Astronomy

During a close flyby of Europa, the Juno spacecraft was at an altitude of just 330 kilometers (220 miles) above the moon's surface. It caught some awesome images, too.

The Sun has been vying for attention these last couple of weeks. First with the appearance of a fabulous complex sunspot region and then with a plethora of solar flares. On the 14th May, yet another was released, this time an X8.7 class flare from the same complex sunspot regions. It was significantly more powerful than the flare that set off the aurora displays which enchanted much of the planet but alas it was not pointing toward the Earth (

Europa has always held a fascination to me. I think it’s the concept of a world with a sub-surface ocean and the possibility of life that has inspired me and many others. In September 2022, NASAs Juno spacecraft made a flyby, coming within 355 kilometres of the surface. Since the encounter, scientists have been exploring the images and have identified regions where brine may have bubbled to the surface. Other images revealed possible, previously unidentified steep-walled depressions up to 50km wide, this could be caused by a free-floating ocean! 

Juno was launched to Jupiter on 5 August 2011. It took off from the Cape Canaveral site on board an Atlas V rocket and travelled around 3 billion kilometres. It arrived at Jupiter on 4 July 2016 and in September 2022 made its closest flyby of Europa. The frozen world is the second of the four Galilean satellites that were discovered by Galileo over 400 years ago. Visible in small telescopes, the true nature of the moon is only detectable by visiting craft like Juno. 

Artist’s impression of NASA’s Galileo space probe in orbit of Jupiter. Credit: NASA

During its close fly-by, one of the onboard cameras known as Juno-Cam took the highest resolution images of the moon since Galileo took a flyby in 2000. The images supported the long held theory that the icy crusts at the north and south poles are not where they used to be. Another instrument on board, known as the Stellar Reference Unit (SRU), revealed possible activity resembling plumes where brine may have bubbled to the surface. 

The ground track over Europa that was followed by Juno enabled imaging around the equatorial regions. The images revealed the usual, expected blocks of ice, walls, ridges and scarps but also found something else. Steep walled depressions that measured 20 to 50 kilometres across were also seen and they resembled large ovoid pits. 

One of Juno’s enormous solar panels, unfurled on Earth. NASA/JPL. SWrI

The observations of the meanderings of the north/south polar ice and the varied surface features all point towards an outer icy shell that is free-floating upon the sub surface ocean.  This can only happen if the outer shell is not connected to the rocky interior. When this happens, there are high levels of stress on the ice which then causes the fracture pattern witnessed. The images represent the first time such patterns have been seen in the southern hemisphere, the first evidence of true polar wandering. 

The images from the SRU surprisingly provided the best quality images. It was originally designed to detect faint light from stars for navigation. Instead, the team used it to capture images when Europa was illuminated by the gentle glow of sunlight reflected from Jupiter. It was quite a novel approach and allowed complex features to become far more pronounced than before. Intricate networks of ridges criss-crossing the surface were identified along with dark stains from water plumes. One feature in particular stood out, nicknamed ‘the Platypus’, it was a 37 kilometre by 67 kilometre region shaped somewhat like a platypus. 

Source : NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell

The post Juno Reveals Secrets About Europa’s Icy Surface appeared first on Universe Today.

Blue Origin plans to launch six people — including the United States' first-ever black astronaut candidate — on a suborbital spaceflight this weekend.

Some AI firms think nuclear power can help meet the electricity demand from Silicon Valley’s data centres, but building new nuclear power stations takes too long to plug the gap in the short term

SpaceX stacked its giant Starship rocket ahead of the vehicle's fourth test flight, which could launch just a few weeks from now.

Lithuania signed the Artemis Accords on Wednesday (May 15), bringing the number of nations in the moon-exploration pact to 40.

In season 1 premiere 'Space Babies', the Doctor tells Ruby and the cosmic infants that he's the last of the Time Lords. Here's what that means.

The thrusters of Mercury-bound spacecraft BepiColombo are operating at less than full capacity, and operators are racing to find a solution.

The four winners of the Stephen Hawking Medal 2024 were announced during a medal ceremony at Starmus VII science and music festival in Bratislava, Slovakia.

Strange quantum characteristics of molecules can weather the chaos of chemical reactions, which may benefit quantum technologies or unveil hidden natural phenomena

Strange quantum characteristics of molecules can weather the chaos of chemical reactions, which may benefit quantum technologies or unveil hidden natural phenomena

The tension between quantum mechanics and relativity has long been a central split in modern-day physics. Developing a theory of quantum gravity remains one of the great outstanding challenges of the discipline. And yet, no one has yet been able to do it. But as we collect more data, it shines more light on the potential solution, even if some of that data happens to show negative results.

That happened recently with a review of data collected at IceCube, a neutrino detector located in the Antarctic ice sheet, and compiled by researchers at the University of Texas at Arlington. They looked for signs that gravity could vary even a minuscule amount based on quantum mechanical fluctuations. And, to put it bluntly, they didn’t find any evidence of that happening.

To check for these minuscule fluctuations, they analyzed more than 300,000 detected neutrinos that IceCube had captured. IceCube is an impressive engineering feat, with thousands of sensors buried over one sq km in the ice. When one of the detectors is triggered by one of a hundred trillions of neutrinos passing through it every second, data on whether it was affected by any perturbations in the local gravity of that area can be collected.

Fraser discusses the neutrino detectors of IceCube.

Such massive data sets allowed for a very accurate reading—”over a million times more [accurate],” according to Dr. Benjamin Jones, one of over 300 physicists who worked on a paper detailing IceCube’s findings, which he described in a press release from the University of Texas at Arlington. Despite that, the researchers were still unable to find any evidence for those quantum fluctuations in the local gravitational field.

That’s not all bad news, though. Eliminating one possible explanation for quantum gravity could lead to work on others. Dr. Jones sees that prospect as he describes how his lab’s efforts are shifting to studying the mass of neutrinos themselves. Understanding more about these elusive particles certainly won’t hurt efforts to understand the overall physical model of the universe. Still, many scientists are likely disappointed by this newest failure to find a potential lead in the solution to a “theory of everything.”

For now, IceCube will keep collecting data, and scientists will continue to analyze it. But efforts to find a new theory of quantum gravity seem to be back at the theoretical drawing—which is a necessary step before they can be tested, no matter how fancy the detector itself is.

PBS Spacetime explains the idea behind quantum gravity.

Learn More:
UTA – UTA SCIENTISTS TEST FOR QUANTUM NATURE OF GRAVITY
IceCube Collaboration – Search for decoherence from quantum gravity with atmospheric neutrinos
UT – Scientists are Recommending IceCube Should be Eight Times Bigger
UT – IceCube Makes a Neutrino Map of the Milky Way

Lead Image:
IceCube Lab under the stars in the Antarctic.
Credit – IceCube/NSF

The post Scientists Test for Quantum Gravity appeared first on Universe Today.

The Indian Space Research Organization has released solar storm data from ground stations and spacecraft, including the Chandrayaan-2 lunar orbiter.

The first trailer for Max's "Dune: Prophecy" prequel spinoff has just arrived, revealing the origins of the franchise's mysterious Bene Gesserit sisterhood.

"For the girls or women in science — or in any profession or job — opportunities are more abundant than they were previously. Sometimes you need to take bold steps. Just a little push, and then you will get there." — Dr. Yihua (Eva) Zheng, Space Physics and Space Weather Scientist, Heliophysics Science Division, NASA's Goddard Space Flight Center

You can blank out certain types of background noise and focus on just one conversation using prototype noise-cancelling headphones

You can blank out certain types of background noise and focus on just one conversation using prototype noise-cancelling headphones

A massive Mars impact crater dominates a new view from the ExoMars Trace Gas Orbiter (TGO).

After comparing people with brain injuries whose life support was continued with those who had it turned off, scientists calculated that around 40 per cent in the latter group may have made some recovery