A Berry Bowl of Martian Spherules

Thousands of unusual gray spherules made of iron and rock and dubbed blueberries were found embedded in and surrounding rocks near the landing site of the robot Opportunity rover on Mars in 2004. To help investigate their origin, Opportunity found a surface dubbed the Berry Bowl with an indentation that was rich in the Martian orbs. The Berry Bowl is pictured here, imaged during rover's 48th Martian day. The average size of a Martian blueberry rock is only about 4 millimeters across. By analyzing a circular patch in the rock surface to the left of the densest patch of spherules, Opportunity obtained data showing that the underlying rock has a much different composition than the hematite rich blueberries. This information contributes to the growing consensus that these small, strange, gray orbs were slowly deposited from a bath of dirty water.

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Two Worlds, Two Analemmas

On the left, Earth's figure-8 analemma was traced by combining wide-angle digital images recorded during the year from December 2011 through December 2012. But the shape of an analemma depends on the eccentricity of a planet's orbit and the tilt of its axis of rotation, so analemma curves can look different for different worlds. Take Mars for example. The Red Planet's axial tilt is similar to Earth's, but its orbit around the same sun is more eccentric (less circular) than Earth's orbit. As seen from the Martian surface, the analemma traced in the right hand panel is shaped more like a tear drop. The Mars rover Opportunity captured the images used over the Martian year corresponding to Earth dates July 2006 to June 2008. Of course, each world's solstice dates still lie at the top and bottom of their different analemma curves. The last Mars northern summer solstice was May 29, 2025. Our fair planet's 2025 northern summer solstice is at June 21, 2:42 UTC.

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Solar Eclipse

On April 20, 2023 the shadow of a New Moon raced across planet Earth's southern hemisphere. When viewed along a narrow path that mostly avoided landfall, the Moon in silhouette created a hybrid solar eclipse. Hybrid eclipses are rare and can be seen as a total eclipse or an annular "ring of fire" eclipse depending on the observer's position. Viewers of this much anticipated hybrid event were able to witness a total solar eclipse while anchored in the Indian Ocean near the centerline of the eclipse track off the coast of western Australia. This ship-borne image from renowned eclipse chaser Fred Espenak captured the active Sun's magnificent outer atmosphere, or solar corona, streaming into space. The composite of 11 exposures ranging from 1/2000 to 1/2 second, taken during the 62 seconds of totality, records an extended range of brightness to follow alluring details of the corona not quite visible to the eye.

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2023 July 4

Aurora over Icelandic Waterfall
* Image Credit & Copyright: Cari Letelier
instagram.com/cariletelier/

Explanation:
It seemed like the sky exploded. The original idea was to photograph an aurora over a waterfall. After waiting for hours under opaque clouds, though, hope was running out. Others left. Then, unexpectedly, the clouds moved away. Suddenly, particles from a large solar magnetic storm were visible impacting the Earth's upper atmosphere with full effect. The night sky filled with colors and motion in a thrilling auroral display. Struggling to steady the camera from high Earthly winds, the 34 exposures that compose the featured image were taken. The resulting featured composite image shows the photogenic Godafoss (Goðafoss) waterfall in northern Iceland in front of a very active aurora in late February. The solar surface explosion that expelled the energetic particles occurred a few days before. Our Sun is showing an impressive amount of surface activity as it approaches solar maximum, indicating that more impressive auroras are likely to appear in Earth's northern and southern sky over the next few years.

apod.nasa.gov/apod/ap230704.ht…

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2023 March 27

Aurora Over Arctic Henge
* Image Credit & Copyright: Cari Letelier
cariletelier.com/about/

Explanation:
Reports of powerful solar flares started a seven-hour quest north to capture modern monuments against an aurora-filled sky. The peaks of iconic Arctic Henge in Raufarhöfn in northern Iceland were already aligned with the stars: some are lined up toward the exact north from one side and toward exact south from the other. The featured image, taken after sunset late last month, looks directly south, but since the composite image covers so much of the sky, the north star Polaris is actually visible at the very top of the frame. Also visible are familiar constellations including the Great Bear (Ursa Major) on the left, and the Hunter (Orion) on the lower right. The quest was successful. The sky lit up dramatically with bright and memorable auroras that shimmered with amazing colors including red, pink, yellow, and green -- sometimes several at once.

apod.nasa.gov/apod/ap230327.ht…

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"I wish you a wonderful and peaceful
good morning with this fantastic panorama by Jeff Dai"

2024 June 26
Timelapse: Aurora, SAR, and the Milky Way
* Video Credit & Copyright: Jeff Dai (TWAN);
twanight.org/profile/jeff-dai/

* Music: Ibaotu catalog number 771024 (Used with permission)

Explanation:
What's happening in the sky this unusual night? Most striking in the featured 4.5-hour 360-degree panoramic video, perhaps, is the pink and purple aurora. That's because this night, encompassing May 11, was famous for its auroral skies around the world. As the night progresses, auroral bands shimmer, the central band of our Milky Way Galaxy rises, and stars shift as the Earth rotates beneath them. Captured here simultaneously is a rare red band running above the aurora: a SAR arc, seen to change only slightly. The flashing below the horizon is caused by passing cars, while the moving spots in the sky are satellites and airplanes. The featured video was captured from Xinjiang, China with four separate cameras

apod.nasa.gov/apod/ap240626.ht…

#space #earth #aurora #astrophotography #photography #NASA #science #nature

"This thread on the subject of auroras will soon be continued. For today, however, I wish you a good, peaceful night and wonderful magical dreams .."

2023 July 30

Spiral Aurora over Icelandic Divide
* Image Credit & Copyright: Juan Carlos Casado (Starry Earth, TWAN)
twanight.org/profile/juan-carl…
flickr.com/photos/starryearth/…

Explanation:
Admire the beauty but fear the beast. The beauty is the aurora overhead, here taking the form of a great green spiral, seen between picturesque clouds with the bright Moon to the side and stars in the background. The beast is the wave of charged particles that creates the aurora but might, one day, impair civilization. In 1859, following notable auroras seen all across the globe, a pulse of charged particles from a coronal mass ejection (CME) associated with a solar flare impacted Earth's magnetosphere so forcefully that it created the Carrington Event. This assault from the Sun compressed the Earth's magnetic field so violently that it created high currents and sparks along telegraph wires, shocking many telegraph operators. Were a Carrington-class event to impact the Earth today, speculation holds that damage might occur to global power grids and electronics on a scale never yet experienced. The featured aurora was imaged in 2016 over Thingvallavatn Lake in Iceland, a lake that partly fills a fault that divides Earth's large Eurasian and North American tectonic plates.

apod.nasa.gov/apod/ap230730.ht…

#space #earth #aurora #astrophotography #photography #NASA #science #nature