Astronomy – Sinia Planeta http://sinia-planeta.com/ Fri, 13 May 2022 21:09:17 +0000 en-US hourly 1 https://wordpress.org/?v=5.9.3 https://sinia-planeta.com/wp-content/uploads/2021/10/icon-50-120x120.png Astronomy – Sinia Planeta http://sinia-planeta.com/ 32 32 What makes supermassive black holes like Sagittarius A* shine? https://sinia-planeta.com/what-makes-supermassive-black-holes-like-sagittarius-a-shine/ Thu, 12 May 2022 13:47:11 +0000 https://sinia-planeta.com/what-makes-supermassive-black-holes-like-sagittarius-a-shine/ Black holes are, by definition, places where gravity is so strong that not even light can escape. So they are black – dark – and impossible to imagine. To the right? As evidenced by the success of the Event Horizon telescope, we can pictures of black holes. But what these pictures show is shadow of […]]]>

Black holes are, by definition, places where gravity is so strong that not even light can escape. So they are black – dark – and impossible to imagine. To the right?

As evidenced by the success of the Event Horizon telescope, we can pictures of black holes. But what these pictures show is shadow of the black hole on a brighter background. The light you see does not come from the black hole itself, but from a region around it called the accretion disk. It is a disc-like structure of matter falling inward, pulled to its doom by the gravity of the black hole. Once it crosses the event horizon, or the point of no return, it disappears from view. But outside the event horizon, we can still see it – and any light it gives off.

Build an accretion disk

Why is there a disk? Can’t everything that falls fall into the black hole at the same time? It can’t! Because everything in the universe has its own moment (in particular, angular momentum), it cannot fall directly into the gaping maw of a black hole. Instead, it has to lose that momentum first, and it does so by swirling around in a disk, getting closer and closer until it finally crosses the event horizon and disappears.

The physics behind this is complex, but the simplified story is that accretion disks transfer angular momentum from their inner regions to their outer regions through processes such as turbulence and friction. Essentially, as matter swirls closer to the black hole, it collides and rubs against After material already on disk. This slows the fall of materials and generates heat. And when it heats up (here, we take tens of millions of degrees), it shines.

And astronomers are real pros at looking for things that sparkle.

We see light from accretion disks over a wide swath of the electromagnetic spectrum. X-rays or visible light usually come from the hot disc itself. Also, the light coming directly from the accretion disk is not constant. It changes, flickering on timescales that can range from minutes and hours for small stellar-mass black holes to weeks or months for supermassive black holes that sit at the centers of galaxies. This flickering is random, and the researchers suspect it may be due to processes within the disk, such as regions of higher turbulence or even clumps of matter approaching or falling into the black hole.

The rate of variability – although still random – scales with the mass of the black hole. More massive black holes with larger accretion disks change more slowly than those with less mass and smaller accretion disks. The Event Horizon Telescope (EHT) has detected changes in accretion disks around supermassive black holes in M87 (the first black hole ever photographed, released in April 2019) and 3C 279 “over the course of a week”, Dan Marrone at the University of Arizona, a member of the EHT scientific council and coordinator of the data analysis working group, said Astronomy in 2019. “And since Sgr A* is 1,500 times less massive than M87, it varies all the more quickly. Reduce a week by 1,500 times, you’re talking minutes.

Taking a clear photo is extremely difficult when the subject you are trying to photograph literally changes from minute to minute, while you try to capture it. So when it came to getting an image of Sgr A*, Marrone said, it wasn’t necessarily about getting more data. Instead, “figuring out how to deal with a source that changes while we’re watching it is a bigger deal.”

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Can we protect the Earth from an asteroid hurtling towards us https://sinia-planeta.com/can-we-protect-the-earth-from-an-asteroid-hurtling-towards-us/ Thu, 12 May 2022 03:54:00 +0000 https://sinia-planeta.com/can-we-protect-the-earth-from-an-asteroid-hurtling-towards-us/ The best-known asteroid to collide with Earth is the Chicxulub crater, which struck the Yucatán Peninsula 65 million years ago. It is known for having wiped out the dinosaurs, as well as three quarters of life on the planet. Other huge craters like the Vredefort Crater in South Africa and the Sudbury Basin in Ontario, […]]]>

The best-known asteroid to collide with Earth is the Chicxulub crater, which struck the Yucatán Peninsula 65 million years ago. It is known for having wiped out the dinosaurs, as well as three quarters of life on the planet. Other huge craters like the Vredefort Crater in South Africa and the Sudbury Basin in Ontario, Canada were even larger and likely headed our way a few billion years ago.

In recent years, meteoroids have hit us, the smaller cousin of the asteroid. Tunguska hit Siberia in 1908 and lit up the skies as far away as London; and Chelyabinsk, another Russian hit, was filmed in 2013.

A big one hasn’t hit us in a while, but the next one is somewhat inevitable, according to Nancy Chabot, a planetary scientist at Johns Hopkins University. “Although there are currently no known asteroids that are about to hit us in the foreseeable future, asteroids have been hitting Earth for billions of years and it is truly a cosmic inevitability,” Chabot says.

But what will happen when a huge object rushes towards us? Will we know in advance and will we be able to defend ourselves?

Asteroid Tracking

According to Chabot, scientists already track about 90% of the largest asteroids (about a kilometer or more), using ground-based telescopes that take multiple photos over multiple nights. They then trace their orbit. Once we track asteroids, we can know where they are for decades or even a century. None of these currently pose a threat.

However, planetary defense experts are much more concerned with smaller objects, a few hundred meters or even longer. These asteroids could do a lot of damage to the planet and we only track less than half of them, says Chabot. They are smaller and therefore harder to find. Although the objects we know of are not currently a threat, there is a world of undiscovered asteroids or comets that could hit the planet without warning.

“If something this smaller in size hit Earth, it wouldn’t necessarily be an extinction-level event, but it would be regional devastation,” Chabot says.

NASA’s next big thing in planetary defense is putting a telescope in space that’s “good for finding asteroids,” she says. It would be an infrared telescope, or infrared telescope, that could detect infrared radiation and find those smaller, darker objects hidden deep in the night sky.

“Most of the telescopes we put up in space are designed to observe very distant objects, but these objects are very close to the Earth in our solar system, so they move very quickly. This telescope should be good for observing the things nearby,” explains Chabot.

Intercept asteroids

Once we know where the asteroids are, we will have enough time to warn us if they are heading our way. That’s where NASA’s latest planetary defense project, Double Asteroid Redirection Test (DART), comes in. DART is an autonomous rocket that can nudge or deflect asteroids to slightly alter their trajectory so they don’t hit not the planet. DART uses “kinetic impact technology,” which Chabot says is like crashing a spacecraft into an object to slightly redirect its orbit. DART lifted off last November and will reach the Didymos asteroid system around September. It will test its deflection technology on a 160-meter-wide asteroid.

But the only way DART works is if you have enough warning time to send your rocket into space and start pushing it. What happens when we miss the window and it’s ready to crash into the planet?

Phillip Lubin majors in planetary defense at the University of California, Santa Barbara. His recent research describes a technique called Pulverize It (PI) that would use “penetrating rods” to smash the asteroid into fragments small enough to burn before hitting Earth. If it was a “planet killer” sized asteroid, nuclear-capable interceptors would have to break up the object and scatter the pieces. All the while, they were far enough away not to touch the planet.

Ultimately, we need to know where the objects are, and then we need to know the possibility of intercepting them to push or break them. But Lubin says, we’re not there yet. We potentially have the technology that could stop most threats, but we are still in a “detailed analysis and simulation phase”.

“Humanity does not currently have a robust planetary defense program – period. We largely track threats and hope they don’t hit us,” Lubin says.

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Should earthlings blow up our location in the cosmos https://sinia-planeta.com/should-earthlings-blow-up-our-location-in-the-cosmos/ Tue, 10 May 2022 19:35:13 +0000 https://sinia-planeta.com/should-earthlings-blow-up-our-location-in-the-cosmos/ Sending new messages Nearly half a century after the Arecibo message, two international teams of astronomers are planning new attempts at extraterrestrial communication. One uses a giant new radio telescope and the other chooses a compelling new target. One of these new messages will be sent by the world’s largest radio telescope, in China, sometime […]]]>

Sending new messages

Nearly half a century after the Arecibo message, two international teams of astronomers are planning new attempts at extraterrestrial communication. One uses a giant new radio telescope and the other chooses a compelling new target.

One of these new messages will be sent by the world’s largest radio telescope, in China, sometime in 2023. The telescope, 1,640 feet (500 meters) in diameter, will emit a series of radio pulses on a wide strip of sky. These on-off pulses are like the 1s and 0s of digital information.

The message is called “The Beacon in the Galaxy” and includes prime numbers and mathematical operators, the biochemistry of life, human forms, the location of Earth, and a timestamp. The team sends the message to a group of millions of stars near the center of the Milky Way galaxy, about 10,000 to 20,000 light-years from Earth. While this maximizes the pool of potential extraterrestrials, it means it will be tens of thousands of years before Earth receives a response.

The other attempt targets only one star, but with the potential for a much faster response. On October 4, 2022, a team from the Goonhilly satellite earth station in England will send a message to the star TRAPPIST-1. This star has seven planets, three of which are Earth-like worlds in the so-called “Goldilocks Zone,” meaning they could also harbor liquid and potentially life. TRAPPIST-1 is only 39 light-years away, so it could take intelligent life 78 years to get the message and Earth to get the answer.

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Bad astronomy | Why does the asteroid Bennu launch small rocks into space? https://sinia-planeta.com/bad-astronomy-why-does-the-asteroid-bennu-launch-small-rocks-into-space/ Mon, 09 May 2022 13:00:09 +0000 https://sinia-planeta.com/bad-astronomy-why-does-the-asteroid-bennu-launch-small-rocks-into-space/ Why does Bennu spit pebbles into space? It’s one of the weirdest things he does, and that’s saying something. Bennu is a small asteroid just over 500 meters across. It has the shape of two cones glued together base to base. It’s not a solid rock, but rather a pile of rubble, like a bag […]]]>

Why does Bennu spit pebbles into space?

It’s one of the weirdest things he does, and that’s saying something. Bennu is a small asteroid just over 500 meters across. It has the shape of two cones glued together base to base. It’s not a solid rock, but rather a pile of rubble, like a bag of rocks held together by gravity. It has a huge rock that protrudes 22 meters high called Benben Saxum.

And, also, well, it spits rocks into space.

Bennu is a near-Earth asteroid, moving around the Sun in a slightly elliptical orbit the same size as Earth’s orbit. It can approach up to half a million miles from us, so it’s classified as a potentially dangerous object, although at least for the next three centuries it won’t come close enough to us to pose a real threat. . Still, we want to know more about these rocks that could potentially hit us and ruin our day, so NASA sent the OSIRIS-REx mission there to map Bennu and possibly send samples back to Earth for scientists to study.

One of the many discoveries of this mission is that Bennu somehow pulls small rocks from its surface into space. It was one of the biggest surprises of the mission, and it’s unclear how it turns out. A likely cause is small micrometeorite impacts hitting the surface and detonating shrapnel. Another is heat stress: the day/night cycle when Bennu rotates causes the rocks on the surface to expand and contract as they move in and out of sunlight, eventually cracking them. It may throw small pieces.

The size of these spittoons seen ranged from very small to about 10 centimeters in diameter. Gravity on Bennu is little more than a whisper, just a few millionths of Earth’s, but if you can go back to the dark memories of high school science, you might remember van der force Waals, where some tightly packed molecules attract or repel each other. others due to their electron clouds. This force is weak, but in an asteroid whose surface is made up of jagged rock, it can help build a cohesive force that holds the asteroid together. That too has to be overcome, and throwing a boulder the size of your fist at speeds of a few centimeters to a few meters per second takes some effort, so it’s impressive that Bennu can muster that kind of punch.

But is this the only way to eject the stones? Just because we can think of two that cover most bases doesn’t mean they cover them all. A team of scientists has therefore looked into another possible launch mechanism: electrostatic charge. [link to paper].

The Sun’s ultraviolet light is very powerful, and when a UV photon hits Bennu’s surface, it can knock an electron away from an atom. As more hits and more electrons are lost, the rocks acquire a positive charge. If enough charge builds up, a rock can feel a force that pushes it away from its fellows, and that might be enough to overcome low gravity and launch it into space.

The Sun also blows a wind of subatomic charged particles, and this solar wind can also hit the surface and build up a static charge, and in the end can also launch pieces of rock into space. It’s the cosmic equivalent of rubbing a balloon over your hair and sticking it to a wall, although in this case you get an attractive force instead of a repulsive force, but it’s the same physics.

This buildup of electrostatic charge almost certainly occurs on Bennu, but what scientists have been investigating is the possibility that it is actually strong enough to spit rocks. What they discovered is that it is possible, but the force is quite weak, so it only works if the rock is small enough; assuming that no van der Waals cohesion can be projected up to about a centimeter. So that’s probably not why we’re seeing the bigger ones being ejected, but it might keep the smaller ones away.

Interestingly, some of the rocks seen ejected were on the night side of Bennu. Sunlight obviously can’t explain them at all, but solar wind still can. When the particles blow in front of Bennu, they block them on the day side, leaving a shadow behind them, a hole, as if you had to stand downwind of a building to protect yourself from the wind. It’s called a plasma wake, and the physics are pretty fierce, but the wind’s magnetic field can still connect to the surface on the downwind side of the asteroid, allowing particles to hit it. . However, by modeling this, the scientists discovered that the force was much weaker, too weak to explain rocks being thrown during the local night on Bennu.

So it seems that electrostatic charge is at best a minor force at work here, but it’s still valuable research. On the one hand, it can still work on the smallest bits and is probably very good at removing dust from the surface. Also, the electrostatic cohesion properties of rubble-pile asteroids are not well known, so a study like this is a good step in understanding that.

There will be a time in the future when a small bag of rocks like Bennu will be aimed at us, and we will have to do something to keep it from touching. In this case, the more we know about it, especially the forces that hold it together, the better. We probably wouldn’t want to blow it up, but rather set it aside, but even then we need to understand its structure to be able to do that.

It’s not every day that astronomy can literally save the world, but that day will come.

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Exploring Space – A Beginner’s Guide to Astronomy https://sinia-planeta.com/exploring-space-a-beginners-guide-to-astronomy/ Sat, 07 May 2022 10:00:00 +0000 https://sinia-planeta.com/exploring-space-a-beginners-guide-to-astronomy/ Published: 11:00 a.m. 7 May 2022 Alan Willison, President of the Hertford Astronomy Group, continues his beginner’s guide to getting started in astronomy. An astrophysicist at Bayfordbury Observatory in Hertfordshire. – Credit: Danny Loo / Archant. Space observation is one of the oldest sciences. Ever since mankind stared into space, hypotheses have been created and […]]]>

Published:
11:00 a.m. 7 May 2022



Alan Willison, President of the Hertford Astronomy Group, continues his beginner’s guide to getting started in astronomy.


An astrophysicist at Bayfordbury Observatory in Hertfordshire.
– Credit: Danny Loo / Archant.

Space observation is one of the oldest sciences. Ever since mankind stared into space, hypotheses have been created and the desire to test them has grown.

Early observers noticed that star patterns remained fixed relative to each other and that cultures around the world created stories related to the clusters.

These stories were independent of other cultures, although they often chose the same star patterns to base their stories on.

These patterns are known as constellations and are still very important to astronomers as they act like a map of the sky and help us find our way around the night sky.

The names of many of these constellations are known to us through astrological horoscopes that we may be familiar with.

Indeed, making horoscopes was considered a source of income for Johannes Kepler, who made important discoveries in astronomy.

Sometimes what looked like a star appeared and wandered through the constellations. They were the planets – the wanderers.

Astrology and astronomy began to separate in the 17th century and became completely separate disciplines in the 18th century.

Galileo gave astronomy its huge boost when he made a telescope and pointed it at Jupiter and discovered some of its moons.

Other people started making and using telescopes and the age of space exploration had really begun.

Until then, the five planets – Mercury, Venus, Mars, Saturn and Jupiter – were familiar objects in the sky, with Earth making up the sixth known planet.

Then, in 1781, William Herschel found a seventh. William was living in Bath and studying the constellation Gemini for a long time when he noticed that one of the background “stars” had changed position.

Originally, William thought it was a comet, but using a telescope he had built himself, he concluded that it was a planet. !

He wanted to name it after the monarch George III, but then it was decided to stick to naming objects according to classical mythology and it was given the name Uranus.

William was not alone in his astronomical work as he lived with his sister Caroline, who was also a dedicated astronomer and worked closely with her brother.


William Herschel's 40-foot telescope, 1789

William Herschel’s 40-foot telescope, 1789
– Credit: author unknown, public domain, via Wikimedia Commons

Bath has a small museum acknowledging the work of the Herschels in the home of William and Caroline.

The house has been completely restored in the authentic style of the period and Dr. Brian May, Queen’s lead guitarist, is the patron of the museum.

This is rather appropriate since, like William Herschel before him, he is both a musician and an astronomer.

Uranus from Digswell


Uranus seen from Digswell, photographed by Richard Sheppard

Uranus seen from Digswell, photographed by Richard Sheppard

– Credit: Richard Sheppard

Uranus can be seen through a telescope and will appear as a small blue circle as seen in Richard Sheppard’s photo.

However, it is too aligned with the Sun to do so currently, so request a telescope for Christmas and start looking for it at this time of year.

Want to know more about William and Caroline Herschel? Come to the Hertford Astronomy Group meeting on May 11 at the University of Hertfordshire when Professor Mike Dworetski will give his lecture ‘Backyard Astronomy in the 18th Century’.

Details and tickets can be obtained at https://hertsastro.org.uk

Picture of the month


Solar flares photographed by Steve Heliczer

Solar flares photographed by Steve Heliczer
– Credit: Steve Heliczer

The Sun goes through 11-year periods of activity and is currently in its 25th (as records have been kept).

This results in an increase in the number of sunspots and solar flares.

On April 15, multiple coronal mass ejections left the Sun but fortunately none were directed towards Earth.

This photo shows many solar flares on the limb (edge) of the Sun and it is reasonable to assume that there are as many on the side facing us.

The photo was taken in my garden in Cuffley.

Steve Heliczer

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National Astronomy Day Celebration at River Ridge Observatory Saturday https://sinia-planeta.com/national-astronomy-day-celebration-at-river-ridge-observatory-saturday/ Thu, 05 May 2022 16:36:20 +0000 https://sinia-planeta.com/national-astronomy-day-celebration-at-river-ridge-observatory-saturday/ They are hosting a day of sky-related events from 4-10 p.m. on Saturday, May 7, in honor of National Astronomy Day, and it will be well worth your time to sign up. The observatory is north of Maumelle Lake in far eastern Perry County, about 35 feet from the I-430 and Highway 10 interchange. (You […]]]>

They are hosting a day of sky-related events from 4-10 p.m. on Saturday, May 7, in honor of National Astronomy Day, and it will be well worth your time to sign up. The observatory is north of Maumelle Lake in far eastern Perry County, about 35 feet from the I-430 and Highway 10 interchange. (You will get more specific directions after you sign up.)

Details (including what to bring and what NOT to bring) and a registration link:

National Astronomy Day Solar and Lunar Observing Event – River Ridge Observatory.

This special event is free, but attendance will be limited to 80 people. All ages are welcome. A link to register is below, and you must register to attend. If you register and have a plan change, please email info@caasastro.org.

Presentations and activities:

4:00 – 6:00 Solar observation with h-alpha sunglasses and Sunspotter.
4:00 p.m. – 6:00 p.m. Giant bubbles and Stomp rockets – Observation field
4:00 p.m. – 6:00 p.m. Celestial Art Competition for Children – Bridge
4:00 p.m. – 8:00 a.m. Information tables:
Viewing the 2024 Solar Eclipse – Darcy Howard
Arkansas Natural Sky Association Board
UALR Meteor Collection
4:15 p.m. – 4:25 p.m. Welcome to the RRO Etiquette & Star Party – Amphitheater
4:30 – 5:15 Novice Observer Program – Classroom
5:15 – 6:00 p.m. Saving the Night Sky for Wildlife and People – Classroom
6:00 p.m. – 7:00 p.m. Dinner, presentation and presentation of the telescope, questions and answers and help with the telescope – Observing Field
7:00 a.m. – 7:25 a.m. Using binoculars to observe the sky, go from one star to another and hunt for celestial treasure – Amphitheater
7:30 a.m. – 7:45 a.m. Constellation Tours – Viewing Field, Bridge, and Parking Area
7:45 a.m. – 10:00 a.m. Telescope observation and celestial treasure hunt

Instructions and suggestions:
This is not a dark sky event, as always on NAD, a quarter moon will rise. However, white flashlights, flashing shoes and the like are not permitted on the viewing field and cell phones must be turned off. You can use a white flashlight to get to and from your vehicle as parking will be on the road. Otherwise, you probably don’t need a flashlight unless you’re doing the celestial treasure hunt. If you think you might want a light on the viewing scope, bring a red flashlight or place red film (available at some arts and crafts stores or auto parts stores) over a white light, or purchase a small red keychain at the event. ($5 with choker).

Collapsible chairs, ground blankets, insect repellent and warmer clothes than you think might come in handy. If you want to try your hand at celestial treasure hunting and have binoculars, bring them. There will be a few binoculars to lend, first come first served. You want help setting up a telescope, bring it. If you register, please plan to attend the entire event. In any case, the last entry is at 9:15 am. No drugs, alcohol or pets, please.

Eat and drink

CAAS is not a food retail establishment and you may bring your own food. However, grilled chili dogs, sausages and sides will be available. Suggested donation of $6 for adults, $4 for children appreciated. Snacks and drinks will be available for sale.

Ok, if you are ready to participate, register here.

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Quad-Cities Popular Astronomy Club: May Features a ‘Blood Flower Moon’ | Local News https://sinia-planeta.com/quad-cities-popular-astronomy-club-may-features-a-blood-flower-moon-local-news/ Wed, 04 May 2022 21:50:50 +0000 https://sinia-planeta.com/quad-cities-popular-astronomy-club-may-features-a-blood-flower-moon-local-news/ By Alan Sheidler People’s Astronomy Club I must admit that I have always been interested in speed. The speed at which things move has always fascinated me. What is the speed of an airliner, an automobile, a galloping horse, a snail or a horsefly? Granted, a jet airliner is faster than a garden snail on […]]]>

By Alan Sheidler People’s Astronomy Club

I must admit that I have always been interested in speed. The speed at which things move has always fascinated me.

What is the speed of an airliner, an automobile, a galloping horse, a snail or a horsefly? Granted, a jet airliner is faster than a garden snail on a miles per hour (or kilometers per hour) basis – but is that the best way to compare their speeds? What if we consider the size of the object and compare the time it takes for the accelerating object to move its own length?

Quad-Cities Skywatch logo

For example, let’s say a Boeing 747 (which is 70.6 meters long) is cruising at 900 kilometers per hour. If you divide the length of this airliner by its speed, you find that it takes just under three tenths of a second to travel its own length. Seems pretty quick to me.

But compare the 747 to a horse. I won’t bore you with the math, but a galloping horse can cover its own length in less than two-tenths of a second. Therefore, a horse is actually faster than the 747 when you factor in speed versus size.

People also read…

And a gadfly? I was surprised to learn that a male gadfly pursuing a female was measured at 145 km/h! Absolutely, it’s fast. But considering its small size (1 inch or 25 millimeters), this male gadfly moves its own length in an incredibly fast 0.00063 seconds. Now it’s really fast!

So now consider the modest garden snail. We’ve all seen one of these little guys go at a breakneck speed of one hundredth (0.01) km/h. It is indeed slow on an absolute basis, but considering that the average size of a snail is maybe 1.2 inches, and dividing its length by its speed, we see that a garden snail moves over its own length in just under 11 seconds, which is faster than I thought.

Now consider a very fast moving object – the moon. The moon’s actual speed varies a bit because its orbit is slightly elliptical. But its average speed in orbit around the Earth is about 3,660 km/h, or more than 2,200 miles per hour.

Everyone would agree that it’s fast, right? But now consider that the moon is 3,475 kilometers in diameter. Adjusting the moon’s speed to its size, we find that it travels its own diameter in just under an hour – about 57 minutes, to be exact. Compared to a garden snail, the moon is downright quiet. In fact, the moon is one of the few objects that moves by its own diameter in about an hour.

We will have the opportunity on Sunday May 15 to see the movement of the moon in real time. A lunar eclipse will begin that evening around 9:28 p.m. Central Time.

At this time – assuming the sky is clear – we will see the moon enter the darkest part of Earth’s shadow, called the umbra. At around 9:45 p.m. you should see a “bite” on one side of the moon’s disk and watch it gradually grow larger as the eclipse progresses.

This partial eclipse phase will continue as the moon dips deeper and deeper into Earth’s shadow for about an hour. At 10:29 p.m., the moon will be completely in shadow and will continue to be fully eclipsed for about 85 minutes as it gradually passes through Earth’s dark shadow.

The moon will be deepest in shadow at 11:12 p.m. Totality will end at 11:54 p.m. when the moon begins to re-emerge from the shadows. The remaining partial phase of the eclipse will continue until 12:56 a.m. Monday morning as the moon leaves the shadow and is gradually re-illuminated by sunlight.

During partial eclipse phases, the moon will move its own diameter from light to shadow and then back again. The time needed to do this is just over an hour because the moon’s path is slightly offset from the center of the Earth’s shadow. This means that the moon will have to travel a bit further to go from light to dark and vice versa.

Nevertheless, a lunar eclipse is a good opportunity to observe the movement of the moon in real time and prove to yourself that the moon indeed moves by its own diameter in about an hour.

This month’s lunar eclipse will also be a great opportunity for anyone who wants to enjoy one of nature’s most interesting and beautiful astronomical events. As the lunar eclipses go, this will be one of the best in a long time.

During the eclipse, Earth’s dark shadow will cover the moon’s surface for 85 minutes, during which time there will be no direct sunlight on the moon’s surface. The moon should theoretically be invisibly dark during the time it is in shadow; however, there will still be refracted light from Earth’s atmosphere that will make its way to the lunar surface.

As a result, we’ll see a dimly lit moon that can take on a very interesting color – a dull shade of red, brick red, orange, copper, or even gray. We won’t know the colors we will actually see until the eclipse occurs.

Imagine you are an astronaut standing on the surface of the moon and looking up at the sky during the eclipse. What you would see would be something beautiful and miraculous.

Watching the Earth pass in front of the Sun, you would always see the Earth’s atmosphere glow like a reddish halo as sunlight is refracted or bent around the Earth. This reddish halo is caused the same way we have red sunsets or sunrises on Earth.

Sunlight refracted from Earth’s atmospheric halo dimly illuminates the moon’s surface. So even if there is no direct sunlight falling on the part of the moon in shadow, it will still be visible to us as a pale reddish color.

The colors seen on the moon can be very different depending on whether there were recent volcanic eruptions, thick clouds, or thunderstorms on Earth before the eclipse. Dust particles and clouds can filter sunlight, causing dramatic shades of red.

A total lunar eclipse is called a “blood moon” because it can look almost blood red. The May full moon is sometimes referred to as the “flower moon” because May is the month when flowers bloom.

This month’s Lunar Eclipse might be called the “Blood Flower Moon” but whatever we call it, it should be good. Look for a spot with a clear view of the southwest sky and bring a pair of binoculars or a small telescope.

Often when we hear or read the word “eclipse” it is followed by some sort of warning to protect your eyes. This warning, however, only applies to solar eclipses. During a lunar eclipse there is no danger to your eyes, so you can safely view it without any eye protection and use binoculars or a telescope without a filter.

As you may have understood, a lunar eclipse is only possible when the moon is full. Because the full moon is very bright, its light drowns out darker deep sky objects.

As the lunar eclipse unfolds, however, the moon darkens and allows other nearby objects to shine through. Watch the moon darken and other nearby stars appear.

You won’t want to miss this event. Let’s hope for clear skies and keep looking up.

PAC invites the public to its next viewing session at Niabi Zoo on May 21 at sunset and on the third Saturday of each month until November. To learn more, visit the PAC website at popularastronomyclub.org or search for the club on Facebook.

The longest partial lunar eclipse in 600 years will occur this week

Popular Astronomy Club Photographs Recently Discovered Comet Leonard

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Bad astronomy | Martian rocks show signs they were created explosively https://sinia-planeta.com/bad-astronomy-martian-rocks-show-signs-they-were-created-explosively/ Tue, 03 May 2022 15:15:45 +0000 https://sinia-planeta.com/bad-astronomy-martian-rocks-show-signs-they-were-created-explosively/ In the distant past, Mars was extremely volcanic. In some ways this is obvious. The Tharsis region, a little smaller than the continental United States, has 12 major volcanoes, including Olympus Mons, the largest known volcano in the entire solar system. It is 22 km high and 600 km wide, the width of Colorado. Additionally, […]]]>

In the distant past, Mars was extremely volcanic.

In some ways this is obvious. The Tharsis region, a little smaller than the continental United States, has 12 major volcanoes, including Olympus Mons, the largest known volcano in the entire solar system. It is 22 km high and 600 km wide, the width of Colorado.

Additionally, the planet’s surface is covered in basalt, a dark gray volcanic rock. It’s everywhere, indicating that most of the surface rocks were put in place by volcanoes. Later this was modified by air, water – almost all gone now, but 3 or 4 billion years ago Mars was quite wet – and asteroid/comet impacts.

But there are different types of volcanic eruptions. Some are explosive and catastrophic, but others are slow and less violent. They produce different types of rocks, which can tell a lot about the history of an area.

Nili Fossae is a region of Mars characterized by long concentric depressions in the ground called graben. These can be stress-induced cracks from nearby impacts or swelling of the surface due to subsurface activity. It’s unusual for Mars in that it’s very rich in the mineral olivine, which forms on Earth in the mantle.

Presumably on Mars, this was also the case. It can be ejected by volcanoes or carved out by large impacts and distributed around. It is also rich in carbonates, another mineral found in volcanic eruptions.

The Jezero crater is in Nili Fossae, which is convenient: this is where the Perseverance rover is currently moving. This means that mineral assays taken from orbit can be compared to literal ground truth.

And this is where the fun begins: another crater was also found to be abnormally rich in olivines and carbonates: the Gusev crater, where the Spirit rover explored from 2004 to 2010. Nili Fossae and Gusev are the two regions most richest in olivine on Mars.

What is strange is that they are 6,000 kilometers apart! It is unlikely that they had the same source of olivines and carbonates, which implies that whatever made them so must have happened in at least two places on Mars, which in turn implies that this was an important process in Martian geology.

So were these minerals gently deposited on the surface of Mars in these two regions, or were the deposits more violent?

Regarding Nili Fossae in particular, there has been a lot of debate about it. But new work strongly suggests it was the latter: whatever enriched these two wildly separated areas was very violent. And not only that, but Many times violent.

A team of scientists examined images of Jezero and Gusev provided by the rovers using their close-up cameras, getting magnified views of rock structures [link to paper]. Curious dark streaks have been observed in the rocks of Gusev, shaped something like flames. This type of structure is called fiamme (Italian for “flame”) and indicates pumice rocks that have been crushed under pressure and heated. This is also seen on Earth.

It’s interesting! This kind of thing happens during violent volcanic eruptions called pyroclastic flows, where superheated gas and ash shoot out of a volcanic vent and screech down at speeds of hundreds of miles per hour. This material is deposited again and again in layers during episodic energetic eruptions, so you end up with a bizarre mixture of igneous and sedimentary rocks: they are volcanic, therefore igneous, but stratified, therefore sedimentary. The weight of the layers above plus the heat can weld and deform the pumice stone to make it flame.

This type of rock in general is called ignimbrite — from the Latin fire (igni) and rain (imbri), thus a shower of fiery debris. This would imply that the Nili Fossae and Gusev deposits were indeed created during terrifying events.

There is more. At Nili Fossae, orbital images show long, roughly parallel cracks in the rock surface that geologists call joints. This is common in the cooling of ignimbrite, which contracts on cooling and generates a series of joints. This was also obvious to scientists, who noted that the same is seen on Earth, always in welded ignimbrite deposits, again strongly implying that these rocks were not smoothly made.

They also advance other more subtle arguments, but in the end all their evidence points to titanic and repeated violent eruptions. I will note that the evidence supports this, but it is circumstantial. There could be other ways to make these structures on Mars that we don’t yet know about. But still, if I were to bet, it looks like good odds.

No doubt we will learn more as new missions are sent to the red planet. The story of Mars is, like Earth, a study of long, slow processes punctuated by sudden, frightening ones. Volcanism played an outsized role, so just knowing what type of volcanism it was is a good step forward.

And we still don’t know what happened to its air and water. Much of Mars has been mapped, and in great detail, and we are even learning about its interior. But it’s a big planet. Smaller than Earth, but it’s far away and difficult to study. Scientists are getting better all the time, and this flood of data from the last few years will take decades to sort through. This argument is not over yet, and even when it is, it will have to fit into the bigger picture of Mars. There is much more to discover.

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Five Thousand Exoplanets at NASA’s Exoplanet Archive https://sinia-planeta.com/five-thousand-exoplanets-at-nasas-exoplanet-archive/ Mon, 02 May 2022 15:53:31 +0000 https://sinia-planeta.com/five-thousand-exoplanets-at-nasas-exoplanet-archive/ Christiansen, J. in Handbook of exoplanets (eds Deeg, H. & Belmonte, J.) 1933–1947 (Springer, 2018). Wolszczan, A. & Frail, DA Nature 355145-147 (1992). Article on Google Scholar Ads Wolszczan, A. Science 264538–542 (1994). Article on Google Scholar Ads Sigurdsson, S. et al. Science 301193–196 (2003). Article on Google Scholar Ads Bailes, M. et al. Science […]]]>
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    Partial Solar Eclipse – Space and Astronomy Coming April 30 https://sinia-planeta.com/partial-solar-eclipse-space-and-astronomy-coming-april-30/ Sat, 30 Apr 2022 09:56:31 +0000 https://sinia-planeta.com/partial-solar-eclipse-space-and-astronomy-coming-april-30/ April 30 will be full of astronomical events: a partial solar eclipse is coming, which will not be visible from Italy, and at the same time Venus and Jupiter will put on a show at dawn. “These are two of the brightest planets to observe and they will rise just before the sun in the […]]]>

    April 30 will be full of astronomical events: a partial solar eclipse is coming, which will not be visible from Italy, and at the same time Venus and Jupiter will put on a show at dawn. “These are two of the brightest planets to observe and they will rise just before the sun in the constellation Pisces,” Paolo Volpini of the Union of Italian Astronomers (Uai) told ANSA. “The unavoidable pairing scene will be very visible – he adds – even if the two planets are very low on the horizon.”

    On the other hand, the cause of the partial solar eclipse is the phenomenon of the black moon: “During the day, there will be a second new moon for April”, explains Volpini, “which thus welcomes five lunar phases instead of the usual four. “. .” At this time, the Sun, Moon and Earth are aligned, but not completely, so the Moon’s shadow falling on Earth will partially block the Sun. “The eclipse will be visible in South America and the South Pacific.” , Volpini’s comments.

    During the month of April, it was also possible to admire all the other planets in the morning, with the exception of Mercury, which became visible in the second part of the month in the evening. Moreover, the best time of the year to observe it falls precisely on these days, when the planet sets about two hours after the sun.

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