Sommaire pour March 2025 de Astronomy

GAMMA-RAY GLOW Thunderclouds produce gamma rays in short bursts and longer-lasting glows. Airborne observations have now also discovered intermediate-length gamma-ray flickers; understanding them could help predict lightning strikes. ALTERED STATE Temporary changes brought on by a blast of solar wind could explain the strange magnetic field observed at Uranus by Voyager 2 in 1986. RED MONSTERS JWST spotted three dusty, Milky Way-sized galaxies within 1 billion years of the Big Bang. Their size at this time indicates that early stars may have formed faster than previously thought.…

DARK MATTER SEARCH A supernova in the Milky Way could solve the mystery of dark matter, a UC Berkeley team calculates. In such an explosion, NASA’s Fermi space telescope could detect axions — a proposed dark-matter particle — as they transform into high-energy gamma rays. FARSIDE VOLCANISM Early analysis of samples from China’s Chang’e 6 — the first mission to retrieve rocks from the Moon’s farside — found volcanic samples with an age of 2.8 billion years. The find indicates volcanism on the farside was surprisingly long-lived. MAGNETAR ORIGINS The enigmatic events known as fast radio bursts (FRBs) are more likely in massive star-forming galaxies, says a Nov. 6 Nature paper. This suggests that the intense magnetic fields of magnetars — thought to be the source of most FRBs —…

DURING THE COLD WAR, the U.S. and USSR raced to be first to send robotic and human explorers to the Moon, traversing lunar terrain and returning samples to Earth. These exploits and their scientific returns were crucial to unlocking the history of the Moon — and by extension, the history of our solar system. But after these initial forays, exploration of our natural satellite hit the doldrums. Following the USSR’s Luna 24 sample-return mission in 1976, the Moon’s surface remained undisturbed by visitors for decades, save for the occasional impact. Finally, the 1990s saw a revival in robotic lunar exploration as the U.S. and Europe carried out flybys and Japan deployed its first lunar orbiter. This movement gained steam in the 2000s as China and India launched their first robotic…

A total eclipse of the Moon is the highlight of this month, visible across North and South America. Venus remains very bright and transitions from evening to morning late in the month. Mercury joins Venus for a few evenings, offering the best opportunity to see both planets in twilight. Mars and Jupiter dominate the late evenings, providing many hours of planetary observation with tantalizing features to see in small scopes. Both the inner planets, Mercury and Venus, stand together in the evening twilight during early March. Look for them soon after sunset. They will appear near the western horizon, so avoid any obstacles that may hamper your view. Venus will be most obvious because it is so bright, shining at magnitude −4.8 on March 1. It becomes obvious within 30…

REGULUS is the sparkling beacon in the east almost halfway up the sky during March evenings. Also known as Cor Leonis, the heart of the Lion, Regulus anchors a pattern of stars called the Sickle, which for modern observers resembles a backwards question mark. (Few folk these days have held a sickle, a common tool of farmers of the past.) 29 Amphitrite sports a diameter of 124 miles, shining with reflected sunlight at magnitude 9.5, and this month curves 4° south of Lambda (λ) Leo. Far from the Milky Way, the background here is sparse, making pattern recognition easy to identify the space rock. On the 9th, Amphitrite looks like the fainter component of a wide double, sitting just over an arcminute from an 8th-magnitude field star. Return three hours…

Percival Lowell gave rousing public lectures and wrote several popular books. He captured his perspective on the importance of sharing science with nonspecialists in his 1906 book, Mars and Its Canals. In it he wrote: “To set forth science in a popular, that is, in a generally understandable, form is as obligatory as to present it in a more technical manner. If men are to benefit from it, it must be expressed to their comprehension. To do this should be feasible for him who is master of his subject and is both the best test of, and the best training to, that post. Especially vital is it that the exposition should be done at first hand; for to describe what a man has himself discovered comes as near as possible…

Molly is an avid astrophotographer active in STEM outreach. She has a Ph. D. in nuclear engineering. During the night of March 13, most of North and South America will be treated to a total lunar eclipse, an event popularly referred to as a Blood Moon. The event is aptly named — the Moon is cast in a dark red, brown, or orange color during totality, giving it an eerie appearance in the night sky. A lunar eclipse occurs when the Moon lies directly behind Earth from the Sun, an arrangement that occurs two or three times per year. Any given location on Earth is graced with a total lunar eclipse every 2.5 years on average. One might think that this should occur every month at Full Moon, but the…

You could forgive M17 for having an identity crisis. Observers refer to this emission region as the Omega, the Swan, and even the Checkmark Nebula. M17 doesn’t even know what constellation to call home — most of it lies in Sagittarius, but its northern edge crosses into Serpens. Yet no one can deny the stellar nursery’s good looks. This infrared view penetrates much of the dust that obscures the budding star cluster emerging within M17. Astronomers captured the Swan, which resides 5,500 light-years from Earth, with the 4.1-meter Visible and Infrared Telescope for Astronomy (VISTA) located on Cerro Paranal in Chile. The image is just a tiny piece of a giant infrared map covering an area equal to 8,600 Full Moons. The survey took 13 years to complete and captured…

Citing environmental concerns, 120 astronomers and researchers implored the Federal Communications Commission (FCC) in an Oct. 24 letter to halt launches of internet satellites like SpaceX’s Starlink. The letter, which was organized by the Public Interest Research Group (PIRG), also urged FCC Space Bureau Chief Julie Kearney to investigate the potential negative environmental and health impacts of the vast projected increase in satellites being disposed of in the atmosphere. The number of existing satellites has increased by a factor of 12 in the last five years, with SpaceX alone launching around 60 percent of them. And in 2022, the U.S. Government Accountability Office (GAO) predicted 58,000 satellites would be launched by the end of the decade. Under existing practices, to avoid the possibility of long-term defunct space junk, satellites in…

Stephen is a globetrotting observer who is always looking for the next great celestial event. All lunar eclipses — whether penumbral, partial, or total — offer us thought-provoking views of Earth’s shadow. Frequently, lunar eclipses offer up peculiar color effects, with the shadowed Moon appearing reddish due to the state of Earth’s atmosphere. But the March 14, 2025, total lunar eclipse all but guarantees additional optical phenomena of a different kind, some of which could distort one’s perception of reality, even if momentarily. Let’s start with the color effects. Take, for instance, the peculiar pink Moon that Brian Cudnik of Houston observed during the total lunar eclipse of Nov. 7/8, 2022. Cudnik captured the eclipse by holding his Samsung Galaxy up to the 41mm eyepiece of a Celestron 11 telescope.…

IN JULY 1969, NEIL ARMSTRONG AND BUZZ ALDRIN planted the American flag on the Moon’s Sea of Tranquility — though not as an act of conquest, nor a proclamation of ownership. Indeed, no nation has legal ownership nor exclusive rights to the Moon. But future disputes over such issues are practically inevitable. The largest effort to create a framework for the modern politics of lunar exploration is the Artemis Accords, an international agreement spearheaded by the U.S. in 2020; as of November 2024, they have been signed by 48 nations. The crux of the document proclaims activities on the Moon shall be for peaceful purposes in accordance with international law. Scientific lunar data should be transparently shared and major lunar infrastructure systems should be compatible across nations. Further, efforts should…

OBSERVERS IN NORTH AMERICA are perfectly placed to watch a few points of light on the Moon evolve into a prominent letter X on the evening of the 6th. It’s just a chance alignment of light and shadow as the Sun rises over a group of crater walls, but fun to see because it tickles our pattern-recognition fancy, called pareidolia. If you take video clips every five to 10 minutes, you can create a time-lapse movie of the X emerging, peaking, and disappearing all in one evening. In the east, start looking soon after sunset. Focus in on a spot about halfway between the equator and the south pole, using the twin craters Aliacensis and Werner as your guide to the X, just to their northwest. Watch points of light…

To the Moon University of Chicago Press Chicago, IL Lunar: A History of the Moon in Myths, Maps, and Matter compiles 44 hand-drawn cartographic charts created by illustrator-cartographers from the U.S. Geological Survey. This 256-page hardback contains 500 color images, as well as commentary on Earth’s natural satellite from experts and scholars, combining scientific observations and explanations with stories of the Moon’s impact on human art, history, and culture. $65.00 custserv@press.uchicago.edu https://press.uchicago.edu Nebulous addition Celestron Torrance, CA Celestron has created a new nebula filter exclusively for their Origin Home Observatory. The accessory is used to block light pollution and accentuate the light from Hα at 656 nanometers, Hβ at 486 nm, and OIII at 496/501 nm wavelengths. It is constructed with an antireflective coating and a patented glass to prevent…

Inside the unassumingly named nebula Gum 55 lies a rift of dust grains that absorb visible light, creating a swath of darkness against the glowing gas. Fittingly named for its shape, the Dark Wolf Nebula is no mere puppy — it spans an area some four times the size of the Full Moon. Gum 55 is even bigger, a huge stellar nursery birthing fiercely-burning stars whose radiation pushes away the material that formed them, creating shells and pillars of denser material. These complex layers create beautiful and evocative shapes, including the piles of dark dust that comprise the Dark Wolf Nebula. The Dark Wolf and Gum 55 reside in Scorpius near the heart of the Milky Way, some 5,300 light-years distant. The European Southern Observatory’s (ESO) VLT Survey Telescope at…

THE NEW WAVE OF INTERNATIONAL ROBOTIC EXPLORATION is already bearing scientific fruit and changing the established timeline of the Moon’s formation. India’s Chandrayaan-3 mission has contributed to our understanding of the Moon’s early history. Its landing site is farther south than any other soft landing, with the exception of IM-1. Yet data from that mission’s Pragyan rover published in August 2024 shows that the composition of anorthosite rocks at that location are remarkably similar to those returned by Luna and Apollo missions that landed over 1,100 miles (1,800 kilometers) to the north. That likeness suggests that these rocks all came from a global primordial ocean of magma that covered the Moon just after it was formed in a cataclysmic collision between Earth and a Mars-sized body. Meanwhile, China’s Chang’e missions…

Bright pillar EARLY SPRING is not well known for meteor showers, with no major events occurring this month. It is, however, a great month to spot the zodiacal light. The best opportunities occur when the Moon is out of the way, in the first three days of March and again during the last two weeks of the month. Look for a delicate cone-shaped glow extending above the horizon through Pisces, Aries, and Taurus. Try using peripheral vision to spot the arching cone of light by scanning your eyes left to right along the western horizon. You’ll need a clear, dark horizon unaffected by lights or distant city glows, which mask the effect. The zodiacal light is aligned with the ecliptic, Earth’s orbital plane, and comes from sunlight reflecting off fine,…

THE POPULARITY of the deep sky increased as larger scopes became affordable, inspiring comet fans to coin their viewing as “shallow-sky,” perhaps to entice galaxy fans to check out our solar system’s primordial snowballs. However, the only known comets coming up will require 10-inch or larger scopes to go deep from a dark site. C/2022 E2 (ATLAS) is a 12th-magnitude pollen puff floating near the butterfly-winged nebula M76. Its curving trajectory keeps it within 2° of 51 Andromedae, which glows an easy magnitude 3.6 in any finder scope. Zero in on the field and push the power past 150x, even to 250x. The overall view will be darker, but the 1'- to 2'-wide comet then has a chance to tickle the dark-adapted rods of your retina. Perhaps start to the…

LAST NOVEMBER, LOWELL OBSERVATORY HERALDED a new era of public astronomy outreach with the opening of its Marley Foundation Astronomy Discovery Center (ADC) in Flagstaff, Arizona. The blend of exquisitely detailed planning and state-of-the-art technology makes this a 40,000-square-foot (3,720 square meters) factory of awe and wonder for people of all ages. Combine this with the observatory’s rich, 130-year heritage as a leading center of astronomical research and education, as well as Flagstaff’s reputation as the world’s first International Dark Sky City, and the new center is truly unique in the world. The ADC is not merely an upgrade of the observatory’s current Steele Visitor Center (SVC), but a completely new facility situated west of the SVC. This new facility came about in response to ever-increasing interest in the observatory’s public…