Feed aggregator

The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought. This time, it has detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang – one of the earliest galaxies ever observed.

“Earlier research suggested that carbon started to form in large quantities relatively late – about one billion years after the Big Bang,” said Kavli Institute Professor Roberto Maiolino. “But we’ve found that carbon formed much earlier – it might even be the oldest metal of all.”

‘Metal’ is the name astronomers give to any element heavier than hydrogen or helium, and seeing metals like carbon so early is a surprise. Carbon is, of course, one of the building blocks of life on Earth, but it also plays a role in galaxy and solar system formation. It is one of the materials that can accumulate in the protoplanetary disks around stars, snowballing to become planets, moons, and asteroids.

But astronomers weren’t expecting to see that process happening so early.

When the first stars (called population-III stars) were born, in an era of the universe known as Cosmic Dawn, the only plentiful elements around were hydrogen and helium. All heavier elements didn’t yet exist. They were only able to form later, inside the cores of stars, therefore wouldn’t be detectable until well after the deaths of the first stars.

Dying population-III stars that explode as supernovas throw their heavier elements out into the universe, allowing future populations of stars to develop rocky planets with more interesting chemistry.

The galaxy in question, named GS-z12, is thought to contain largely second generation stars, built from the remains of those first supernovas. Astronomers didn’t expect the building blocks of the galaxy to be carbon-rich:

“We were surprised to see carbon so early in the universe, since it was thought that the earliest stars produced much more oxygen than carbon,” said Maiolino. “We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently.”

JWST’s Near Infrared Spectrograph allowed astronomers to break down the light coming from the distant galaxy into its constituent parts, revealing all the different wavelengths present. Every element and chemical compound has its own signature when viewed via spectroscopy, and the signal for carbon was very strong. There was also a fainter signal for neon and oxygen, though those remain tentative detections for the moment.

How carbon emerged before oxygen is an open question, but one hypothesis proposes that scientists now need to revisit their models of population-III star supernovas. If these supernovas occurred with less energy than previously thought, then they would scatter carbon from the stars’ outer shells, while most of the oxygen present would be captured within the event horizon as the stars collapsed into black holes.

Regardless of how it happened, there is now a strong case for heavy elements early in the universe – far earlier than anyone guessed. JWST is revealing unexpected details about the first galaxies that will ultimately make scientists’ predictions about the evolution of the universe far more robust. And perhaps most significantly, it also tells us about the very first step towards creating life.

“These observations tell us that carbon can be enriched quickly in the early universe,” said Francesco D’Eugenio of the Kavli Institute. “And because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier – although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.”

Learn More:

“Earliest detection of metal challenges what we know about the first galaxies.” University of Cambridge.

D’Eugenio et al. “JADES: Carbon enrichment 350 Myr after the Big Bang in a gas-rich galaxy.” ArXiv preprint (accepted to Astronomy & Astrophysics).

The post Carbon is Surprisingly Abundant in an Early Galaxy appeared first on Universe Today.

An exclusive look at "Dune: The Graphic Novel, Book 3: The Prophet," which comes out on July 16.

The three-body problem is a physics conundrum that has boggled scientists since Isaac Newton's day. But what is it, why is it so hard to solve and is the sci-fi series of the same name really possible?

World leaders must make plans to remove more carbon dioxide from the atmosphere, a new report says

Two astronauts performed tests inside full-scale mock ups of SpaceX’s Starship Human Landing System to test spacesuits and other hardware for NASA's Artemis 3 moon mission.

Prospective memory is a skill that can be practiced, making it more likely that someone can remember an appointment or meet a deadline

An interview with Raven Baxter and NASA's Ronald Gamble about the Stellar Dreams Project, which will give 100 telescopes to 100 families.

Magnificent island universe

There are likely millions of “rogue” or free-floating planets (FFPs) spread through the galaxy. These planets, which aren’t big enough to become stars but also aren’t beholden to a star’s gravity, are some of the hardest objects for astronomers to spot, as they don’t give off their own light, and can only be seen when they cross in front of something that does give off its own light. Enter Euclid, a space telescope that launched last year. Its primary mission is to observe the universe’s history, but a new paper describes an exciting side project – finding FFPs in Orion.

In particular, it is finding FFPs around a system known as Sigma Orionis. Famously located on the eastern side of Orion’s Belt, this “star” is a system of at least five different stars, all gravitationally bound in one way or another, forming what is known as a “cluster.” It’s also surrounded by a “dust wave” of particles pointing at the nearby Horsehead Nebula, all of which lends itself to being a place where it would be easy to find FFPs. 

Free-floating planets of this type can also be considered “failed stars” as they did not have enough mass to start the fusion process that comes with star formation. This isn’t the first time they’ve been found in star-forming regions. Other FFPs have been found in NGC 1333, Collider 69, and even the Orion Nebula. This isn’t even the first time they’ve been found in Sigma Orionis – but it is the first time they’ve been detected with the accuracy Euclid allows. As the paper’s authors put it, they “appear to be ubiquitous and numerous.”

Fraser interviews Dr. Maggie Lieu about Euclid and its capabilities

So, what’s unique about what Euclid did? Admittedly, the paper was a sort of test run for the telescope. The observations were taken back in October, only a few months after it launched in the middle of 2023. Those observations also focused on regions well known to contain tons of FFPs already. So what did it find?

They found a bunch of much smaller FFPs than had previously been found. Astronomers use an algorithm called the Initial Mass Function (IMF) to describe the number of stars of specific sizes that would be formed. FFPs define the lower limit of that IMF – i.e., if an object isn’t big enough to become a star, it becomes an FFP. Sufficiently smaller FFPs help astronomers define the limits of the IMF in certain regions, but so far, they have escaped the notice of less sensitive detectors.

That’s where Euclid comes in. The authors point out how the lower end of the IMF is not well defined and describe how the data collected by Euclid could be used to flesh out models at the lower end of the spectrum. However, they also point out that this is still very early in Euclid’s data collection cycle, and plenty more systems could prove exciting hunting grounds for smaller FFPs than have ever been seen before.

Fraser discusses rogue planets in the Orion Nebula

For now, though, this is an excellent first test case of Euclid’s capabilities. Given the sheer number of objects that could be floating out there in the void, it will have plenty of other opportunities to find more, and it has already started looking in several other well-known places, according to the paper. It’s got more than five years left on its planned mission duration, so there will undoubtedly be more papers describing many more FFPs in the future.

Learn More:
Martín et al – Euclid: Early Release Observations – A glance at free-floating new-born planets in the ? Orionis cluster
UT – Enjoy Five New Images from the Euclid Mission
UT – Euclid Begins its 6-Year Survey of the Dark Universe
UT – Phew, De-Icing Euclid’s Instruments Worked. It’s Seeing Better Now

Lead Image:
Multi-color mosaic of the Euclid pointing studied in this work. The area covered is 0.58 square degrees
Credit – Martín et al

The post Euclid is Finding Free Floating Planets in Orion Too appeared first on Universe Today.

Researchers want to create an AI system that can quickly detect and debunk false or misleading claims about climate change

Europe's new Ariane 6 heavy-lift rocket is set to launch for the first time on July 9 after a series of delays.

It should not be surprising that Venus is dry. It is famous for its hellish conditions, with dense sulphurous clouds, rains of acid, atmospheric pressures comparable to a 900 meter deep lake, and a surface temperature high enough to melt lead. But it’s lack of water is not just a lack of rain and oceans: there’s no ice or water vapour either. Like Earth, Venus is found within our Solar System’s goldilocks zone, so it would have had plenty of water when it was first formed. So where did all of Venus’s water go?

Venus is an extremely dry planet, although it wasn’t always like this. At some point in its history, a run-away greenhouse effect began, ending with its current extreme state. Most models agree that this process would have driven off most of its original water, but that there should still be some remaining. And yet, observations show us that there is practically no water at all. Planetary scientists at the University of Colorado Boulder believe that they have found an explanation: a molecule called HCO+ high in Venus’s atmosphere may be responsible. Unfortunately, they may have to wait for future missions to Venus before they can confirm it.

Until the middle of the 20th century, Venus was thought of as Earth’s twin. Both planets are approximately the same size and mass, and they’re both within the sun’s habitable zone – the region where temperatures can exist that are warm enough to melt ice, but not so hot that water boils into steam. It was long assumed that, beneath its shining white cloud cover, Venus must have a similar climate to Earth. Science fiction authors even wrote stories about visitors to Venus exploring verdant jungles and meeting exotic civilizations. But the truth is much harsher: Venus is an extreme place, with sulphuric acid rains, crushing atmospheric pressure, and a surface temperature hot enough to melt lead. But it wasn’t always like that.

The general assumption among astronomers and planetary scientists is that both Earth and Venus started life with similar amounts of water. But something happened to release enormous quantities of carbon dioxide into its atmosphere, leading to an extreme runaway greenhouse effect. The high temperatures melted off any ice, and boiled away any liquid water, filling the atmosphere with water vapour. Much of this hot vapour would eventually blow off into space, drying out the planet, but some should remain. The puzzle is that the usual models predict a great deal more remaining water vapour than what is actually there. So, what happened?

According to a study, led by Dr Eryn Cangi and Dr Mike Chafin, both of the Laboratory for Atmospheric and Space Physics (LASP), the answer may be a molecule named HCO+. In their earlier work studying the atmosphere of Mars, they discovered a process by which this molecule can remove water from planetary atmospheres. In their new paper, they suggest that the same process could be at work on Venus. The only catch is that this molecule has never been detected in the Venusian atmosphere.

Unfortunately, there is little evidence to confirm this theory. HCO+ has never been detected in the atmosphere of Venus. However, Cangi and Chafin point out that this is because nobody has ever looked for it, and none of the missions sent to Venus so far were equipped with instruments that could detect it. They are optimistic for future missions, however.

Illustration of NASA’s DAVINCI probe falling to the surface of Venus. (Credit: NASA GSFC visualization by CI Labs Michael Lentz and others)

“One of the surprising conclusions of this work is that HCO+ should actually be among the most abundant ions in the Venus atmosphere,” says Chaffin.
“There haven’t been many missions to Venus,” adds Cangi. “But newly planned missions will leverage decades of collective experience and a flourishing interest in Venus to explore the extremes of planetary atmospheres, evolution and habitability.”

The planetary science community has gotten increasingly interested in Venus, and a number of future missions are planned to study it in more detail. NASA’s planned Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission is one example. DAVINCI will drop a probe down to the surface, which will study the atmosphere at different altitudes as it falls. Unfortunately for Cangi and Chafin, it is not designed specifically to look for HCO+, but it may reveal other clues to either confirm or disprove their theory. But they remain optimistic that additional missions will be sent in future that will carry the necessary instruments that they can use to test their work.

For more information, visit CU Boulder’s announcement at https://www.colorado.edu/today/2024/05/06/venus-has-almost-no-water-new-study-may-reveal-why

The post Where Did Venus's Water Go? appeared first on Universe Today.

On Episode 114 of This Week In Space, Rod and Tariq talk about the launches of Boeing's Starliner and SpaceX's Starship.

During a successful fourth flight test of Starship this week, SpaceX stated another big goal: Building one megarocket a day at its new Starfactory.

Fields Medalist Terence Tao explains how proof checkers and AI programs are dramatically changing mathematics

NASA astronaut William Anders

The following is a statement from NASA Administrator Bill Nelson on the passing of Apollo astronaut Maj. Gen. (ret.) William “Bill” Anders, who passed away June 7, in San Juan Islands, Washington state, at the age of 90.

“In 1968, as a member of the Apollo 8 crew, as one of the first three people to travel beyond the reach of our Earth and orbit the Moon, Bill Anders gave to humanity among the deepest of gifts an explorer and an astronaut can give. Along with the Apollo 8 crew, Bill was the first to show us, through looking back at the Earth from the threshold of the Moon, that stunning image – the first of its kind – of the Earth suspended in space, illuminated in light and hidden in darkness: the Earthrise.

“As Bill put it so well after the conclusion of the Apollo 8 mission, ‘We came all this way to explore the Moon, and the most important thing is that we discovered the Earth.’

“That is what Bill embodied – the notion that we go to space to learn the secrets of the universe yet in the process learn about something else: ourselves. He embodied the lessons and the purpose of exploration.

“The voyage Bill took in 1968 was only one of the many remarkable chapters in Bill’s life and service to humanity. In his 26 years of service to our country, Bill was many things – U.S. Air Force officer, astronaut, engineer, ambassador, advisor, and much more.

“Bill began his career as an Air Force pilot and, in 1964, was selected to join NASA’s astronaut corps, serving as backup pilot for the Gemini XI and Apollo 11 flights, and lunar module pilot for Apollo 8.

“He not only saw new things but inspired generation upon generation to see new possibilities and new dreams – to voyage on Earth, in space, and in the skies. When America returns astronauts to the Moon under the Artemis campaign, and ultimately ventures onward to Mars, we will carry the memory and legacy of Bill with us.

“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. 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: Bill Anders.”

For more information about Anders’ NASA career, and his agency biography, visit:

https://www.nasa.gov/former-astronaut-william-a-anders/

-end-

Kuiper Belt Object Arrokoth, the farthest object ever explored by a spacecraft, likely tastes sweet — and soapy.

Bill Anders, who as an Apollo 8 astronaut was one of the first people to fly to the moon in 1968, was killed on June 7 when the vintage plane he was piloting crashed off the coast of Washington.