Solar system – Sinia Planeta http://sinia-planeta.com/ Sat, 14 May 2022 05:14:48 +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 Solar system – Sinia Planeta http://sinia-planeta.com/ 32 32 Cosmic Fossils: What Meteorites Reveal About Our Solar System https://sinia-planeta.com/cosmic-fossils-what-meteorites-reveal-about-our-solar-system/ Thu, 12 May 2022 02:20:57 +0000 https://sinia-planeta.com/cosmic-fossils-what-meteorites-reveal-about-our-solar-system/ First visitors Humans have seen rocks falling from the sky for thousands of years. One of the earliest potential recorded accounts dates back to 1478 BC. AD, when, according to the Chronicle of Parian, a “lightning stone” fell on the island of Crete. In 465 BC. BC, the Greek poet Pindar saw a meteorite land […]]]>

First visitors

Humans have seen rocks falling from the sky for thousands of years. One of the earliest potential recorded accounts dates back to 1478 BC. AD, when, according to the Chronicle of Parian, a “lightning stone” fell on the island of Crete. In 465 BC. BC, the Greek poet Pindar saw a meteorite land not far from the hill where he was sitting. And in 1492, a stone fell from the sky just outside the town of Ensisheim, France, becoming a wonder in Europe for centuries. It was widely believed that these stones formed in the clouds and, when heavy enough, simply fell to Earth. Where could these ordinary-looking rocks come from?

But at the beginning of the 19th century, a number of events occurred that changed the way people understood and studied these objects. On April 26, 1803, the villagers of L’Aigle, France saw and heard an astonishing fall. Over 3,000 stones were recovered, making the event impossible to ignore. Just two years earlier, astronomer Giuseppe Piazzi had discovered the asteroid Ceres, clearly showing that there were other objects than planets circling the Sun. Geologists and chemists were also making great strides in understanding Earth’s rocks and developing techniques to reveal their structure.

Around the year 1800, British chemist Edward Charles Howard acquired several suspected meteorites, including examples of each of the three main types of meteorites recognized today: stony, ferrous, and ferrous. Howard was the first to dissect and subject these alien stones to chemical analysis. In 1802 he reported that all three types of meteorites had a high level of nickel, a composition unprecedented in Earth rocks.

Two years later, a British mineralogist, William Thomson, tried to polish an iron meteorite with nitric acid, revealing a striking crystalline pattern. These became known as the Widmanstätten lines after Count Alois von Beckh Widmanstätten, who made a similar discovery in 1808. No such pattern is seen in mined iron on Earth. These two men had discovered the ancient frozen crystal structure of iron meteorites, unchanged for billions of years.

Leapfrogging into the 20th and 21st centuries, meteorite research has advanced thanks to new techniques and equipment used to study these cosmic visitors. These investigations included, unexpectedly, an archaeological mystery. In 1911, British archaeologist Gerald Avery Wainwright discovered iron necklace beads in a 5,500-year-old Egyptian cemetery at Gerzeh, about 70 km south of modern Cairo. And when British archaeologist Howard Carter opened the tomb of Pharaoh Tutankhamun in 1922, he found – among many fine artifacts – a magnificent ceremonial dagger with a gold hilt and an iron blade.

The presence of these iron artifacts was obvious, because during Tutankhamun’s lifetime 3,300 years earlier, the Egyptians had not yet mastered the art of iron smelting and were still using bronze for their weapons. Chemical tests indicated a high level of nickel in the beads of Gerzeh and the blade of Tutankhamun, indicating an extraterrestrial origin. However, in the 1980s, some archaeo-metallurgists suggested that nickel-rich iron ores found on Earth may have been the source of these artifacts.

Finally, in 2016, researchers reported in Meteoritics and Planetary Science a non-invasive examination of King Tutankhamun’s iron dagger that confirmed its meteoritic origins. The team used a portable X-ray fluorescence spectrometer, which examines the wavelengths of fluorescent elements to determine their abundance. The researchers found that the dagger contained almost 11% nickel and around 0.6% cobalt, whereas earth iron produced before the 19th century rarely exceeds 4% nickel. They then compared this to iron meteorites found within a 1,200 mile (1,930 km) radius of Tutankhamun’s tomb and found a possible match – the Kharga meteorite, discovered in 2000 near the city of Marsa Matruh, in Egypt. Using similar tests, the Gerzeh pearls were shown in 2013 to have originated from an iron meteorite.

]]>
The Solar System Is Really Messed Up (And That Could Mean Planet 9 Exists) https://sinia-planeta.com/the-solar-system-is-really-messed-up-and-that-could-mean-planet-9-exists/ Sat, 07 May 2022 13:30:07 +0000 https://sinia-planeta.com/the-solar-system-is-really-messed-up-and-that-could-mean-planet-9-exists/ Billions of years ago, when it first emerged from the clouds of gas and dust, the solar system was supposed to be in order. Then gravitational forces turned everything upside down. What happened in the first solar system was not exactly like the thermonuclear explosion that knocked the Moon out of orbit in Space: 1999. […]]]>

Billions of years ago, when it first emerged from the clouds of gas and dust, the solar system was supposed to be in order. Then gravitational forces turned everything upside down.

What happened in the first solar system was not exactly like the thermonuclear explosion that knocked the Moon out of orbit in Space: 1999. Even though no nuclear waste was lying around like in the movie, the phenomena that happened back then still had enough power to throw huge planets around. The gas giants – Jupiter, Saturn, Neptune, Uranus and possibly another unknown body that could have been the elusive Planet 9 – floated around the nascent Sun in circular orbits and even…until they be disturbed.

How did these huge planets end up where they are now? As the dusty, gaseous protoplanetary disk slowly dissipated, the orbits of the gas giants are believed to have changed from evenly spaced and circular to irregularly spaced and oblong. the nice model (as in Nice, France) states that it happened due to chaotic instability. University of Michigan researcher Seth Jacobson, co-author of a study recently published in Natureand his team suspected something else and wanted to find out what was really behind this change.

“Terrestrial planets would have finished forming at the time of the Nice instability, but their orbits don’t appear to register such massive dynamical instability,” Jacobson told SYFY WIRE. “This got us wondering if a different giant instability triggered earlier in the solar system’s history could explain many of the same phenomena as the original Nice model.”

Something else that looks almost out of Space: 1999 caused Jacboson to rethink this model. The Moon was thought to have suffered rapid impacts from asteroids and other objects in what was called a terminal cataclysm. But he thinks those strikes, which eventually formed huge pools, probably didn’t all happen at once. It was more likely a series of impacts that occurred over a long period of time as chunks of rock left over from the planetary formation hit the lunar surface. Maybe those planetesimals were jealous.

Instead of the kind of lunar instability and bombardment suggested by the Nice model, it’s possible that a “bounce” effect reorbited the gas giants. These planets tend to crawl towards their star during its early stages of development. When the protostar reaches puberty, it has already accumulated most of the primordial gas around it, and the gas in the disc becomes less dense. It also heats up and creates a photoevaporation front. This is where the disk is eaten from the inside out, the gas closest to the star being ionized (molecules gain or lose electrons) by its intense radiation.

“The gravitational interactions between each planet and the disk change because there is no longer as much gas inside the planet as there was before photoevaporation,” Jacobson said. “This causes a change in the direction of the planet’s migration, what we call the rebound effect.”

So when the gas giants were too close to the photoevaporation front, that explains why they started to retreat. The only exception is Jupiter because it has already vented enough gas into the disk to grow to the immense size it is now. However, when the others retreated from the Sun, they destabilized the solar system. Their orbital resonances caused by the movement towards the Sun have been disturbed. An orbital resonance is the gravitational influence of bodies orbiting in space on each other because their orbital periods are in a ratio of two whole numbers (such as 3:5). After the resonances of the gas giants were shattered, everything they passed reacted to them.

The chaos finally subsided, so the new orbits of the gas giants stabilized, but their eccentric orbits bear witness to this ancient disturbance. Jacobson and his team created simulations of these interactions in which gravitational forces constantly change the positions and speeds of the Sun and planets. But what does all this have to do with Planet 9? Southwest Research Institute (SwRI) researcher David Nesvory thinks a shift in Jupiter’s axis could have thrown an additional ice giant in the solar system.

“If the solar system was still in its natal stellar birth cluster, then it’s possible that, rather than this hypothetical ice giant becoming a free-floating planet, it could have been deflected by nearby stars into a distant orbit around our Sun, just like the alleged Planet 9,” Jacobson said.

There’s a chance there really is a rejected ice giant 50 billion kilometers from the Sun. So you get an idea of ​​the distance, it’s 47 billion miles further from our star than Neptune. Maybe one day he will come out of hiding.

Resident Alien Season 2

]]>
What was the “childhood” of the solar system like? https://sinia-planeta.com/what-was-the-childhood-of-the-solar-system-like/ Fri, 06 May 2022 01:40:00 +0000 https://sinia-planeta.com/what-was-the-childhood-of-the-solar-system-like/ How did the planets form? How did the solar system evolve? Teacher. LIU Beibei from Zhejiang University School of Physics, in collaboration with Professor Sean Raymond of the University of Bordeaux in France and Professor Seth Jacobson of Michigan State University in the United States, proposed a new model for the evolution of the orbits […]]]>

How did the planets form? How did the solar system evolve?

Teacher. LIU Beibei from Zhejiang University School of Physics, in collaboration with Professor Sean Raymond of the University of Bordeaux in France and Professor Seth Jacobson of Michigan State University in the United States, proposed a new model for the evolution of the orbits of the giant planets of the solar system. They pointed out that the scattering of the Sun’s gaseous protoplanetary disk likely triggered the instability of the giant planets.

LIU Beibei (middle) and his students

This groundbreaking discovery was published in Nature April 27.

The planetary orbits of the solar system that we see today are significantly different from what they were in its “infancy”. At the start of the solar system, a concentration of interstellar dust and hydrogen gas called a molecular cloud contracted. The proto-Sun formed at the hot, dense center and the rest of the cloud formed a swirling disk called the solar nebula. This period is also known as the gas disc period. Scientists believe that the four giant planets – Jupiter, Saturn, Uranus and Neptune – migrated to a chain of orbital resonances.

Four giant planets migrated in a chain of orbital resonances.

Today, however, the orbits of the giant planets seem to be more widely distributed, and these planets have deviated from their original resonances. The orbital structure is thought to have been sculpted by an episode of dynamic instability among the giant planets.

The Nice Model, originally developed by an international team of scientists in 2005 in Nice, France, is the most popular model explaining the evolution of the solar system. He postulates that the orbital instability occurred hundreds of millions of years after the formation of the solar system. As the protoplanetary disk dispersed, the giant planets interacted with the outer stellar disk to exchange orbital energy and were eventually freed from resonances, thereby triggering dynamic stability. Due to the extremely slow process, this orbital instability is considered a “late instability”.

Together with Jacobson and Raymond, Liu proposed that disk dispersion could explain the evolution of planetary orbits, a factor not taken into account in previous models.

The idea started with a conversation Raymond and Jacobsen had in 2019. They then contacted Liu, who pioneered the idea of ​​the rebound effect through extensive simulations of gas disks and large exoplanets – planets from other solar systems – that orbit close to their stars.

“In the late phase of the gas disk, the high-energy photons emitted from the Sun directly hit the planetary disk, the strong light pressure blew the gas near the Sun, and a hollow structure formed inside the planetary disk. planetary disk. The subsequent slight pressure gradually dispersed the gas remaining in the upside-down disk, and the mass of the disk decreased with the outward expansion of the disk. This process is known as photoevaporation”, said Liu, “The Sun was like a giant hair dryer, constantly ‘blowing’ gas into the disc.”

Theoretical calculations by Liu and his team showed that due to the rapid dissipation at the inner edge of the disk, the planet was subject to the outward gas force, which differed greatly from the inward forces at the others. places on the disc. When the inner rim of the disk extended outward, the planet migrated outward instead of migrating inward. This mechanism is called “rebound”. Due to their different masses, the giant planets would migrate outwards at different speeds, thus breaking the original state of orbital resonance and triggering dynamical instability.

Pattern of rebound effects, similar to the game of badminton, where the shuttlecock changes course and bounces outward with the face of the racket

The dynamic instability of the first orbits caused the four giant planets and one other ice giant planet to undergo substantial orbital variations during the dissipation of the gas. The giant ice planet was catapulted out of the solar system after its near collision with Jupiter. The final orbital configuration of the four giant planets is consistent with what we observe today.

The giant planets find themselves close to their current orbit after the instability triggered by the dispersion of the disk of gas.

“Our study indicates that the dynamical instability following gas disk dispersion occurred about five to ten million years after the formation of the solar system, earlier than the Nice model suggests,” said Liu.

“We are able to find new evidence for the age of lunar craters,” Liu said. “The dynamic instability of the giant planets could perturb the rest of the solar system, and their powerful gravitational disturbances could force small bodies around them to continually collide with other planets and moons, leaving craters on the surface. of celestial bodies. Lunar craters differ significantly in age. Asteroid impact events naturally decrease over time, which is also consistent with the early instability model study proposed by our team.

“Early dynamic instability is more consistent with the timing of asteroid impacts in other celestial bodies in the solar system. Our model can also provide a deep understanding of the masses and orbital configurations of terrestrial planets,” Liu said.

“In the future, our team will further explore the impact of changing orbits of giant planets on the formation of Earth and the origin of water,” Liu added.

Photo credit: LU Shaoqing and LIU Beibei

/Public release. This material from the original organization/authors may be ad hoc in nature, edited for clarity, style and length. The views and opinions expressed are those of the author or authors.View Full here.

]]>
Extended Exploration for 8 Planetary Science Missions – NASA Solar System Exploration https://sinia-planeta.com/extended-exploration-for-8-planetary-science-missions-nasa-solar-system-exploration/ Wed, 27 Apr 2022 20:18:49 +0000 https://sinia-planeta.com/extended-exploration-for-8-planetary-science-missions-nasa-solar-system-exploration/ Following a thorough evaluation, NASA has extended the planetary science missions of eight of its spacecraft due to their scientific productivity and their potential to further our knowledge and understanding of the solar system and beyond. These missions have been selected for continuation, assuming their spacecraft remain in good condition: Mars Odyssey Mars […]]]>

Following a thorough evaluation, NASA has extended the planetary science missions of eight of its spacecraft due to their scientific productivity and their potential to further our knowledge and understanding of the solar system and beyond.

These missions have been selected for continuation, assuming their spacecraft remain in good condition:

  1. Mars Odyssey
  2. Mars reconnaissance orbiter
  3. MAVEN
  4. Mars science lab (Curiosity rover)
  5. InSight Lander
  6. Lunar reconnaissance orbiter
  7. OSIRIS-REx
  8. New Horizons

“Extended missions provide us with the opportunity to leverage NASA’s significant investments in exploration, allowing science operations to continue at a cost far below the cost of developing a new mission,” said Lori Glaze, director of the Planetary Science Division at NASA Headquarters in Washington. “Maximizing taxpayer dollars in this way allows missions to gain valuable new science data and, in some cases, allows NASA to explore new targets with entirely new science goals.”

Most assignments will be extended for three years; however, OSIRIS-REx will be continued for nine years in order to reach a new destination, and InSight will continue until the end of 2022, unless the spacecraft’s electrical power permits longer operations.

Each extended mission proposal was reviewed by a panel of independent experts from academia, industry and NASA. In total, more than 50 reviewers assessed the scientific return of the respective proposals. Two independent review chairs oversaw the process and, based on the panel’s assessments, confirmed that these eight science missions held substantial potential to continue to deliver new discoveries and address compelling new scientific questions.

In addition to providing significant programmatic benefits to NASA, several of these missions promise multidivisional science benefits across NASA’s Science Mission Directorate (SMD), including their use as data relays for landers. and Mars surface rovers, as well as to support other NASA initiatives such as as Commercial Lunar Payload Services (CLPS).

Two of the extended missions, MAVEN and OSIRIS-REx, welcome new Principal Investigators (PIs).

OSIRIS-APEx

Principal Investigator: Dr. Daniella DellaGiustina, University of Arizona)J

The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission is currently on its way back to Earth to deliver the samples from asteroid Bennu it collected in 2020. Dante Lauretta, OSIRIS- REx PI, will remain in place for the main mission, while DellaGiustina begins her role as newly appointed PI for OSIRIS-APophis EXplorer (OSIRIS-APEX). With a new name to reflect the new objectives of the extended mission, the OSIRIS-APEX team will redirect the spacecraft to encounter Apophis, an asteroid approximately 1,200 feet (about 370 meters) in diameter that will come within 20,000 miles (32,000 kilometers) from Earth in 2029. OSIRIS-APEX will enter orbit around Apophis shortly after the asteroid’s Earth flyby, providing an unprecedented close look at this S-type asteroid. It plans to study the changes in the asteroid caused by its close flyby of Earth and to use the spacecraft’s gas thrusters to attempt to dislodge and study dust and small rocks on and below Apophis’ surface.

MAVEN

Principal Investigator: Dr Shannon Curry, University of California, Berkeley

The Mars Atmosphere and Volatile Evolution (MAVEN) mission plans to study the interaction between the atmosphere and the magnetic field of Mars during the next solar maximum. MAVEN’s observations as the Sun’s activity level increases toward the peak of its 11-year cycle will deepen our understanding of how Mars’ upper atmosphere and magnetic field interact with the Sun.

Insight

Principal Investigator: Dr. Bruce Banerdt, JPL

Since landing on Mars in 2018, the Inland Exploration using Seismic, Geodetic and Heat Transport (InSight) mission has operated the only active seismic station beyond Earth. His seismic monitoring of “marsquakes” has provided constraints on the interior, formation and current activity of Mars. The extended mission will continue InSight’s seismic and weather monitoring if the spacecraft remains in good condition. However, due to dust accumulation on its solar panels, InSight’s power generation is low and the mission is unlikely to continue operations for the duration of its current extended mission unless its solar panels are cleaned by a “dust devil” passing on Mars. atmosphere.

Lunar reconnaissance orbiter (LRO)

Project Scientist: Dr Noah Petro, GSFC)

LRO will continue to study the surface and geology of the Moon. The evolution of LRO’s orbit will allow it to study new regions far from the poles in unprecedented detail, including permanently shaded regions (PSRs) near the poles where water ice can be found. LRO will also provide significant programmatic support to NASA’s efforts to return to the Moon.

Mars Science Laboratory (MSL)

Project Scientist: Dr. Ashwin Vasavada, JPL

The Mars Science Laboratory and its Curiosity rover have traveled more than 27 km across the surface of Mars, exploring the history of habitability in Gale Crater. In its fourth extended mission, MSL will climb to higher altitudes, exploring critical sulfate-bearing layers that provide unique insight into the history of water on Mars.

New Horizons

Principal Investigator: Dr. Alan Stern, SwRI)

New Horizons flew by Pluto in 2015 and the Kuiper Belt Object (KBO) Arrokoth in 2019. In its second extended mission, New Horizons will continue to explore the distant solar system up to 63 astronomical units (AU) from the Earth. The New Horizons spacecraft can potentially perform multidisciplinary observations relevant to the solar system and NASA’s heliophysical and astrophysical divisions. Additional details regarding New Horizons’ science plan will be provided at a later date.

Mars Odyssey

Project Scientist: Dr. Jeffrey Plaut, JPL

The extended Mars Odyssey mission will perform new thermal studies of rocks and ice below the surface of Mars, monitor the radiation environment, and continue its long-running climate monitoring campaign. The Odyssey orbiter also continues to provide unique support for real-time data relay from other Mars spacecraft. Odyssey’s extended mission duration may be limited by the amount of propellant remaining on board the spacecraft.

Mars reconnaissance orbiter (MRO)

Project Scientist: Dr. Rich Zurek, JPL

MRO has provided a wealth of data regarding processes on the surface of Mars. In its sixth extended mission, MRO will study the evolution of the surface, ice, active geology, atmosphere and climate of Mars. In addition, MRO will continue to provide important data relay service to other Mars missions. The MRO’s CRISM instrument will be completely shut down, after the loss of its cryocooler put an end to the use of one of its two spectrometers.

NASA’s Planetary Science Division currently operates 14 spacecraft across the solar system, has 12 missions in formulation and implementation, and partners with international space agencies on seven others.

Learn more about the Planetary Science Main Exam 2022: https://science.nasa.gov/solar-system/documents/senior-review

]]>
The US Space Command has confirmed that the first meteor from outside the solar system has hit Earth https://sinia-planeta.com/the-us-space-command-has-confirmed-that-the-first-meteor-from-outside-the-solar-system-has-hit-earth/ Tue, 26 Apr 2022 18:23:55 +0000 https://sinia-planeta.com/the-us-space-command-has-confirmed-that-the-first-meteor-from-outside-the-solar-system-has-hit-earth/ An asteroid is a rocky object in space that is smaller than a planet. Meteoroids are smaller space rocks than asteroids and can range from the size of a speck of dust to a large boulder. When a meteoroid enters the Earth’s atmosphere and burns up, it becomes a meteor. Larger meteoroids can sometimes survive […]]]>

An asteroid is a rocky object in space that is smaller than a planet. Meteoroids are smaller space rocks than asteroids and can range from the size of a speck of dust to a large boulder. When a meteoroid enters the Earth’s atmosphere and burns up, it becomes a meteor. Larger meteoroids can sometimes survive passage through Earth’s atmosphere before completely burning up and scattering debris that makes it to the planet’s surface. When this happens, they become meteorites. With those definitions established, US Space Command confirmed that a 2014 meteor was the first recorded interstellar object to enter Earth’s atmosphere.

NASA constantly tracks space objects to detect possible collision paths with Earth (NASA/JPL-Caltech)

In October 2017, scientists discovered what was believed to be the first interstellar object to enter our solar system. The object, named 1I/’Oumuamua, was about 400 meters long and shaped like a fire extinguisher. While the origin of the single object most likely came from outside the solar system, Dr. Amir Siraj and Dr. Abraham Loeb of Harvard University’s Department of Astronomy determined that an earlier meteor was in made the first interstellar object in our solar system.

In 2014, a meteor designated CNEOS 2014-01-08 crossed the sky near Manus Island, Papua New Guinea. At just 1 meter in diameter, the meteor has mostly burned up with very few meteorites scattered over the Pacific Ocean. The meteor was observed and added to a public database by NASA and the DOD. After eight months of studying Oumuamua, Siraj and Loeb consulted this database and realized that the Manus Island meteor in 2014 might be an even older interstellar object.

The US Space Command has confirmed that the first meteor from outside the solar system has hit Earth
An artist’s concept by Oumuamua (European Southern Observatory/M. Kornmesser)

According to scientific research, a celestial object traveling at over 42 kilometers per hour could come from outside the solar system. With the Manus Island meteor in 2014 hitting Earth’s atmosphere at around 45 kilometers per second, Siraj and Loeb were confident of their discovery. The certainty was heightened after the duo conferred with other scientists. However, the accuracy of the data collected by the government could only be confirmed by an anonymous source through a private conversation. To formalize their discovery, Siraj and Loeb needed an official memo.

The US Space Command has confirmed that the first meteor from outside the solar system has hit Earth
The official Space Command memo confirming the interstellar object (US Space Command)

In 2022, scientists got the official recognition they were looking for. On March 1, US Space Force Deputy Commander Lt. Gen. John E. Shaw signed a memo to NASA confirming Siraj and Loeb’s findings. The memo was also signed by Space Force Space Operations Command chief scientist Dr. Joel Mozer. “I had the pleasure of signing a memo with @ussfspocChief Scientist Dr. Mozer to confirm that a previously detected interstellar object was indeed an interstellar object, a confirmation that has helped the wider astronomical community,” read a tweet from US Space Command.

]]>
The largest moons in our solar system https://sinia-planeta.com/the-largest-moons-in-our-solar-system/ Tue, 19 Apr 2022 14:40:28 +0000 https://sinia-planeta.com/the-largest-moons-in-our-solar-system/ The solar system does not lack moons. Like the planets they orbit, they are each unique in their own way. Some moons are so large that if they were orbiting the Sun instead of a planet, they would likely be considered planets in their own right. Others are so small that they are more closely […]]]>

The solar system does not lack moons. Like the planets they orbit, they are each unique in their own way. Some moons are so large that if they were orbiting the Sun instead of a planet, they would likely be considered planets in their own right. Others are so small that they are more closely related to asteroids and meteors than to planets. The solar system contains hundreds of individual moons, the majority of which orbit Jupiter and Saturn. In fact, Jupiter and Saturn have so many moons that scientists keep discovering more in their orbits. Since there are so many moons, it would be difficult to list them all and compare their size. Let’s focus instead on the ten largest moons in the solar system.

Ganymede

An illustration of Jupiter and its largest moon, Ganymede

Orbiting the planet Jupiter is the largest moon in the solar system. Called Ganymede, it is 3,275 miles (5,270 kilometers) in diameter. This makes Ganymede even larger than the planet Mercury, which is 3,032 miles (4,879 kilometers) in diameter. If Ganymede formed orbiting the Sun rather than Jupiter, it would likely be defined as a planet. Ganymede was one of the first planets discovered in our solar system. In 1610, astronomer Galileo Galilei pointed a telescope at Jupiter and identified four bright spots surrounding the giant planet. After several observations, Galileo determined that these four luminous points were in orbit around Jupiter. Galileo found these four objects to be moons orbiting Jupiter, and they were later named the Galilean moons of Jupiter. Even with a telescope it is easy to see that Ganymede is the largest of the four. In terms of appearance, Ganymede resembles Earth’s moon: a heavily cratered, gray-colored surface. However, appearances can be deceiving. Ganymede is a unique planet, and it is the only moon in the solar system that produces its own magnetic field. Additionally, Ganymede is thought to have an ocean of liquid water beneath its crust. Ganymede orbits Jupiter at a distance of 1.07 million kilometers and completes one orbit every seven Earth days.

Titan

Titan
Saturn and its largest moon, Titan

The second largest moon in the solar system is Saturn’s largest moon, Titan. It is only slightly smaller than Ganymede, with a diameter of 3,200 miles (5,150 kilometers). Like Ganymede, if Titan were to orbit the Sun rather than a planet, it would be considered a planet itself. Titan was discovered by astronomer Christiaan Huygens in 1655, but just about everything about Titan will remain a mystery for centuries. In 1944, astronomer Gerard Kuiper discovered that Titan has a large atmosphere, unlike most moons in the solar system. It may be similar in size to Ganymede, but Titan is a very different world. Not only does it have an atmosphere, but it also has an intriguing surface.

Unfortunately, Titan’s surface is hidden beneath its dense hydrocarbon atmosphere. It wasn’t until the Cassini mission, launched in 1997, that scientists got their first glimpse of Titan and its mysterious surface. When Cassini arrived on Saturn in 2004, he deployed the Huygens probe. Huygens’ mission was to enter Titan’s atmosphere and land on the surface. Huygens gave scientists their first good look at the surface, revealing a world that looked more like Earth than a typical moon. The exterior was covered with rivers, streams, lakes and seas. However, unlike Earth, temperatures on Titan are far too cold for water to exist in liquid form. Instead, the liquid on Titan’s surface is liquid methane and ethane. It even rains liquid methane on the surface. Titan and Earth are the only two known worlds in the solar system where it rains. Titan orbits Saturn at a distance of 759,000 miles (1.2 million kilometers) and completes one orbit every 16 Earth days.

Callisto

calliste
Jupiter behind its second largest moon, Callisto

In 1610, Galileo discovered the four large moons of Jupiter. The farthest from Jupiter was called Callisto. Callisto is Jupiter’s second largest moon and the third largest in the entire solar system, with a diameter of 2,995 miles (4,820 kilometers). Callisto’s surface is heavily cratered and is probably the least active world in the solar system. There is little or no history of geologic activity on Callisto, so its surface has seen virtually no change in its 4.5 billion year history. Callisto has the oldest known surface in the solar system. Callisto orbits Jupiter at a distance of 1.17 million miles (1.88 million kilometers), making it the farthest moon from Jupiter. It takes Callisto 17 Earth days to orbit Jupiter.

Io

io moon
An image of Io, one of Jupiter’s moons, with a volcanic eruption depicted on the surface

Io is one of four Galilean moons of Jupiter discovered by Galileo in 1610. Io is Jupiter’s innermost moon and is 2,264 miles (3,643 kilometers) in diameter. Although Galileo discovered Io over 400 years ago, virtually everything about Io was a mystery until Voyager flybys in the late 1970s. When scientists received the first close-up images of Io , what they saw was incredible. The surface was entirely devoid of impact craters, which is odd given the number of craters on other moons around Jupiter. Stranger still, the surface of Io was covered in different colors, including yellow, red, and green. Io looked completely different from any other moon. When scientists were analyzing images of Io taken by Voyager, one stood out.

This particular image of Io had a strange crescent shape just on the surface of Io. At first, scientists assumed that this crescent was just another moon behind Io. However, the orbital paths of nearby moons did not match the image. They soon realized they were observing a volcanic eruption on Io. The crescent was volcanic material rising from the surface and escaping into space. Io was found to be the most volcanically active world in the solar system, with over 400 confirmed active volcanoes. This was a surprise for a moon barely larger than our moon.

Generally, small planets lose their internal heat quickly after they form. As a result, most moons in the solar system are cold and inactive. There is no energy to fuel geologic activity without any internal heat that would otherwise reshape the surface. This is why most moons are covered in craters. Io apparently breaks this rule. It’s a small world, but it must contain enough internal heat to power hundreds of active volcanoes. Io’s internal heat source comes from friction in its core. This friction is created when Jupiter’s gravity pulls on Io, compressing and stretching the moon. Io orbits Jupiter at a distance of 262,000 miles (421,700 kilometers) and completes an orbit every 1.8 Earth days.

The ten biggest moons












Rank Moon Planet Diameter

1

Ganymede

Jupiter

3,275 miles (5,270 km)

2

Titan

Saturn

3,200 miles (5,150 km)

3

Callisto

Jupiter

2,995 miles (4,820 km)

4

Io

Jupiter

2,264 miles (3,643 km)

5

Moon

Earth

2,159 miles (3,475 km)

6

Europe

Jupiter

1,940 miles (3,122 km)

7

Triton

Neptune

1,682 miles (2,707 km)

8

Titania

Uranus

980 miles (1,578 kilometers)

9

Rhea

Saturn

950 miles (1,529 km)

ten

Oberon

Uranus

946 miles (1,523 kilometers)

]]>
Pluto Wasn’t the First: A Brief History of the Forgotten Planets of Our Solar System https://sinia-planeta.com/pluto-wasnt-the-first-a-brief-history-of-the-forgotten-planets-of-our-solar-system/ Sat, 16 Apr 2022 14:00:00 +0000 https://sinia-planeta.com/pluto-wasnt-the-first-a-brief-history-of-the-forgotten-planets-of-our-solar-system/ A kindergartener in 2005 and a kindergartener in 2006 would have learned very different facts about the number of planets in the solar system. 2006, of course, was the year Pluto was reclassified as a dwarf planet – a move that sparked outrage from a public that tends to romanticize our solar system. But long […]]]>

A kindergartener in 2005 and a kindergartener in 2006 would have learned very different facts about the number of planets in the solar system. 2006, of course, was the year Pluto was reclassified as a dwarf planet – a move that sparked outrage from a public that tends to romanticize our solar system.

But long before the “controversy” of Pluto, other objects moved in and out of the official list of planets in the solar system. Indeed, a kindergarten child in the early 1800s would have learned that Ceres was a planet.

So while the planet argument may seem like a modern astronomical debate, astronomers in the 19th century were plagued with this question of how to define what actually counts as a planet.

RELATED: Hubble Discovers Jupiter-Like Planet Forming in a Very Weird Way

And, as mentioned, Ceres predates Pluto in its controversy. The asteroid belt, which lies roughly between Mars and Jupiter, is filled with planets and minor asteroids. One of these celestial bodies, Ceres, has a surface covered with minerals like clay and carbonates, as well as water ice. It’s a strange world, of course: because it’s not completely frozen and is covered in salt water, scientists think Ceres could harbor microbial life. This puts Ceres in stark contrast to Pluto, which sits on the other side of the solar system and has an entirely frozen surface. Additionally, while Ceres is a dull monochromatic gray, Pluto’s colors range from white and black to bright orange.

Yet Ceres and Pluto have one very important thing in common: astronomers once thought they should be classified as planets, but then changed their minds. It all comes down to size, which in the case of planetary science really matters.

Flashback to the early 19th century. An Italian priest and astronomer named Giuseppe Piazzi at the Palermo Observatory had answered a nearly three-decade-old question: why did the orbits of Mars and Jupiter indicate that a planet existed between them when neither could have been found? On January 1, 1801, Piazzi seemed to answer this question by announcing that he had found a “star” that had moved from its position in the constellation Taurus. Scientists quickly concluded that it must be the missing planet and assumed the problem was solved.


Want more health and science stories in your inbox? Subscribe to Salon The Vulgar Scientist’s weekly newsletter.


Then another “planet” was discovered. On March 28, 1802, the German physician and astronomer Heinrich Olbers discovered Pallas; this was soon followed by Juno in 1804 and Vesta in 1807. Each was duly designated as a planet, although astronomers began to doubt that this increasingly cumbersome system worked. Although scientists had a break for a few decades, a plethora of new discoveries between 1845 and 1852 left the astronomical community with 15 asteroids to consider. None of the news was labeled as a planet, but it was becoming increasingly clear that reforms would be needed. By 1867, it was clear that Ceres was too small to be grouped with a body like Earth, and so it was given a new designation: minor planet. And instead of being given fancy names and symbols, they would be labeled with numbers based on when they were discovered or their orbital determination.

This brings us to Pluto. While Ceres has a diameter of 588 miles (compared to Earth’s diameter of 7918 miles), Pluto has a comparatively heavier diameter of 1477 miles. Still, that didn’t stop Pluto from getting the ax as a planet when the International Astronomical Union met in 2006. The reason was, quite simply, that astronomers had decided there was three criteria to be considered a planet:

Thus, the IAU’s three criteria for a life-size planet are:

It is in orbit around the Sun.

It has sufficient mass to assume hydrostatic equilibrium (an almost round shape).

It “cleaned up the neighborhood” around its orbit.

Because Pluto failed to meet the third requirement – it did not “clean up the neighborhood” around its orbit – it lost its planetary status. Clearing the neighborhood means that the region of space near which it orbits the sun is devoid of larger bodies, having been absorbed by the planet. Ceres, like Pluto, clearly does not meet this criterion: the asteroid belt in which Ceres resides is evidence of a “stranded” planet that has not cleared its vicinity. Indeed, there are several other relatively massive bodies – Vesta, Pallas and Hygiea – also near Ceres.

Pluto had held this planetary distinction for 76 years, beginning with its discovery in 1930 by American astronomer Clyde W. Tombaugh. The demotion of Pluto into a dwarf planet remains controversial, and not just among lay astronomers. A team of American scientists published an article in December in the scientific journal Icarus arguing that a “planet” should be defined as any geologically active celestial body. A co-author argued that we should say that there are “probably more than 150 planets in our solar system”; the article asserted that the need to distinguish planets from moons is cultural, not scientific, and hinders a proper understanding of astronomy.

“We found that during the 1800s the non-scientific public in the Latin West developed its own popular taxonomy on the planets reflecting the concerns of astrology and theology, and that this popular taxonomy eventually affected scientists,” the scientists explained. They then concluded that “using the geophysical planet concept with subcategories for individual characteristics (including gravitational dominance) makes the planet concept both useful and deeply insightful for communicating with the public”. This did not happen in 2006, they claim, because “because the necessary time was not taken to sort out these issues”, the resulting vote led to “a deeper division in the community”.

Ironically, even as Pluto was retrograde, Ceres almost got a promotion. An earlier 21st century proposal to define a planet would have done so by describing a planet as having enough mass to be nearly round and to orbit a star without being a satellite of a planet or a star itself. If this definition had been accepted, Ceres would have become the fifth planet from the Sun.

For more articles from the Salon on astronomy:

]]>
Biggest comet to date is heading towards the inner solar system https://sinia-planeta.com/biggest-comet-to-date-is-heading-towards-the-inner-solar-system/ Fri, 15 Apr 2022 07:00:00 +0000 https://sinia-planeta.com/biggest-comet-to-date-is-heading-towards-the-inner-solar-system/ See bigger. | Using these Hubble Space Telescope Wide Field Camera 3 images taken on January 8, 2022, astronomers have confirmed that the largest comet ever discovered is heading towards the inner solar system. Picture via Nasa. Scientists announcement on April 12, 2022, that they created a high quality image confirming that C/2014 UN271 (Bernardinelli-Bernstein), […]]]>
See bigger. | Using these Hubble Space Telescope Wide Field Camera 3 images taken on January 8, 2022, astronomers have confirmed that the largest comet ever discovered is heading towards the inner solar system. Picture via Nasa.

Scientists announcement on April 12, 2022, that they created a high quality image confirming that C/2014 UN271 (Bernardinelli-Bernstein), affectionately nicknamed BB, is the largest Oort Cloud comet yet discovered. The new comet coreor nucleus, is about 120 km across, about twice the size of comet Hale-Bopp, which gave us such a good show in 1997. And BB is now heading into the inner regions of the solar system.

The good news is that NASA says it won’t come anywhere near Earth. From NASA official announcement:

The giant comet, C/2014 UN271 (Bernardinelli-Bernstein) is hurtling in this direction at 22,000 miles per hour (35,400 km/h), from the outskirts of the solar system. But do not worry. It will never approach closer than a billion kilometers from the sun, which is slightly further than the distance from the planet Saturn. And it won’t be until 2031.

The team behind the study published their results on April 10, 2022, in the Peer-reviewed Astrophysical Journal Letters.

Discovery of the largest comet to date

University of Pennsylvania astronomers Pedro Bernardinelli and Gary Bernstein discovered the comet. They were examining footage from 2014 to 2018 of the Dark Energy Investigation as part of their computer-aided search for trans-Neptunian objects.

Comparison of comet nucleus sizes.
See bigger. | This diagram compares the size of the solid, icy core of comet C/2014 UN271 (Bernardinelli-Bernstein or BB) to several other comets. The majority of cometary nuclei are smaller than Halley’s Comet. They are usually a mile in diameter or less. Comet C/2014 UN271 currently holds the record for large comets. Although astronomers know this comet must be big for them to see it more than 2 billion miles from Earth, only the Hubble Space Telescope has the sharpness and sensitivity to make a definitive estimate of the size of the comet. core. Picture via Nasa/ ESA/ Zena Levy (STScI).

So how big is it?

At the time of the initial discovery, scientists estimated the comet’s icy, dusty core to be 62 to 230 miles (100 to 370 km) wide. The new imagery refines the estimate to a range of between 66 and 86 miles (105 to 140 km), making it about twice the size of comet Hale-Bopp. Comet Hale-Bopp appeared with the naked eye in 1997 and delighted observers around the world. The previous record holder for the largest comet nucleus was C/2002 VQ94 (LINEAR)which measures about 60 miles (100 km) at its widest.

The cosmic block’s new big kid is far from alone, says David Jewitt, professor of planetary sciences and astronomy at UCLA and co-author of the study that refined the measurements of the comet. According to NASA’s announcement:

This comet is literally the tip of the iceberg for many thousands of comets that are too faint to be seen in the farthest parts of the solar system. We always suspected that this comet must be big because it is so bright at such a great distance. Now we confirm it.

Biggest comet to date is getting closer

While the discovery of Comet BB was in 2014, its first appearance on image data was in 2010. At that time, BB was 3 billion miles (4.8 billion km) from Earth , coincidentally around the middle distance of Neptune. Now the object is about a billion kilometers closer, but still well outside the solar system.

Already, the core is releasing gas and dust at an impressive rate of about 2,200 pounds (1,000 kg) per second. The authors of the paper described it as:

…a huge (although uncertain) rate of mass loss.

It was this voluminous outpouring of gas and dust from a body so far away in the solar system that prompted the research team to try to measure what they suspected to be a huge cometary body. Man in Hui from Macau University of Science and Technology, Taipa, Macau, led the team. Hui said:

It’s an amazing object, given how active it is while still so far from the sun. We guessed the comet might be quite large, but we needed the best data to confirm that.

Obtain images of Comet BB

To collect this data, Hui’s team used the Hubble Space Telescope’s Wide Field Camera 3 to take five photos of the comet on January 8, 2022.

In announcing the team’s discovery, NASA described the process the team members used to discern the size of the nucleus against the background of the coma glare and comet tails:

The comet is currently too far away for its nucleus to be visually resolved by Hubble. Instead, the Hubble data shows a bright peak of light at the location of the nucleus. Hui and his team then created a computer model of the surrounding coma and adjusted it to fit the Hubble images. Then the coma glow was subtracted to leave behind the star-shaped core.

By combining the Hubble dataset with radio observations made by the Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile, the team was able to assign upper and lower bounds to the size of C/2014 UN271.

The team also discovered that the comet is less reflective than originally thought. According to Jewitt:

It’s big and it’s blacker than coal.

Conclusion: Comet C/2014 UN271, also known as Comet Bernardinelli-Bernstein or BB, is the largest comet to date, as new images from Hubble confirm. The comet is about twice as large as comet Hale-Bopp, about 120 km wide.

Source: Detection by the Hubble Space Telescope of the nucleus of comet C/2014 UN271 (Bernardinelli–Bernstein)

Via NASA

]]>
Largest comet ever seen passes through our solar system https://sinia-planeta.com/largest-comet-ever-seen-passes-through-our-solar-system/ Thu, 14 Apr 2022 07:00:00 +0000 https://sinia-planeta.com/largest-comet-ever-seen-passes-through-our-solar-system/ A huge comet with a solid center more than twice the width of Rhode Island is on an orbital path that will swing it inside our cosmic neighborhood, astronomers say. The icy intruder is traveling at 22,000 mph from the edge of the solar system towards the sun. In a study published Tuesday in The […]]]>

A huge comet with a solid center more than twice the width of Rhode Island is on an orbital path that will swing it inside our cosmic neighborhood, astronomers say.

The icy intruder is traveling at 22,000 mph from the edge of the solar system towards the sun. In a study published Tuesday in The Astrophysical Journal Lettersscientists said the comet was not of concern as it would not pass anywhere near Earth.

Even when the comet makes its closest approach to the sun, in 2031, it will still be at least 1 billion miles away, said study co-author David Jewitt, professor of planetary sciences and astronomy at UCLA.

This sequence shows how the nucleus of comet C/2014 UN271 was isolated from a vast shell of dust and gas surrounding the solid, icy core.NASA, ESA

“It won’t even cross Saturn’s orbit, so it’s definitely not a threat to us,” he said. The comet, officially known as comet C/2014 UN271, is the largest such object ever observed by astronomers, Jewitt said.

Its core – the solid center, which is usually made up of ice, rock and dust – measures about 85 miles in diameter. This makes it about 50 times larger than most known comets, with an estimated mass 100,000 times that of a typical comet, according to the study.

“That’s a huge amount of matter in one body,” Jewitt said.

Astronomers used the Hubble Space Telescope to observe the colossal comet and determine the size of its nucleus. Hubble took five photos of the icy object on January 8, revealing its luminous core shrouded in a glowing cloud of dust and gas, known as a coma.

“It’s an amazing object, given how active it is when it’s still so far from the sun,” said study lead author Man-To Hui, an assistant professor at the University of Science. and technologies from Macau. said in a press release at the Space Telescope Science Institute, which operates Hubble.

Scientists used a computer model developed from previous observations of the comet through ground and space telescopes to see past the dusty coma and map the core.

In addition to its immense size, astronomers have discovered that the surface of the comet’s nucleus is darker than previously thought.

“Only 3% of the light that hits its surface bounces back,” Jewitt said. “It’s a really, really dark surface. It’s blacker than coal.”

Further research is needed to understand why the core is so dark. Jewitt said it’s possible that prolonged exposure to high-energy cosmic rays “baked” the surface, coating it with a charred material similar to charcoal.

Comet C/2014 UN271 was first detected in 2010 by astronomers Pedro Bernardinelli and Gary Bernstein, when it was 3 billion kilometers from the sun. Although scientists have spent more than a decade studying the comet, the new study is the first to confirm its massive size.

Jewitt said it likely formed more than 4 billion years ago, when the solar system was in its infancy. It is possible, he said, that it developed in the region between Jupiter and Neptune, developing alongside the nascent planets.

“As it grew and the planets grew simultaneously, we think the gravity of the planets may have propelled the comet out of the planetary region,” Jewitt said.

He added that the expelled comet and other similar objects likely ended up in what is known as the Oort cloud, a region beyond Pluto where astronomers believe icy objects orbit the solar system. in a spherical bubble.

Sometimes the gravitational forces of passing stars can jostle distant comets in the Oort cloud, “throwing them into the solar system,” Jewitt said.

Comet C/2014 UN271 is less than 2 billion kilometers from the sun, according to the study. And in a few million years, it will migrate back into the Oort cloud, Jewitt said.

Astronomers hope to continue observing the comet until its closest approach in 2031. Jewitt said studying such objects can reveal information about the solar system and help solve the lingering mysteries of the cosmos.

“It’s a reminder that the outer solar system is not a very well-known place,” he said. “As you move away from the sun, everything is so dim that all kinds of things are waiting to be discovered.”

]]>
Here’s everything we know about the alien object https://sinia-planeta.com/heres-everything-we-know-about-the-alien-object/ Thu, 14 Apr 2022 07:00:00 +0000 https://sinia-planeta.com/heres-everything-we-know-about-the-alien-object/ A meteor that hit Earth in January 2014 has now been confirmed by the US Space Command (USSC) as the first interstellar object from another solar system Representative image of the Milky Way. Nasa A meteor that hit Earth in January 2014 has now been confirmed by the US Space Command (USSC) as the first […]]]>

A meteor that hit Earth in January 2014 has now been confirmed by the US Space Command (USSC) as the first interstellar object from another solar system

Representative image of the Milky Way. Nasa

A meteor that hit Earth in January 2014 has now been confirmed by the US Space Command (USSC) as the first interstellar object from another solar system.

Last week, the USSC shared a note on Twitter confirming the work of Harvard astronomers Amir Siraj and Abraham Loeb that a space rock from another star system hit Earth in 2014.

According to the memo, the speed and trajectory of the meteor suggested it came from a different solar system. The meteor, measuring 1.5 feet in diameter, “was indeed an interstellar object.”

Let’s find out more about Earth’s interstellar visitor:

Known as CNEOS 2014-01-08, the meteor crashed along the northeast coast of Papua New Guinea on January 8, 2014.

Only one more entry remained in NASA’s Center for Near Earth Object Studies database, until Harvard researcher Amir Siraj went in search of information about ‘Oumuamua, the first known interstellar object in our solar system discovered in 2017.

While investigating ‘Oumuamua, Harvard University science professor Siraj and Loeb came across this meteor in the database.

The duo identified the object as an interstellar meteor in a study co-authored in 2019.

What is the reasoning behind the identification as interstellar?

According to CNNit was the high speed of the meteor that caught Siraj’s attention.

The researchers found that the meteor was moving at a speed of about 45 kilometers per second relative to Earth, but that was not the speed it was actually moving at.

To define its trajectory and orbit, its heliocentric velocity was measured relative to the sun. It is calculated based on the angle at which a meteor strikes the Earth.

However, the planet is moving in one direction around the sun, so the meteor could have hit the Earth from the front, i.e. in the direction opposite to the direction of the planet, or from behind, in the same direction as the Earth.

Since the meteor struck Earth from behind, Siraj’s calculations put the meteor’s speed at around 60 kilometers per second relative to the sun.

Based on this velocity, Siraj mapped its course and discovered that it was in an unbound orbit. Other meteors and planets, which are part of the solar system, travel in a closed orbit around the sun.

The trajectory of this meteor suggests that it does not orbit the sun and that it is coming from outside the solar system.

Why haven’t we heard of this discovery before?

Since NASA does not release information about the accuracy of the readings, Siraj and Loeb were unable to publish their findings in a journal.

According to CNNSiraj had forgotten about the research when they received official confirmation from John Shaw, Deputy Commander of US Space Command, that “the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory”.

With approval, Siraj and Loeb will resubmit their findings for publication in a scientific journal.

With contributions from agencies

Read all Latest news, New trends, Cricket News, bollywood news,
India News and Entertainment News here. follow us on Facebook, Twitter and instagram.

]]>