher than governments are reporting
Categories: Science

Dawkins in the Spectator on that pesky “God-shaped hole”

Why Evolution is True Feed - Fri, 01/03/2025 - 7:15am

I’ve posted several times on the claim that humans have an innate longing for God that must be filled by either religion or some simulacrum of religion. This is the famous “God-shaped hole” in our psyche claimed by believers and those whom Dan Dennett called “believers in belief.” This trope appears regularly, and the last time I discussed the “God-shaped hole” was on Christmas Eve when a Free Press article described an atheist mother lamenting the absence of religious traditions to which she could expose her children on Christmas.

With the recent kerFFRFle in which some people (including me) argue that wokeness and gender activism have taken the form of a quasi-religion—a claim that’s the subject of a whole book by John McWhorter—some people have taken to blaming atheists for creating this hole and for the need for something to replace traditional faiths. By taking away people’s religion, they say, we have made society worse as erstwhile believers start glomming onto all kinds of nonsense. (Apparently religion is a good form of nonsense.)

Well, yes, some people do need god, but that need has declined steadily in the West, and in many places the hole doesn’t seem to be filled with quasi-religions.  Northern Europe and Scandinavia, for instance, have long become largely atheistic. Exactly 0% of Icelanders under 25 believe that God created the world, and 40% of them identify as atheists.  But is Scandinavia filled with especially woke people, clinging to crystals and other forms of woo, and being the most gender-activist people in the world? Not that I know of.  So my thesis is that while some people will always need God, many do not, and their numbers will decrease over time as the world population becomes better and better off. (Religiosity is negatively correlated with well being and other indices of happiness.)

And really, isn’t it condescending to say that we atheists should not publicly criticize belief in gods because it might create even worse forms of religion?  Are we supposed to shut up about the harms and false claims of traditional faiths? That’s simply a “little people” argument, one founded on “belief in belief.”

In today’s Spectator, Richard Dawkins takes up the god-shaped hole argument, though he concentrates largely on recent accusations that he himself helped dig that hole. Click the headline below to read, or find the article archived here.

Here are two people accusing Richard of wielding the Atheistic Shovel:

An irritating strain of the Great Christian Revival is the myth of the God-shaped hole. “When men choose not to believe in God, they then believe in anything.” The famous aphorism, which GK Chesterton never uttered, is enjoying one of its periodic dustings-off, following the vogue for women with penises and men who give birth. Whenever I sound off against this modish absurdity, I’m met with a barrage of accusations. “Frankly Richard, you did this. You defended woke BS for years” (of course I didn’t: quite the opposite but, for this believer in the God-shaped hole, discouraging theism is indistinguishable from encouraging woke BS). “But don’t you see, you helped to bring this about.” “What do you expect, if people give up Christianity?” Then there’s this, from a Daily Telegraph opinion column:

“New Atheists allowed the trans cult to begin. . . By discrediting religion, Dawkins and his acolytes created a void that a new, dangerous ideology filled.”

And here’s Debbie Hayton on The Spectator’s website, writing (mostly reasonably) about a recent episode in which Jerry Coyne, Steven Pinker and I resigned from the Honorary Board of an atheist organisation that’s been taken over by the trans cult:

“An atheistic organisation worth its salt would oppose these movements in the same way that it opposes established religion, so Coyne, Pinker and Dawkins are right to walk away. But maybe the key lesson from this sorry debacle is that it is not so easy to expunge the need for religion from human beings than atheists might like to think. If there is a God-shaped hole in us then without established religion, something else is likely to take its place.”

There are other arguments, but  Dawkinss concludes that the rejection of what he calls “trans nonsense” (I’d call it “gender-activist extremism”) should be based not on the fact that it replaces the supposed benefits of religion, but on science itself:

The scientific reasons are more cogent by far. They are based on evidence rather than scripture, authority, tradition, revelation or faith. I’ve spelled them out elsewhere, and will do so again but not here. I’ll just support the claim that the trans-sexual bandwagon is a form of quasi-religious cult, based on faith, not evidence. It denies scientific reality. Like all religions it is philosophically dualistic: where conventional religions posit a “soul” separate from the body, the trans preacher posits some kind of hovering inner self, capable of being “born in the wrong body”. The cult mercilessly persecutes heretics. It abuses vulnerable children too young to know their own mind, encouraging them to doubt the reality of their own bodies, in extreme cases inflicting on those bodies irreversible hormonal, and even surgical damage.

. . . How patronising, how insulting to imply that, if deprived of a religion, humanity must ignominiously turn to something equally irrational. If I am to profess a faith here, it is a faith in human intelligence strong enough to doubt the existence of a God-shaped hole.

This dispels the argument that people must hold irrational beliefs—”quasi religions”—to replace real religions.  I would extend the argument a bit further, though.  While admitting that it’s hard for some folks to let go of gods, I’ll also argue that quasi-religion nonsense can be laid at the door not of atheism, but of the kind of faith that leads people to embrace important beliefs without good evidence.

Categories: Science

Climate change may have killed ancient 'hobbit' hominins

New Scientist Feed - Fri, 01/03/2025 - 7:00am
Homo floresiensis, a metre-tall ancient hominin, lived on the South Pacific island of Flores and hunted dwarf elephants until about 50,000 years ago – and now it seems climate change played a role in the downfall of both species
Categories: Science

Readers’ wildlife photos

Why Evolution is True Feed - Fri, 01/03/2025 - 6:15am

We have photos from a new contributor, reader Lesli Sagan. She keeps bees and sends us photos of honeybees.  Lesli’s notes are indented, and you can enlarge her photos by clicking on them.

All of these photos were taken in Ithaca, NY this past summer and fall, 2024. I’ve been keeping bees for decades and tend to garden for them: asters, oregano, mountain mint, coneflowers, and anything else I think they would like are my garden favorites. There’s some question in my mind whether European honey bees (Apis mellifera) are truly “wild,” given that we’ve selectively bred them. However, they are free to go anytime and often do return to the wild by absconding or swarming.

Unused bee equipment is attractive to all sorts of critters, including honey bees who may either be looking for a new home or are attracted, during lean times, to the scent of honey.

These are bees emerging through an opening in the cover of their hive.

Asters bloom until the first hard frost, and so are valuable sources of nectar and pollen for honey bees and all sorts of other insects.

This closer look of a honey bee shows her body is still fuzzy and her wings are whole. Honey bees live about a month in summer and they can be nearly bald and their wings quite ragged towards the end of the lives. This bee is probably a couple of weeks old.

While this bee is likely going for the nectar, we can still see yellow pollen on her face.

In contrast to the young bee above, this old girl has lost much of her fuzziness and her wings have been literally flown to bits. Mountain mint is a favorite of all sorts of bees.

The top bee on mountain mint is Apis mellifera, and the bee below may be as well. Not all domesticated honey bees are the familiar gold and black; darker varieties exist. None of my hives have the darker variety, so if this is Apis mellifera, she’s not from my hives.

This is an unremarkable scene at a hive entrance. Bees are coming and going, and while a few are likely guards, there are no hornets or other predators trying to break in just now.

Another fuzzy young bee, this time on oregano. She is collecting pollen, as you can see from the white pollen ball on her back leg. Pollen colors don’t always match the color of the flowers, but in this case, the petals and pollen are bright white.

This hive has windows, and here you can see the worker bees preparing cells for the honey flow.

If anyone wants to watch a complete hive inspection from this past summer, here’s a link to a GoPro video.

Categories: Science

US teens are using less of every substance – except for one

New Scientist Feed - Fri, 01/03/2025 - 5:00am
Teenagers in the US roughly doubled their use of nicotine pouches in 2024, despite turning away from alcohol and other drugs
Categories: Science

Glowing biological quantum sensor could track how cells form

New Scientist Feed - Fri, 01/03/2025 - 1:00am
A quantum sensor based on a protein from bioluminescent jellyfish can be made by the body itself and it may be able to help us track how cells form or detect disease at an early stage
Categories: Science

NASA Scientists Discover “Dark Comets” Come in Two Populations.

Universe Today Feed - Thu, 01/02/2025 - 7:05pm

On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar object, named 1I/2017 U1 ‘Oumuamua (the Hawaiin word for “scout”). This object created no shortage of confusion since it appeared as an asteroid but behaved like a comet (based on the way it accelerated out of the Solar System). Since then, scientists have noticed a lot of other objects that behave the same way, known as “dark comets.”

These objects are defined as “small bodies with no detected coma that have significant nongravitational accelerations explainable by outgassing of volatiles,” much like ‘Oumuamua. In a recent NASA-supported study, a team of researchers identified seven more of these objects in the Solar System, doubling the number of known dark comets. Even more important, the researchers were able to discern two distinct populations. They consist of larger objects that reside in the outer Solar System and smaller ones in the inner Solar System.

The study was led by Darryl Z. Seligman, an NSF Astronomy and Astrophysics Postdoctoral Fellow from the Carl Sagan Institute at Cornell University and Michigan State University. He was joined by researchers from the European Space Agency’s Near-Earth Object Coordination Centre (NEOCC), the European Southern Observatory (ESO), the Planetary Science Institute (PSI), Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, NASA’s Jet Propulsion Laboratory. Their findings were published on December 9th in the Proceedings of the National Academy of Sciences (PNAS).

Astronomers are discovering more objects that look like asteroids but behave like comets. Credit: N. Bartmann (ESA/Webb), ESO/M. Kornmesser and S. Brunier, N. Risinger (skysurvey.org)

Scientists got their hint that dark comets exist in 2016 when they found that the “asteroid” 2003 RM had deviated slightly from its expected orbit. This behavior could not be explained by the Yarkovsky effect, where asteroids absorb solar energy and re-radiate it into space as heat. Said study co-author Davide Farnocchia of NASA JPL said in a NASA press release:

“When you see that kind of perturbation on a celestial object, it usually means it’s a comet, with volatile material outgassing from its surface giving it a little thrust. But try as we might, we couldn’t find any signs of a comet’s tail. It looked like any other asteroid — just a pinpoint of light. So, for a short while, we had this one weird celestial object that we couldn’t fully figure out.”

The next piece of the puzzle came in 2017 with the detection of the first interstellar object (‘Oumuamua). While it appeared as a single point of light to telescopes and had no coma, its trajectory changed as if it were outgassing volatile material from its surface. “‘Oumuamua was surprising in several ways,” said Farnocchia. “The fact that the first object we discovered from interstellar space exhibited similar behaviors to 2003 RM made 2003 RM even more intriguing.”

By 2023, seven dark comets had been identified, leading the astronomical community to designate them as a distinct category of celestial objects. With this latest study, the authors identified seven more of these objects in the Solar System and noticed some interesting traits among them. “We had a big enough number of dark comets that we could begin asking if there was anything that would differentiate them,” said Seligman. “By analyzing the reflectivity,” or albedo, “and the orbits, we found that our solar system contains two different types of dark comets.”

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

One group, which the team calls “outer dark comets,” is similar to the “families” of asteroids that orbit Jupiter. In addition to being larger, measuring hundreds of meters or more across, the first group has highly elliptical orbits. The second group, “inner dark comets,” are smaller (tens of meters or less) and travel in nearly circular orbits within the orbits of Mercury, Venus, Earth, and Mars. In addition to expanding astronomer’s knowledge of dark comets, the team’s research raises several additional questions regarding their origin, behavior, and composition.

Of particular interest is whether these objects could contain water ice, which would have implications for our understanding of how water (and possibly life) was distributed throughout the Solar System billions of years ago. “Dark comets are a new potential source for having delivered the materials to Earth that were necessary for the development of life,” said Seligman. “The more we can learn about them, the better we can understand their role in our planet’s origin.”

Further Reading: NASA, PNAS

The post NASA Scientists Discover “Dark Comets” Come in Two Populations. appeared first on Universe Today.

Categories: Science

Could There Be Bacteria Living on Mars Today?

Universe Today Feed - Thu, 01/02/2025 - 3:23pm

Mars is often considered to be the planet most similar to the Earth. Earth however, is capable of supporting life, Mars on the other hand could not. There was once a time when it was warmer and wetter and could support life. Exploring life on Earth shows us that bacteria known as extremophiles can live in the most harsh conditions on Earth, it may just be possible that there are places on Mars that could also support these hardy forms of life. A new paper explores that possibility by studying the most extreme Earth-based bacteria that could survive under ground on Mars. 

Mars, often referred to as the “Red Planet” because of its reddish appearance. It’s the fourth planet from the Sun orbiting at an average distance of 228 million kilometres. It has a thin atmosphere, made up mostly of carbon dioxide with surface temperatures from about -125°C to 20°C. Mars has some fascinating geological features including the largest volcano in the solar system; Olympus Mons, and a vast canyon system; Valles Marineris. Unlike Earth, Mars has two moons Phobos and Deimos which are thought to be captured asteroids. 

A full-disk view of Mars, courtesy of VMC. Credit: ESA

The atmosphere of Mars is thin and, whilst carbon dioxide is the main component, there is also methane in small amounts, around 0.00003% of the whole. It’s origins in the Martian atmosphere are not fully understood and it may be that it is there as a result of biological processes such as the metabolism of microbes. It could also be there due to geological processes such as volcanic eruptions. The presence of methane has also excited researchers who have been exploring whether Mars could in anyway support more extreme forms of primitive life. 

Image of the Martian atmosphere and surface obtained by the Viking 1 orbiter in June 1976. (Credit: NASA/Viking 1)

In a paper recently authored by Butturini A from the University of Barcelona and team, they explore the Martian environment and its suitability to support extremophiles known as methanogens (from the Methanobacteriaceae family.) These primitive forms of bacteria are found in some of the most inhospitable regions of Earth. They have been found thriving in the hot groundwater of Lidy Hot Springs in Idaho, and are based upon methane biology. It raises an interesting possibility that areas of Mars could provide a habitat for them. 

The conditions on the surface of Mars are well understood. With high energy radiation from cosmic rays and solar radiation, along with dry and cold conditions and a high temperature differential between day and night, the surface is not conducive to any known forms of life. Look a little deeper however and the conditions seem a little more favourable. Lower levels on Mars however may be more habitable than the surface. A few metres underground and the surface material offers protection from the incoming radiation. Temperatures lower down would be higher and less variable too giving the possibility that liquid water may be present. It has already been seen that subsurface water has in some areas of Mars found its way to the surface only to evaporate when met with the surface conditions. With the presence of salt too the subsurface water can be present as liquid at a lower temperature. 

The team conclude that methanogens seem to be thriving in hostile environments on Earth which are analogous to some areas of Mars. They identify the southern area of Acidalia Planitia as somewhere to search due to the high levels of radiogenic heat producing elements which suggest subsurface water may be present. It raises the interesting possibility that, theoretically at least, primitive life could exist on Mars, even today, we just need to find it!

Source:  Potential habitability of present-day Mars subsurface for terrestrial-like methanogens

The post Could There Be Bacteria Living on Mars Today? appeared first on Universe Today.

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