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NASA’s Newly Arrived OSIRIS-REx Spacecraft Already Discovers Water on Asteroid
Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.
During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.
Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.
“The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”
Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.
One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).
Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.
“Our initial data show that the team picked the right asteroid as the target of the OSIRIS-REx mission. We have not discovered any insurmountable issues at Bennu so far,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “The spacecraft is healthy and the science instruments are working better than required. It is time now for our adventure to begin.”
The mission currently is performing a preliminary survey of the asteroid, flying the spacecraft in passes over Bennu’s north pole, equator, and south pole at ranges as close as 4.4 miles (7 km) to better determine the asteroid’s mass. The mission’s scientists and engineers must know the mass of the asteroid in order to design the spacecraft’s insertion into orbit because mass affects the asteroid’s gravitational pull on the spacecraft. Knowing Bennu’s mass will also help the science team understand the asteroid’s structure and composition.
This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations, now that the spacecraft is in proximity to Bennu.
The spacecraft’s first orbital insertion is scheduled for Dec. 31, and OSIRIS-REx will remain in orbit until mid-February 2019, when it exits to initiate another series of flybys for the next survey phase. During the first orbital phase, the spacecraft will orbit the asteroid at a range of 0.9 miles (1.4 km) to 1.24 miles (2.0 km) from the center of Bennu — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.
Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.
For more information about OSIRIS-REx, visit:
https://www.nasa.gov/osiris-rex
Image:
1. This preliminary shape model of asteroid Bennu was created from a compilation of images taken by OSIRIS-REx’s PolyCam camera during the spacecraft’s approach toward Bennu during the month of November. This 3D shape model shows features on Bennu as small as six meters.
Credits: NASA/Goddard/University of Arizona
2. This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24 km).
Credits: NASA/Goddard/University of Arizona
#NASA #Goddard #OSIRISREx #Spacecraft #Asteroids #Water #Bennu #Earth #TheSun #SolarSystem #OCAMS #OLA #KinetX #Aerospace #CanadianSpaceAgency #PreliminarySurvey #AGU18
Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.
During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.
Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.
“The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”
Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.
One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).
Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.
“Our initial data show that the team picked the right asteroid as the target of the OSIRIS-REx mission. We have not discovered any insurmountable issues at Bennu so far,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “The spacecraft is healthy and the science instruments are working better than required. It is time now for our adventure to begin.”
The mission currently is performing a preliminary survey of the asteroid, flying the spacecraft in passes over Bennu’s north pole, equator, and south pole at ranges as close as 4.4 miles (7 km) to better determine the asteroid’s mass. The mission’s scientists and engineers must know the mass of the asteroid in order to design the spacecraft’s insertion into orbit because mass affects the asteroid’s gravitational pull on the spacecraft. Knowing Bennu’s mass will also help the science team understand the asteroid’s structure and composition.
This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations, now that the spacecraft is in proximity to Bennu.
The spacecraft’s first orbital insertion is scheduled for Dec. 31, and OSIRIS-REx will remain in orbit until mid-February 2019, when it exits to initiate another series of flybys for the next survey phase. During the first orbital phase, the spacecraft will orbit the asteroid at a range of 0.9 miles (1.4 km) to 1.24 miles (2.0 km) from the center of Bennu — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.
Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.
For more information about OSIRIS-REx, visit:
https://www.nasa.gov/osiris-rex
Image:
1. This preliminary shape model of asteroid Bennu was created from a compilation of images taken by OSIRIS-REx’s PolyCam camera during the spacecraft’s approach toward Bennu during the month of November. This 3D shape model shows features on Bennu as small as six meters.
Credits: NASA/Goddard/University of Arizona
2. This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24 km).
Credits: NASA/Goddard/University of Arizona
#NASA #Goddard #OSIRISREx #Spacecraft #Asteroids #Water #Bennu #Earth #TheSun #SolarSystem #OCAMS #OLA #KinetX #Aerospace #CanadianSpaceAgency #PreliminarySurvey #AGU18
12/10/18
صورتان (2) - عرض الألبوم
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#Space | #Dione and #Rhea captured by #Cassini
This lovely photo seems to show the two moon stuck to each other, but that's just an optical illusion.
Sorry, no Hindi version today.
Via +Elizabeth Therese Niwel
This lovely photo seems to show the two moon stuck to each other, but that's just an optical illusion.
Sorry, no Hindi version today.
Via +Elizabeth Therese Niwel
Saturn's snowman
Dione and Rhea appear as one
Sometimes it’s all about perspective. This very convincing image of a conjoined moon masquerading as a snowman is actually two separate Saturnian moons – Dione and Rhea – taken from such an angle by the international Cassini spacecraft that they appear as one.
Dione (top) was actually closer to the spacecraft at the time the image was taken, at around 1.1 million kilometres, compared to Rhea (bottom) which was around 1.6 million kilometres from Cassini. Dione has a diameter of 1123 kilometres and Rhea is larger with a diameter of 1528 kilometres, but they appear to have a similar size in this image due to the difference in distance.
The moons also orbit Saturn at different distances: Dione lies at roughly the same distance as the Moon from the Earth and orbits around the ringed planet in just 2.7 days, while Rhea sits slightly further away and has a 4.5 day orbit.
Dione has a large crater called Evander, centred at the south polar region, which allows the two moons to blend seamlessly together in this view. They also have a similar reflectivity, contributing to the snowman-like appearance, while also pointing to a comparable surface composition.
Dione is made of around one third rock, comprising the core, and two thirds ice with a suspected subsurface ocean.
Interestingly, the moon is more heavily cratered on the hemisphere that faces away from the direction of motion compared to the hemisphere that faces the direction of motion, opposite to what is expected as the forward facing side of the moon should be bombarded with more material. This unusual cratering pattern suggests that it suffered an impact which spun the moon around 180 degrees.
Rhea is Saturn’s second largest moon, after Titan, and is similar to Dione in density, but is around one quarter rock mixed with three quarters ice – a giant frozen dirty snowball.
The image was taken on 27 July 2010 by Cassini in visible light using the narrow-angle camera. The resolution is seven kilometres per pixel on Dione and ten kilometres per pixel on Rhea. Saturn is towards the right and out of view. The Cassini mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. The mission concluded in September 2017.
http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens/Cassini_concludes_pioneering_mission_at_Saturn
Credit: ESA
Image Copyright: NASA/JPL/Space Science Institute
#Saturn #Rhea #Dione #Cassini #Titan #ESA #NASA #JPL #TheSun #SolarSystem #Satellites #Telescopes #SpaceCraft #SpaceScience #Astronomy #Earth #Planets #Moons #spaceMissions
Dione and Rhea appear as one
Sometimes it’s all about perspective. This very convincing image of a conjoined moon masquerading as a snowman is actually two separate Saturnian moons – Dione and Rhea – taken from such an angle by the international Cassini spacecraft that they appear as one.
Dione (top) was actually closer to the spacecraft at the time the image was taken, at around 1.1 million kilometres, compared to Rhea (bottom) which was around 1.6 million kilometres from Cassini. Dione has a diameter of 1123 kilometres and Rhea is larger with a diameter of 1528 kilometres, but they appear to have a similar size in this image due to the difference in distance.
The moons also orbit Saturn at different distances: Dione lies at roughly the same distance as the Moon from the Earth and orbits around the ringed planet in just 2.7 days, while Rhea sits slightly further away and has a 4.5 day orbit.
Dione has a large crater called Evander, centred at the south polar region, which allows the two moons to blend seamlessly together in this view. They also have a similar reflectivity, contributing to the snowman-like appearance, while also pointing to a comparable surface composition.
Dione is made of around one third rock, comprising the core, and two thirds ice with a suspected subsurface ocean.
Interestingly, the moon is more heavily cratered on the hemisphere that faces away from the direction of motion compared to the hemisphere that faces the direction of motion, opposite to what is expected as the forward facing side of the moon should be bombarded with more material. This unusual cratering pattern suggests that it suffered an impact which spun the moon around 180 degrees.
Rhea is Saturn’s second largest moon, after Titan, and is similar to Dione in density, but is around one quarter rock mixed with three quarters ice – a giant frozen dirty snowball.
The image was taken on 27 July 2010 by Cassini in visible light using the narrow-angle camera. The resolution is seven kilometres per pixel on Dione and ten kilometres per pixel on Rhea. Saturn is towards the right and out of view. The Cassini mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. The mission concluded in September 2017.
http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens/Cassini_concludes_pioneering_mission_at_Saturn
Credit: ESA
Image Copyright: NASA/JPL/Space Science Institute
#Saturn #Rhea #Dione #Cassini #Titan #ESA #NASA #JPL #TheSun #SolarSystem #Satellites #Telescopes #SpaceCraft #SpaceScience #Astronomy #Earth #Planets #Moons #spaceMissions
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nasa What a beauty?! 😍 During its 16th close flyby of the gas giant planet, our @NASAJuno spacecraft captured colorful swirling clouds in Jupiter's North Equatorial Belt. At the time, Juno was about 2,100 miles from the planet's cloud tops. In other words, the spacecraft was about as close to Jupiter as San Francisco is to Chicago, which is quite close when racing over a planet that's 11 times wider than Earth.
Since 2016, Juno has been penetrating Jupiter's deep, colorful zones and belts in a quest to answer fundamental questions about the planet’s origin and evolution.
Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson
#nasa #space #jupiter #astronomy #gasgiant #clouds #solarsystem #science #spacecraft #beautiful #picoftheday
Since 2016, Juno has been penetrating Jupiter's deep, colorful zones and belts in a quest to answer fundamental questions about the planet’s origin and evolution.
Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson
#nasa #space #jupiter #astronomy #gasgiant #clouds #solarsystem #science #spacecraft #beautiful #picoftheday
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Remember Rosetta?
Rosetta witnesses birth of baby bow shock around comet
A new study reveals that, contrary to first impressions, Rosetta did detect signs of an infant bow shock at the comet it explored for two years – the first ever seen forming anywhere in the Solar System.
From 2014 to 2016, ESA’s Rosetta spacecraft studied Comet 67P/Churyumov-Gerasimenko and its surroundings from near and far. It flew directly through the ‘bow shock’ several times both before and after the comet reached its closest point to the Sun along its orbit, providing a unique opportunity to gather in situ measurements of this intriguing patch of space.
http://www.esa.int/Our_Activities/Space_Science/Rosetta/The_surprising_comet
Comets offer scientists an extraordinary way to study the plasma in the Solar System. Plasma is a hot, gaseous state of matter comprising charged particles, and is found in the Solar System in the form of the solar wind: a constant stream of particles flooding out from our star into space.
http://blogs.esa.int/rosetta/2015/07/29/rosetta-shows-how-comet-interacts-with-the-solar-wind/
As the supersonic solar wind flows past objects in its path, such as planets or smaller bodies, it first hits a boundary known as a bow shock. As the name suggests, this phenomenon is somewhat like the wave that forms around the bow of a ship as it cuts through choppy water.
Bow shocks have been found around comets, too – Halley’s comet being a good example. Plasma phenomena vary as the medium interacts with the surrounding environment, changing the size, shape, and nature of structures such as bow shocks over time.
https://www.esa.int/Our_Activities/Space_Science/Rosetta/Giotto_s_comet_results
Rosetta looked for signs of such a feature over its two-year mission, and ventured over 1500 km away from 67P’s centre on the hunt for large-scale boundaries around the comet – but apparently found nothing.
https://www.esa.int/Our_Activities/Space_Science/Rosetta/Giotto_s_comet_results
“We looked for a classical bow shock in the kind of area we’d expect to find one, far away from the comet’s nucleus, but didn’t find any, so we originally reached the conclusion that Rosetta had failed to spot any kind of shock,” says Herbert Gunell of the Royal Belgian Institute for Space Aeronomy, Belgium, and Umeå University, Sweden, one of the two scientists who led the study.
“However, it seems that the spacecraft actually did find a bow shock, but that it was in its infancy. In a new analysis of the data, we eventually spotted it around 50 times closer to the comet’s nucleus than anticipated in the case of 67P. It also moved in ways we didn’t expect, which is why we initially missed it.”
On 7 March 2015, when the comet was over twice as far from the Sun as the Earth and heading inwards towards our star, Rosetta data showed signs of a bow shock beginning to form. The same indicators were present on its way back out from the Sun, on 24 February 2016.
This boundary was observed to be asymmetric, and wider than the fully developed bow shocks observed at other comets.
“Such an early phase of the development of a bow shock around a comet had never been captured before Rosetta,” says co-lead Charlotte Goetz of the Institute for Geophysics and Extraterrestrial Physics in Braunschweig, Germany.
“The infant shock we spotted in the 2015 data will have later evolved to become a fully developed bow shock as the comet approached the Sun and became more active – we didn't see this in the Rosetta data, though, as the spacecraft was too close to 67P at that time to detect the ‘adult’ shock. When Rosetta spotted it again, in 2016, the comet was on its way back out from the Sun, so the shock we saw was in the same state but ‘unforming’ rather than forming.”
Herbert, Charlotte, and colleagues explored data from the Rosetta Plasma Consortium, a suite of instruments comprising five different sensors to study the plasma surrounding Comet 67P. They combined the data with a plasma model to simulate the comet’s interactions with the solar wind and determine the properties of the bow shock.
The scientists found that, when the forming bow shock washed over Rosetta, the comet’s magnetic field became stronger and more turbulent, with bursts of highly energetic charged particles being produced and heated in the region of the shock itself. Beforehand, particles had been slower-moving, and the solar wind had been generally weaker – indicating that Rosetta had been ‘upstream’ of a bow shock.
“These observations are the first of a bow shock before it fully forms, and are unique in being gathered on-location at the comet and shock itself,” says Matt Taylor, ESA Rosetta Project Scientist.
“This finding also highlights the strength of combining multi-instrument measurements and simulations. It may not be possible to solve a puzzle using one dataset, but when you bring together multiple clues, as in this study, the picture can become clearer and offer real insight into the complex dynamics of our Solar System – and the objects in it, like 67P.”
See also video (00:30) at: http://www.esa.int/spaceinvideos/Videos/2018/12/Simulated_view_of_Rosetta_spying_an_infant_bow_shock_at_the_comet
or
on YT: https://youtu.be/n9kvnY9UsFw
#Rosetta #ESA #SolarSystem #Comets #TheSun #Earth #67P #Space #SpaceScience #SpaceMissions #ChuryumovGerasimenko #BowShock #Astronomy #SpaceObservations #SpaceCraft #Satellites #CyanSatellite #RPC
Rosetta witnesses birth of baby bow shock around comet
A new study reveals that, contrary to first impressions, Rosetta did detect signs of an infant bow shock at the comet it explored for two years – the first ever seen forming anywhere in the Solar System.
From 2014 to 2016, ESA’s Rosetta spacecraft studied Comet 67P/Churyumov-Gerasimenko and its surroundings from near and far. It flew directly through the ‘bow shock’ several times both before and after the comet reached its closest point to the Sun along its orbit, providing a unique opportunity to gather in situ measurements of this intriguing patch of space.
http://www.esa.int/Our_Activities/Space_Science/Rosetta/The_surprising_comet
Comets offer scientists an extraordinary way to study the plasma in the Solar System. Plasma is a hot, gaseous state of matter comprising charged particles, and is found in the Solar System in the form of the solar wind: a constant stream of particles flooding out from our star into space.
http://blogs.esa.int/rosetta/2015/07/29/rosetta-shows-how-comet-interacts-with-the-solar-wind/
As the supersonic solar wind flows past objects in its path, such as planets or smaller bodies, it first hits a boundary known as a bow shock. As the name suggests, this phenomenon is somewhat like the wave that forms around the bow of a ship as it cuts through choppy water.
Bow shocks have been found around comets, too – Halley’s comet being a good example. Plasma phenomena vary as the medium interacts with the surrounding environment, changing the size, shape, and nature of structures such as bow shocks over time.
https://www.esa.int/Our_Activities/Space_Science/Rosetta/Giotto_s_comet_results
Rosetta looked for signs of such a feature over its two-year mission, and ventured over 1500 km away from 67P’s centre on the hunt for large-scale boundaries around the comet – but apparently found nothing.
https://www.esa.int/Our_Activities/Space_Science/Rosetta/Giotto_s_comet_results
“We looked for a classical bow shock in the kind of area we’d expect to find one, far away from the comet’s nucleus, but didn’t find any, so we originally reached the conclusion that Rosetta had failed to spot any kind of shock,” says Herbert Gunell of the Royal Belgian Institute for Space Aeronomy, Belgium, and Umeå University, Sweden, one of the two scientists who led the study.
“However, it seems that the spacecraft actually did find a bow shock, but that it was in its infancy. In a new analysis of the data, we eventually spotted it around 50 times closer to the comet’s nucleus than anticipated in the case of 67P. It also moved in ways we didn’t expect, which is why we initially missed it.”
On 7 March 2015, when the comet was over twice as far from the Sun as the Earth and heading inwards towards our star, Rosetta data showed signs of a bow shock beginning to form. The same indicators were present on its way back out from the Sun, on 24 February 2016.
This boundary was observed to be asymmetric, and wider than the fully developed bow shocks observed at other comets.
“Such an early phase of the development of a bow shock around a comet had never been captured before Rosetta,” says co-lead Charlotte Goetz of the Institute for Geophysics and Extraterrestrial Physics in Braunschweig, Germany.
“The infant shock we spotted in the 2015 data will have later evolved to become a fully developed bow shock as the comet approached the Sun and became more active – we didn't see this in the Rosetta data, though, as the spacecraft was too close to 67P at that time to detect the ‘adult’ shock. When Rosetta spotted it again, in 2016, the comet was on its way back out from the Sun, so the shock we saw was in the same state but ‘unforming’ rather than forming.”
Herbert, Charlotte, and colleagues explored data from the Rosetta Plasma Consortium, a suite of instruments comprising five different sensors to study the plasma surrounding Comet 67P. They combined the data with a plasma model to simulate the comet’s interactions with the solar wind and determine the properties of the bow shock.
The scientists found that, when the forming bow shock washed over Rosetta, the comet’s magnetic field became stronger and more turbulent, with bursts of highly energetic charged particles being produced and heated in the region of the shock itself. Beforehand, particles had been slower-moving, and the solar wind had been generally weaker – indicating that Rosetta had been ‘upstream’ of a bow shock.
“These observations are the first of a bow shock before it fully forms, and are unique in being gathered on-location at the comet and shock itself,” says Matt Taylor, ESA Rosetta Project Scientist.
“This finding also highlights the strength of combining multi-instrument measurements and simulations. It may not be possible to solve a puzzle using one dataset, but when you bring together multiple clues, as in this study, the picture can become clearer and offer real insight into the complex dynamics of our Solar System – and the objects in it, like 67P.”
See also video (00:30) at: http://www.esa.int/spaceinvideos/Videos/2018/12/Simulated_view_of_Rosetta_spying_an_infant_bow_shock_at_the_comet
or
on YT: https://youtu.be/n9kvnY9UsFw
#Rosetta #ESA #SolarSystem #Comets #TheSun #Earth #67P #Space #SpaceScience #SpaceMissions #ChuryumovGerasimenko #BowShock #Astronomy #SpaceObservations #SpaceCraft #Satellites #CyanSatellite #RPC
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Voyager 2 reached
NASA’s Voyager 2 has become the second human-made object in history to reach the edge of our solar system, after the spacecraft exited the protective bubble of particles and magnetic fields created by the Sun, the US space agency said.
Read More: https://www.ksgindia.com/index.php/study-material/news-for-aspirants/18010-voyager-2-reached #Voyager2 #NASA #PLS #IBEX #spacecraft
NASA’s Voyager 2 has become the second human-made object in history to reach the edge of our solar system, after the spacecraft exited the protective bubble of particles and magnetic fields created by the Sun, the US space agency said.
Read More: https://www.ksgindia.com/index.php/study-material/news-for-aspirants/18010-voyager-2-reached #Voyager2 #NASA #PLS #IBEX #spacecraft
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Evidence of water discovered on Bennu
Scientists have discovered evidence of water on asteroid Bennu, using data from NASA’s OSIRIS-REx spacecraft which recently reached the rocky cosmic body to unravel its mysteries.
Read More: https://www.ksgindia.com/index.php/study-material/news-for-aspirants/18011-evidence-of-water-discovered-on-bennu #OSIRIS #NASA #spacecraft #LPL #hydroxyls
Scientists have discovered evidence of water on asteroid Bennu, using data from NASA’s OSIRIS-REx spacecraft which recently reached the rocky cosmic body to unravel its mysteries.
Read More: https://www.ksgindia.com/index.php/study-material/news-for-aspirants/18011-evidence-of-water-discovered-on-bennu #OSIRIS #NASA #spacecraft #LPL #hydroxyls
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#NASA: #OSIRIS-REx #Spacecraft Arrives at #Asteroid #Bennu
astrocometal.blogspot.com
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Saturn and its moons at opposition
Cassini ended its 13-year mission at Saturn on 15 September 2017 when it plunged into the gas giant's atmosphere, but the NASA/ESA Hubble Space Telescope is still keeping an eye on the ringed planet.
This is a composite image taken by Hubble on 6 June 2018 showing a fully-illuminated Saturn and its rings, along with six of its 62 known moons. The visible moons are (from left to right) Dione, Enceladus, Tethys, Janus, Epimetheus and Mimas (click here for an annotated version).
https://www.spacetelescope.org/images/heic1814e/
Dione is the largest moon in the picture, with a diameter of 1123 km, compared to the smallest, oddly-shaped Epimetheus with a diameter around 116 km.
https://solarsystem.nasa.gov/resources/16228/imminent-approach-to-dione/
https://solarsystem.nasa.gov/resources/16281/examining-epimetheus/
During Cassini’s mission, Enceladus was identified as one of the most intriguing moons, with the discovery of water vapour jets spewing from the surface implying the existence of a subsurface ocean. Icy moons with subsurface oceans could potentially offer the conditions to harbour life, and understanding their origins and properties are essential for furthering our knowledge of the Solar System. ESA's JUpiter ICy moons Explorer (Juice), due to launch in 2022, aims to continue this theme by studying Jupiter's ocean-bearing moons: Ganymede, Europa, and Callisto.
http://sci.esa.int/juice/
The Hubble image shown here was taken shortly before Saturn's opposition on 27 June, when the Sun, Earth and Saturn were aligned so that the Sun fully illuminated Saturn as seen from Earth. Saturn's closest approach to Earth occurs around the same time as opposition, which makes it appear brighter and larger and allows the planet to be imaged in greater detail.
In this image the planet’s rings are seen near their maximum tilt towards Earth. Towards the end of Cassini’s mission, the spacecraft made multiple dives through the gap between Saturn and its rings, gathering spectacular data in this previously unchartered territory.
https://solarsystem.nasa.gov/news/13032/nasa-spacecraft-dives-between-saturn-and-its-rings/
The image also shows a hexagonal atmospheric feature around the north pole, with the remnants of a storm, seen as a string of bright clouds. The hexagon-shaped cloud phenomenon is a stable and persistent feature first seen by the Voyager 1 space probe when it flew past Saturn 1981. In a study published just last week, scientists using Cassini data collected between 2013 and 2017, as the planet approached northern summer, identified a hexagonal vortex above the cloud structure, showing there is still much to learn about the dynamics of Saturn’s atmosphere.
http://sci.esa.int/cassini-huygens/60589-saturn-s-famous-hexagon-may-tower-above-the-clouds/
The Hubble observations making up this image were performed as part of the Outer Planet Atmospheres Legacy (OPAL) project, which uses Hubble to observe the outer planets to understand the dynamics and evolution of their complex atmospheres. This was the first time that Saturn was imaged as part of OPAL.
This image was first published on 26 July.
https://www.spacetelescope.org/news/heic1814/
Credits: NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI); CC BY 4.0
#ESA #NASA #Planets #Earth #Saturn #Jupiter #Moons #Dione #Enceladus #Tethys #Janus #Epimetheus #Mimas #Ganymede #Europa #Callisto #Telescopes #SpaceCraft #Cassini #Hubble #Juice #Voyager1 #OPAL #Space #SolarSystem #STScI #GSFC #PlanetsAtmosphere #PlanetsEvolution #Astronomy #MilkyWay #SpaceStorm #SpaceScience
Cassini ended its 13-year mission at Saturn on 15 September 2017 when it plunged into the gas giant's atmosphere, but the NASA/ESA Hubble Space Telescope is still keeping an eye on the ringed planet.
This is a composite image taken by Hubble on 6 June 2018 showing a fully-illuminated Saturn and its rings, along with six of its 62 known moons. The visible moons are (from left to right) Dione, Enceladus, Tethys, Janus, Epimetheus and Mimas (click here for an annotated version).
https://www.spacetelescope.org/images/heic1814e/
Dione is the largest moon in the picture, with a diameter of 1123 km, compared to the smallest, oddly-shaped Epimetheus with a diameter around 116 km.
https://solarsystem.nasa.gov/resources/16228/imminent-approach-to-dione/
https://solarsystem.nasa.gov/resources/16281/examining-epimetheus/
During Cassini’s mission, Enceladus was identified as one of the most intriguing moons, with the discovery of water vapour jets spewing from the surface implying the existence of a subsurface ocean. Icy moons with subsurface oceans could potentially offer the conditions to harbour life, and understanding their origins and properties are essential for furthering our knowledge of the Solar System. ESA's JUpiter ICy moons Explorer (Juice), due to launch in 2022, aims to continue this theme by studying Jupiter's ocean-bearing moons: Ganymede, Europa, and Callisto.
http://sci.esa.int/juice/
The Hubble image shown here was taken shortly before Saturn's opposition on 27 June, when the Sun, Earth and Saturn were aligned so that the Sun fully illuminated Saturn as seen from Earth. Saturn's closest approach to Earth occurs around the same time as opposition, which makes it appear brighter and larger and allows the planet to be imaged in greater detail.
In this image the planet’s rings are seen near their maximum tilt towards Earth. Towards the end of Cassini’s mission, the spacecraft made multiple dives through the gap between Saturn and its rings, gathering spectacular data in this previously unchartered territory.
https://solarsystem.nasa.gov/news/13032/nasa-spacecraft-dives-between-saturn-and-its-rings/
The image also shows a hexagonal atmospheric feature around the north pole, with the remnants of a storm, seen as a string of bright clouds. The hexagon-shaped cloud phenomenon is a stable and persistent feature first seen by the Voyager 1 space probe when it flew past Saturn 1981. In a study published just last week, scientists using Cassini data collected between 2013 and 2017, as the planet approached northern summer, identified a hexagonal vortex above the cloud structure, showing there is still much to learn about the dynamics of Saturn’s atmosphere.
http://sci.esa.int/cassini-huygens/60589-saturn-s-famous-hexagon-may-tower-above-the-clouds/
The Hubble observations making up this image were performed as part of the Outer Planet Atmospheres Legacy (OPAL) project, which uses Hubble to observe the outer planets to understand the dynamics and evolution of their complex atmospheres. This was the first time that Saturn was imaged as part of OPAL.
This image was first published on 26 July.
https://www.spacetelescope.org/news/heic1814/
Credits: NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI); CC BY 4.0
#ESA #NASA #Planets #Earth #Saturn #Jupiter #Moons #Dione #Enceladus #Tethys #Janus #Epimetheus #Mimas #Ganymede #Europa #Callisto #Telescopes #SpaceCraft #Cassini #Hubble #Juice #Voyager1 #OPAL #Space #SolarSystem #STScI #GSFC #PlanetsAtmosphere #PlanetsEvolution #Astronomy #MilkyWay #SpaceStorm #SpaceScience
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