Oct 8, 2025 11:17 PM
(This post was last modified: Oct 9, 2025 08:50 PM by C C.)
Astronomers find mystery dark object in distant universe
https://www.eurekalert.org/news-releases/1101400
INTRO: Using a global network of telescopes, astronomers have detected the lowest-mass dark object yet found in the universe. Finding more such objects and understanding their nature could rule out some theories about the nature of dark matter, the mystery substance that makes up about a quarter of the universe. The work is described in two papers published Oct. 9 in Nature Astronomy and Monthly Notices of the Royal Astronomical Society.
Because the object does not emit any light or other radiation, it was detected by the way its gravity distorts light passing through or near it. This effect is called gravitational lensing. Based on the distortion, astronomers can infer the amount of matter in the unseen object.
In fact, the new object is so small that it was detected by inducing a small pinch in the distorted image caused by a much larger object, like a flaw in a funhouse mirror.
“It’s an impressive achievement to detect such a low mass object at such a large distance from us,” said Chris Fassnacht, professor in the Department of Physics and Astronomy at the University of California, Davis, who is a co-author on the Nature Astronomy paper. “Finding low-mass objects such as this one is critical for learning about the nature of dark matter.”
The mystery object has a mass about 1 million times that of our Sun. Its nature is unknown: It could be a clump of dark matter 100 times smaller than any previously detected, or it might be a very compact, inactive dwarf galaxy.
Although imperceptible except for its gravitational effects, dark matter is thought to shape the distribution of galaxies, stars and other visible bodies across the sky. A key question for astronomers is whether dark matter can exist in small clumps without any stars. This could confirm or refute some theories about the nature of dark matter... (MORE - details, no ads)
Dancing dust devils trace raging winds on Mars
https://www.eurekalert.org/news-releases/1100744
INTRO: We’ve been seeing dust devils for decades with Mars rovers and orbiters. This research takes a big step further, being the first to track the motion of so many of these twisters to find out how exactly they travel across Mars’s surface.
The study was led by Valentin Bickel from the University of Bern in Switzerland. Their catalogue is the first ever to include the speeds and directions of motions for dust devils all over Mars.
“Dust devils make the normally invisible wind visible,” explains Valentin. “By measuring their speed and direction of travel we have started mapping the wind all over Mars’s surface. This was impossible before because we didn’t have enough data to make this kind of measurement on a global scale.”
Mars is a dramatic planet, with vast volcanoes and cavernous craters. Why should we focus on something as seemingly dull as dust?
Dust can shield the Sun to keep daytime temperatures cooler, and act like a blanket to keep nighttime temperatures warmer. And particles of dust can act as the starting point for clouds to form, whilst dust storms can even force water vapour to escape into space.
Unlike on Earth, where it is washed out of the air by rain, dust can stay in Mars’s atmosphere for a long time, being blown all around the planet. So, for a better understanding of Mars’s climate, scientists are keen to understand when, where and how dust is lifted off the surface into the atmosphere.
For this new study, researchers trained a neural network to recognise dust devils and then comb through images taken by Mars Express since 2004 and ExoMars TGO since 2016 to build up a catalogue of 1039 of them... (MORE - details, no ads)
Six months ago ... https://youtu.be/YHKIZGKPZm4
https://www.youtube-nocookie.com/embed/YHKIZGKPZm4
https://www.eurekalert.org/news-releases/1101400
INTRO: Using a global network of telescopes, astronomers have detected the lowest-mass dark object yet found in the universe. Finding more such objects and understanding their nature could rule out some theories about the nature of dark matter, the mystery substance that makes up about a quarter of the universe. The work is described in two papers published Oct. 9 in Nature Astronomy and Monthly Notices of the Royal Astronomical Society.
Because the object does not emit any light or other radiation, it was detected by the way its gravity distorts light passing through or near it. This effect is called gravitational lensing. Based on the distortion, astronomers can infer the amount of matter in the unseen object.
In fact, the new object is so small that it was detected by inducing a small pinch in the distorted image caused by a much larger object, like a flaw in a funhouse mirror.
“It’s an impressive achievement to detect such a low mass object at such a large distance from us,” said Chris Fassnacht, professor in the Department of Physics and Astronomy at the University of California, Davis, who is a co-author on the Nature Astronomy paper. “Finding low-mass objects such as this one is critical for learning about the nature of dark matter.”
The mystery object has a mass about 1 million times that of our Sun. Its nature is unknown: It could be a clump of dark matter 100 times smaller than any previously detected, or it might be a very compact, inactive dwarf galaxy.
Although imperceptible except for its gravitational effects, dark matter is thought to shape the distribution of galaxies, stars and other visible bodies across the sky. A key question for astronomers is whether dark matter can exist in small clumps without any stars. This could confirm or refute some theories about the nature of dark matter... (MORE - details, no ads)
Dancing dust devils trace raging winds on Mars
https://www.eurekalert.org/news-releases/1100744
INTRO: We’ve been seeing dust devils for decades with Mars rovers and orbiters. This research takes a big step further, being the first to track the motion of so many of these twisters to find out how exactly they travel across Mars’s surface.
The study was led by Valentin Bickel from the University of Bern in Switzerland. Their catalogue is the first ever to include the speeds and directions of motions for dust devils all over Mars.
“Dust devils make the normally invisible wind visible,” explains Valentin. “By measuring their speed and direction of travel we have started mapping the wind all over Mars’s surface. This was impossible before because we didn’t have enough data to make this kind of measurement on a global scale.”
Mars is a dramatic planet, with vast volcanoes and cavernous craters. Why should we focus on something as seemingly dull as dust?
Dust can shield the Sun to keep daytime temperatures cooler, and act like a blanket to keep nighttime temperatures warmer. And particles of dust can act as the starting point for clouds to form, whilst dust storms can even force water vapour to escape into space.
Unlike on Earth, where it is washed out of the air by rain, dust can stay in Mars’s atmosphere for a long time, being blown all around the planet. So, for a better understanding of Mars’s climate, scientists are keen to understand when, where and how dust is lifted off the surface into the atmosphere.
For this new study, researchers trained a neural network to recognise dust devils and then comb through images taken by Mars Express since 2004 and ExoMars TGO since 2016 to build up a catalogue of 1039 of them... (MORE - details, no ads)
Six months ago ... https://youtu.be/YHKIZGKPZm4