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Astronomers Discover 'Mega-Earth' Exoplanet GJ 523b, Challenging Planet Formation Models

Astronomers Discover 'Mega-Earth' Exoplanet GJ 523b, Challenging Planet Formation Models

Astronomers have identified a new exoplanet, GJ 523b, which is 23.5 times the mass of Earth and 2.55 times its radius. Despite its significant mass, standard planet-formation models struggle to explain why it did not accumulate a substantial hydrogen-helium envelope. The planet is extraordinarily dense, with a bulk density of 7.8 grams per cubic centimeter, approximately 40 percent greater than Earth's, suggesting it is primarily composed of rock and metal with very little light gas. This discovery, detailed in a preprint submitted to The Astronomical Journal, indicates that GJ 523b possesses the dimensions of a sub-Neptune but the density of a much heavier, rocky world. The planet orbits a K dwarf star located about 87 light-years from Earth and is relatively young, estimated to be around 169 million years old. Its youth further deepens the mystery, as there has been insufficient time for a massive primordial atmosphere to dissipate through ordinary atmospheric escape. The discovery relied on data from NA...

Astronomers Discover Rocky 'Mega-Earth' Exoplanet GJ 523b, Challenging Planetary Formation Models

Astronomers Discover Rocky 'Mega-Earth' Exoplanet GJ 523b, Challenging Planetary Formation Models

Astronomers have identified a new exoplanet, GJ 523b, which is approximately 23.5 times the mass of Earth but only 2.55 times its radius. This high density suggests that GJ 523b is predominantly rocky with a relatively small amount of gas in its atmosphere, leading researchers to informally categorize it as a 'mega-Earth.' The planet orbits its star in 17.75 days, and its system is estimated to be nearly 170 million years old. The exoplanet candidate was initially detected by NASA’s TESS satellite, which observes periodic dips in stellar brightness caused by transiting planets. Subsequent observations using the ground-based 3.5-meter WIYN telescope at Kitt Peak Observatory in Arizona allowed scientists to measure the planet’s gravitational influence on its star. The parameters of GJ 523b, particularly its mass exceeding the threshold where gas giants typically accumulate massive gas envelopes, present a significant challenge to current planetary formation models.

NASA's mission to save Swift Observatory fails. Here's what went wrong

NASA's mission to save Swift Observatory fails. Here's what went wrong

NASA took a big risk when it mounted a rescue mission to boost its aging Swift Observatory further into orbit. Here's why it didn't succeed.

Hera Mission Flyby Data Informs New Study on Deimos's Formation

Hera Mission Flyby Data Informs New Study on Deimos's Formation

A new study, informed by flyby images from the European Space Agency’s (ESA) Hera asteroid mission, suggests that Mars’s outer moon Deimos was significantly reshaped by a single, violent asteroid impact. This impact is believed to be responsible for Deimos's unusually smooth and youthful appearance, attributed to a thick layer of dust, or regolith, that covered its surface after the collision. The study, published in Nature Astronomy, utilized high-resolution impact simulation software to recreate the event. Researchers, led by Sabina Raducan of the University of Bern, International Space Science Institute (ISSI), and VUB Brussels University, ran approximately one hundred simulations. Their findings indicate that a slanting, 45-degree impact from a relatively small 320-meter-wide asteroid, striking at high speed, excavated a broad depression at Deimos's south pole and dispersed a large amount of material across its surface. Much of this debris subsequently fell back, forming a global blanket of loose regol...

A SpaceX rocket slammed into the moon. NASA's new photos show aftermath

A SpaceX rocket slammed into the moon. NASA's new photos show aftermath

NASA's lunar orbiter returned photos from the crash site where a SpaceX Falcon 9 rocket had left a 60-foot crater on the surface of the moon.

Hubble and James Webb Telescopes Collaborate to Capture 'Black Eye Galaxy' Image

Hubble and James Webb Telescopes Collaborate to Capture 'Black Eye Galaxy' Image

The Hubble Space Telescope and the James Webb Space Telescope (JWST) have collaborated to produce a composite image of the 'Black Eye Galaxy,' also known as Messier 64. This spiral galaxy is situated 17 million light-years from Earth in the constellation Coma Berenices. The galaxy is notable for its unique internal motion, where the gas in its outer regions rotates in the opposite direction to the gas and stars closer to its core. To create this detailed image, astronomers combined observations from JWST, which captured near and mid-infrared wavelengths, with Hubble's data from ultraviolet, visible, and near-infrared wavelengths. This joint effort showcases the complementary capabilities of these powerful space observatories.

NASA Offers Free Downloadable Books for Space Enthusiasts

NASA Offers Free Downloadable Books for Space Enthusiasts

NASA is providing a collection of free downloadable books for individuals interested in space, science, and aeronautics. These resources are available directly from NASA and cover a wide range of topics, including aeronautics, the Hubble Space Telescope, various scientific missions, and NASA's history. The aeronautics section features titles such as 'NASA’s Contributions to Aeronautics' and a book on the X-15 aircraft, along with information on facilities like the giant wind tunnel at Langley. For Hubble enthusiasts, there are books with stunning images, an overview of the telescope, and a focus on gravitational lensing. The science category delves into subjects like black holes, the Landsat program, the Cassini mission, and the Spitzer telescope. Historical accounts include research on near-Earth objects and lessons from the Columbia tragedy. Notably, a book titled 'Archaeology, Anthropology, and Interstellar Communication' is also available. These books are typically offered in EPUB or PDF formats, makin...

NASA's Curiosity Rover Discovers Extensive Polygonal Terrain on Mars

NASA's Curiosity Rover Discovers Extensive Polygonal Terrain on Mars

NASA's Mars Curiosity rover has recently transmitted images revealing a vast landscape characterized by polygon-like features. This marks the first instance of the Curiosity rover observing such terrain, although similar polygonal patterns have been documented in other Martian regions. Scientists hypothesize that these features are ancient mud cracks, a theory supported by a 2023 study published in Nature. That study suggested these cracks formed during intense wet-dry cycles within Gale Crater, a period estimated to be between 3.8 and 3.6 billion years ago, known as the Noachian-Hesperian transition. Dr. Ashwin Vasavada, a Curiosity rover mission scientist at NASA’s Jet Propulsion Laboratory, expressed excitement about the discovery, stating that the team is meticulously analyzing the shapes and chemistry of these polygons for clues about their formation. While ground-level observations by Curiosity show polygons with diameters of approximately 4 to 8 centimeters, orbital observations by NASA’s High Resol...

On This Day: Voyager 2 Launched on Its Historic Journey in 1977

On This Day: Voyager 2 Launched on Its Historic Journey in 1977

Launched by NASA on August 20, 1977, Voyager 2 embarked on an ambitious journey that would redefine our understanding of the outer solar system. As...

NASA Shut Down a Voyager 2 Instrument to Preserve Its Remaining Power

NASA Shut Down a Voyager 2 Instrument to Preserve Its Remaining Power

After successfully visiting Jupiter, Saturn, Uranus, and Neptune, the spacecraft entered its extended mission, focusing on the vast, uncharted terr...

Mimas's Subsurface Ocean Discovered to be Younger Than the Himalayas, Challenging Ocean World Assumptions

Mimas's Subsurface Ocean Discovered to be Younger Than the Himalayas, Challenging Ocean World Assumptions

In 2024, an international team of scientists reported the discovery of a global ocean beneath the surface of Mimas, one of Saturn's moons. This finding was unexpected because Mimas's surface appears old, heavily cratered, and shows no obvious signs of geological activity, unlike other ocean worlds like Enceladus or Europa. The evidence for the ocean came from analyzing tiny details of Mimas's rotational wobble and the precession of its periapsis, using data from NASA's Cassini mission. These movements could only be reconciled by the presence of a liquid layer beneath 20 to 30 kilometers of ice. Crucially, the ocean is estimated to have formed less than 25 million years ago, making it younger than the Himalayas. This youth may explain why Mimas's ancient-looking exterior has not yet betrayed the significant changes occurring beneath its surface.

Hubble and Gaia Telescopes Uncover Ancient Galactic Collision That Transformed the Milky Way

Hubble and Gaia Telescopes Uncover Ancient Galactic Collision That Transformed the Milky Way

New data from the NASA/ESA Hubble Space Telescope, combined with measurements from ESA's Gaia mission, has provided definitive evidence of an ancient collision between the young Milky Way galaxy and a dwarf galaxy named LKH (Low-energy–Kraken–Heracles) approximately 11.8 billion years ago. This event, occurring just 2 billion years after the Big Bang, predates previously identified major mergers in the Milky Way's history, such as the collision with the Gaia–Sausage–Enceladus (GSE) galaxy 10 billion years ago. Researchers identified a third population of globular clusters within the Milky Way that are neither native to our galaxy nor from the GSE merger. By precisely measuring the age and metal content of these clusters, scientists determined they originated from LKH, a dwarf galaxy with a total mass of about 500 million times the mass of our sun, which was a significant fraction of the Milky Way's mass at that early stage.