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Hubble and Webb Telescopes Uncover Secrets of Trans-Neptunian Objects, Challenging Planet Formation Theories

Hubble and Webb Telescopes Uncover Secrets of Trans-Neptunian Objects, Challenging Planet Formation Theories

Scientists have, for the first time, combined observations from NASA’s Hubble Space Telescope and the James Webb Space Telescope to study some of the smallest and dimmest Trans-Neptunian Objects (TNOs) beyond Neptune. These icy worlds are considered relics from the early solar system, representing planetesimals that never fully developed into planets. The collaborative effort, led by PhD candidates Marielle Eduardo (University of Victoria) and Anastasia Morgan (Northern Arizona University), involved simultaneous observations where Hubble recorded visible light and Webb measured infrared signatures. They examined the colors, compositions, sizes, and orbits of 27 newly discovered TNOs, some as small as 5 kilometers across, which are beyond the reach of ground-based telescopes. The findings, published in The Astronomical Journal, revealed fewer tiny TNOs than expected and indicated that their surfaces have preserved their primordial states far better than previous models predicted. This suggests that collisio...

LAGEOS-1 Satellite, a Passive 'Disco Ball' in Orbit, Continues to Provide Geodynamic Data Decades Later

LAGEOS-1 Satellite, a Passive 'Disco Ball' in Orbit, Continues to Provide Geodynamic Data Decades Later

Launched in 1976, LAGEOS-1 (LAser GEOdynamic Satellite) is a unique scientific satellite that remains in service despite lacking any instrumentation, electronics, power supply, or propulsion. Weighing just under 407 kg and spherical in shape, it resembles a disco ball due to its surface being covered with corner cube retroreflectors. These retroreflectors are designed to reflect incident light directly back to its source. Ground stations on Earth fire short laser pulses at LAGEOS-1 and measure the time it takes for the light to return, a technique known as time-of-flight ranging. Because LAGEOS-1 maintains an exceptionally stable orbit, it serves as a reliable reference point for precisely measuring minute changes in Earth's characteristics, including its size, shape, and rotation. Data from LAGEOS-1 and its successor, LAGEOS-2 (launched in 1992), has also been utilized in tests of general relativity. Its design and orbit were specifically chosen to minimize atmospheric drag and other disturbances, ensurin...

LAGEOS-1 Satellite Continues Passive Geodynamic Measurements Decades After Launch

LAGEOS-1 Satellite Continues Passive Geodynamic Measurements Decades After Launch

The LAGEOS-1 (LAser GEOdynamic Satellite), launched in 1976, remains an active scientific satellite despite lacking internal instrumentation, electronics, or propulsion. This spherical satellite, weighing nearly 407 kg, is designed for entirely passive operation. Its surface is covered with corner cube retroreflectors, which precisely return incident laser light to its source. Ground stations on Earth emit short laser pulses towards LAGEOS-1 and measure the time it takes for the light to return. This time-of-flight ranging technique, combined with LAGEOS-1's highly stable orbit, provides a reliable reference point for detecting minute changes in Earth's characteristics. The satellite's design minimizes atmospheric drag and other disturbances, ensuring its longevity. LAGEOS-1 also carries two plaques designed by Dr. Carl Sagan, intended as a message to the future. LAGEOS-2, a similar satellite, was launched in 1992, and data from both have been utilized in tests of general relativity.

Citizen Scientists Aid Hubble in Discovering Over 1,000 Unknown Asteroids

Citizen Scientists Aid Hubble in Discovering Over 1,000 Unknown Asteroids

In 2019, a citizen science project called 'Hubble Asteroid Hunter' engaged 11,482 volunteers to help analyze 37,000 archival images from the Hubble Space Telescope. The primary goal was to identify asteroid trails that had inadvertently appeared in images originally taken for other astronomical purposes. This collaborative effort, which combined human pattern recognition with artificial intelligence, led to the discovery of 1,701 asteroid trails. Of these, 1,031 were identified as previously unknown objects. According to a 2024 study published in Astronomy & Astrophysics by astronomer Pablo García Martín and his team, this initiative demonstrated the significant impact that citizen science can have on astronomical research. While the project successfully identified numerous new asteroids, the study noted that calculating their full orbits would be challenging due to the age of the images and the inability to re-observe these specific trails.

Hubble Space Telescope Discovers Giant 10-Sided Atmospheric Wave Around Saturn's South Pole

Hubble Space Telescope Discovers Giant 10-Sided Atmospheric Wave Around Saturn's South Pole

NASA's Hubble Space Telescope has identified a giant, evolving 10-sided atmospheric wave encircling Saturn's South Pole. This discovery, termed a 'decagon,' marks the first observation of a large, regular-sided jet pattern in Saturn's Southern Hemisphere. Scientists note its similarity to the well-known hexagon in Saturn's Northern Hemisphere but believe it represents a new atmospheric phenomenon. The wave is situated within one of Saturn's powerful jet streams and extends through multiple atmospheric layers, indicating it is a vertically extended structure rather than merely a cloud-level feature. Researchers pieced together Hubble images dating back to 2023, observing subtle signs of the structure's emergence before it became a distinct pattern. These observations were part of Hubble’s Outer Planet Atmospheres Legacy (OPAL) program, which annually photographs the outer planets. The findings were published in the Journal Science Advances.

Intermediate-Mass Black Holes Can Trigger Lopsided Supernovae by Shredding White Dwarfs

Intermediate-Mass Black Holes Can Trigger Lopsided Supernovae by Shredding White Dwarfs

New simulations reveal that intermediate-mass black holes (IMBHs), which weigh between 100 and 100,000 times the mass of the Sun, can cause a unique type of supernova by tidally disrupting white dwarfs. These IMBHs are difficult to detect directly but are thought to reside in the dense cores of some star clusters. When a white dwarf, a dense stellar remnant, strays too close to an IMBH, it can be torn apart. This disruption can lead to a thermonuclear supernova, an explosion that resembles those from double-white-dwarf mergers but exhibits a strong dependence on the viewing angle for its brightness and spectra. The study, led by CITA Postdoctoral Fellow Pavan Vynatheya, used high-resolution hydrodynamic simulations and radiative-transfer modeling to predict how these events would appear from Earth.

Mercury's Shrinkage Exceeds Previous Estimates, New Research Reveals

Mercury's Shrinkage Exceeds Previous Estimates, New Research Reveals

New research indicates that the planet Mercury has shrunk significantly more than previously understood. Scientists have long known that Mercury is contracting due to the cooling of its interior, which causes its rocky outer layers to crumple and crack, forming distinctive wrinkles on its surface. However, a study published on September 10 in the journal Geophysical Research Letters suggests that Mercury may have shrunk by up to 30% more than earlier estimates. This means the planet could have lost as much as 14.5 miles of its diameter since its formation, a considerable increase from the previously estimated range of 2.5 to 10 miles. The discrepancy is attributed to debris and depressions from asteroid and comet impacts, which have obscured the full extent of these shrinkage-related wrinkles. Researchers combined existing geological maps with newer maps that account for Mercury's roughened surface to arrive at these revised figures.

Andromeda Galaxy's Earth-like Planets Remain Undetectable by Current Telescopes

Andromeda Galaxy's Earth-like Planets Remain Undetectable by Current Telescopes

The Andromeda galaxy, visible to the naked eye from Earth as a faint blur, contains hundreds of billions of stars, yet an Earth-like planet orbiting one of them remains far beyond the detection capabilities of any existing telescope. While the collective light from Andromeda's vast stellar population allows it to be seen from 2.5 million light-years away, isolating a single Earth-Sun analogue within it presents immense observational challenges. According to Space Daily, such a planet would be approximately ten billion times fainter than its host star in visible reflected light. Furthermore, the apparent separation between the planet and its star, even at the widest point of its orbit, would be only about 1.3 microarcseconds. This combination of extreme contrast and minuscule angular separation makes direct imaging impossible with current technology. NASA's Hubble Space Telescope has resolved an estimated 200 million stars in Andromeda, but these are only a fraction of the galaxy's total, and individual Sun...

Astronomers Reconstruct Continuous Video of Black Hole Jet, Revealing Plasma Motion

Astronomers Reconstruct Continuous Video of Black Hole Jet, Revealing Plasma Motion

Astronomers have successfully reconstructed a continuous, high-resolution video of a relativistic outflow from a black hole, providing unprecedented detail into plasma motion within its jet. This achievement was made possible by compiling 116 Very Long Baseline Array (VLBA) observations collected over 27 years. Researchers developed a new imaging framework called 'kine,' which uses neural fields to reconstruct continuous radio videos from sparse interferometric data. This technique allows for the measurement of the continuous physical flow of plasma, moving beyond previous methods that only tracked isolated emission features. The study, published in Nature, applied this method to the blazar 3C 345, reconstructing all observational epochs simultaneously and recovering fine-scale kinematics across both space and time. This advancement offers a more comprehensive understanding of how magnetized flows transport energy, which is crucial for broader astrophysics.

Astronomers Discover Massive Exomoon Candidate Orbiting Brown Dwarf CD-35 2772 B

Astronomers Discover Massive Exomoon Candidate Orbiting Brown Dwarf CD-35 2772 B

Astronomers have identified a new dwarf planet candidate, roughly Jupiter-sized, orbiting the brown dwarf CD-35 2772 B, located approximately 71 light-years from Earth. This discovery, made using the European Southern Observatory's Very Large Telescope in Chile, could represent the first confirmed exomoon beyond our solar system. The host object, CD-35 2772 B, is a brown dwarf, which is larger than a planet but lacks the mass to sustain nuclear fusion like a star, possessing about 33 times Jupiter's mass. The team, led by Kevin Hoy, detected the candidate through the gravitational wobble it induces on the brown dwarf, rather than direct observation, due to the faintness of the system. This unusual system challenges traditional definitions of moons and planets, as the 'moon' is comparable in size to Jupiter, while its host is significantly more massive than any planet in our solar system.

NASA's International Cometary Explorer Achieves Historic First Comet Flyby in 1985

NASA's International Cometary Explorer Achieves Historic First Comet Flyby in 1985

On September 11, 1985, the International Cometary Explorer (ICE) made history by becoming the first spacecraft to fly by a comet. Originally launched in 1978 as the International Sun-Earth Explorer-3 (ISEE-3), the probe was part of a joint effort by NASA, the European Space Research Organization, and the European Space Agency to study space weather. After completing its primary mission of observing the Sun-Earth environment from the L1 Lagrange point, NASA scientists repurposed the spacecraft. Through a series of maneuvers, including five lunar flybys, ICE was redirected to intercept Comet Giacobini-Zinner, flying directly through its plasma tail. Six months later, it also conducted a long-distance flyby of Halley's Comet. This mission confirmed theories about comets, such as their composition as 'dirty snowballs,' and collected detailed data on their tails.

The Summer Triangle Remains Prominent in Autumn Sky, Posing Seasonal Mystery

The Summer Triangle Remains Prominent in Autumn Sky, Posing Seasonal Mystery

Even in clear September evenings and as late as mid-November, the Summer Triangle—composed of the brilliant stars Vega, Altair, and Deneb—remains a prominent feature in the overhead darkness. This celestial landmark's persistent visibility well into autumn raises a question about its name: why is it still called the Summer Triangle? The answer lies not in the calendar but in its movement across the sky. During summer, the Triangle is visible from dusk until dawn, appearing in the east-northeast at nightfall, overhead at midnight, and descending in the west-northwest by daybreak. In autumn, however, it begins to drop beyond the west-northwest horizon by dawn, making it not visible all night. The stars themselves vary greatly in distance and true luminosity: Altair is 16.7 light-years away, Vega is 25 light-years, and Deneb is vastly farther at approximately 1,600 light-years, yet it shines brightly due to being a blue supergiant.