ASTRONOMY - Zodiacal Light and Mars

 2021 March 11

Zodiacal Light and Mars
Image Credit & Copyright: Joshua Rhoades

Explanation: Just after sunset on March 7, a faint band of light still reaches above the western horizon in this serene, rural Illinois, night skyscape. Taken from an old farmstead, the luminous glow is zodiacal light, prominent in the west after sunset during planet Earth's northern hemisphere spring. On that clear evening the band of zodiacal light seems to engulf bright yellowish Mars and the Pleiades star cluster. Their close conjunction is in the starry sky above the old barn's roof. Zodiacal light is sunlight scattered by interplanetary dust particles that lie near the Solar System's ecliptic plane. Of course all the Solar System's planets orbit near the plane of the ecliptic, within the band of zodiacal light. But zodiacal light and Mars may have a deeper connection. A recent analysis of serendipitous detections of interplanetary dust by the Juno spacecraft during its Earth to Jupiter voyage suggest Mars is the likely source of the dust that produces zodiacal light.

ASTRONOMY - NGC 1499: The California Nebula

 2021 March 10

NGC 1499: The California Nebula
Image Credit & Copyright: Yannick Akar

Explanation: Could Queen Calafia's mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way's Orion Arm, only about 1,000 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades.

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ASTRONOMY - Stereo Eros

 2021 Mars 09

Stereo Eros
Image Credit: NEAR Project, JHU APL, NASA

Explanation: Get out your red/blue glasses and float next to asteroid 433 Eros. Orbiting the Sun once every 1.8 years, the near-Earth asteroid is named for the Greek god of love. Still, its shape more closely resembles a lumpy potato than a heart. Eros is a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders and valleys. Its unsettling scale and unromantic shape are emphasized in this mosaic of images from the NEAR Shoemaker spacecraft processed to yield a stereo anaglyphic view. Along with dramatic chiaroscuro, NEAR Shoemaker's 3-D imaging provided important measurements of the asteroid's landforms and structures, and clues to the origin of this city-sized chunk of Solar System. The smallest features visible here are about 30 meters across. Beginning on February 14, 2000, historic NEAR Shoemaker spent a year in orbit around Eros, the first spacecraft to orbit an asteroid. Twenty years ago, on February 12 2001, it landed on Eros, the first ever landing on an asteroid's surface. NEAR Shoemaker's final transmission from the surface of Eros was on February 28, 2001.

ASTRONOMY - Three Tails of Comet NEOWISE

 2021 March 8

Three Tails of Comet NEOWISE
Image Credit & Copyright: Nicolas Lefaudeux

Explanation: What created the unusual red tail in Comet NEOWISE? Sodium. A spectacular sight back in the summer of 2020, Comet NEOWISE, at times, displayed something more than just a surprisingly striated white dust tail and a pleasingly patchy blue ion tail. Some color sensitive images showed an unusual red tail, and analysis showed much of this third tail's color was emitted by sodium. Gas rich in sodium atoms might have been liberated from Comet NEOWISE's warming nucleus in early July by bright sunlight, electrically charged by ultraviolet sunlight, and then pushed out by the solar wind. The featured image was captured in mid-July from Brittany, France and shows the real colors. Sodium comet tails have been seen before but are rare -- this one disappeared by late July. Comet C/2020 F3 (NEOWISE) has since faded, lost all of its bright tails, and now approaches the orbit of Jupiter as it heads back to the outer Solar System, to return only in about 7,000 years.

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PEINTURE SPACE ART - Tempête martienne

 

Tempête martienne 

Crédit : Luděk Pešek

ASTRONOMY - Pillars of the Eagle Nebula in Infrared

 2021 March 7

Pillars of the Eagle Nebula in Infrared
Image Credit: NASA, ESA, Hubble, HLA; Processing: Luis Romero

Explanation: Newborn stars are forming in the Eagle Nebula. Gravitationally contracting in pillars of dense gas and dust, the intense radiation of these newly-formed bright stars is causing surrounding material to boil away. This image, taken with the Hubble Space Telescope in near infrared light, allows the viewer to see through much of the thick dust that makes the pillars opaque in visible light. The giant structures are light years in length and dubbed informally the Pillars of Creation. Associated with the open star cluster M16, the Eagle Nebula lies about 6,500 light years away. The Eagle Nebula is an easy target for small telescopes in a nebula-rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake).

ASTRONOMY - A Little Like Mars

 2021 March 5

A Little Like Mars
Image Credit & Copyright: Robert Barsa

Explanation: The surface of this planet looks a little like Mars. It's really planet Earth though. In a digitally stitched little planet projection, the 360 degree mosaic was captured near San Pedro in the Chilean Atacama desert. Telescopes in domes on the horizon are taking advantage of the region's famously dark, clear nights. Taken in early December, a magnificent Milky Way arcs above the horizon for almost 180 degrees around the little planet with Orion prominent in the southern sky. A familiar constellation upside down for northern hemisphere skygazers, Orion shares that southern December night almost opposite the Large and Small Magellanic clouds. But the Red Planet itself is the brightest yellowish celestial beacon in this little planet sky.

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