Astro Blog

By DANIEL CLERY , Science.  Excerpt: Astronomers suspect an unusual near-Earth rocky object is not a typical escapee from the Solar System’s asteroid belt, but is instead a chunk of the Moon blasted into space eons ago by a spectacular impact. Now, a team of researchers has modeled what sort of lunar impact could have ejected such a gobbet of Moon and deposit it in a stable, nearby orbit. Surprisingly, only one strong candidate emerged: the asteroid strike that created the famous Giordano Bruno crater, the youngest large crater on the Moon, the  group reports today  in Nature Astronomy. ...The odd asteroid, known as 469219 Kamo‘oalewa, was discovered in 2016 ...measures between 40 and 100 meters across and rotates particularly fast—once every 28 minutes. It follows an elliptical orbit around the Sun that moves in sync with Earth, giving the impression that the asteroid orbits Earth, even though it is outside the planet’s gravitational influence. The asteroid’s curious orbit and small s

By PAUL VOOSEN , Science.  Excerpt: In its youth, the Solar System underwent a momentous upheaval: Gravitational tugs between the giant planets threw them off track, causing Jupiter’s orbit to jump closer to the Sun, while Saturn, Uranus, and Neptune were flung outward. The gravity of the rampaging giants scattered Pluto and other icy bodies to the Kuiper belt, shepherded the asteroid belt into its current location, and sent countless bodies crashing into the inner Solar System. For many years, researchers believed this “giant planet instability” occurred 600 million years after the Solar System’s birth 4.57 billion years ago, based on the ages of impact craters mapped on the Moon. Recently, evidence has mounted that it  occurred much earlier . And now, some researchers are homing in on a more precise date, just 60 million years after the Solar System’s formation, based on an analysis of rare meteorites derived from an ancient asteroid family, published today in Science. Other recent w

https://eos.org/articles/tatooine-trisolaris-thessia-sci-fi-exoplanets-reflect-real-life-discoveries By Kimberly M. S. Cartier , Eos/AGU.  Excerpt: Astronomers have discovered more than 5,000 extrasolar planets since the 1995 discovery of 51 Pegasi b. When the discoveries  started pouring in , astronomers quickly realized that few exoplanets resembled  anything in the solar system . ...A new study led by Puranen examined how the discovery of real exoplanets has influenced portrayals of fictional ones. The researchers showed that as scientists discovered that real-life exoplanets rarely resembled Earth, sci-fi exoplanets became less Earth-like, too. ...The analysis showed that “fictional exoplanets from after the real-life discovery of exoplanets were less likely to have intelligent native life and less likely to have established populations of non-native humans,” Puranen said. Sci-fi exoplanets became less Earth-like and more likely to feature nonintelligent native biospheres. These re

https://www.science.org/content/article/black-hole-center-milky-way-may-be-blasting-out-jet   By DANIEL CLERY , Science.  Excerpt: The supermassive black holes at the centers of many galaxies generate powerful jets, blasting particles thousands of light-years into space. This new image of the Milky Way’s black hole, known as Sagittarius A* (Sgr A*), suggests it may have one, too, but perhaps of a more modest nature. The image—taken with polarized light—was  released today by the Event Horizon Telescope (EHT) , a worldwide array of radio telescopes that in 2019 produced the  first ever image of a black hole . The new image shows light that is oriented in a particular direction, revealing magnetic field lines around the black hole. Although jets would not be visible in such a zoomed-in image, strong magnetic fields are thought to be essential in launching them.... See also European Southern Observatory press release . 

https://www.science.org/content/article/number-known-moonquakes-tripled-discovery-apollo-archive By  PAUL VOOSEN , Science Excerpt:  THE WOODLANDS, TEXAS— The Moon suddenly seems more alive. From 1969 to 1977, seismometers left on the lunar surface by the Apollo astronauts detected thousands of distinctive “moonquakes.” Now, half a century later, a new analysis has cut through the noise in the old data and nearly tripled the number of moonquakes, adding more than 22,000 new quakes to 13,000 previously identified ones.  The finding,  presented  last week here at the Lunar and Planetary Science Conference, shows “that the Moon may be more seismically and tectonically active today than we had thought,” says Jeffrey Andrews-Hanna, a geophysicist at the University of Arizona unaffiliated with the work, which is  in review  at the  Journal of Geophysical Research . “It is incredible that after 50 years we are still finding new surprises in the data.”

https://www.nytimes.com/2024/03/04/science/moon-landing-sideways-gravity.html By Kenneth Chang , The New York Times.  Excerpt: When the robotic lander  Odysseus last month became the first American-built spacecraft to touch down on the moon  in more than 50 years, it toppled over at an angle. ...Just a month earlier, another spacecraft, the Smart Lander for Investigating Moon, or SLIM, sent by the Japanese space agency, had also tipped during landing,  ending up on its head . ...people pointed to the height of the Odysseus lander — 14 feet from the bottom of the landing feet to the solar arrays at the top — as a contributing factor for its off-kilter touchdown. ...Philip Metzger, a former NASA engineer who is now a planetary scientist at the University of Central Florida, explained  the math and the physics  of why it is more difficult to remain standing on the moon. ...“The side motion that can tip a lander of that size is only a few meters per second in lunar gravity.” ...Odysseus wa

https://www.science.org/content/article/stellar-remains-famed-1987-supernova-found-last By DANIEL CLERY , Science.  Excerpt: When a nearby star exploded in 1987, it created the first supernova visible to the naked eye in 4 centuries and became one of the most intensely studied objects in space. Now, after more than 35 years of searching, researchers have finally discovered the cinder left behind. Using NASA’s new giant space telescope JWST, astronomers spotted  glowing gas at the center of the blast that can only have been energized by something hot and compact inside it , they report this week in Science. They believe a neutron star, all that remains of the shattered star, is responsible.... 

https://www.science.org/content/article/seeking-clear-skies-and-quiet-astronomers-put-telescopes-u-s-moon-lander By DANIEL CLERY , Science. Excerpt: Small scopes on IM-1 mission would be first optical and radio observatories on the lunar surface. ...Astronomers have long eyed the Moon as  a good spot to do their work . Its far side, protected from Earth’s hectic radio noise, is perfect for picking up faint signals from the distant universe. To see infrared signals ... Put the telescope into one of the deep craters at the lunar poles that never receive any sunlight and its sensors will benefit from the crater’s permanent chill....

https://www.smithsonianmag.com/smart-news/what-does-solar-eclipse-mars-look-like-new-breathtaking-images-caught-nasa-perseverance-rover-idea-180983795/ By Carlyn Kranking , Smithsonian Magazine.  Excerpt: The robot recently observed each of the Red Planet’s moons passing across the sun in the Martian sky [see photo in this article]. 

https://www.science.org/content/article/planets-around-dead-stars-offer-glimpse-solar-system-s-future-after-sun-swallows-us By JONATHAN O’CALLAGHAN , Science.  Excerpt: In about 5 billion years the Sun will balloon up into a red giant, consuming Mercury, probably Venus, and maybe even Earth. But even if the outer planets avoid being swallowed up, they might eventually get pulled in or ejected from the Solar System. A new discovery suggests they can survive intact. Using NASA’s JWST space telescope, astronomers have for the first time directly imaged planets on Solar System–like orbits around white dwarfs, the dead stars left after Sun-like stars swell into red giants and subside. The planets follow orbits resembling those of the giant planets in the outer Solar System—big enough for them to have escaped the inferno.... For GSS A Changing Cosmos chapter 1.

https://skyandtelescope.org/astronomy-news/japans-sniper-mission-pinpoints-landing-on-the-moon/ By DAVID DICKINSON , Sky & Telescope.  Excerpt: Today, the Japanese Aerospace Exploration Agency (JAXA  Smart Lander for Investigating the Moon (SLIM)  spacecraft pitched over in its lunar orbit, and began its long descent to the Moon's surface. Touchdown occurred at 10:20 a.m. EST / 15:20 UT; NASA’s  Deep Space Network  in Madrid picked up the lander's signal shortly afterward, but problems have ensued. ...SLIM was designed to test the innovative “smart eyes” landing technology, which involves image-matching to aid navigation. The mission was also designed to demonstrate a pinpoint landing, that is, within 100 meters of the target, on a 6- to 8-degree slope. SLIM has a Multi-Band Camera camera on board and, if it is able to, it will deploy two baseball-size rovers on the lunar surface named Lunar Exploration Vehicle 1 and 2. These will hop and roll along the lunar surface, imagi

https://engineering.berkeley.edu/news/2024/01/small-solar-sails-could-be-the-next-giant-leap-for-interplanetary-space-exploration By Marni Ellery, Berkeley Engineering.  Interview excerpt: ...a team of Berkeley researchers [...proposed] to build a fleet of low-cost, autonomous spacecraft, each weighing only 10 grams and propelled by nothing more than the pressure of solar radiation. These miniaturized solar sails could potentially visit thousands of near-Earth asteroids and comets, capturing high-resolution images and collecting samples. ...They describe their work, the Berkeley Low-cost Interplanetary Solar Sail (BLISS) project, in a  study published  in the journal Acta Astronautica. The BLISS project brings together researchers from the Department of Electrical Engineering and Computer Sciences and the Department of Mechanical Engineering, as well as the  Berkeley Sensor and Actuator Center  and the  Space Sciences Laboratory . Their work builds on other small spacecraft projects, i

https://eos.org/research-spotlights/scientists-investigate-how-heat-rises-through-europas-ocean By Rebecca Owen , Eos/AGU.  Excerpt: Europa, one of Jupiter’s many moons, may be capable of supporting life because its icy surface likely obscures a deep, salty ocean.  Europa’s ocean  is also in direct contact with its mantle rocks, and interactions between rock, water, and ice could provide energy to sustain life. Lemasquerier et al.  examined the way heating from Europa’s mantle could drive ocean circulation under the icy crust. The researchers modeled Europa’s ocean to further understand how heating patterns from deep inside the moon may affect the thickness of its icy surface. ...Mantle heat ...comes in two forms. Radiogenic heating is caused by the decay of radioactive materials in the mantle, and  tidal heating  is caused by the deformation Europa undergoes as it orbits Jupiter and experiences its strong gravitational pull. Tidal heating is uneven; it’s higher at Europa’s poles and l

https://eos.org/articles/mapping-the-moon-to-shield-astronauts-from-radiation By Sierra Bouchér , Eos/AGU.  Excerpt: In October 1989, the Sun spit a blast of high-energy particles into the solar system. Earth’s protective magnetic field kept us safe, but the Moon received an intense dose: More than 8 times the radiation received by plant workers during the Chernobyl nuclear disaster scorched the barren lunar surface. As NASA’s Artemis III mission prepares to return explorers to the Moon in 2025, scientists are working to protect them from this kind of unpredictable outburst from the Sun and other radiation from deep space. To do this, they’re turning to the Moon’s natural barriers. By mapping the topography of the lunar surface, researchers have calculated the shielding potential of each mountain range, crater wall, and shadowed slope near the south pole—Artemis III’s target. Their work will guide decisionmaking for the landing location of this mission and beyond....