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Astronomy Picture of the Day
@apod@mastodon.bot  ·  activity timestamp last week

APOD from 2025-07-30

Coronal Loops on the Sun

Solar loops, shaped by the Sun's magnetic field, can envelop #Earth and last days. These prominences, often near sunspots, were captured in hydrogen light by a personal #telescope in Italy. Some may break and influence Earth's space weather.

HD image at https://apod.nasa.gov/apod/ap250730.html#space #astronomy #universe
Astronomy Picture of the Day
@apod@mastodon.bot  ·  activity timestamp last week

APOD from 2025-07-30

Coronal Loops on the Sun

Solar loops, shaped by the Sun's magnetic field, can envelop #Earth and last days. These prominences, often near sunspots, were captured in hydrogen light by a personal #telescope in Italy. Some may break and influence Earth's space weather.

HD image at https://apod.nasa.gov/apod/ap250730.html#space #astronomy #universe
grobi
@grobi@defcon.social  ·  activity timestamp 2 weeks ago

Asteroid Watch: Keeping an Eye on Near-Earth Objects

Managed for NASA at the Jet Propulsion Laboratory, the Center for Near Earth Object Studies (CNEOS) accurately characterizes the orbits of all known near-Earth objects, predicts their close approaches with Earth, and makes comprehensive impact hazard assessments in support of the agency’s Planetary Defense Coordination Office at NASA Headquarters in Washington.

Near-Earth objects are asteroids and comets with orbits that bring them to within 120 million miles (195 million kilometers) of the Sun, which means they can circulate through the Earth’s orbital neighborhood. Most near-Earth objects are asteroids that range in size from about 10 feet (a few meters) to nearly 25 miles (40 kilometers) across.

The orbit of each object is computed by finding the elliptical path through space that best fits all the available observations, which often span many orbits over many years or decades. As more observations are made, the accuracy of an object's orbit improves dramatically, and it becomes possible to predict where an object will be years or even decades into the future – and whether it could come close to Earth.

The majority of near-Earth objects have orbits that don’t bring them very close to Earth, and therefore pose no risk of impact, but a small fraction of them – called potentially hazardous asteroids – require more attention. These objects are defined as asteroids that are more than about 460 feet (140 meters) in size with orbits that bring them as close as within 4.6 million miles (7.5 million kilometers) of Earth’s orbit around the Sun. CNEOS continuously monitors all known near-Earth objects to assess any impact risk they may pose. [...]
Read more:
https://www.jpl.nasa.gov/asteroid-watch/

#space #earth #science #astronomy #physics #tech #defense#NASA#ESA

The orbital positions of near-Earth objects come from the databases of the Minor Planet Center, the internationally recognized clearinghouse for small-body position measurements. This data is collected by observatories around the world, including significant contributions from amateur observers. The vast majority of asteroid-tracking data, however, is collected by large NASA-funded observatories (such as Pan-STARRS, the Catalina Sky Survey, NASA’s NEOWISE mission and, in the future, NEO Surveyor). Planetary radar projects (including JPL’s Goldstone Solar System Radar Group) are another key component of NASA’s NEO Observations Program. The Center for Near-Earth Object Studies is home of the Sentry impact-monitoring system, which continuously performs long-term analyses of possible future orbits of hazardous asteroids. There is currently no known significant threat of impact for the next hundred years or more. The Center also maintains the Scout system that continually monitors brand-new potential near-Earth object detections, even before they have been confirmed as new discoveries, to see whether any of these generally very small asteroids might pose a threat of short-term (possibly imminent) impact. Credit: NASA/JPL-Caltech
The orbital positions of near-Earth objects come from the databases of the Minor Planet Center, the internationally recognized clearinghouse for small-body position measurements. This data is collected by observatories around the world, including significant contributions from amateur observers. The vast majority of asteroid-tracking data, however, is collected by large NASA-funded observatories (such as Pan-STARRS, the Catalina Sky Survey, NASA’s NEOWISE mission and, in the future, NEO Surveyor). Planetary radar projects (including JPL’s Goldstone Solar System Radar Group) are another key component of NASA’s NEO Observations Program. The Center for Near-Earth Object Studies is home of the Sentry impact-monitoring system, which continuously performs long-term analyses of possible future orbits of hazardous asteroids. There is currently no known significant threat of impact for the next hundred years or more. The Center also maintains the Scout system that continually monitors brand-new potential near-Earth object detections, even before they have been confirmed as new discoveries, to see whether any of these generally very small asteroids might pose a threat of short-term (possibly imminent) impact. Credit: NASA/JPL-Caltech
grobi
@grobi@defcon.social  ·  activity timestamp 2 weeks ago

The Cretaceous–Paleogene (K–Pg) extinction event, formerly known as the Cretaceous-Tertiary (K–T) extinction event, was the mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than 25 kg (55 lb) also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current geological era, the Cenozoic Era.
[...]

As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was caused by the impact of a massive asteroid 10 to 15 km (6 to 9 mi) wide, 66 million years ago causing the Chicxulub impact crater, which devastated the global environment, mainly through a lingering impact winter which halted photosynthesis in plants and plankton. The impact hypothesis, also known as the Alvarez hypothesis, was bolstered by the discovery of the 180 km (112 mi) Chicxulub crater in the Gulf of Mexico's Yucatán Peninsula in the early 1990s, which provided conclusive evidence that the K–Pg boundary clay represented debris from an asteroid impact. The fact that the extinctions occurred simultaneously provides strong evidence that they were caused by the asteroid. A 2016 drilling project into the Chicxulub peak ring confirmed that the peak ring comprised granite ejected within minutes from deep in the earth, but contained hardly any gypsum, the usual sulfate-containing sea floor rock in the region: the gypsum would have vaporized and dispersed as an aerosol into the atmosphere, causing longer-term effects on the climate and food chain.
[...]
Read more
https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event

#space #earth #asteroids #science #history #astronomy #physics #tech #defense#NASA#ESA

Visualization of asteroid impact that killed dinosaurs 65 million years ago, based on accurate research and scientific fact. Created by Radek Michalik (writetoradek@gmail.com) at the Science Institute of Columbia College Chicago. Video Credit Radek Michalik
Visualization of asteroid impact that killed dinosaurs 65 million years ago, based on accurate research and scientific fact. Created by Radek Michalik (writetoradek@gmail.com) at the Science Institute of Columbia College Chicago. Video Credit Radek Michalik
grobi
@grobi@defcon.social  ·  activity timestamp 2 weeks ago

TOPIC> About Planetary Defense

2023 June 30

Orbits of Potentially Hazardous Asteroids
* Illustration Credit: NASA, JPL-Caltech
https://www.nasa.gov/
https://www.jpl.nasa.gov/

Explanation:
Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. To investigate Earth-saving strategies, NASA successfully tested the Double Asteroid Redirection Test (DART) mission in 2022. Of course, rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes create memorable fireball and meteor displays.
https://photojournal.jpl.nasa.gov/catalog/PIA17041
https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event
https://web.archive.org/web/20161210142717/http://nss.org/resources/library/planetarydefense/2000-ReportOfTheTaskForceOnPotentiallyHazardousNearEarthObjects-UK.pdf
https://en.wikipedia.org/wiki/List_of_asteroid_close_approaches_to_Earth

https://www.jpl.nasa.gov/

#space #earth #astrophotography #photography #science #astronomy #physics #tech #defense#NASA#ESA

2023 June 30 A dark background is filled with many light-blue ellipses. Toward the center, near circles that are labelled as the orbits of the inner planets of our Solar System are drawn. Orbits of Potentially Hazardous Asteroids * Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. To investigate Earth-saving strategies, NASA successfully tested the Double Asteroid Redirection Test (DART) mission in 2022. Of course, rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes create memorable fireball and meteor displays. Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
2023 June 30 A dark background is filled with many light-blue ellipses. Toward the center, near circles that are labelled as the orbits of the inner planets of our Solar System are drawn. Orbits of Potentially Hazardous Asteroids * Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. To investigate Earth-saving strategies, NASA successfully tested the Double Asteroid Redirection Test (DART) mission in 2022. Of course, rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes create memorable fireball and meteor displays. Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
2023 June 30 A dark background is filled with many light-blue ellipses. Toward the center, near circles that are labelled as the orbits of the inner planets of our Solar System are drawn. Orbits of Potentially Hazardous Asteroids * Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. To investigate Earth-saving strategies, NASA successfully tested the Double Asteroid Redirection Test (DART) mission in 2022. Of course, rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes create memorable fireball and meteor displays. Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
Biason::Julio::new();
Roni Laukkarinen
Biason::Julio::new(); and 1 other boosted
Roni Laukkarinen
@rolle@mementomori.social  ·  activity timestamp 2 weeks ago

"So here's the catch. If you have the power of geoengineering to turn Mars into Earth, then you have the power of geoengineering to turn Earth back into Earth."
– Neil deGrasse Tyson, astrophysicist and writer

Video clip of showing Neil deGrasse Tyson, American astrophysicist and writer speaking, transcript: Climate change will not make earth uninhabitable. Climate change will make earth a living hell. In fact, I live in New York city where in our harbor we have the statue of liberty and she is holding the declaration of independence in her left arm and her right arm has the torch. The melting ice on land? The ocean level will rise to reach her left elbow. So that takes out all of New York city and basically every other coastal that we've spent tousands of years building since the dawn of civilization. So life will be very very different. So the way I look at it there is people who want to colonize other planets, give us an escape route. We trashed earth, let's move elsewhere and hope we don't trash that. Well, there aren't many places to move. You'll vaporize on Venus, so you're not going to Venus. Mars rotates once every 24 hours. That's kind of interesting. It's tipped on its as earth is, which means it has seasons, it has polar ice caps the way we stil do at this moment, and there is evidence of running water on its surface. So there's a chance we could terraform Mars. My favourite word over the past few decades. You turn something that is not Earth to something that's like Earth. Then you just move there. So here's the catch. If you have the power of geoengineering, to turn Mars into Earth, then you have the power of geoengineering, to turn Earth back into Earth.
Video clip of showing Neil deGrasse Tyson, American astrophysicist and writer speaking, transcript: Climate change will not make earth uninhabitable. Climate change will make earth a living hell. In fact, I live in New York city where in our harbor we have the statue of liberty and she is holding the declaration of independence in her left arm and her right arm has the torch. The melting ice on land? The ocean level will rise to reach her left elbow. So that takes out all of New York city and basically every other coastal that we've spent tousands of years building since the dawn of civilization. So life will be very very different. So the way I look at it there is people who want to colonize other planets, give us an escape route. We trashed earth, let's move elsewhere and hope we don't trash that. Well, there aren't many places to move. You'll vaporize on Venus, so you're not going to Venus. Mars rotates once every 24 hours. That's kind of interesting. It's tipped on its as earth is, which means it has seasons, it has polar ice caps the way we stil do at this moment, and there is evidence of running water on its surface. So there's a chance we could terraform Mars. My favourite word over the past few decades. You turn something that is not Earth to something that's like Earth. Then you just move there. So here's the catch. If you have the power of geoengineering, to turn Mars into Earth, then you have the power of geoengineering, to turn Earth back into Earth.
Roni Laukkarinen
@rolle@mementomori.social  ·  activity timestamp 2 weeks ago

"So here's the catch. If you have the power of geoengineering to turn Mars into Earth, then you have the power of geoengineering to turn Earth back into Earth."
– Neil deGrasse Tyson, astrophysicist and writer

Video clip of showing Neil deGrasse Tyson, American astrophysicist and writer speaking, transcript: Climate change will not make earth uninhabitable. Climate change will make earth a living hell. In fact, I live in New York city where in our harbor we have the statue of liberty and she is holding the declaration of independence in her left arm and her right arm has the torch. The melting ice on land? The ocean level will rise to reach her left elbow. So that takes out all of New York city and basically every other coastal that we've spent tousands of years building since the dawn of civilization. So life will be very very different. So the way I look at it there is people who want to colonize other planets, give us an escape route. We trashed earth, let's move elsewhere and hope we don't trash that. Well, there aren't many places to move. You'll vaporize on Venus, so you're not going to Venus. Mars rotates once every 24 hours. That's kind of interesting. It's tipped on its as earth is, which means it has seasons, it has polar ice caps the way we stil do at this moment, and there is evidence of running water on its surface. So there's a chance we could terraform Mars. My favourite word over the past few decades. You turn something that is not Earth to something that's like Earth. Then you just move there. So here's the catch. If you have the power of geoengineering, to turn Mars into Earth, then you have the power of geoengineering, to turn Earth back into Earth.
Video clip of showing Neil deGrasse Tyson, American astrophysicist and writer speaking, transcript: Climate change will not make earth uninhabitable. Climate change will make earth a living hell. In fact, I live in New York city where in our harbor we have the statue of liberty and she is holding the declaration of independence in her left arm and her right arm has the torch. The melting ice on land? The ocean level will rise to reach her left elbow. So that takes out all of New York city and basically every other coastal that we've spent tousands of years building since the dawn of civilization. So life will be very very different. So the way I look at it there is people who want to colonize other planets, give us an escape route. We trashed earth, let's move elsewhere and hope we don't trash that. Well, there aren't many places to move. You'll vaporize on Venus, so you're not going to Venus. Mars rotates once every 24 hours. That's kind of interesting. It's tipped on its as earth is, which means it has seasons, it has polar ice caps the way we stil do at this moment, and there is evidence of running water on its surface. So there's a chance we could terraform Mars. My favourite word over the past few decades. You turn something that is not Earth to something that's like Earth. Then you just move there. So here's the catch. If you have the power of geoengineering, to turn Mars into Earth, then you have the power of geoengineering, to turn Earth back into Earth.
ProPublica
@ProPublica@newsie.social  ·  activity timestamp 2 weeks ago

The Drying Planet
—

A new study finds that freshwater resources are rapidly disappearing, creating arid “mega” regions and causing sea levels to rise.
https://www.propublica.org/article/water-aquifers-groundwater-rising-ocean-levels?utm_source=mastodon&utm_medium=social&utm_campaign=mastodon-post

#News #Science#Climate#Environment#ClimateChange#Water#Earth