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— Carl Sagan

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This Week's Sky at a Glance, November 28 – December 7

Sky & Telescope Magazine - Fri, 11/28/2025 - 4:51am

Saturn remains super-thin-ringed high after dark. The interstellar comet, 11th magnitude, is now nice and high in the dark before dawn. Don't wait; moonlight approaches.

The post This Week's Sky at a Glance, November 28 – December 7 appeared first on Sky & Telescope.

Categories: Astronomy

Our verdict on sci-fi novel Every Version of You: We (mostly) loved it

New Scientist Space - Cosmology - Fri, 11/28/2025 - 4:47am
New Scientist Book Club members share their thoughts on our November read, Grace Chan's Every Version of You
Categories: Astronomy

Our verdict on sci-fi novel Every Version of You: We (mostly) loved it

New Scientist Space - Space Headlines - Fri, 11/28/2025 - 4:47am
New Scientist Book Club members share their thoughts on our November read, Grace Chan's Every Version of You
Categories: Astronomy

Read an extract from The Player of Games by Iain M. Banks

New Scientist Space - Cosmology - Fri, 11/28/2025 - 4:40am
The New Scientist Book Club is currently reading Iain M. Banks's classic sci-fi novel The Player of Games. In this extract, we meet protagonist Gurgeh for the first time
Categories: Astronomy

Read an extract from The Player of Games by Iain M. Banks

New Scientist Space - Space Headlines - Fri, 11/28/2025 - 4:40am
The New Scientist Book Club is currently reading Iain M. Banks's classic sci-fi novel The Player of Games. In this extract, we meet protagonist Gurgeh for the first time
Categories: Astronomy

Why sci-fi novelist Iain M. Banks was an ‘astounding’ world-builder

New Scientist Space - Cosmology - Fri, 11/28/2025 - 4:35am
The New Scientist Book Club is currently reading the late Iain M. Banks’s Culture novel The Player of Games. Fellow science fiction author Bethany Jacobs reveals how his work inspired her
Categories: Astronomy

Why sci-fi novelist Iain M. Banks was an ‘astounding’ world-builder

New Scientist Space - Space Headlines - Fri, 11/28/2025 - 4:35am
The New Scientist Book Club is currently reading the late Iain M. Banks’s Culture novel The Player of Games. Fellow science fiction author Bethany Jacobs reveals how his work inspired her
Categories: Astronomy

Dione and Rhea Ring Transit

APOD - Fri, 11/28/2025 - 4:00am

Seen to the left of Saturn's banded planetary disk, small icy moons


Categories: Astronomy, NASA

Earth from Space: Eye of the Sahara

ESO Top News - Fri, 11/28/2025 - 4:00am
Image: The Copernicus Sentinel-2 mission captures a spectacular geological wonder in the Sahara Desert of Mauritania: the Richat Structure.
Categories: Astronomy

Supermassive dark matter stars may be lurking in the early universe

New Scientist Space - Cosmology - Fri, 11/28/2025 - 1:00am
Stars powered by dark matter instead of nuclear fusion could solve several mysteries of the early universe, and we may have spotted the first hints that they are real
Categories: Astronomy

Supermassive dark matter stars may be lurking in the early universe

New Scientist Space - Space Headlines - Fri, 11/28/2025 - 1:00am
Stars powered by dark matter instead of nuclear fusion could solve several mysteries of the early universe, and we may have spotted the first hints that they are real
Categories: Astronomy

Rings of Rock in the Sahara 

NASA - Breaking News - Fri, 11/28/2025 - 12:01am
EO

  1. Science
  2. Earth Observatory
  3. Rings of Rock in the Sahara 
  September 13, 2025

In northeastern Africa, within the driest part of the Sahara, dark rocky outcrops rise above pale desert sands. Several of these formations, including Jabal Arakanū, display striking ring-shaped structures.  

Jabal Arkanū (also spelled Arkenu) lies in southeastern Libya, near the border with Egypt. Several other massifs are clustered nearby, including Jabal Al Awaynat (or Uweinat), located about 20 kilometers (12 miles) to the southeast. Roughly 90 kilometers to the west are the similarly named Arkenu structures. These circular features were once thought to have formed by meteorite impacts, but later fieldwork suggested they resulted from terrestrial geological processes.   

Arkanū’s ring-shaped structures also have an earthly origin. They are thought to have formed as magma rose toward the surface and intruded into the surrounding rock. Repeated intrusion events produced a series of overlapping rings, their centers roughly aligned toward the southwest. The resulting ring complex—composed of igneous basalt and granite—is bordered to the north by a hat-shaped formation made of sandstone, limestone, and quartz layers. 

This photograph, taken by an astronaut aboard the International Space Station on September 13, 2025, shows the massif casting long shadows across the desert. The ridges stand nearly 1,400 meters above sea level, or about 800 meters above the surrounding sandy plains. Notice several outwash fans of boulders, gravel, and sand spreading from the mountain’s base toward the bordering longitudinal dunes.   

Two wadis, or typically dry riverbeds, wind through the structure. However, water is scarce in this part of the Sahara. Past research using data from NASA and JAXA’s now-completed Tropical Rainfall Measuring Mission (TRMM) indicated that southeastern Libya, along with adjacent regions of Egypt and northern Sudan, receives only about 1 to 5 millimeters of rain per year. Slightly higher accumulations, around 5 to 10 millimeters per year, occur near Jabal Arkanū and neighboring massifs, suggesting a modest orographic effect from the mountains.  

Astronaut photograph ISS073-E-698446 was acquired on September 13, 2025, with a Nikon Z9 digital camera using a focal length of 800 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 73 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Story by Kathryn Hansen.  

References & Resources Downloads

September 13, 2025

JPEG (4.54 MB)



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Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.

Nighttime Over the Eastern Pacific

2 min read

A long-exposure photo taken from low Earth orbit captured the brilliant illumination coming from airglow, lightning, and stars.

Article

A Northwest Night Awash in Light

3 min read

The glow of city lights, the aurora, and a rising Moon illuminate the night along the northwest coast of North…

Article

A Halo Above the Horizon

3 min read

A subtle arc, formed by the bending of light through high-altitude ice crystals, cradles the Moon above the darkened Earth.

Article


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Keep Exploring Discover More from NASA Earth Science

Subscribe to Earth Observatory Newsletters

Subscribe to the Earth Observatory and get the Earth in your inbox.


Earth Observatory Image of the Day

NASA’s Earth Observatory brings you the Earth, every day, with in-depth stories and stunning imagery.


Explore Earth Science


Earth Science Data

Categories: NASA

Rings of Rock in the Sahara 

NASA News - Fri, 11/28/2025 - 12:01am
EO

  1. Science
  2. Earth Observatory
  3. Rings of Rock in the Sahara 
  September 13, 2025

In northeastern Africa, within the driest part of the Sahara, dark rocky outcrops rise above pale desert sands. Several of these formations, including Jabal Arakanū, display striking ring-shaped structures.  

Jabal Arkanū (also spelled Arkenu) lies in southeastern Libya, near the border with Egypt. Several other massifs are clustered nearby, including Jabal Al Awaynat (or Uweinat), located about 20 kilometers (12 miles) to the southeast. Roughly 90 kilometers to the west are the similarly named Arkenu structures. These circular features were once thought to have formed by meteorite impacts, but later fieldwork suggested they resulted from terrestrial geological processes.   

Arkanū’s ring-shaped structures also have an earthly origin. They are thought to have formed as magma rose toward the surface and intruded into the surrounding rock. Repeated intrusion events produced a series of overlapping rings, their centers roughly aligned toward the southwest. The resulting ring complex—composed of igneous basalt and granite—is bordered to the north by a hat-shaped formation made of sandstone, limestone, and quartz layers. 

This photograph, taken by an astronaut aboard the International Space Station on September 13, 2025, shows the massif casting long shadows across the desert. The ridges stand nearly 1,400 meters above sea level, or about 800 meters above the surrounding sandy plains. Notice several outwash fans of boulders, gravel, and sand spreading from the mountain’s base toward the bordering longitudinal dunes.   

Two wadis, or typically dry riverbeds, wind through the structure. However, water is scarce in this part of the Sahara. Past research using data from NASA and JAXA’s now-completed Tropical Rainfall Measuring Mission (TRMM) indicated that southeastern Libya, along with adjacent regions of Egypt and northern Sudan, receives only about 1 to 5 millimeters of rain per year. Slightly higher accumulations, around 5 to 10 millimeters per year, occur near Jabal Arkanū and neighboring massifs, suggesting a modest orographic effect from the mountains.  

Astronaut photograph ISS073-E-698446 was acquired on September 13, 2025, with a Nikon Z9 digital camera using a focal length of 800 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 73 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Story by Kathryn Hansen.  

References & Resources Downloads

September 13, 2025

JPEG (4.54 MB)



You may also be interested in:

Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.

Nighttime Over the Eastern Pacific

2 min read

A long-exposure photo taken from low Earth orbit captured the brilliant illumination coming from airglow, lightning, and stars.

Article

A Northwest Night Awash in Light

3 min read

The glow of city lights, the aurora, and a rising Moon illuminate the night along the northwest coast of North…

Article

A Halo Above the Horizon

3 min read

A subtle arc, formed by the bending of light through high-altitude ice crystals, cradles the Moon above the darkened Earth.

Article


1

2


3


4


Keep Exploring Discover More from NASA Earth Science

Subscribe to Earth Observatory Newsletters

Subscribe to the Earth Observatory and get the Earth in your inbox.


Earth Observatory Image of the Day

NASA’s Earth Observatory brings you the Earth, every day, with in-depth stories and stunning imagery.


Explore Earth Science


Earth Science Data

Categories: NASA

Massive Computer Simulation Creates a Hyper-Realistic Model of the Milky Way

Universe Today - Thu, 11/27/2025 - 5:45pm

Research led by the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) in Japan has successfully performed the world’s first Milky Way simulation that accurately represents more than 100 billion individual stars over the course of 10,000 years.

Categories: Astronomy

Galaxies Struggle To Grow In Crowded Environments

Universe Today - Thu, 11/27/2025 - 4:51pm

New research shows how a galaxy's surroundings influence its development. Its size, shape, and growth rate are all affected. It's all based on "the finer details of the cosmic landscape."

Categories: Astronomy

Origin story of domestic cats rewritten by genetic analysis

New Scientist Space - Cosmology - Thu, 11/27/2025 - 2:00pm
Domestic cats originated in North Africa and spread to Europe in the past 2000 years, according to DNA evidence, while in China a different species of cat lived alongside people much earlier
Categories: Astronomy

Origin story of domestic cats rewritten by genetic analysis

New Scientist Space - Space Headlines - Thu, 11/27/2025 - 2:00pm
Domestic cats originated in North Africa and spread to Europe in the past 2000 years, according to DNA evidence, while in China a different species of cat lived alongside people much earlier
Categories: Astronomy

The Incredible, Unlikely Story of How Cats Became Our Pets

Scientific American.com - Thu, 11/27/2025 - 2:00pm

Two new studies dig into the long, curving path that cats took toward domestication

Categories: Astronomy

Physicists have worked out a universal law for how objects shatter

New Scientist Space - Cosmology - Thu, 11/27/2025 - 1:00pm
Whether it is a cube of sugar or a chunk of a mineral, a mathematical analysis can identify how many fragments of each size any brittle object will break into
Categories: Astronomy

Physicists have worked out a universal law for how objects shatter

New Scientist Space - Space Headlines - Thu, 11/27/2025 - 1:00pm
Whether it is a cube of sugar or a chunk of a mineral, a mathematical analysis can identify how many fragments of each size any brittle object will break into
Categories: Astronomy