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Sai Charan 1,098 President, International Amateur Astronomical Association
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A Composite image showing the Sun in white light (top) and in H-alpha (bottom). We can study the sun in either white light or in several narrow wavelengths, the most common of which are red hydrogen-alpha and violet calcium K-line light. White light filters reveal the glaring face of the Sun called the photosphere, home to granulation, a rice-grain texture of rising and sinking convective cells; faculae, bright patches of concentrated magnetic energy; and sunspot groups that come and go as the rotating Sun carries them in and out of view. Nothing matches the view through an H-alpha (Hα) filter. Viewed in a narrow slice of the spectrum centered in the ruby-red H-alpha line, the Sun throbs with activity. In the red of hydrogen light emitted by hydrogen atoms with a wavelength of 6562.8Å (656 nm), we peer into the solar chromosphere, the layer directly above the photosphere. Besides the features in the white light image, several other features are visible in the H-alpha image such as Active & Quiescent Prominences, dark Filaments and bright Plages, Active Regions such as AR 2871, AR 2872 & AR 2973.
Image Credit: Prabhu S Kutti
Location: Abu Shagara, Sharjah, United Arab Emirates
Amateur Astronomers spotted a bright flash on Jupiter at 22:39:27 UTC on September 13, possibly an impact. However, due to the impacting object's small size (100m across or so), we don't see any dark impact spots.
Brazilian amateur astronomer Pereira was likely the first to report it. Later reports confirmed that at least 7 observers independently saw or recorded the incident. If confirmed, it would be the eighth recorded impact at Jupiter since the first in July 1994, when fragments of sundered Comet Shoemaker-Levy 9 slammed into the planet and left a trail of prominent dark scars.
Video from José Luis Pereira (Via YouTube)
Scientists love a mystery. It’s satisfying when a prediction is shown to be correct, but it’s intriguing when an experiment turns up a result that deviates from expectations.
Several such anomalies have shown up in recent years in particle physics and astrophysics.
Sometimes results like these can be explained by faulty equipment. Sometimes they disappear with more rigorous measurement. But sometimes they stay put and demand to be understood.
What’s interesting about some recent anomalies is that they each have the potential to be explained by the influence of an undiscovered particle or force. Any one of them could be a sign of the existence of dark matter—a mysterious substance that makes up about 85% of matter in our universe.
The muon (the electron’s heavier cousin) acts strangely in a magnetic field. Earlier this year, Fermilab’s Muon g-2 collaboration announced a measurement of the amount a muon “wobbles” in a magnetic field, upholding a 2001 result. The problem is that both results seem to differ greatly from what the Standard Model predicts.
As the Muon g-2 collaboration continues to take measurements and theorists continue their own calculations, it’s possible that the theoretical and experimental values of g-2 will converge. However, many physicists suspect that this anomaly will remain, and if it does, it may have a natural solution through dark matter.
The Hubble tension
Our universe is expanding, but the rate of the universe’s expansion called the Hubble constant (H0), is the subject of one of the biggest disputes in modern cosmology. That’s because the Hubble constant has been calculated using two different methods that yield irreconcilable results.
This tension has existed for decades and persists even as the measurements get more precise. Could dark matter account for the discrepancy? Sophia Gad-Nasr, a Ph.D. candidate in cosmology at UC Irvine, says it is possible, but only if dark matter decays.
The KOTO excess
One of the most recent curious results that may be linked to dark matter came in 2019 from J-PARC’s KOTO experiment, which studies a very rare decay of a subatomic particle called a kaon. The decay is so rare in predictions based on the Standard Model that the collaboration didn’t expect to see it at all when they began taking data. Surprisingly, they observed four.
In March 2020, researchers proposed three explanations for the seeming excess, including one that could be due to a new meta-stable particle potential occurrences of the decay.
The proton radius puzzle
In 2010, the Charge Radius Experiment with Muonic Atoms (CREMA) made an incredibly precise measurement of the proton’s radius by shooting a laser beam at (as its name suggests) hydrogen atoms made with muons instead of electrons.
Strangely, the measurement was nearly 4% smaller than the then-official value set in 2006 by the Committee on Data of the International Science Council (CODATA), derived from multiple spectroscopy experiments that used ordinary hydrogen.
The unexpected result caused excitement among theorists. Why did the different experimental methods produce such disparate values? Some wondered if “new physics”—like dark matter—was causing a difference between the ways that electrons and muons behave, resulting in the discrepancy between radius measurements with ordinary and muonic hydrogen.
How will we know?
Ultimately, only time—and more precise measurements and predictions—will tell whether these anomalies stick around.
Using the powerful 570-megapixel Dark Energy Camera (DECam) in Chile, astronomers discovered an asteroid with the shortest orbital period of any known asteroid in the Solar System. The orbit of the approximately 1-kilometer-diameter asteroid takes it as close as 20 million kilometers (12 million miles or 0.13 au), from the Sun every 113 days. Asteroid 2021 PH27, revealed in images acquired during twilight, also has the smallest mean distance (semi-major axis) of any known asteroid in our Solar System — only Mercury has a shorter period and smaller semi-major axis. The asteroid is so close to the Sun’s massive gravitational field, it experiences the largest general relativistic effects of any known Solar System object.
(With Inputs from NOIRLab)
Scientists last autumn revealed that the gas phosphine was found in trace amounts in Venus’ upper atmosphere. That discovery promised the slim possibility that phosphine serves as a biological signature for the hot, toxic planet.
Now Cornell scientists say phosphine’s chemical fingerprints support a different and important scientific find: evidence of explosive volcanoes on the mysterious planet.
“The phosphine is not telling us about the biology of Venus,” said Jonathan Lunine, the David C. Duncan Professor in Physical Sciences and chair of the Department of Astronomy in the College of Arts and Sciences. “It’s telling us about the geology. Science is pointing to a planet that has active explosive volcanism today or in the very recent past.”
Lunine and Ngoc Truong, a doctoral candidate in geology, have authored the study, “Volcanically Extruded Phosphides as an Abiotic Source of Venusian Phosphine,” published July 12 in the Proceedings of the National Academy of Sciences.
Truong and Lunine argue that volcanism is the means for phosphine to get into Venus’ upper atmosphere, after examining observations from the ground-based, submillimeter-wavelength James Clerk Maxwell Telescope atop Mauna Kea in Hawaii, and the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile.
“Volcanism could supply enough phosphide to produce phosphine,” Truong said. “The chemistry implies that phosphine derives from explosive volcanoes on Venus, not biological sources.”
Our planetary neighbor broils with an almost 900-degree Fahrenheit average surface temperature and features a carbon dioxide-filled atmosphere enveloped in sulfuric acid clouds, according to NASA.
If Venus has phosphide – a form of the phosphorous present in the planet’s deep mantle – and, if it is brought to the surface in an explosive, volcanic way and then injected into the atmosphere, those phosphides react with the Venusian atmosphere’s sulfuric acid to form phosphine, Truong said.
He found published laboratory data confirming that the phosphide reacts with sulfuric acid to produce phosphines efficiently.
Volcanism on Venus is not necessarily surprising, Lunine said. But while “our phosphine model suggests explosive volcanism occurring, radar images from the Magellan spacecraft in the 1990s show some geologic features could support this.”
In 1978, on NASA’s Pioneer Venus orbiter mission, scientists uncovered variations of sulfur dioxide in Venus’ upper atmosphere, hinting at the prospect of explosive volcanism, Truong said, similar to the scale of Earth’s Krakatoa volcanic eruption in Indonesia in 1883.
Said Truong: “Confirming explosive volcanism on Venus through the gas phosphine was totally unexpected.”
Funding for the research was provided by the NASA Goddard Space Flight Center in Greenbelt, Maryland.
Courtesy of the Cornell Chronicle. (c) Cornell Chronicle.
In early 2021, just after the Perseverance Rover landed on Mars, a purported image of the Martian night sky went viral. In that image, above the sleek metal of a Mars rover, the clearly defined Milky Way cuts from horizon to horizon, crossing a sky filled with so many stars that there is no darkness.
Millions of people were excited to see the unblemished night sky from another planet, with no light pollution from cities, no flashing aircraft, and no significant satellite presence.
The photo is not real; rather, it is a clever juxtaposition of NASA images and long-exposure astrophotography. So why did it go viral?
The threatened night sky
Urban light pollution has vastly changed our relationship with the night sky: 80 percent of North Americans cannot see the Milky Way from where they live today. Electricity is so cheap and plentiful that we use it to shine lights into the sky for no reason other than laziness and poor planning.
The lack of darkness that many people now experience due to urban light pollution has been linked to many physical and mental health issues, both in humans and wildlife.
But we are now faced with a new source of light pollution: systems of tens of thousands of communications satellites. The construction of these so-called mega-constellations is already changing the night sky.
Indeed, observations by professional astronomers have shown that many of the current Starlink mega-constellation satellites are visible to the naked eye when sunlit.
Megaconstellations have the potential to significantly benefit society by increasing the connectivity of isolated communities, a significant challenge in many parts of Canada. At the same time, the negative effects of mega-constellations must be understood by decision-makers and properly regulated.
While urban residents might not notice this change, many people around the world will — especially those from cultures that have strong ties to stargazing and traditional knowledge of the sky.
Canada has an obligation to consult with First Nations so that each may independently make a decision before allowing the development of a resource that Indigenous Canadians have traditionally had access to for cultural practices.
The damage to science
Astronomy organizations worldwide are concerned about the damage to science that will be caused by mega-constellations and other forms of light and radio pollution, and have responded through efforts such as the “Dark and Quiet Skies Report” and the “SATCON1 Report.”
Astronomers will require more telescope time to carry out the same taxpayer-funded science goals and will need to spend time and money studying the brightness of these satellites and developing new software for mitigation efforts.
Radio astronomers expect to lose even more of the radio spectrum to mega-constellations communication noise, requiring additional investments in research and development.
At the request of the Canadian Astronomical Society, we wrote a report that contains a list of recommendations for what Canada can do to address the many negative impacts of mega-constellations at the national and international levels.
A satellite-filled sky
We ran a simulation with 65,000 satellites on their proposed orbits (this includes Starlink, OneWeb, Kuiper, and StarNet/GW). We found that there will be more than 1,500 sunlit satellites at any given moment all night, every night in the summertime from Canada. Not all of these will be visible, as their brightness depends on the shape, reflective properties, and orbit of each satellite. But there are currently no regulations that limit their brightness.
There are currently about 20,000 tracked objects in orbit, including active satellites, defunct satellites, rocket bodies, and pieces of space junk. There are 10 to 100 times more pieces of untracked space junk that are small but still dangerous: tiny bits of debris from rocket launches, satellite deployment, fragmentations (explosions), and even tools dropped by astronauts.
These small objects seem innocuous, but in Low Earth Orbit (LEO), they travel at speeds over seven kilometers per second, many times faster than a bullet, on randomly crossing orbits. Companies are making substantial progress toward placing at least 65,000 satellites into LEO. Current leader SpaceX has over 1,600 Starlink satellites already in orbit, in a region inhabited by a troubling density of untracked debris.
When two satellites collide (as happened for the first time in 2009), they produce a spray of fast-moving debris. One destroyed satellite makes hundreds to thousands of pieces of trackable space junk, each of which could destroy other satellites, producing still more space junk. Any major fragmentation event will place limitations on space use, endanger crewed space habitation of LEO, and could cause widespread disruptions to services that we rely on every day.
Space junk re-entries
As highlighted by the recent uncontrolled re-entries of the Long March 5B rocket booster over the Indian Ocean in May 2021 and the SpaceX Falcon 9 rocket stage over the Pacific Northwest in March 2021, re-entries are not without risks. A portion of the March 2021 Falcon 9 rocket even survived to impact with the ground in a farmer’s field in Washington State.
The current rules date to the Space Race era. There is a framework for liability, but the only time this was tested was when a U.S.S.R. satellite spread nuclear waste across the Northwest Territories in 1978.
There are also environmental impacts, both from rocket launches and the disposal of satellites. SpaceX plans for 42,000 Starlink satellites which will be replaced every five years. This means on average six tonnes of satellites will be destroyed every day. That material will be deposited in the upper atmosphere upon re-entry. While this is less than the 54 tonnes of meteoroids that hit Earth’s atmosphere every day, the composition is very different: Starlink satellites are mainly aluminum by weight; meteoroids are one percent.
We do not know what could happen when several tonnes of aluminum is deposited in the upper atmosphere every single day. SpaceX is going to run this experiment without any environmental oversight.
Because of the orientation of the proposed satellite orbits, much of Canada’s population will sit under some of the highest densities of satellites, so we can expect to see a disproportionate share of de-orbiting space junk.
Regulation of satellites is key
We need to recognize that LEO is intimately connected to our atmosphere, oceans, and land. We need regulation of satellites now before there is irreparable damage to our sky. We hope the Government of Canada will act on these recommendations with an urgency that matches the frenetic speed of space development.
While several mega-constellation companies are already in dialogue with astronomers, the improvements they make to their satellites for the benefit of astronomy are entirely voluntary. We shouldn’t have to make a choice between the night sky and the global internet. With proper regulation of satellites in LEO, we can have both.
Japanese astronomers have developed a new artificial intelligence (AI) technique to remove noise in astronomical data due to random variations in galaxy shapes. After extensive training and testing on large mock data created by supercomputer simulations, they then applied this new tool to actual data from Japan’s Subaru Telescope and found that the mass distribution derived from using this method is consistent with the currently accepted models of the Universe. This is a powerful new tool for analyzing big data from current and planned astronomy surveys.
Wide area survey data can be used to study the large-scale structure of the Universe through measurements of gravitational lensing patterns. In gravitational lensing, the gravity of a foreground object, like a cluster of galaxies, can distort the image of a background object, such as a more distant galaxy. Some examples of gravitational lensing are obvious, such as the “Eye of Horus.” The large-scale structure, consisting mostly of mysterious “dark” matter, can distort the shapes of distant galaxies as well, but the expected lensing effect is subtle. Averaging over many galaxies in an area is required to create a map of foreground dark matter distributions.
But this technique of looking at many galaxy images runs into a problem; some galaxies are just innately a little funny looking. It is difficult to distinguish between a galaxy image distorted by gravitational lensing and a galaxy that is actually distorted. This is referred to as shape noise and is one of the limiting factors in research studying the large-scale structure of the Universe.
To compensate for shape noise, a team of Japanese astronomers first used ATERUI II, the world’s most powerful supercomputer dedicated to astronomy, to generate 25,000 mock galaxy catalogs based on real data from the Subaru Telescope. They then added realist noise to these perfectly known artificial data sets, and trained an AI to statistically recover the lensing dark matter from the mock data.
After training, the AI was able to recover previously unobservable fine details, helping to improve our understanding of the cosmic dark matter. Then using this AI on real data covering 21 square degrees of the sky, the team found a distribution of foreground mass consistent with the standard cosmological model.
“This research shows the benefits of combining different types of research: observations, simulations, and AI data analysis.” comments Masato Shirasaki, the leader of the team, “In this era of big data, we need to step across traditional boundaries between specialties and use all available tools to understand the data. If we can do this, it will open new fields in astronomy and other sciences.”
These results appeared as Shirasaki et al. “Noise reduction for weak lensing mass mapping: an application of generative adversarial networks to Subaru Hyper Suprime-Cam first-year data” in the June 2021 issue of Monthly Notices of the Royal Astronomical Society.
Courtesy of the National Astronomical Observatory of Japan. (c) NAOJ.