ASTRONOMY - Found on the Moon: Candidate for Oldest Known Earth Rock

 2021 February 3

Found on the Moon: Candidate for Oldest Known Earth Rock
Video Credit: NASA, Astromaterials 3D, Erika Blumenfeld et al.

Explanation: Was the oldest known rock on Earth found on the Moon? Quite possibly. The story opens with the Apollo 14 lunar mission. Lunar sample 14321, a large rock found in Cone crater by astronaut Alan Shepard, when analyzed back on Earth, was found to have a fragment that was a much better match to Earth rocks than other Moon rocks. Even more surprising, that rock section has recently been dated back 4 billion years, making it older, to within measurement uncertainty, than any rock ever found on Earth. A leading hypothesis now holds that an ancient comet or asteroid impact launched Earth rocks into the Solar System, some of which fell back to the Moon, became mixed with heated lunar soil and other rocks, cooled, and re-fragmented. The video features an internal X-ray scan of 14321 showing multiple sections with markedly different chemistries. Moon rocks will continue to be studied to learn a more complete history of the Moon, the Earth, and the early Solar System. Friday marks the 50th Anniversary of the Apollo 14 landing on the Moon.

ASTRONOMY - A Colorful Quadrantid Meteor

 2021 February 2

A Colorful Quadrantid Meteor
Image Credit & Copyright: Frank Kuszaj

Explanation: Meteors can be colorful. While the human eye usually cannot discern many colors, cameras often can. Pictured is a Quadrantids meteor captured by camera over Missouri, USA, early this month that was not only impressively bright, but colorful. The radiant grit, likely cast off by asteroid 2003 EH1, blazed a path across Earth's atmosphere. Colors in meteors usually originate from ionized elements released as the meteor disintegrates, with blue-green typically originating from magnesium, calcium radiating violet, and nickel glowing green. Red, however, typically originates from energized nitrogen and oxygen in the Earth's atmosphere. This bright meteoric fireball was gone in a flash -- less than a second -- but it left a wind-blown ionization trail that remained visible for several minutes.

ASTRONOMY - Lunar Halo over Snowy Trees

 2021 February 1

Lunar Halo over Snowy Trees
Image Credit & Copyright: Göran Strand

Explanation: Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, which corresponds to the radius of the Moon Halo. A similar Sun Halo may be visible during the day. Exactly how ice-crystals form in clouds remains a topic of research. In the featured image taken last week from Östersund, Sweden, a complete lunar halo was captured over snowy trees and rabbit tracks.

PRACTICAL - Way to open a lock with matches

 

ASTRONOMIA - Lua colorida

Na noite de 23 para 24 de janeiro, o fotógrafo italiano Alberto Ghizzi Panizza tirou centenas de fotografias à Lua em Parma, norte de Itália. O resultado é esta foto colorida de um halo lunar.

Um halo lunar é um fenómeno ótico provocado pela refração da luz - quando a luz emitida pela Lua atravessa os vários e minúsculos cristais de gelo em suspensão na atmosfera, explica o IPMA.

Sic Noticias - Portugal

ASTRONOMY - The Vertical Magnetic Field of NGC 5775

 2021 January 27

The Vertical Magnetic Field of NGC 5775
Image Credit: NRAO, NASA, ESA, Hubble; Processing & Text: Jayanne English (U. Manitoba)

Explanation: How far do magnetic fields extend up and out of spiral galaxies? For decades astronomers knew only that some spiral galaxies had magnetic fields. However, after NRAO's Very Large Array (VLA) radio telescope (popularized in the movie Contact) was upgraded in 2011, it was unexpectedly discovered that these fields could extend vertically away from the disk by several thousand light-years. The featured image of edge-on spiral galaxy NGC 5775, observed in the CHANG-ES (Continuum Halos in Nearby Galaxies) survey, also reveals spurs of magnetic field lines that may be common in spirals. Analogous to iron filings around a bar magnet, radiation from electrons trace galactic magnetic field lines by spiraling around these lines at almost the speed of light. The filaments in this image are constructed from those tracks in VLA data. The visible light image, constructed from Hubble Space Telescope data, shows pink gaseous regions where stars are born. It seems that winds from these regions help form the magnificently extended galactic magnetic fields.

ASTRONOMY - Central NGC 1316: After Galaxies Collide

 2021 January 26

Central NGC 1316: After Galaxies Collide
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Daniel Nobre

Explanation: How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. Inspection indicates that NGC 1316 is an enormous elliptical galaxy that somehow includes dark dust lanes usually found in a spiral galaxy. Detailed images taken by the Hubble Space Telescope shows details, however, that help in reconstructing the history of this gigantic tangle. Deep and wide images show huge collisional shells, while deep central images reveal fewer globular clusters of stars toward NGC 1316's interior. Such effects are expected in galaxies that have undergone collisions or merging with other galaxies in the past few billion years. The dark knots and lanes of dust, prominent in the featured image, indicate that one or more of the devoured galaxies were spiral galaxies. NGC 1316 spans about 50,000 light years and lies about 60 million light years away toward the constellation of the Furnace (Fornax).

ASTRONOMY - The Milky Ring

 2021 January 23

The Milky Ring
Image Credit & Copyright: Alvin Wu

Explanation: An expanse of cosmic dust, stars and nebulae along the plane of our Milky Way galaxy form a beautiful ring in this projected all-sky view. The creative panorama covers the entire galaxy visible from planet Earth, an ambitious 360 degree mosaic that took two years to complete. Northern hemisphere sites in western China and southern hemisphere sites in New Zealand were used to collect the image data. Like a glowing jewel set in the milky ring, the bulge of the galactic center, is at the very top. Bright planet Jupiter is the beacon just above the central bulge and left of red giant star Antares. Along the plane and almost 180 degrees from the galactic center, at the bottom of the ring is the area around Orion, denizen of the northern hemisphere's evening winter skies. In this projection the ring of the Milky Way encompasses two notable galaxies in southern skies, the large and small Magellanic clouds.

AERONAUTIQUE - L’avion avec cabine éjectable

Et pas uniquement celle des pilotes évidemment (allez salut, c’est trop la merde, nous on se casse). En cas de risque de crash, la partie accueillant les passagers se désolidariserait du reste de l’appareil, pour venir atterrir tranquillement sur le plancher des vaches grâce à d’immenses parachutes. Une idée lumineuse qui rassurerait un paquet de flippés en avion. Toutefois, le projet en est encore au stade de concept et il va malheureusement encore falloir serrer les fesses pendant un bon bout de temps.

ASTRONOMY - The Mountains of NGC 2174

 2021 January 16

The Mountains of NGC 2174
Image Credit: NASA, ESA, Hubble Heritage Team (STScI/AURA)

Explanation: This fantastic skyscape lies near the edge of NGC 2174 a star forming region about 6,400 light-years away in the nebula-rich constellation of Orion. It follows mountainous clouds of gas and dust carved by winds and radiation from the region's newborn stars, now found scattered in open star clusters embedded around the center of NGC 2174, off the top of the frame. Though star formation continues within these dusty cosmic clouds they will likely be dispersed by the energetic newborn stars within a few million years. Recorded at infrared wavelengths by the Hubble Space Telescope in 2014, the interstellar scene spans about 6 light-years. Scheduled for launch in 2021, the James Webb Space Telescope is optimized for exploring the Universe at infrared wavelengths.