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09/03/2022

ASTRONOMY - A Flower-shaped rock on Mars

 2022 March 9

The featured image shows a penny-sized rock on Mars
discovered by the Curiosity Rover in late February 2022.
The rock is unusual because it has several appendages that
make it appear a bit like a flower. 
Please see the explanation for more detailed information.

A Flower-Shaped Rock on Mars
Image Credit: NASAJPL-CaltechMSSS

Explanation: It is one of the more unusual rocks yet found on Mars. Smaller than a penny, the rock has several appendages that make it look, to some, like a flower. Although it would be a major discovery if the rock was truly a fossilized ancient Martian flower, there are less spectacular -- and currently preferred -- explanations for its unusual structure. One theory that has emerged is that the rock is a type of concretion created by minerals deposited by water in cracks or divisions in existing rock. These concretions can be compacted together, can be harder and denser than surrounding rock, and can remain even after the surrounding rock erodes away. The flower structure may also be caused by crystal clusters. The small rock, named Blackthorn Salt, has similarities to previously imaged Martian pebbles. The featured image was taken by the Curiosity rover on Mars in late February. Scientists will continue to study data and images taken of this -- and similar -- surprising Martian rocks.

08/03/2022

ASTRONOMY - Moon in Inverted Colors

 2022 March 8

The featured image shows Moon in inverted colors,
with the dark parts appearing bright, and the bright
parts appearing dark. More surface detail is visible.
Please see the explanation for more detailed information.

Moon in Inverted Colors
Image Credit & Copyright: Dawid Glawdzin

Explanation: Which moon is this? It's Earth's moon -- but in inverted colors. Here, the pixel values corresponding to light and dark areas have been translated in reverse, or inverted, producing a false-color representation reminiscent of a black and white photographic negative. However, this is an inverted color image -- where the muted colors of the moon are real but digitally exaggerated before inversion. Normally bright rays from the large crater Tycho dominate the southern (bottom) features as easily followed dark green lines emanating from the 85-kilometer diameter impact site. Normally dark lunar mare appear light and silvery. The image was acquired in Southend-on-SeaEnglandUK. Historically, astronomical images recorded on photographic plates were directly examined on inverted-color negatives because it helped the eye pick out faint details.

07/03/2022

ASTRONOMY - A lion in Orion

 2022 March 7

The featured image shows the the part of the 
constellation of Orion where the Horsehead and Flame
Nebulas reside. The gaseous wisps above the Horsehead
can appear, in this deep exposure, to be a lion's head.
Please see the explanation for more detailed information.

A Lion in Orion
Image Credit & Copyright: Maroun Mahfoud

Explanation: Yes, but can you see the lion? A deep exposure shows the famous dark indentation that looks like a horse's head, visible just left and below center, and known unsurprisingly as the Horsehead Nebula. The Horsehead Nebula (Barnard 33) is part of a vast complex of dark absorbing dust and bright glowing gas. To bring out details of the Horsehead's pasture, an astrophotographer artistically combined light accumulated for over 20 hours in hydrogen (orange), oxygen (blue), and sulfur (green). The resulting spectacular picture captured from RaachineLebanon, details an intricate tapestry of gaseous wisps and dust-laden filaments that were created and sculpted over eons by stellar winds and ancient supernovas. The featured composition brings up another pareidolic animal icon -- that of a lion's head -- in the expansive orange colored gas above the horse's head. The Flame Nebula is visible just to the left of the Horsehead. The Horsehead Nebula lies 1,500 light years distant towards the constellation of Orion.

06/03/2022

ASTRONOMY - Venus and the Triply Ultraviolet Sun

 022 March 6

An image of the Sun in three bands of ultraviolet light
showing the transit circle of Venus, a deep coronal hole, and
Please see the explanation for more detailed information.

Venus and the Triply Ultraviolet Sun
Image Credit: NASA/SDO & the AIA, EVE, and HMI teams; Digital Composition: Peter L. Dove

Explanation: This was a very unusual type of solar eclipse. Typically, it is the Earth's Moon that eclipses the Sun. In 2012, though, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun. Eventually the alignment became perfect and the phase of Venus dropped to zero. The dark spot of Venus crossed our parent star. The situation could technically be labeled a Venusian annular eclipse with an extraordinarily large ring of firePictured here during the occultation, the Sun was imaged in three colors of ultraviolet light by the Earth-orbiting Solar Dynamics Observatory, with the dark region toward the right corresponding to a coronal hole. Hours later, as Venus continued in its orbit, a slight crescent phase appeared again. The next Venusian transit across the Sun will occur in 2117.

04/03/2022

ASTRONOMY - The Multiwavelength crab

 2022 March 4

See Explanation.  Clicking on the picture will download
the highest resolution version available.

The Multiwavelength Crab
NASAESAG. Dubner (IAFE, CONICET-University of Buenos Aires) et al.;
A. Loll et al.; T. Temim et al.; F. Seward et al.; VLA/NRAO/AUI/NSF; Chandra/CXC;
Spitzer/JPL-Caltech; XMM-Newton/ESA; Hubble/STScI

Explanation: The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from massive star's death explosion, witnessed on planet Earth in 1054 AD. This brave new image offers a 21st century view of the Crab Nebula by presenting image data from across the electromagnetic spectrum as wavelengths of visible light. From space, Chandra (X-ray) XMM-Newton (ultraviolet), Hubble (visible), and Spitzer (infrared), data are in purple, blue, green, and yellow hues. From the ground, Very Large Array radio wavelength data is shown in red. One of the most exotic objects known to modern astronomers, the Crab Pulsar, a neutron star spinning 30 times a second, is the bright spot near picture center. Like a cosmic dynamo, this collapsed remnant of the stellar core powers the Crab's emission across the electromagnetic spectrum. Spanning about 12 light-years, the Crab Nebula is 6,500 light-years away in the constellation Taurus.

Microphotography - Mareck Mis - Air bubbles

 

Air bubbles formed from melted ascorbic acid (vitamin C) crystals
FuturaSciences

03/03/2022

ASTRONOMY - Spiral Galaxy NGC 2841

 2022 March 3

See Explanation.  Clicking on the picture will download
the highest resolution version available.

Spiral Galaxy NGC 2841
Image Credit & CopyrightVitali Pelenjow

Explanation: A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa MajorThis deep view of the gorgeous island universe was captured during 32 clear nights in November, December 2021 and January 2022. It shows off a striking yellow nucleus, galactic disk, and faint outer regions. Dust lanes, small star-forming regions, and young star clusters are embedded in the patchy, tightly wound spiral arms. In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way. X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.

02/03/2022

AERONAUTIQUE - Avions de légende - Le Canadair CL-415

 

Bombardier d'eau à la capacité impressionante, le Canadair CL-415 est un avion fabriqué par la firme canadienne Bombardier Aéronautique. Spécialisé dans la lutte contre les incendies, il est utilisé par de nombreux pays, dont la France où il est affublé du surnom de « Pélican ». Cet avion réputé pour sa fiabilité possède deux réservoirs qui peuvent emmagasiner un peu plus de 6.000 litres d’eau.

© Claudio, CC by-nc 2.0
FuturaSciences

ASTRONOMY - Record Prominence Imaged by Solar Orbiter

 2022 March 2

The featured image shows the Sun undergoing a large 
eruption in mid-Feburary where a large prominence is
visible.
Please see the explanation for more detailed information.

Record Prominence Imaged by Solar Orbiter
Image Credit: Solar OrbiterEUI TeamESA & NASAh/tBum-Suk Yeom

Explanation: What's happened to our Sun? Last month, it produced the largest prominence ever imaged together with a complete solar disk. The record image, featured, was captured in ultraviolet light by the Sun-orbiting Solar Orbiter spacecraft. A quiescent solar prominence is a cloud of hot gas held above the Sun's surface by the Sun's magnetic field. This solar prominence was huge -- spanning a length rivaling the diameter of the Sun itself. Solar prominences may erupt unpredictably and expel hot gas into the Solar System via a Coronal Mass Ejection (CME). When a CME strikes the Earth and its magnetosphere, bright auroras may occur. This prominence did produce a CME, but it was directed well away from the Earth. Although surely related to the Sun's changing magnetic field, the energy mechanism that creates and sustains a solar prominence remains a topic of research.

01/03/2022

ASTRONOMY - Dueling Bands in the Night

 2022 March 1

The featured image shows a nightscape over China
featuring bands of zodiacal light, on the left, and the central
band of our Milky Way Galaxy, on the right.
Please see the explanation for more detailed information.

Dueling Bands in the Night
Image Credit & Copyright: Jeff Dai (TWAN)

Explanation: What are these two bands in the sky? The more commonly seen band is the one on the right and is the central band of our Milky Way galaxy. Our Sun orbits in the disk of this spiral galaxy, so that from inside, this disk appears as a band of comparable brightness all the way around the sky. The Milky Way band can also be seen all year -- if out away from city lights. The less commonly seem band, on the left, is zodiacal light -- sunlight reflected from dust orbiting the Sun in our Solar System. Zodiacal light is brightest near the Sun and so is best seen just before sunrise or just after sunset. On some evenings in the north, particularly during the months of March and April, this ribbon of zodiacal light can appear quite prominent after sunset. It was determined only this century that zodiacal dust was mostly expelled by comets that have passed near Jupiter. Only on certain times of the year will the two bands be seen side by side, in parts of the sky, like this. The featured image, including the Andromeda galaxy and a meteor, was captured in late January over a frozen lake in KandingSichuanChina.

ASTRONOMIE - LES PLUS BEAUX ASTRES DE LA VOIE LACTéE - Antiope : l’astéroïde double

Découvert en 1866, (90) Antiope est un astéroïde qui possède la caractéristique d'être binaire . Cela signifie qu'il est constitué ...