Astronomy – Sinia Planeta http://sinia-planeta.com/ Wed, 03 Nov 2021 04:03:07 +0000 en-US hourly 1 https://wordpress.org/?v=5.8 https://sinia-planeta.com/wp-content/uploads/2021/10/icon-50-120x120.png Astronomy – Sinia Planeta http://sinia-planeta.com/ 32 32 Foothill College Astronomy Events | Virtual Solar System Exploration Research Institute https://sinia-planeta.com/foothill-college-astronomy-events-virtual-solar-system-exploration-research-institute/ https://sinia-planeta.com/foothill-college-astronomy-events-virtual-solar-system-exploration-research-institute/#respond Tue, 02 Nov 2021 21:11:44 +0000 https://sinia-planeta.com/foothill-college-astronomy-events-virtual-solar-system-exploration-research-institute/ Two interesting events: 1) On Wednesday November 17, 2021 at 7:00 p.m. PDT, Arizona State University’s Dr. Jim Bell will be giving a free, illustrated, non-technical talk on “Postcards from Mars: The Latest from the International Armada of Robot Explorers” Join live online on YouTube: http://www.youtube.com/SVAstronomyLectures[note that a recording will be made available] The lecture […]]]>

Two interesting events:

1) On Wednesday November 17, 2021 at 7:00 p.m. PDT, Arizona State University’s Dr. Jim Bell will be giving a free, illustrated, non-technical talk on “Postcards from Mars: The Latest from the International Armada of Robot Explorers”

Join live online on YouTube: http://www.youtube.com/SVAstronomyLectures
[note that a recording will be made available]

The lecture is part of the Silicon Valley Astronomy Lecture Series, now in its 22nd year.

Ten missions have been successfully landed on Mars since 1976, including six rovers that have covered a total of nearly 50 km of land on the Red Planet. Arizona State University Professor Jim Bell served as the Principal or Associate Scientist in charge of science cameras for NASA’s Spirit, Opportunity, Curiosity and Perseverance rovers, and had an incredible front row spot for their photographic and geological adventures. . In this presentation, Professor Bell will share his favorite images and stories from ‘inside’ mission operations and describe the major scientific discoveries made by these roving and landed missions over the past 45 years, with a particular focus on latest results from the still. -Rovers Active Curiosity and Perseverance. He will also be talking about plans for the next exciting Mars rover and lander adventure – sample return!

Jim Bell is a professor in the School of Earth & Space Exploration at Arizona State University. He is an astronomer and planetologist who participated in the exploration of the solar system using data from the Hubble Space Telescope, Martian rovers, Voyager 2 and orbiters sent to Mars, the Moon and several asteroids. His research focuses on the use of remote sensing imagery and spectroscopy to assess the geology, composition and mineralogy of the surfaces of planets, moons, asteroids and comets. He is also the author of numerous popular science books related to space exploration, including Postcards from Mars, The Space Book, The Interstellar Age, The Ultimate Interplanetary Travel Guide, and Hubble Legacy. He was President of the Planetary Society from 2008 to 2020 and received the Carl Sagan Medal from the American Astronomical Society for Public Communication in Science.

The conference is co-sponsored by:

* The Science, Technology, Engineering and Mathematics Division of Foothill College

* The SETI Institute

* The Astronomical Society of the Pacific

* University of California observatories (including Lick Observatory).

Past lectures in the series can also be found on YouTube at: http://youtube.com/svastronomylectures and as audio podcasts at: https://www.buzzsprout.com/1805595

2) An almost total lunar eclipse, from November 18 to 19

You probably already had this in your schedule, but just in case we wanted to warn you that there will be an almost total lunar eclipse on the late evening of November 18 and the early morning of November 19. It will be visible nationwide, safe to look at, and easy to see (as long as it’s not cloudy or foggy.)

We have a blog post with all the details on when and how to watch: https://www.fraknoi.com/eclipse/an-eclipse-of-the-moon-nov-18-19/

Posted by: Soderman Staff / SSERVI
Source: Foothill College


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Small telescope beyond Saturn could trump giant telescopes near Earth https://sinia-planeta.com/small-telescope-beyond-saturn-could-trump-giant-telescopes-near-earth/ https://sinia-planeta.com/small-telescope-beyond-saturn-could-trump-giant-telescopes-near-earth/#respond Mon, 01 Nov 2021 17:18:00 +0000 https://sinia-planeta.com/small-telescope-beyond-saturn-could-trump-giant-telescopes-near-earth/ In 2011, scientists used a camera on the EPOXI mission in the asteroid belt to find and weigh a Object the size of Neptune floating freely among the stars of the Milky Way. Only a few rogue planets have been found, but astronomers suspect they are very common and may hold clues to the formation […]]]>

In 2011, scientists used a camera on the EPOXI mission in the asteroid belt to find and weigh a Object the size of Neptune floating freely among the stars of the Milky Way. Only a few rogue planets have been found, but astronomers suspect they are very common and may hold clues to the formation of solar systems and prevalence of planets around stars.

But perhaps the most interesting use of a telescope in the Outer Solar System would be the possibility of using the gravitational field of the Sun itself as a giant lens. This type of measurement can allow astrophysicists to map planets in other star systems. Maybe one day we can name continents on an Earth-like planet around a distant star.

Coming soon?

Since Pioneer 10 became the first man-made object to pass through Jupiter’s orbit in 1973, only a few astrophysical studies have been done beyond Earth’s orbit. Missions to the outer solar system are rare, but many teams of scientists are doing studies to show how an extrasolar telescope project would work and what we could learn from it.

Every 10 years or so, leaders in astrophysics and astronomy come together to set goals for the next decade. This plan for the 2020s is expected to be released on November 4, 2021. I expect to see discussions about the next telescope that could revolutionize astronomy. Taking a telescope into the Outer Solar System, while ambitious, is well within the technological capabilities of NASA or other space agencies. I hope that one day soon, a small telescope on a solitary mission in the dark areas of the solar system will provide us with incredible information about the universe.


This story was originally published with The conversation. Read the original here.


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Astronomical lecture series to examine black holes | Local News https://sinia-planeta.com/astronomical-lecture-series-to-examine-black-holes-local-news/ https://sinia-planeta.com/astronomical-lecture-series-to-examine-black-holes-local-news/#respond Sun, 31 Oct 2021 06:00:00 +0000 https://sinia-planeta.com/astronomical-lecture-series-to-examine-black-holes-local-news/ The Southwestern Oregon Community College Physics and Astronomy Lecture Series welcomes Raymond Frey from the Department of Physics at the University of Oregon on Thursday, November 4 at 6:30 p.m. to discuss the new field of gravitational wave observation with the Gravitational-Wave Observatory laser interferometer and its implications on the frontiers of astronomy. Join us […]]]>

The Southwestern Oregon Community College Physics and Astronomy Lecture Series welcomes Raymond Frey from the Department of Physics at the University of Oregon on Thursday, November 4 at 6:30 p.m. to discuss the new field of gravitational wave observation with the Gravitational-Wave Observatory laser interferometer and its implications on the frontiers of astronomy. Join us via Livestream at https://livestream.com/swocc/physicsandastronomy2021-22.

Frey led the University of Oregon’s research as part of the LIGO team when the first gravitational wave observations were made in 2015. Over the past six years, many doors have opened in the gravitational astronomy.

Frey says of his lecture: “It has been just over six years since LIGO first observed gravitational waves from the merger of two black holes of 30 solar masses, and just over four years since gravitational waves a fusion of binary neutron stars ushered in a new era of multi-messenger astronomy. In total, around 100 confirmed gravitational wave events have now been observed by LIGO. I discuss the detectors, the initial findings, some of the scientific results so far obtained from the observations, the role of the UO group, and the promising future of the field of gravitational wave astronomy.

The Southwestern Physics and Astronomy Lecture Series is sponsored in part by the Southwestern Foundation. For more information on this conference and future events, contact Aaron Coyner, Associate Professor of Physics, at 541-888-7244 or aaron.coyner@socc.edu. To learn more about physics and engineering degrees at Southwestern, visit https://physics.socc.edu/.


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Astronomy – GeekWeek, Science – Geekweek Interia https://sinia-planeta.com/astronomy-geekweek-science-geekweek-interia/ https://sinia-planeta.com/astronomy-geekweek-science-geekweek-interia/#respond Sat, 30 Oct 2021 13:21:10 +0000 https://sinia-planeta.com/astronomy-geekweek-science-geekweek-interia/ Last Thursday (October 28) the sun’s surface reached A series of X-ray bursts, including the most powerful of this solar cycle, Class X1.0As the plasma cloud began to rush towards Earth. According to NASA, the solar wind is full of charged particles, It will reach the magnetic poles of the Earth on Saturday (30:10) or […]]]>

Last Thursday (October 28) the sun’s surface reached A series of X-ray bursts, including the most powerful of this solar cycle, Class X1.0As the plasma cloud began to rush towards Earth.

According to NASA, the solar wind is full of charged particles, It will reach the magnetic poles of the Earth on Saturday (30:10) or in the night from Saturday to Sunday (30 / 31:10), causing a strong geomagnetic storm in the ionosphere and exosphere.

It will show the amazing Northern Lights, which will be admired not only by the inhabitants of the Far North, but also by us. The latest forecasts indicate Geomagnetic storm of at least G3 (Kp = 7)This means that the dawn will also dance over Poland.

The stronger the storm, the more colorful the Northern Lights and the greater the sky coverage. To see it you have to go to a dark placeSheltered from artificial lighting and looking towards the northern sky. With a stronger storm, the Northern Lights could be seen even at its peak.

However, severe geomagnetic thunderstorms also have a dangerous face, as they can cause Interfere with radio and satellite communicationsand damage sensitive electronic devices and the power grid.

At dusk, airline passengers, as well as astronauts were on board International space station, receiving more radiation than usual, which may affect their health.

Northern Lights It forms in the upper layers of the Earth’s atmosphere, in the ionosphere and exosphere, at an altitude of 65 to 400 km above the surface, usually at a distance of 20 to 25 degrees from the north magnetic poles and south.

The amazing colors of the aurora are due to the interplay of particles solar wind with air particles. The streaks are usually red when combining with nitrogen and green when reacting with oxygen. Other colors including pearl, pink and purple mix them.


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The sky this week from October 29 to November 5 https://sinia-planeta.com/the-sky-this-week-from-october-29-to-november-5/ https://sinia-planeta.com/the-sky-this-week-from-october-29-to-november-5/#respond Fri, 29 Oct 2021 13:49:26 +0000 https://sinia-planeta.com/the-sky-this-week-from-october-29-to-november-5/ Monday November 1The American Association of Variable Star Observers is an amateur organization dedicated to observing celestial objects whose brightness changes over time. This year, they highlight a different star each month, and that of November featured variable featured is Almaaz, also known as Epsilon (ϵ) Aurigae. Almaaz is a 3rd magnitude star located just […]]]>

Monday November 1
The American Association of Variable Star Observers is an amateur organization dedicated to observing celestial objects whose brightness changes over time. This year, they highlight a different star each month, and that of November featured variable featured is Almaaz, also known as Epsilon (ϵ) Aurigae.

Almaaz is a 3rd magnitude star located just under 3.5 ° southwest of Capella, easy to spot. The pair will rise around 5:30 p.m. local time tonight roughly tied, with Capella on the left and Almaaz on the right. Wait a bit for them to rise, then focus on Almaaz, which is part of a little asterism called The Kids. With Haedus I (Zeta [ζ] Aur) and Haedus II (Eta Aur), these three stars form a tall, thin triangle south-southwest of Capella.

Almaaz itself is a rare and hot F-type supergiant star that is also found in a binary eclipse system. This means he has a partner star that crosses him every 27 years – and each eclipse lasts for 2 years! When eclipsed, Almaaz appears of roughly the same brightness as Haedus I (magnitude 3.7); when not eclipsed, it is magnitude 3. The last eclipse occurred between 2009 and 2011, so Almaaz is currently un-eclipsed and at its peak. Compare it to Haedus I 2.8 ° south to see the difference.

Sunrise: 7:30
Sunset: 5:57 p.m.
Moonrise: 03:27
Moon setting: 4:33 p.m.
Moon phase: Ascending descending (14%)

Tuesday, November 2
Taurus the Bull now rises in the evening, and he has his eye – literally – on a visitor from the asteroid belt. The dwarf planet 1 Ceres is barely brushing 7 ‘south of the bright star Aldebaran tonight and tomorrow morning.

In the middle of the evening, Aldebaran is already at an altitude of 15 ° to the east. This red giant star shines with a brilliant magnitude of 0.9 and is easy to find east-southeast of the famous Pleiades star cluster (M45). Ceres is 7.7 magnitude – much fainter, of course, but still brighter than any other faint star within 20 feet of Aldebaran. You can catch the pair with binoculars or a telescope, although the former can be more difficult in light-polluted city skies.

The largest body in the Main Belt, Ceres has been promoted from asteroid to dwarf planet. Just under 965 kilometers in diameter, it was first spotted in 1801 by Giuseppe Piazzi. This relatively nearby icy world was visited in 2015 by NASA’s Dawn spacecraft, which spent the next three years in orbit, until the ship’s fuel depletion brought the mission to an end.

Sunrise: 7:31
Sunset: 5:56 p.m.
Moonrise: 04:37
Moon setting: 5:00 p.m.
Moon phase: Descending descending (7%)

Wednesday, November 3
The thin crescent Moon is suspended near Mercury in Virgo this morning; see if you can catch a glimpse of the view before the sun rises.

But the pair have more in store for us today: Our satellite passes in front of the planet Mercury in an occultation that can be seen during daylight hours from the eastern half of the United States and Canada. The exact time the blackout occurs depends on your location, for example 2:38 p.m. CST in Chicago and an hour earlier, 1:38 a.m. CST, in Kansas City, Missouri.

If you plan to watch the event, be extremely careful – the pair will only be 15 ° from the Sun. If possible, try to observe from an area where the sun will be blocked, such as through foliage or buildings. Make sure your telescope is properly aligned and calibrated before setting out to search for the sight and if you are particularly inexperienced, avoid trying to find it yourself. Instead, ask for help or visit a local club with experienced members.

The Moon later passes 1.2 ° due north of Mercury at 3:00 p.m. EDT.

Sunrise: 7:32
Sunset: 5:55 p.m.
Moonrise: 05:51
Moon setting: 5:28 p.m.
Moon phase: Descending descending (2%)


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Astronomy fans: YOU are invited to a free conference on “The search for life in the universe” https://sinia-planeta.com/astronomy-fans-you-are-invited-to-a-free-conference-on-the-search-for-life-in-the-universe/ https://sinia-planeta.com/astronomy-fans-you-are-invited-to-a-free-conference-on-the-search-for-life-in-the-universe/#respond Thu, 28 Oct 2021 23:01:16 +0000 https://sinia-planeta.com/astronomy-fans-you-are-invited-to-a-free-conference-on-the-search-for-life-in-the-universe/ Astronomy fans: YOU are invited to a free conference on “The search for life in the universe” Phoenix, AZ – The Phoenix Astronomical Society PASAZ.ORG is proud to announce that Dr. Klaus Brasch will be our guest speaker on November 4, 2021, at our ZOOM meeting starting at 7:00 p.m. The link to this meeting […]]]>

Astronomy fans: YOU are invited to a free conference on “The search for life in the universe”

Phoenix, AZ – The Phoenix Astronomical Society PASAZ.ORG is proud to announce that Dr. Klaus Brasch will be our guest speaker on November 4, 2021, at our ZOOM meeting starting at 7:00 p.m.

The link to this meeting can be obtained on the PASAZ.ORG website under the heading “PAS Calendar” and the date of this meeting. Klaus’ lecture is entitled “The Search for Life in the Universe”. The search for life in the universe has become a driving force behind much of current space exploration, including current and planned missions to Mars, Europe, Enceladus, and other bodies in our solar system. A fundamental question for humanity: “Are we alone in the cosmos? Klaus has the answers you’re looking for.

Dr Brasch obtained a doctorate. at Carleton University in Ottawa, and is now a retired biomedical scientist and volunteer at the Lowell Observatory in Flagstaff, AZ. He joined the Faculty of Biology at Queen’s University in Kingston, Ont., Where he teamed up with renowned radio astronomer Alan Bridle to deliver the first astrobiology course in Canada. In 1990, he joined California State University, San Bernardino, where he served as department chair, dean of science, and director of campus research. This talk is open to the public, so please tell a friend




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Backyard Astronomy: the sky is full of stars – and planets https://sinia-planeta.com/backyard-astronomy-the-sky-is-full-of-stars-and-planets/ https://sinia-planeta.com/backyard-astronomy-the-sky-is-full-of-stars-and-planets/#respond Tue, 26 Oct 2021 22:38:00 +0000 https://sinia-planeta.com/backyard-astronomy-the-sky-is-full-of-stars-and-planets/ It is estimated that 300 billion stars make up the Milky Way and each may have one or more exoplanets orbiting. For thousands of years, the night sky was just a splash of random dots. Over time, constellations have formed by connecting the brightest points of light in a certain area of ​​the sky. Here, […]]]>

It is estimated that 300 billion stars make up the Milky Way and each may have one or more exoplanets orbiting.

For thousands of years, the night sky was just a splash of random dots. Over time, constellations have formed by connecting the brightest points of light in a certain area of ​​the sky. Here, imaginary shapes formed representing an object, a person, an animal or even a god – the constellations. Then came the mythological stories and how they interacted in the heavenly theater. Those who looked at the sky regularly would notice that a star or stars brighter than usual roamed the sky for weeks, months and years. Unknown at the time, they are the members of our solar system.

The word planet comes from the early Greeks meaning “wanderer” or “wandering star” and for obvious reasons. Seen with the naked eye are Mercury, Venus, Mars, Jupiter and Saturn. Uranus and Neptune were discovered via the telescope in 1781 and 1846 respectively. Pluto was discovered in 1930 but was demoted to minor planet status in 2006, so the tally remains at eight major planets orbiting its parent star – the sun. Brilliant Venus is seen low in the southwestern sky after sunset while bright Jupiter is seen in the southeast with fainter Saturn about five inches to the right of Jupiter at arm’s length.

Once the planets were identified and studied, we thought we were the only solar system in our Milky Way galaxy. We didn’t know everything that was going to change in the early 1990s. The first discovery of an exoplanet (a planet that orbits a star outside the solar system) dates back to 1992. Three planets orbit it. pulsar located 2300 light years away. Pulsars are very energetic stars resulting from the explosive death of a massive star called a supernova. If these three worlds had life on them before the star exploded, the supernova’s shock wave has stripped its atmosphere and bathes the lifeless planets in deadly radiance.

However, the big discovery took place in 1995 when the first exoplanet orbiting a sun-like star was discovered. The star named 51 Pegasi is located 50.8 light years away in the constellation Pegasus – seen above these chilly nights. This star is visible to the naked eye on a clear moonless night. Of course, you won’t see the exoplanet named Bellerophon even with a telescope, but knowing that a world is orbiting this tiny point of light is mind-blowing.

The search did not end in 1995. Thanks to ground-based telescopes and the orbiting Kepler Space Telescope, the tally to date is 4,531 confirmed planets with 7,798 candidates. These discoveries were made from a small part of the sky. Some astronomers have stated that every star in the night sky has at least one exoplanet around it. Many are too close to their star to support life as we know it, but there are a few in the Living Zone or Goldilocks where liquid water remains fluid, like the oceans here on Earth. Finding an exoplanet with water is the key to finding life.

The Milky Way contains around 300 billion stars. Imagine if a single grain of table salt represented a star, you could fill a sandbox 20 feet long by 20 feet wide by a foot high. There are approximately two trillion galaxies in the observable universe. Think about all of these worlds and the possibility of life.

Look at the sky, look at a sky full of planets.

See you next time, clear skies.

Known as “The Backyard Astronomer,” Gary Boyle is Professor of Astronomy, Guest Lecturer and Monthly Columnist for the Royal Astronomical Society of Canada. He has been interviewed on over 50 Canadian radio stations as well as on television across Canada and the United States. Follow him on Twitter @astroeducator or visit his website www.wondersofastronomy.com.


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How astronomers probe the Sun’s explosive past https://sinia-planeta.com/how-astronomers-probe-the-suns-explosive-past/ https://sinia-planeta.com/how-astronomers-probe-the-suns-explosive-past/#respond Tue, 26 Oct 2021 16:31:04 +0000 https://sinia-planeta.com/how-astronomers-probe-the-suns-explosive-past/ The memory of a million years of the moon This terrestrial limitation raises a question: Is solar activity during the Holocene special? To answer this, scientists must look to a completely different planetary body: the Moon. “Lunar rock or any rock not protected by the atmosphere is a coarse spectrometer,” explains Ilya Usoskin from the […]]]>

The memory of a million years of the moon

This terrestrial limitation raises a question: Is solar activity during the Holocene special? To answer this, scientists must look to a completely different planetary body: the Moon.

“Lunar rock or any rock not protected by the atmosphere is a coarse spectrometer,” explains Ilya Usoskin from the University of Oulu in Finland. When a cosmic ray hits a rock, it induces a nuclear reaction and creates isotopes, which can be analyzed in the laboratory. Some of these cosmic rays are charged particles from the Sun; others (which tend to be more energetic) come from sources further away from the Milky Way, beyond our solar system.

The Apollo missions returned with many lunar rock samples – including a deep, 8 feet long (2.4 meters) drill core collected on Apollo 15. This nucleus is important because galactic cosmic rays, more abundant at high energies than solar particles, plant isotopes deep in rocks. In contrast, solar cosmic rays only leave their imprints in shallower rocks. The deep core of Apollo 15 allows scientists to understand the contributions of galactic cosmic rays, which means they can then distinguish the contributions of solar particles in the shallower layers to better understand the behavior of the Sun over time. .

Scientists can only extract information about an average particle bombardment over several million years. Nevertheless, the method provides valuable information. For example, isotope concentrations suggest that, on average, solar activity has remained relatively constant over the past millions of years. In addition, the number of super-eruptions deduced from lunar rocks agrees well with the observed number of events marked by isotope deposits in tree rings.

In other words, we shouldn’t expect the Sun’s activity to stop anytime soon.

Solar adolescence

Sometimes, however, we have to look to distant stars to learn more about the Sun’s distant past. “Other stars tell us how the Sun behaved over time,” says Veronig. For example, younger stars generally spin faster. And because a star’s rotation drives its magnetic dynamo, faster rotation produces stronger magnetic fields, leading to stronger flaring events. Scientists therefore believe that the Sun was much more active in its youth.

The activity of the young Sun may not be so relevant to us today, but it was very important to our early prehistoric predecessors. “The history of the Sun is linked to the history of the planets because strong flares and CMEs interact with the planets,” says Veronig. For example, having a few pushes can help build complex molecules like RNA and DNA from simpler building blocks. But too many intense eruptions can strip entire atmospheres, rendering a planet uninhabitable.


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Bad astronomy | Dozens of other Saturn moons discovered https://sinia-planeta.com/bad-astronomy-dozens-of-other-saturn-moons-discovered/ https://sinia-planeta.com/bad-astronomy-dozens-of-other-saturn-moons-discovered/#respond Mon, 25 Oct 2021 13:00:20 +0000 https://sinia-planeta.com/bad-astronomy-dozens-of-other-saturn-moons-discovered/ If someone asks you how many moons Saturn has, the correct answer is “a lot”. A slightly more correct answer would be “at least 82”. The best answer would probably be now: “150, plus / minus 30, if you’re talking more than 2.8 kilometers in diameter and only counting irregulars.” “ Yes, it is quite […]]]>

If someone asks you how many moons Saturn has, the correct answer is “a lot”.

A slightly more correct answer would be “at least 82”.

The best answer would probably be now: “150, plus / minus 30, if you’re talking more than 2.8 kilometers in diameter and only counting irregulars.” “

Yes, it is quite precise. But this last piece is because new research indicates this is the likely number extrapolating from what is known about the population of Saturn’s moons.

The question of the number of moons of a planet comes up often, especially when astronomers find a multitude of new ones around one planet or another … like when ten were announced around Jupiter, or 20 more around Saturn. But it also oversimplifies the situation; Saturn’s rings are made up of countless small pieces of water ice; so does it have billions of moons? What is the size of an object that you consider to be a moon?

And of course he sidesteps the fact that these are known moons. And that’s the problem with these planets: finding these moons is difficult. They are small, they are weak, they are next to a large bright planet, the planets move against the background of stars from night to night (word planet is Greek for “wandering”), the moons move around the planet … it is hard.

There’s also the issue of whether the moving blip you see in your sighting is something no one has seen before or really a new discovery. For example, many faint moons of Saturn were observed some time ago, and their orbits were not well enough determined to predict their exact positions very far into the future.

To solve both problems – to search deeper to find weaker moons around Saturn and to find previously observed “lost” or near-lost moons – in the new work that astronomers have turned to the Canada-France-Hawaii telescope, a 3.6-meter telescope in Hawaii. Over the course of two nights, they observed two large areas of the sky on either side of Saturn look for the weak moons.

And not just any faint moons, but irregular those. It’s a bit of a fuzzy definition, but regular moons are those that orbit in the same direction as Saturn (called prograde) and with an orbit inclined less than a few degrees from Saturn’s equator. Most large moons are regular satellites and likely formed with Saturn, or were created when large regular satellites were impacted and the resulting debris melted into smaller moons.

Irregulars orbit backwards – retrograde – and may have orbits slightly inclined with respect to the equator of the gas giant. These are probably captured planetesimals (1 km or more of chunks of matter that formed from the disc of matter surrounding the Sun when the planets were formed), although it is not known exactly how they were captured. They cannot simply orbit Saturn; they need a mechanism to slow down in passing. They may have been caught in Saturn’s gravity early on and slowed down by matter around the planet while it was still forming, for example. If the planetesimal were binary, then one could orbit Saturn while the other was ejected (or collided with Saturn itself); the second removes enough energy for the first to be captured.

This is another reason why astronomers searched for these moons; the more we find, the better we can understand them.

They took dozens of short exposure images (to minimize smudging from a moon’s orbital motion), then did something clever to search for moons. They used a fixed reference (in this case the first frame taken) and then shifted subsequent frames by the amount an irregularly tilted retrograde moon could move between exposures. The stars will become blurry or streaky, but all moons will become brighter in images using such a method. They then scanned all possible moons this way with the naked eye, literally having two astronomers on the team visually inspect each frame – I did something like that, and it’s fun at first. but it becomes tedious really quick, so kudos to them.

They then started again, shifting the images using a different value for orbital motion and tilt, and then watched again. And even. And even.

When they were done, they found 120 moving objects that match their settings, 74 of which were fairly firm detections. They then compared them to known moons and found that out of the 42 they expected to see, they found 34. The eight they didn’t see were because they were too close to the edge. of the image, or were in images where the viewing conditions were not as clean. They are therefore convinced that they would have seen all the known moons they could.

That still leaves several dozen new ones that they have found. They are not yet confirmed, so for now they are moon candidates. Yet, extrapolating from the number they found to the low light they could see, they think there are 150 irregular moons (± 30) up to 2.8 km in size. That’s probably three times more than Jupiter has.

Discovering them is good, but scientists want more. They want to know why they are there and what they are doing, and what it means to understand the Saturn system.

Phoebe is Saturn’s largest irregular moon*, about 200 km wide and 8 million km from Saturn. Some of the moons they found have orbits similar to Phoebe’s, and therefore are likely remnants of past collisions with this moon.

But many of them had orbits different enough from Phoebe’s that it was highly unlikely that they were associated with them. Astronomers believe they may have formed when a smaller retrograde moon crashed into catastrophic collisions, forming a lot of debris that became those moons. Given their size distribution – over time other collisions shrink the moons to smaller sizes – they believe this collision may have happened over the past few hundred million years. It’s recent ! Remember, the solar system is 4.6 billion years.

And there’s more. There is a huge but very weak and diffuse ring of matter around Saturn called the phoebe ring, and this is likely caused by debris blown from the surface of its eponymous moon. However, it is too much big: The impacts on Phoebe alone can’t explain how certain particles got away from Phoebe. The new work indicates that there are likely many more tiny moons with orbits similar to Phoebe but further away from Saturn, and the impacts on them could contribute to the matter of the ring.

What all of this shows us is that a) Saturn’s lunar system is complicated, and 2) there is a parcel of moons there, whatever you call a moon. Myself, I’m not worried about an exact number, since there isn’t one, really! I’m more interested in how many there are above a given size, and how they orbit, and how they formed, and what they have done in the meantime to create and contribute to the wild environment. and strange around Saturn.

It’s much more important than a single number always will change the more we look at Saturn. Or on any planet.

Don’t sweat the records. Focus on the big picture: Saturn is amazing.


*Supposing it is not actually an extraterrestrial vehicle loaded with protomolecule.


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Here is the sunspot! – Astronomy now https://sinia-planeta.com/here-is-the-sunspot-astronomy-now/ https://sinia-planeta.com/here-is-the-sunspot-astronomy-now/#respond Sun, 24 Oct 2021 12:22:30 +0000 https://sinia-planeta.com/here-is-the-sunspot-astronomy-now/ The Sun on October 24, showing sunspot AR2887 near the southeastern limb of the Sun. Image: SDO / HMI. A new major sunspot has just turned in the area of ​​the southeast limb of the Sun’s photosphere. Sunspot officially designated AR2887, it was first seen around the limb of the Sun on October 22. Just […]]]>
The Sun on October 24, showing sunspot AR2887 near the southeastern limb of the Sun. Image: SDO / HMI.

A new major sunspot has just turned in the area of ​​the southeast limb of the Sun’s photosphere. Sunspot officially designated AR2887, it was first seen around the limb of the Sun on October 22. Just 24 hours later, it had doubled in size and exhibited dramatically increased complexity as it cleaned the limb from the Sun and astronomers could better observe it.

The Sun captured on October 24 in extreme ultraviolet (304 angstroms – 0.00000000304 m) by NASA’s Solar Dynamics Observatory (SDO). Sunspot AR2887 is clearly very active and more active regions are located in the eastern limb.

Additionally, solar spacecraft are keeping an eye out for three other active regions on the other side of the Sun (not yet numbered) that will soon be visible. Indeed, the image above, taken on October 24 by the Solar Dynamics Observatory of NASA, already shows evidence at the level of the eastern limb of the Sun.

What are sunspots?

Sunspots are temporary regions of intense magnetic disturbance that result in cooler regions on the Sun’s photosphere that appear darker in contrast to their surroundings. Sunspots can appear individually or in groups and can last for weeks or months.

Sunspots occur on an average cycle of 11 years and currently the Sun is not long in cycle 25, which began in December 2019 and is expected to continue until 2030. In 2019, 281 days – 77% – were spotless to 208 spotless days. days (57%) in 2020. So far this year, only 60 days (20%) have passed without a visible sunspot, so solar activity resumes as we move towards the solar maximum and experience a maximum sunspots; so the Sun never seems to be without some sunspots. The last solar maximum took place in 2013/2014.

A release of accumulated energy in the sunspot region can cause solar flares and colossal solar storms called coronal mass ejections (CMEs). The Space Weather Prediction Center (SWPC) of the National Oceanic and Atmospheric Administration (NOAA) previously reported that AR2887 produced several Class B flares (flares are rated A, B, C, M or X, X being the most powerful).

As AR2887 turns to Earth over the coming week, astronomers will be on the lookout for other ejections that could potentially be heading our way. CMEs can interact with the Earth’s magnetic field to provide us with splendid auroral displays. On a more sober note, very powerful flares can cause CMEs that can wreak havoc with orbiting satellites and even affect terrestrial technologies such as power grids and long-range radio communications.

Observe the AR2887 sunspot for yourself

Although the Sun is currently peaking at a relatively low elevation compared to summer, you can still easily track the progress of the AR2887 and potential new sunspots. One of the safest and easiest methods to observe the Sun in white light is the proven projection method.

The Sun’s disk can easily be projected through a small refractive telescope onto a piece of white cardboard. Note the cardboard shield. Image: Geoff Elston.

A small telescope with an aperture of 60 to 100 mm (2.5 to 4 inches) (or a pair of binoculars) is used to project the image of the Sun onto a piece of white card held about eight inches behind the ocular. Never look directly at the Sun when you point your telescope; rather, watch for the tube’s tiniest shadow on the ground. Indeed, never look directly at the Sun at any time, as the ding can cause serious and even irreversible damage to your eyesight.

A dedicated H-alpha telescope offers great views of sunspots and other solar phenomena such as prominences.

A full aperture white light solar filter, made of a metallized Mylar film or, preferably, coated glass, and supplied by a reputable astronomy dealer, will give great views. You can also go the H-alpha or Calcium route by purchasing a small dedicated telescope, like those made by Lunt and Coronado.


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