"Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled out daily in high schools."
--1921 New York Times editorial about Robert Goddard's revolutionary rocket work.

"Correction: It is now definitely established that a rocket can function in a vacuum. The 'Times' regrets the error."
NY Times, July 1969.

— New York Times

Astronomy

'Starfield' unveils 1st look at 'Shattered Space' expansion (video)

Space.com - Tue, 06/11/2024 - 6:00pm
Starfield might have disappointed some at launch, but in typical Bethesda fashion, it's continuing to expand and giving more power to the players.
Categories: Astronomy

Chinese moon researchers gearing up for June 25 arrival of far side samples

Space.com - Tue, 06/11/2024 - 5:30pm
More than 200 Chinese scientists gathered in Beijing recently for a seminar about the geology of the Chang'e 6 mission's landing area. Samples from the site are scheduled to arrive on Earth on June 25.
Categories: Astronomy

Frost Seen on Olympus Mons for the First Time

Universe Today - Tue, 06/11/2024 - 5:12pm

It’s been known for years that there are large quantities of water ice locked up in the Martian poles. Around the equator however it is a barren dry wasteland devoid of any surface ice. Recent observations of Mars have discovered frost on the giant shield volcanoes but it only appears briefly after sunrise and soon evaporates. Estimates suggest that 150,000 tons of water cycle between the surface and atmosphere on a daily basis. 

The polar caps of Mars have been the subject of many studies in particular, since the discovery of water ice in 2008. They are permanent but vary in size with the seasons. During the winter and in complete darkness, the surface chills allowing gas in the atmosphere to deposit on the surface as great bit chunks of carbon dioxide ice. Then the poles are exposed to sunlight again the frozen carbon dioxide sublimes straight back into a gas. 

Mars’ north polar ice cap, captured by NASA’s Mars Global Surveyor. Credit: NASA/JPL-Caltech/MSSS

Aside from the carbon dioxide, the poles are mostly composed of frozen water ice. The carbon dioxide deposits are relatively thin compared to the water ice, only about 1metre thick over the north pole. The south pole has a more permanent carbon dioxide cap about 8 metres thick. 

A team of planetary scientists led by Adomas Valantinas, a postdoctoral fellow at Brown University who led the work as a PhD student at the University of Bern have detected water frost on top of the Tharsis volcanoes on Mars. These volcanoes are among the tallest on the planet and indeed one of them; Olympus Mons is the tallest in the solar system. 

Olympus Mons, captured by the ESA’s Mars Express mission from orbit. Credit: ESA/DLR/FUBerlin/AndreaLuck

The frost was discovered using high-resolution images from the Colour and Stereo Surface Imaging System (CaSSIS) which is just one of the instruments on the ESA Trace Gas Orbiter. The discovery was validated using further independent observations from the High Resolution Stereo Camera on Mars Express Orbiter. 

Visualisation of the ExoMars Trace Gas Orbiter aerobraking at Mars. Credit: ESA/ATG medialab.

This is the first time water frost has been discovered in the vicinity of the planet’s equator calling for a rethink of the planets climate dynamics. Until now, we thought it was quite unlikely for frost to form around the equator due to the levels of solar radiation and the thin atmosphere. The conditions mean the surface temperatures can reach reasonably high temperatures, too high for frosts to form even at the top of the volcanoes. 

The study seems to show that frost is only fleeting present for a few hours after sunrise before the high temperatures cause it to evaporate in the solar radiation. It is important to note that even though the frost is only a very thin later (just about the width of a human hair) it is thought that there is something like 150,000 tons of water that cycles between the surface and the atmosphere every day. 

The frost the team have discovered deposits in the caldera of the volcanoes. These hollows are the openings at the summit of the volcano where eruptions have previously exploded out through the crust. It is now thought that there are unusual microclimates at the tops of the volcanoes which allows the thin layers of frost to form. 

The discovery means we need to model how the frost forms to get a real understanding of where water might exist on Mars, how it moves and how it interacts with the atmosphere. 

Source : In a significant first, researchers detect water frost on solar system’s tallest volcanoes

The post Frost Seen on Olympus Mons for the First Time appeared first on Universe Today.

Categories: Astronomy

'Supernova discovery machine' James Webb Space Telescope finds most distant star explosion on record

Space.com - Tue, 06/11/2024 - 5:00pm
The JWST has proven itself to be a "supernova discovery machine" by finding 80 exploding stars in the infant universe, including the most distant and earliest supernova ever seen.
Categories: Astronomy

Remembering Apollo 8 Astronaut Bill Anders

Universe Today - Tue, 06/11/2024 - 4:07pm

Apollo 8 astronaut William Anders, who took the iconic “Earthrise” photo of our home planet from the Moon in 1968, was killed on June 7, 2024. Anders was flying alone in his Beechcraft T-34 Mentor aircraft  when the plane plunged into the waters off the San Juan Islands in Washington state. Anders was 90.

“At every step of Bill’s life was the iron will of a pioneer, the grand passion of a visionary, the cool skill of a pilot, and the heart of an adventurer who explored on behalf of all of us,” said NASA Administrator Bill in Nelson in a statement. “His impact will live on through the generations. All of NASA, and all of those who look up into the twinkling heavens and see grand new possibilities of dazzling new dreams, will miss a great hero who has passed on.”

A video of the accident taken by a bystander who witnessed the crash appears to show Anders failing to pull up at the bottom of a loop, with the plane impacting the water at high speed.

His family issued a statement that they were devastated. “He was a great pilot and we will miss him terribly,” they said.

After becoming a fighter pilot in the Air Force, Anders was selected as an astronaut by NASA in 1964. He was backup pilot for the Gemini XI and Apollo 11 flights, and he was lunar module pilot for Apollo 8, the first mission with humans on board to enter lunar orbit.  

During the first three orbits around the Moon, the Apollo 8 crew of Frank Borman, Jim Lovell and Bill Anders kept the Apollo Command Module’s windows pointing down toward the surface of the Moon while they hurriedly filmed and photographed the craters and mountains below. One of their main tasks was reconnaissance for future Apollo landings.

The Earth rising over the Moon’s surface, as seen by the Apollo 8 mission. Credit: NASA

On the fourth swing around from the Moon’s farside, Borman rolled the spacecraft to a different orientation, pointing the windows toward the horizon to get a navigational fix. A few minutes later, Anders spotted a blue and white object appearing over the Moon’s horizon, a heart-catching sight of planet Earth, a “grand oasis in the vast loneliness of space,” as Lovell later described it.

“Oh my God, look at that picture over there!” Anders said. “There’s the Earth coming up. Wow, is that pretty!” Anders called for Lovell to quickly grab some color film.

Apollo 8’s flight was a bold and unexpected move by NASA to send a crew to lunar orbit, but the audacious flight in December 1968 set the stage for the Apollo 11 Moon landing seven months later. Apollo 8 also capped off a turbulent year on Earth, following the assassinations of Martin Luther King Jr. and Robert Kennedy, the escalating Vietnam War and anti-war protests that led to violence, and an intensifying Cold War with the USSR. After the Apollo 8 crew returned home, a well-wisher sent a telegram to the crew, saying that they had saved 1968.

Apollo 8 crew. Credit: NASA

The Earthrise photo has been called one of the most important images ever taken.

On Earth Day in 2008, Anders reflected on the famous picture that’s become one of the most frequently used images ever. Anders said even though it wasn’t in the original flight plan to take pictures of Earth, it didn’t take much time for him to realize how striking this view of the Earth was, and quickly snapped the celebrated image.

“I instantly thought it was ironic; we had come all this way to study the moon, and yet it was this view of the Earth that was one of the most important events for Apollo,” said Anders in an interview on NASA TV.

“There are basically two messages that came to me,” Anders said of the picture. “One of them is that the planet is quite fragile. It reminded me of a Christmas tree ornament. But the other message to me, and I don’t think this one has really sunk in yet, is that the Earth is really small. We’re not the center of the universe; we’re way out in left field on a tiny dust mote, but it is our home and we need to take care of it.”

Anders said it didn’t take long after the crew had returned home for this photograph to become iconic for the environmental movement.

Earthrise in the original orientation that was seen by the Apollo 8 astronauts. Image credit: NASA

“Back in the 60’s, it gave us a sense that the world was a place we all shared together,” Anders said. “We couldn’t see any boundaries from space.”

Anders left NASA in 1969 to become the executive secretary of the National Aeronautics and Space Council. In 1973, he was appointed to the Atomic Energy Commission, where he led all nuclear and non-nuclear power research and development. Later, he was named the U.S. chairman of the technology exchange program for nuclear fission and fusion power with the Soviet Union.

Very saddened about the passing of my friend, USAF Major Gen Bill Anders. Bill, you will always be an inspiration and you will be missed. My deepest condolences to Bill’s family during this difficult time. pic.twitter.com/ccDf8Pblbv

— Dr. Buzz Aldrin (@TheRealBuzz) June 8, 2024

In 1975, Anders was named the first chairman of the Nuclear Regulatory Commission. At the end of his term, he was appointed as the U.S. Ambassador to Norway, a position he held until 1977.

Anders served on several organizational boards and joined General Electric as its vice president and the general manager of its nuclear products division and later the general manager of GE’s aircraft equipment division. Then he became vice chairman of General Dynamics and, in 1991, its chairman and chief executive officer. He retired as CEO in 1993 and the left the company in 1994.

Anders retired from the Air Force reserves in 1988 with the rank of major general.

In retirement, Anders  and his family founded the Heritage Flight Museum in Washington state, which features a variety of aircraft, several antique military vehicles, a library and many artifacts donated by veterans, according to the museum’s website.

The National Transportation Safety Board and FAA are investigating the crash that killed Anders.

Bill Anders forever changed our perspective of our planet and ourselves with his famous Earthrise photo on Apollo 8. He inspired me and generations of astronauts and explorers. My thoughts are with his family and friends. https://t.co/duYdSbSZ0C

— Senator Mark Kelly (@SenMarkKelly) June 8, 2024

“Bill Anders forever changed our perspective of our planet and ourselves with his famous Earthrise photo on Apollo 8,” said retired NASA astronaut Mark Kelly, who is now a US Senator from Arizona Senator.  “He inspired me and generations of astronauts and explorers. My thoughts are with his family and friends.”

The post Remembering Apollo 8 Astronaut Bill Anders appeared first on Universe Today.

Categories: Astronomy

A Mission To Find 10 Million Near Earth Asteroids Every Year

Universe Today - Tue, 06/11/2024 - 4:04pm

So far, scientists have found around 34,000 near-Earth asteroids (NEAs) that could serve as humanity’s stepping stone to the stars. These balls of rock and ice hold valuable resources as we expand throughout the solar system, making them valuable real estate in any future space economy. But the 34,000 we know of only make up a small percentage of the total number of asteroids in our vicinity – some estimates theorize that up to 1 billion asteroids larger than a modern car exist near Earth. A project from the Trans Astronautics Corp (TransAstra), an asteroid-hunting start-up based in California, hopes to find the missing billion.

The Sutter Ultra project is funded by NASA’s Institute for Advanced Concepts and received a Phase II grant in 2021. Before we get into what Sutter Ultra is, it’s best to understand why we have such a hard time finding the hundreds of millions of small asteroids in our vicinity.

To put it bluntly, the problem is twofold—brightness and speed. Most ground-based observatories have long exposure times, allowing them to capture brighter but more stationary objects. NEAs, on the other hand, zip by the planet quickly and typically are so faint that the long exposure times on most observatories fail to see them at all. Since they move multiple pixels during each exposure, they don’t appear bright enough to capture in this kind of survey.

Presentation at the end of NIAC Phase II by TransAstra President Joel Sercel.
Credit – TransAstra YouTube Channel

That’s where Sutter Ultra comes in. It’s named after the Sutter Mill discovery that started the California gold rush of 1849 (and unfortunately, not after our own resident astrophysics expert – Paul Sutter). However, TransAstra’s idea is significantly more technologically advanced than the prospector’s pan used in that discovery. Sutter Ultra would be three separate systems, each containing over one hundred 30 cm telescopes. They would fly in coordination in a type of orbit called a heliocentric Psuedo Geocentric Distant Retrograde (PRO) oribt. This would allow all three spacecraft to regularly focus on Earth and triangulate their readings in a way that wouldn’t otherwise be possible.

Once the data has been captured, TransAstra has developed an algorithm to track individual asteroids on the paths they could travel throughout the image. They also released a neat explainer video that details the process they use and how it’s superior to existing asteroid tracking techniques.

The company’s calculations show that it is by far superior. Their write-up for the Sutter Ultra project estimates that the program could find 300x the total number of NEAs humanity has ever found in only its first year of operation. That would garner an astonishing 10 million asteroid finds every year, or 19 every minute of every day. And yet, it would still only be 1% of the total number of NEAs out there.

NEAs are some of the most dangerous objects in the solar system, as Fraser explains.

If that wasn’t enough reason to be interested in the project, Sutter Ultra can also be used to track space debris, which is becoming an ever-increasing problem as most and most junk starts to fill the orbital space. Plenty of companies have developed business models around deorbiting space junk or zapping it with lasers, but if it lives up to the hype, Sutter Ultra would be by far the best way to track it.

For now, the company is tempering its ambitions with a three-step approach, which would make the $400 million potential price tag a bit more digestible for funding agencies. TransAstra has a ground system in place as part of its NIAC Phase II project. They’re currently focusing on defining a “Sutter Alpha” mission utilizing a CubeSat platform as a proof of concept. A Sutter Survey mission would then follow with three crafts in LEO with four telescopes each.

That means timing for the Sutter Ultra mission is still unclear, and the end goal of the original grant is in jeopardy. But even with a scaled down version that is more palatable to funding agencies, TransAstra is leading the charge on surveying systems for nearby asteroids. If they are lucky they might just strike more gold than even the Californian 49ers could dream of.

Learn More:
Joel Sercel – Sutter Survey: Telescope Breakthrough Enables MicroSats to Map Accessible NEOs
UT – A New Space Telescope will Map the Universe and Help Protect the Earth from Asteroids
UT – Next-Generation Radar Will Map Threatening Asteroids
UT – What are Asteroids?

Lead Image:
Artist’s depiction of a Sutter demonstration mission.
Credit – Sercel / TransAstra Corporation / Anthony Longman

The post A Mission To Find 10 Million Near Earth Asteroids Every Year appeared first on Universe Today.

Categories: Astronomy

Solar storm douses Mars in radiation as auroras flicker in the Red Planet sky (video)

Space.com - Tue, 06/11/2024 - 4:00pm
NASA's fleet of robotic Martian explorers measured the effects of May's dramatic solar storms, experiencing the equivalent of undergoing about 30 chest X-rays all at once.
Categories: Astronomy

Celebrating Pride at NASA’s Ames Research Center

NASA Image of the Day - Tue, 06/11/2024 - 3:29pm
The Intersex Progress Pride flag flies beneath the American flag on the center pole with the California state and NASA flag at either side. The Intersex Progress Pride flag flies for the first time at any NASA center in front of the Ames Administration Building, N200, to commemorate Pride Month.
Categories: Astronomy, NASA

Millions of Joro Spiders Are Moving Up the East Coast. Here’s What to Expect

Scientific American.com - Tue, 06/11/2024 - 3:20pm

Millions of hand-size Joro spiders are moving up the East Coast. Don’t panic

Categories: Astronomy

India's Aditya-L1 solar probe snaps shots of our hyperactive sun during May outburst (photos)

Space.com - Tue, 06/11/2024 - 3:00pm
India's Aditya-L1 spacecraft imaged the sun a week after it unleashed the rare G5 geomagnetic storm that sparked some of the strongest auroras in centuries.
Categories: Astronomy

A Recent Solar Storm Even Had an Impact on Mars

Universe Today - Tue, 06/11/2024 - 2:34pm

Planet Earth is in for some amazing geomagnetic storms in the next year or so. That’s because it’s in a period of peak activity called “solar maximum” (solar max, for short). But, what happens at other planets, especially Mars, during this time? Mars mission scientists got a sneak peek at the effect of a major solar storm thanks to one hitting the Red Planet on May 20th, 2024.

During that event, the Curiosity Mars rover’s Radiation Assessment Detector (RAD) measured a very sharp increase in radiation during the solar storm. At the same time, the navigation camera captured views of a wind gust stirring up surface dust. The radiation count was the highest the instrument has seen since the rover landed on Mars. In space, the Mars Odyssey orbiter’s star camera also experienced a shower of solar particles. The bombardment knocked the camera out for a short time. During its recovery time, the spacecraft continued collecting data. That included information about the x-rays, gamma rays, and other charged particles streaming from the Sun.

NASA’s MAVEN spacecraft also collected data about the bombardment from the May 20th event. “This was the largest solar energetic particle event that MAVEN has ever seen,” said MAVEN Space Weather Lead, Christina Lee of the University of California, Berkeley’s Space Sciences Laboratory. “There have been several solar events in past weeks, so we were seeing wave after wave of particles hitting Mars.”

The purple color in this video shows auroras on Mars’ nightside. The ultraviolet instrument aboard NASA’s MAVEN orbiter detected them between May 14 and 20, 2024. The brighter the purple, the more auroras that were present.  Credit: NASA/University of Colorado/LASP What Protects Planets from the Solar Storm?

There’s not much we as a species can do to protect our planet from a solar storm. However, we’re lucky—we have a strong magnetic field to ward off the worst solar outbursts. Mars is not so lucky. It doesn’t have as much of a magnetic field to ward off the deadly radiation. Space weather experts estimated that if someone had been standing on the Martian surface during that storm, they would have been irradiated with the equivalent of 30 chest X-rays in just a short time.

That storm, and others have sparked auroras on Mars (as well as on Earth). A storm earlier in May sparked off major auroral displays on Earth on May 10-11, but otherwise didn’t severely damage any vital systems. Solar storms, however, do offer a good chance for scientists to track the Sun’s outbursts as they rampage across the Solar System. The data they get gives more insight into solar activity. However, the data from the Mars missions also provides a chilling look at just what kind of risky environment Mars is for future explorers.

Sheltering from the Solar Storm on Mars

Here on Earth, if we have plenty of notice of a solar outburst, people can get ready for the inevitable damage a solar storm can cause. For example, satellite operators can prepare their assets to protect them. NASA can advise astronauts in space to take shelter and other precautions. Ground-based power and telecommunications operators have plans in place to protect their systems from the tremendously strong ground currents that get stirred up by solar storms.

But, what if you’re on your way to Mars when a storm hits? Or, you’re actually ON Mars? Those questions occupy a lot of study time at NASA and other space agencies. People in space, whether orbiting Earth or en route to the Moon or Mars can take shelter inside their craft. In those cases, they have to depend on hardened shelters to keep them safe. But, on Mars, things are different. There’s no strong magnetic field to ward off the strong particles from the Sun. Inhabitants will have to take shelter, according to Don Hassler of Southwest Research Institute’s Solar System Science and Exploration Division.

“Cliffsides or lava tubes would provide additional shielding for an astronaut from such an event. In Mars orbit or deep space, the dose rate would be significantly more,” Hassler said.“I wouldn’t be surprised if this active region on the Sun continues to erupt, meaning even more solar storms at both Earth and Mars over the coming weeks.”

What Happened on May 20th?

The storm that Curiosity recorded began with an X12-class solar flare. That’s one of the strongest solar flares recorded and, if it had been aimed at Earth, could have caused some major damage. As it turns out, Mars was in the pathway of that flare and a subsequent coronal mass ejection. It launched a cloud of charged particles through space. When the outburst from the flare and the CME arrived at Mars, it triggered auroral displays on the Martian night side. At the same time, the outbursts showered the surface with charged particles. If someone had been on Mars and working outside a shelter, they would have been dosed with the equivalent of 30 chest X-rays. That’s not a deadly exposure, but over time if someone experienced many such events, the damage to their body would add up.

Luckily, the storm did no damage to Curiosity or any of the spacecraft at Mars. But, that won’t always be the case, and mission planners can use the data from this storm and others to figure out how best to protect future explorers.

A NASA video about how a solar storm affected Mars. For More Information

NASA Watches Mars Light Up During Epic Solar Storm
NASA Curiosity Mars Mission

The post A Recent Solar Storm Even Had an Impact on Mars appeared first on Universe Today.

Categories: Astronomy

Was Earth’s Climate Affected by Interstellar Clouds?

Universe Today - Tue, 06/11/2024 - 2:10pm

Scientists scour the Earth and the sky for clues to our planet’s climate history. Powerful and sustained volcanic eruptions can alter the climate for long periods of time, and the Sun’s output can shift Earth’s climate over millions of years.

But what about interstellar hydrogen clouds? Can these regions of gas and dust change Earth’s climate when the planet encounters them?

Interstellar clouds aren’t all the same. Some are diffuse, while some are much denser. New research in Nature Astronomy says that our Solar System may have passed through one of the dense clouds two or three million years ago. The effect could’ve altered the chemistry of Earth’s atmosphere, affecting cloud formation and the climate.

The research is “A possible direct exposure of the Earth to the cold dense interstellar medium 2–3 Myr ago.” The lead author is Merav Opher from the Radcliffe Institute for Advanced Study at Harvard University and the Astronomy Department at Boston University.

“Our results open a new window into the relationship between the evolution of life on Earth and our cosmic neighborhood.”

Avi Loeb, co-author, Harvard University’s Institute for Theory and Computation

The Sun is moving through a large cavity in the interstellar medium (ISM) called the Local Bubble. Inside the LB, the Sun’s solar output creates a cocoon called the heliosphere. It shields the Solar System from cosmic radiation.

Inside the LB, there’s more than just the Sun. It also contains other stars, and the Local Interstellar Cloud (LIC). The Sun has been moving through the LIC and will leave it in a few thousand years. The LIC is not very dense.

But in the last few million years, as the Sun has traversed the Local Bubble, it’s encountered clouds that are much denser than the LIC. The researchers examined the effect these encounters had on the Sun’s ability to carve out a cocoon for the Solar System and what effect this had on Earth.

“Stars move, and now this paper is showing not only that they move, but they encounter drastic changes.”

Merav Opher, Professor of Astronomy, BU College of Arts & Sciences

“Here we show that in the ISM that the Sun has traversed for the last couple of million years, there are cold, compact clouds that could have drastically affected the heliosphere. We explore a scenario whereby the Solar System went through a cold gas cloud a few million years ago,” Opher and her colleagues write.

Most of what the Sun travels through is thin ISM. The Sun constantly moves through the thin ISM with no effect. “These clouds are plentiful around the Sun but have too low a density to contract the heliosphere to distances <130au,” the authors explain. For comparison, the Kuiper Belt spans from 30 to 55 AU away from the Sun.

However, the denser clouds in the ISM are dense enough to dramatically affect the protective heliosphere. “The ISM in the vicinity of the Solar System also harbours a few, rare, dense, cold clouds that are called the Local Ribbon of Cold Clouds,” they write.

One of the clouds in that ribbon is called the Local Leo Cold Cloud (LLCC). It’s one of the largest clouds in the ribbon, and astronomers have studied it extensively. They know its density and its temperature. Researchers haven’t paid as much attention to the other clouds in the ribbon, but they expect them to be similar.

The authors of this paper say that there’s a small chance, about 1.3%, that the Sun passed through the tail of the LLCC. “We name that portion the Local Lynx of Cold Clouds (LxCCs). The LxCCs represent nearly half of all the mass of the LRCC and are more massive than the more well-studied LLCC,” they write.

This diagram from the research shows how the Sun may have passed through the tail of the LRCC about 2 to 3 million years ago. Image Credit: Opher et al. 2024.

There are questions about the nature of these clouds in the past. “Note that these clouds are anomalous and unexplained structures in the ISM, and their origin and physics are not well understood,” the authors write. Their work is based on the assumption that they haven’t changed substantially in the 2 million years since the purported encounter. “We have assumed here that these clouds have not undergone any substantial change over the last 2~Myr, though future work may provide more insight into their evolution.”

The researchers used simulations to study the dense cloud’s effect on the heliosphere and, by extension, our planet. They say that the cloud’s hydrogen density pushed back on the Sun, shrinking the heliosphere smaller than the Earth’s orbit around the Sun. It brought both the Sun and the Moon into contact with the dense, cold ISM. “Such an event may have had a dramatic impact on the Earth’s climate,” they explain.

These images from the simulations show the heliosphere being distorted by passage through the tail of the Local Lynx of Cold Clouds. a is a side view, and b is a top view. The red circle shows Earth’s orbit around the Sun. The simulations show that for a period of time, Earth was outside of the Sun’s protective heliosphere. Image Credit: Opher et al. 2024.

The encounter is supported by the presence of the radioisotope 60Fe on Earth. 60Fe is predominantly produced in supernovae and has a half-life of 2.6 million years. Previous research linked the 60Fe to a supernova explosion, where it became entrenched in dust grains and then delivered to Earth. It’s also present on the Moon. 244Pu was delivered at the same time, also in supernovae ejecta.

While there’s a lot of uncertainty, the researchers say the deposition of 60Fe on Earth lines up with our Solar System’s hypothetical passage through a dense cloud that compressed the protective heliosphere, allowing the isotopes to reach Earth. “Our proposed scenario agrees with the geological evidence from 60Fe and 244Pu isotopes that Earth was in direct contact with the ISM during that period,” they write.

But if a supernova delivered the radioisotopes, it would have to have been pretty close, and other evidence discounts the supernova source. “A close supernova explosion contradicts the recent model of the Local Bubble formation,” the authors explain. “The scenario does not require the absorption of 60Fe and 244Pu into dust particles that deliver them specifically to Earth, like the scenario with nearby supernova explosions.”

The question at the heart of this issue is, how did this affect Earth?

An in-depth study of the consequences is outside the scope of this research. The team did comment on some possibilities, while also cautioning that very little research has been done on this matter.

“Very few works have investigated the climatic effects of such encounters quantitatively in the context of encounters with dense giant molecular clouds. Some argue that such high densities would deplete the ozone in the mid-atmosphere (50–100?km) and eventually cool the Earth,” they write.

It’s a leap, but some research suggests that this cooling could have contributed to the rise of our species. “The hypothesis is that the emergence of our species, Homo sapiens, was shaped by the need to adapt to climate change. With the shrinkage of the heliosphere, the Earth was exposed directly to the ISM,” they write.

In their conclusion, they remind us that the probability that this encounter took place is low. But not zero.

“Stars move, and now this paper is showing not only that they move, but they encounter drastic changes,” said Opher, a BU College of Arts & Sciences professor of astronomy and member of the University’s Center for Space Physics.

“Although the coincidence of the Sun’s past motion with these rare clouds is truly remarkable, the turbulent nature of the ISM and the small current angular size of these clouds mean that the past location error ellipse is much larger than the clouds and, absent any other information, the probability of their encounter is measured to be low,” they write in their conclusion. It’s up to future work to dig more deeply into the matter.

Even if this particular encounter may not have happened, the research is still fascinating. There appear to be a bewildering number of variables that led to us, and it’s not a stretch to imagine that passing through dense clouds in the ISM played some role at some point.

“Only rarely does our cosmic neighborhood beyond the solar system affect life on Earth,” said Avi Loeb, director of Harvard University’s Institute for Theory and Computation and coauthor on the paper. “It is exciting to discover that our passage through dense clouds a few million years ago could have exposed the Earth to a much larger flux of cosmic rays and hydrogen atoms. Our results open a new window into the relationship between the evolution of life on Earth and our cosmic neighborhood.”

“We hope that our present work will incentivize future works detailing the climate effects due to an encounter of the heliosphere with the LRCC and possible consequences for evolution on Earth,” the authors conclude.

The post Was Earth’s Climate Affected by Interstellar Clouds? appeared first on Universe Today.

Categories: Astronomy

An interstellar cloud may have caused an ice age on Earth. Here's how

Space.com - Tue, 06/11/2024 - 2:00pm
The sun protects our solar system's planets from the harsh environment of interstellar space; 2 million years ago, a dense cloud of matter could have curtailed this shielding.
Categories: Astronomy

A missing link in the timeline of Earth's chemistry may have been found

Space.com - Tue, 06/11/2024 - 1:00pm
Scientists may have found missing pieces in the timeline that connects ancient Earth chemistry to modern day metabolic reactions.
Categories: Astronomy

First Promethium ‘Complex’ Created, Revealing Mysterious Element’s Secrets

Scientific American.com - Tue, 06/11/2024 - 1:00pm

Promethium, one of the rarest and most mysterious elements in the periodic table, has finally given up some crucial chemical secrets

Categories: Astronomy

SpaceX's Inspiration4 astronauts got genetically younger in space: study

Space.com - Tue, 06/11/2024 - 12:15pm
Scientists have found that the members of the first all-civilian space mission, Inspiration 4, got genetically younger during their stay in space. But the effects did not last long.
Categories: Astronomy

What "naked" singularities are revealing about quantum space-time

New Scientist Space - Cosmology - Tue, 06/11/2024 - 12:12pm
Are points of infinite curvature, where general relativity breaks down, always hidden inside black holes? An audacious attempt to find out is shedding light on the mystery of quantum gravity
Categories: Astronomy

What "naked" singularities are revealing about quantum space-time

New Scientist Space - Space Headlines - Tue, 06/11/2024 - 12:12pm
Are points of infinite curvature, where general relativity breaks down, always hidden inside black holes? An audacious attempt to find out is shedding light on the mystery of quantum gravity
Categories: Astronomy

Astronaut medical records reveal the health toll of space travel

New Scientist Space - Cosmology - Tue, 06/11/2024 - 12:00pm
The largest collection yet of detailed medical data and tissue samples from astronauts should help researchers better understand the impacts of space flight on health
Categories: Astronomy

Astronaut medical records reveal the health toll of space travel

New Scientist Space - Space Headlines - Tue, 06/11/2024 - 12:00pm
The largest collection yet of detailed medical data and tissue samples from astronauts should help researchers better understand the impacts of space flight on health
Categories: Astronomy