jeudi 25 février 2021

ExoMars orbiter images Perseverance at landing site

 







ESA & ROSCOSMOS - ExoMars Mission patch.


Feb. 25, 2021

The ESA-Roscosmos Trace Gas Orbiter has spotted NASA’s Mars 2020 Perseverance rover, along with its parachute, heat shield and descent stage, in the Jezero Crater region of Mars.

ExoMars orbiter images Perseverance landing site

The images were captured with the orbiter’s CaSSIS camera on 23 February. The components are seen as dark or bright pixels in the images.

The rover landed on Mars on 18 February 2021, and was first identified in images from NASA’s Mars Reconnaissance Orbiter.

ExoMars orbiter images Perseverance landing site (labelled)

Perseverance will explore the Jezero Crater region of Mars, which is thought to have once hosted a lake, searching for signs of past microbial life. It will collect and cache samples of martian rocks and soil for subsequent missions to collect and return to Earth as part of the joint ESA-NASA Mars Sample Return campaign.

ExoMars Trace Gas Orbiter (TGO)

The ExoMars Trace Gas Orbiter provided significant data relay services around the landing of Perseverance, including supporting the return of the videos and imagery taken by the mission’s onboard cameras during the descent of the rover to the surface of Mars. The orbiter will continue to provide data relay support between Earth and Mars for NASA’s surface missions, and for the next ExoMars mission, which will see the European Rosalind Franklin rover and Russian Kazachok surface platform arrive at the Red Planet in 2023. At the same time, the Trace Gas Orbiter continues its own science mission, focusing on analysing the planet’s atmosphere with a special emphasis on searching for gases that may be linked to active geological or biological processes.

Related links:

Mars Perseverance Rover: http://www.nasa.gov/perseverance

ExoMars: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars

Images, Text, Credits: ESA/Roscosmos/CaSSIS; acknowledgement P. Grindrod.

Best regards, Orbiter.ch

Reflections from a Black Hole

 







NASA - Chandra X-ray Observatory patch.


Feb. 25, 2021


This 2003 composite X-ray (blue and green) and optical (red) image of the active galaxy, NGC 1068, shows gas blowing away in a high-speed wind from the vicinity of a central supermassive black hole. Regions of intense star formation in the inner spiral arms of the galaxy are highlighted by both optical and X-ray emission.

The elongated shape of the gas cloud is thought to be due to the funneling effect of a torus, or doughnut-shaped cloud, of cool gas and dust that surrounds the black hole. The torus, which appears as the elongated white spot in the accompanying 3-color X-ray images, has a mass of about 5 million Suns. Radio observations indicate that the torus extends from within a few light years of the black hole out to about 300 light years.

Chandra X-ray Observatory

The X-rays observed from the torus are scattered and reflected X-rays that are probably coming from a hidden disk of hot gas formed as matter swirls very near the black hole. The torus is one source of the gas in the high-speed wind, but the hidden disk may also be involved. X-ray heating of gas further out in the galaxy contributes to the slower, outer parts of the wind.

Related links:

Black Holes: https://www.nasa.gov/black-holes

Chandra X-ray Observatory: http://chandra.harvard.edu/

Hubble Space Telescope: https://www.nasa.gov/mission_pages/hubble/main/index.html

Image, Animation Credits: X-ray: NASA/CXC/MIT/UCSB/P.Ogle et al.; Optical: NASA/STScI/A.Capetti et al./Text Credits: NASA/Yvette Smith.

Greetings, Orbiter.ch

Comet Makes a Pit Stop Near Jupiter's Asteroids

 







NASA - Hubble Space Telescope patch.


Feb 25, 2021

After traveling several billion miles toward the Sun, a wayward young comet-like object orbiting among the giant planets has found a temporary parking place along the way. The object has settled near a family of captured ancient asteroids, called Trojans, that are orbiting the Sun alongside Jupiter. This is the first time a comet-like object has been spotted near the Trojan population.


Image above: Astronomers found a roaming comet taking a rest stop before possibly continuing its journey. The wayward object made a temporary stop near giant Jupiter. The icy visitor has plenty of company. It has settled near the family of captured asteroids known as Trojans that are co-orbiting the Sun alongside Jupiter. This is the first time a comet-like object has been spotted near the Trojan asteroid population. Hubble Space Telescope observations reveal the vagabond is showing signs of transitioning from a frigid asteroid-like body to an active comet, sprouting a long tail, outgassing jets of material, and enshrouding itself in a coma of dust and gas. Image Credits: NASA, ESA, and B. Bolin (Caltech).

The unexpected visitor belongs to a class of icy bodies found in space between Jupiter and Neptune. Called "Centaurs," they become active for the first time when heated as they approach the Sun, and dynamically transition into becoming more comet-like.

Visible-light snapshots by NASA's Hubble Space Telescope reveal that the vagabond object shows signs of comet activity, such as a tail, outgassing in the form of jets, and an enshrouding coma of dust and gas. Earlier observations by NASA's Spitzer Space Telescope gave clues to the composition of the comet-like object and the gasses driving its activity.

"Only Hubble could detect active comet-like features this far away at such high detail, and the images clearly show these features, such as a roughly 400,000-mile-long broad tail and high-resolution features near the nucleus due to a coma and jets," said lead Hubble researcher Bryce Bolin of Caltech in Pasadena, California.

Describing the Centaur's capture as a rare event, Bolin added, "The visitor had to have come into the orbit of Jupiter at just the right trajectory to have this kind of configuration that gives it the appearance of sharing its orbit with the planet. We’re investigating how it was captured by Jupiter and landed among the Trojans. But we think it could be related to the fact that it had a somewhat close encounter with Jupiter."

The team's paper appears in the February 11, 2021 issue of The Astronomical Journal: https://iopscience.iop.org/1538-3881

The research team's computer simulations show that the icy object, called P/2019 LD2 (LD2), probably swung close to Jupiter about two years ago. The planet then gravitationally punted the wayward visitor to the Trojan asteroid group's co-orbital location, leading Jupiter by about 437 million miles.

Hubble Spots Comet Near Jupiter

Video above: After traveling several billion miles toward the Sun, a wayward young comet-like object orbiting among the giant planets has found a temporary parking place along the way. The object has settled near a family of captured ancient asteroids, called Trojans, that are orbiting the Sun alongside Jupiter. This is the first time a comet-like object has been spotted near the Trojan population. Video Credits: NASA.

Bucket Brigade

The nomadic object was discovered in early June 2019 by the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS) telescopes located on the extinct volcanoes, one on Mauna Kea and one on Haleakala. Japanese amateur astronomer Seiichi Yoshida tipped off the Hubble team to possible comet activity. The astronomers then scanned archival data from the Zwicky Transient Facility, a wide-field survey conducted at Palomar Observatory in California, and realized that the object was clearly active in images from April 2019.

They followed up with observations from the Apache Point Observatory in New Mexico, which also hinted at the activity. The team observed the comet using Spitzer just days before the observatory's retirement in January 2020, and identified gas and dust around the comet nucleus. These observations convinced the team to use Hubble to take a closer look. Aided by Hubble's sharp vision, the researchers identified the tail, coma structure and the size of the dust particles and their ejection velocity. These images helped them confirm that the features are due to relatively new comet-like activity.

Although LD2's location is surprising, Bolin wonders whether this pit stop could be a common pull-off for some sunward-bound comets. "This could be part of the pathway from our solar system through the Jupiter Trojans to the inner solar system," he said.

The unexpected guest probably will not stay among the asteroids for very long. Computer simulations show that it will have another close encounter with Jupiter in about another two years. The hefty planet will boot the comet from the system, and it will continue its journey to the inner solar system.

"The cool thing is that you're actually catching Jupiter flinging this object around and changing its orbital behavior and bringing it into the inner system," said team member Carey Lisse of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. "Jupiter controls what's going on with comets once they get into the inner system by altering their orbits."

The icy interloper is most likely one of the latest members of the so-called "bucket brigade" of comets to get kicked out of its frigid home in the Kuiper belt and into the giant planet region through interactions with another Kuiper belt object. Located beyond Neptune's orbit, the Kuiper belt is a haven of icy, leftover debris from our planets' construction 4.6 billion years ago, containing millions of objects, and occasionally these objects have near misses or collisions that drastically alter their orbits from the Kuiper belt inward into the giant planet region.

Hubble Space Telescope (HST). Animation Credits: NASA/ESA

The bucket brigade of icy relics endure a bumpy ride during their journey sunward. They bounce gravitationally from one outer planet to the next in a game of celestial pinball before reaching the inner solar system, warming up as they come closer to the Sun. The researchers say the objects spend as much or even more time around the giant planets, gravitationally pulling on them—about 5 million years—than they do crossing into the inner system where we live.

"Inner system, 'short-period' comets break up about once a century," Lisse explained. "So, in order to maintain the number of local comets we see today, we think the bucket brigade has to deliver a new short-period comet about once every 100 years."

An Early Bloomer

Seeing outgassing activity on a comet 465 million miles away from the Sun (where the intensity of sunlight is 1/25th as strong as on Earth) surprised the researchers. "We were intrigued to see that the comet had just started to become active for the first time so far away from the Sun at distances where water ice is barely starting to sublimate," said Bolin.

Water remains frozen on a comet until it reaches about 200 million miles from the Sun, where heat from sunlight converts water ice to gas that escapes from the nucleus in the form of jets. So the activity signals that the tail might not be made of water. In fact, observations by Spitzer indicated the presence of carbon monoxide and carbon dioxide gas, which could be driving the creation of the tail and jets seen on the Jupiter-orbiting comet. These volatiles do not need much sunlight to heat their frozen form and convert them to gas.

Once the comet gets kicked out of Jupiter's orbit and continues its journey, it may meet up with the giant planet again. "Short-period comets like LD2 meet their fate by being thrown into the Sun and totally disintegrating, hitting a planet, or venturing too close to Jupiter once again and getting thrown out of the solar system, which is the usual fate," Lisse said. "Simulations show that in about 500,000 years, there's a 90% probability that this object will be ejected from the solar system and become an interstellar comet."

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, managed the Spitzer mission for NASA's Science Mission Directorate in Washington, D.C. Science operations were conducted at the Spitzer Science Center at IPAC at Caltech. Spitzer's entire science catalogue is available via the Spitzer data archive, housed at the Infrared Science Archive at IPAC. Spacecraft operations were based at Lockheed Martin Space in Littleton, Colorado.

Related link:

Hubble Space Telescope: https://www.nasa.gov/mission_pages/hubble/main/index.html

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA, ESA, and B. Bolin (Caltech)/NASA/Lynn Jenner/JPL/Calla Cofield/GSFC/Claire Andreoli/Space Telescope Science Institute/Donna Weaver/Ray Villard.

Best regards, Orbiter.ch

mercredi 24 février 2021

Astronauts Get Ready for Spacewalks After U.S. Cargo Ship Arrives

 






ISS - Expedition 64 Mission patch.


Feb. 24, 2021

Spacewalks are the focus now aboard the International Space Station as the Expedition 64 crew begins unloading four tons of cargo delivered Monday aboard a U.S. space freighter.

NASA astronauts Kate Rubins and Victor Glover are gearing up for a spacewalk on Sunday, Feb. 28, to ready the station for upcoming solar array upgrades. They will set their U.S. spacesuits to battery power at approximately 6 a.m. EST signifying the start of their spacewalk planned to last six-and-a-half hours. NASA TV will begin its live coverage of the spacewalk activities at 4:30 a.m.


Image above: JAXA (Japan Aerospace Exploration Agency) astronaut Soichi Noguchi works on U.S. spacesuit gear inside the Quest airlock. Image Credit: NASA.

NASA managers will discuss that spacewalk, including a March 5 spacewalk with Rubins and JAXA (Japan Aerospace Exploration Agency) astronaut Soichi Noguchi, on Wednesday during a live briefing on NASA TV set for 2 p.m. The second spacewalk will see Rubins and Noguchi work on upgrading coolant gear and communication systems.

The duo spent Tuesday servicing their spacesuits and practicing safety procedures inside the Quest airlock. Glover cleaned the spacesuit cooling water loops and tested the quality of the water samples collected from the loops. Rubins reviewed the spacesuit caution and warning system then checked glove heaters, helmet cameras and batteries.

Maintenance spacewalk. Animation Credit: NASA

In the midst of the spacewalk preparations, the orbital residents have begun unpacking the Northrop Grumman Cygnus resupply ship. NASA Flight Engineers Michael Hopkins and Shannon Walker have been offloading the new science hardware, crew supplies and station hardware stowed inside Cygnus. Noguchi transferred Cygnus’ science freezers containing biological samples into the station and installed them into specialized science racks. Rubins and Glover also assisted with the cargo transfers.

Commander Sergey Ryzhikov of Roscosmos started the day sampling the station’s air and surfaces for microbial analysis. He then inspected and photographed the hull of the Zvezda service module. Flight Engineer Sergey Kud-Sverchkov worked on Russian life support systems and station cameras while also assisting the commander with the Zvezda inspection duties.

Related links:

Expedition 64: https://www.nasa.gov/mission_pages/station/expeditions/expedition64/index.html

Quest airlock: https://www.nasa.gov/mission_pages/station/structure/elements/joint-quest-airlock

Microbial analysis: https://www.energia.ru/en/iss/researches/biology/02.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/overview.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

Perseverance rover - Mastcam-Z’s First 360-Degree Panorama

 







NASA - Mars 2020 Perseverance Rover logo.


Feb 24, 2021

(Click on the image for enlarge)

Image above: This is the first 360-degree panorama taken by Mastcam-Z, a zoomable pair of cameras aboard NASA’s Perseverance Mars rover. The panorama was stitched together on Earth from 142 individual images taken on Sol 3, the third Martian day of the mission (Feb. 21, 2021). Image Credits: NASA/JPL-Caltech/MSSS/ASU.

This is the first 360-degree panorama taken by Mastcam-Z, a zoomable pair of cameras aboard NASA’s Perseverance Mars rover. The panorama was stitched together on Earth from 142 individual images taken on Sol 3, the third Martian day of the mission (Feb. 21, 2021).

Annotated versions of this panorama include a scale bar and close-ups of rock features seen in the distance.


Image above: This wind-carved rock seen in first 360-degree panorama taken by the Mastcam-Z instrument shows just how much detail is captured by the camera systems. Image Credits: NASA/JPL-Caltech/MSSS/ASU.

A detail shot from the top of the panorama shows the rim of Jezero Crater, Perseverance’s landing site.

(Click on the image for enlarge)

Image above: This shows the rim of Jezero Crater as seen in the first 360-degree panorama taken by the Mastcam-Z instrument aboard NASA’s Perseverance Mars rover.
Image Credits: NASA/JPL-Caltech/MSSS/ASU.

Arizona State University in Tempe leads the operations of the Mastcam-Z instrument, working in collaboration with Malin Space Science Systems in San Diego.

First images from Perseverance’s Mastcam-Z

A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

Perseverance’s Mastcam-Z takes first 360-Degree Panorama

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

NASA’s Jet Propulsion Laboratory in Southern California built and manages operations of the Mars 2020 Perseverance rover for NASA.

For more information about the mission, go to: https://mars.nasa.gov/mars2020

Mars Perseverance Rover: http://www.nasa.gov/perseverance

Images (mentioned), Videos, Text, Credits: NASA/Tony Greicius/JPL-Caltech/MSSS/ASU/SciNews.

Greetings, Orbiter.ch

Parker Solar Probe Offers Stunning View of Venus

 







NASA - Parker Solar Probe patch.


Feb 24, 2021

NASA’s Parker Solar Probe captured stunning views of Venus during its close flyby of the planet in July 2020.

Though Parker Solar Probe’s focus is the Sun, Venus plays a critical role in the mission: The spacecraft whips by Venus a total of seven times over the course of its seven-year mission, using the planet’s gravity to bend the spacecraft’s orbit. These Venus gravity assists allow Parker Solar Probe to fly closer and closer to the Sun on its mission to study the dynamics of the solar wind close to its source.

But — along with the orbital dynamics — these passes can also yield some unique and even unexpected views of the inner solar system. During the mission’s third Venus gravity assist on July 11, 2020, the onboard Wide-field Imager for Parker Solar Probe, or WISPR, captured a striking image of the planet’s nightside from 7,693 miles away.


Image above: When flying past Venus in July 2020, Parker Solar Probe’s WISPR instrument, short for Wide-field Imager for Parker Solar Probe, detected a bright rim around the edge of the planet that may be nightglow — light emitted by oxygen atoms high in the atmosphere that recombine into molecules in the nightside. The prominent dark feature in the center of the image is Aphrodite Terra, the largest highland region on the Venusian surface. Bright streaks in WISPR, such as the ones seen here, are typically caused by a combination of charged particles — called cosmic rays — sunlight reflected by grains of space dust, and particles of material expelled from the spacecraft’s structures after impact with those dust grains. The number of streaks varies along the orbit or when the spacecraft is traveling at different speeds, and scientists are still in discussion about the specific origins of the streaks here. The dark spot appearing on the lower portion of Venus is an artifact from the WISPR instrument. Image Credits: NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and Brendan Gallagher.

WISPR is designed to take images of the solar corona and inner heliosphere in visible light, as well as images of the solar wind and its structures as they approach and fly by the spacecraft. At Venus, the camera detected a bright rim around the edge of the planet that may be nightglow — light emitted by oxygen atoms high in the atmosphere that recombine into molecules in the nightside. The prominent dark feature in the center of the image is Aphrodite Terra, the largest highland region on the Venusian surface. The feature appears dark because of its lower temperature, about 85 degrees Fahrenheit (30 degrees Celsius) cooler than its surroundings.

That aspect of the image took the team by surprise, said Angelos Vourlidas, the WISPR project scientist from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, who coordinated a WISPR imaging campaign with Japan’s Venus-orbiting Akatsuki mission. “WISPR is tailored and tested for visible light observations. We expected to see clouds, but the camera peered right through to the surface.”

“WISPR effectively captured the thermal emission of the Venusian surface,” said Brian Wood, an astrophysicist and WISPR team member from the U.S. Naval Research Laboratory in Washington, D.C. “It’s very similar to images acquired by the Akatsuki spacecraft at near-infrared wavelengths.”


Image above: NASA’s Parker Solar Probe had an up-close view of Venus when it flew by the planet in July 2020. Some of the features seen by scientists are labeled in this annotated image. The dark spot appearing on the lower portion of Venus is an artifact from the WISPR instrument. Image Credits: NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and Brendan Gallagher.

This surprising observation sent the WISPR team back to the lab to measure the instrument’s sensitivity to infrared light. If WISPR can indeed pick up near-infrared wavelengths of light, the unforeseen capability would provide new opportunities to study dust around the Sun and in the inner solar system. If it can’t pick up extra infrared wavelengths, then these images — showing signatures of features on Venus’ surface — may have revealed a previously unknown “window” through the Venusian atmosphere.

“Either way,” Vourlidas said, “some exciting science opportunities await us.”

For more insight into the July 2020 images, the WISPR team planned a set of similar observations of the Venusian nightside during Parker Solar Probe’s latest Venus flyby on Feb. 20, 2021. Mission team scientists expect to receive and process that data for analysis by the end of April.

“We are really looking forward to these new images,” said Javier Peralta, a planetary scientist from the Akatsuki team, who first suggested a Parker Solar Probe campaign with Akatsuki, which has been in orbiting Venus since 2015. “If WISPR can sense the thermal emission from the surface of Venus and nightglow — most likely from oxygen — at the limb of the planet, it can make valuable contributions to studies of the Venusian surface.”

Parker Solar Probe

Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. Johns Hopkins APL designed, built and operates the spacecraft.

Related links:

Venus: http://www.nasa.gov/venus

Parker Solar Probe: https://www.nasa.gov/solarprobe

Images (mentioned), Animation, Text, Credits: NASA/Sarah Frazier/GSFC/Karen Fox/Johns Hopkins University Applied Physics Laboratory, by Michael Buckley.

Best regards, Orbiter.ch

CASC - Long March-4C launches Yaogan-31 03

 







CASC - China Aerospace Science and Technology Corporation logo.


Feb 24, 2021

Long March-4C launches Yaogan-31 03

A Long March-4C launch vehicle launched the third group of Yaogan-31 remote-sensing satellites from the Jiuquan Satellite Launch Center, Gansu Province, northwest China, on 24 February 2021, at 02:22 UTC (10:22 local time).

Long March-4C launches Yaogan-31 03

According to official sources, the Yaogan-31 03 (遥感三十一号03) satellites will be used for scientific experiments, land and resources surveys, agricultural production estimation, disaster prevention and mitigation.

Yaogan-31 (遥感三十一号) satellites

Related articles:

CASC - Long March-4C launches Yaogan-31 02 satellites
https://orbiterchspacenews.blogspot.com/2021/01/casc-long-march-4c-launches-yaogan-31.html

Long March-2C launches new Yaogan-30 satellites
https://orbiterchspacenews.blogspot.com/2019/07/long-march-2c-launches-new-yaogan-30.html

Related link:

China Aerospace Science and Technology Corporation (CASC): http://english.spacechina.com/n16421/index.html

Images, Video, Text, Credits: China Central Television/China Aerospace Science and Technology Corporation (CASC)/SciNews/Gunter's Space Page/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Tianwen-1 enters parking orbit around Mars

 







CNSA - Tianwen-1 (天問-1) Mission to Mars logo.

 

Feb. 24, 2021

Tianwen-1 mapping the landing area

On 24 February 2021, at 22:29 (23 February, 06:29 China Standard Time), Tianwen-1’s performed the third braking maneuver and successfully entered into an orbit with a perigee of about 280 kilometers, its preset parking orbit above Mars.

Tianwen-1 enters parking orbit around Mars

Tianwen-1 will remain in this orbit for about three months, mapping the landing area, before releasing its landing capsule. Tianwen-1 rover is scheduled to land on the southern part of Utopia Planitia. Tianwen-1 (天问一号) is China’s first Mars exploration mission with an orbiter, a lander and a rover. The name Tianwen (天问, Questions to Heaven) comes from a poem written by the Chinese poet Qu Yuan.

Tianwen-1 (天問-1) Mars lander. Image Credit: CNSA

Tianwen-1 (天问一号) is China’s first Mars exploration mission with an orbiter, a lander and a rover. Called "Tianwen" ("Questions in heaven"), the Chinese mission has three objectives: to place a probe in Martian orbit, to make it land on the red planet, then to remote-control a robot on the surface to conduct analyzes.

Related articles:

Tianwen-1 Mars Orbit Insertion
https://orbiterchspacenews.blogspot.com/2021/02/tianwen-1-mars-orbit-insertion.html

China in turn (after UAE) begins its journey to Mars
https://orbiterchspacenews.blogspot.com/2020/07/china-in-turn-after-uae-begins-its.html

For more information about China National Space Administration (CNSA), visit: http://www.cnsa.gov.cn/

Images, Videos, Text, Credits: China Central Television (CCTV)/China National Space Administration (CNSA)/SciNews/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

ESA plans mission to explore lunar caves

 





ESA - European Space Agency patch.


Feb. 24, 2021

In a first step towards uncovering the Moon's subterranean secrets, in 2019 we asked for your ideas to detect, map and explore lunar caves. Five ideas were selected to be studied in more detail, each addressing different phases of a potential mission.

Through these five Sysnova studies, three mission scenarios were developed – one to perform a preliminary scout of entry pits and underground caves from the Moon's surface, one to lower a probe into a pit and access the first part of a cave, and one to explore an underground lava tube using autonomous rovers.

Entering a lunar lava tube

"Although the studies were very different in topic and approach, they all provided great insight into potential technologies for exploring and investigating the geology of the Moon's subsurface," says Loredana Bessone, Technical Officer for the studies and Project Manager for ESA CAVES and PANGAEA, speaking soon after the results of the studies were presented. "It's been a fascinating journey, and a great opportunity for ESA to start looking into missions to explore lunar caves."

Marius Hills pit

Images above: Three images of the Marius Hills pit imaged by NASA’s Lunar Reconnaissance Orbiter. This pit is about 34 metres deep and 65 by 90 metres wide. Marius Hills and other pits may be 'skylights' into extensive lava tubes.

Bringing the ideas together with other ESA lunar exploration initiatives

As a combination that would give a maximum scientific return, teams behind two of the studies – one from the University of Würzburg and one from the University of Oviedo – were selected to take part in an ESA Concurrent Design Facility (CDF) study. Both focusing on the second mission scenario, the technologies that these teams have developed would allow a safe exploration and documentation of a lunar pit as well as a first peek inside the tunnels that a pit may lead to.

Kicking off this week, the CDF study is integrating the results of the studies carried out by these two teams with plans for ESA's European Large Logistics Lander (EL3) and Moonlight initiatives. Whilst EL3 is a lander designed to enable a series of ESA missions to the Moon, Moonlight aims to provide navigation and telecommunications capabilities for lunar exploration.

The University of Würzburg has been exploring the concept of lowering a probe using a tether to explore and characterise the entrance, walls and initial part of lunar lava tubes. These huge underground caverns are thought to have formed through lava flows billions of years ago.

Descent and exploration in deep autonomy of lava underground structures

Named Daedalus, the compact, spherical probe would be equipped with 3D lidar, stereo camera vision and an ability to move independently. By creating a 3D model of the inside of a lava tube, the probe could identify geological resources and seek out locations with stable radiation levels and temperature; this information could take us closer to building a human settlement on the Moon.

The University of Oviedo, meanwhile, has investigated deploying a swarm of small robots inside a cave. Working together with the University of Vigo and Alén Space, the focus of their research has been on overcoming the lack of sunlight – and therefore solar power – inside a cave, as well as how to transmit data from the robots to a rover on the Moon's surface.

The team's solution is to use a crane to lower the robots into a lava tube. Equipped with a solar panel, the rover would supply energy to the robots through the crane using a 'charging head' attached to the bottom of the crane. Being in sight of the robots, the charging head would supply energy wirelessly, as well as transmitting and receiving data.

Robotic crane for wireless power and data transmission between surface and cave

Image above: An overview of the University of Oviedo’s idea, where a charging head (CH) attached to the end of a crane can communicate with the underground rovers – cave elements (CEs) – using WiFi.

Looking at the big picture and the small details

Continuing the research, the CDF study will design a lunar caves mission lasting one lunar day (14 Earth days), starting from the deployment of EL3. Focusing on the second mission scenario, the CDF study will also specify the individual subsystems of such a mission and ensure that they would all be able to work together.

"The CDF study will investigate details such as the energy requirements of the mission, the path that could be taken from the landing site to the pit rim, and the power and data budgets for descending into and mapping the pit," explains Francesco Sauro, cave scientist and planetary lava tube expert, as well as technical course director of ESA CAVES and PANGAEA. "It will also look at the interfaces between the rover and the robotic crane, as well as the crane and the Daedalus probe."

European Large Logistic Lander unloading cargo

Image above: Artist’s impression of the European Large Logistics Lander (EL3) unloading cargo. This cargo could include a mission to explore lunar caves.

"Overall, the Sysnova and CDF studies are helping ESA to identify interesting technologies and develop roadmaps for the future. They are supporting the Agency to assess the feasibility of novel concepts for future missions."

Whilst the Moon's surface has been well documented by orbital spacecraft, it hides an underground world that remains a mystery. The shelter that lunar caves provide, as well as the access to water and other resources, could be vital for our future human or robotic exploration of the Moon. This makes these Sysnova studies – and the ensuing CDF study – a major step forward in achieving a lunar mission.

Discover more about each Sysnova study

The following videos, as well as the articles at the end of this page, were put together by the Sysnova study teams.

Scouting and mapping lava tubes from the Moon's surface

Video above: Rover-based system for scouting and mapping lava tubes from the Moon's surface using gravimetric surveying – Canadensys (mission scenario one).

Hopping rovers for lunar exploration

Video above: Hopping rovers for lunar exploration – the University of Manchester (mission scenario one).

Robotic crane for wireless power and data transmission between surface and cave

Video above: Robotic crane for wireless power and data transmission between surface and cave – University of Oviedo (mission scenario two).

Descent and exploration in deep autonomy of lava underground structures

Video above: Descent and exploration in deep autonomy of lava underground structures – University of Würzburg (mission scenario two).

Skylight: A tethered micro-rover for safe semi-autonomous exploration of lava tubes

Video above: Skylight: A tethered micro-rover for safe semi-autonomous exploration of lava tubes – DFKI (mission scenario three).

Related article:

First permanent habitat on Mars, the lava tunnels of Olympus Mons
https://orbiterchspacenews.blogspot.com/2021/02/first-permanent-habitat-on-mars-lava.html

Related links:

Sysnova: https://www.esa.int/Enabling_Support/Preparing_for_the_Future/Discovery_and_Preparation/SysNova2

CAVES and PANGAEA: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/CAVES_and_Pangaea

ESA Concurrent Design Facility (CDF): https://www.esa.int/Enabling_Support/Space_Engineering_Technology/CDF

European Large Logistics Lander (EL3): https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/European_Large_Logistics_Lander

Moonlight: https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Lunar_satellites

Images, Animation, Videos, Text, Credits: ESA/ATG-Medialab/Conor Marsh, University of Manchester/Canadensys/University of Oviedo/University of Würzburg/DFKI.

Best regards, Orbiter.ch

mardi 23 février 2021

NASA Takes Steps to Reduce Aviation Emissions, Invigorate US Economy

 







NASA logo.


Feb 23, 2021

NASA is seeking proposals for ground and flight demonstrations of integrated megawatt-class powertrain systems for subsonic aircraft. The deadline for proposals for this solicitation is 5 p.m. EST April 20.


Image above: NASA illustration of an advanced subsonic aircraft with an electrified aircraft propulsion system. Image Credit: NASA.

The demonstrations will help rapidly mature and transition integrated Electrified Aircraft Propulsion (EAP) technologies and associated EAP vision systems for introduction into the global fleet by 2035. Integrated EAP concepts are rapidly emerging as potentially transformative solutions to significantly improve the environmental sustainability of the next generation of subsonic transport vehicles. EAP electrical systems are being developed to replace or boost fuel-burning aircraft propulsion systems, analogous to how electric or hybrid motors are used in automobiles.

“The release of this request for proposals represents an important next step as NASA partners with industry to further mature critical EAP technologies through demonstrating integrated megawatt-class powertrain systems in flight,” said Lee Noble, NASA’s Integrated Aviation System Program director. “These flight demonstrations have strong applicability to sustainable and highly-efficient aircraft powertrain systems that will facilitate continued U.S. competitiveness for the next generation of commercial transport aircraft.”

Though partnerships with U.S. industry, NASA intends to accelerate integrated megawatt-class powertrain system maturation and transition to the global fleet, as well as identify and address gaps in regulations and standards and acquire necessary ground and flight test data to advance design and modelling tools pertinent to future aircraft products with an EAP system.

NASA and industry studies have shown that EAP concepts can reduce energy use, carbon and nitrogen oxide emissions, and direct operating costs resulting in benefits for both the public and the airline operators. NASA and its industry partners have identified turboprops, regional jets, and single aisle aircraft serving the thin-haul (very short flights), regional, and single-aisle markets as targets of opportunity for this technology.

To turn the promise of EAP benefits into reality, NASA’s Aeronautics Research Mission Directorate has made a critical commitment to demonstrate practical vehicle-level integration of megawatt-class EAP systems, leveraging advanced airframe systems to reinvigorate the regional and emerging smaller aircraft markets, and to strengthen the single-aisle aircraft market. The Electrified Powertrain Flight Demonstration project directly supports retaining U.S. leadership in the aerospace manufacturing sector, the largest net-exporter of all U.S. manufacturing sectors.

NASA is seeking proposals: https://beta.sam.gov/opp/6c070678508b4897a48270073da7edfe/view

For more information about NASA’s aeronautics programs and projects, visit: http://www.nasa.gov/aero/

Aeronautics: https://www.nasa.gov/topics/aeronautics/index.html

Image (mentioned), Text, Credits: NASA/Sean Potter/J.D. Harrington.

Greetings, Orbiter.ch

Mars Perseverance Rover Provides First Audio Recording of Red Planet

 







NASA - Mars 2020 Perseverance Rover logo.


Feb 23, 2021

A microphone attached to the rover did not collect usable data during the descent, but the commercial off-the-shelf device survived the highly dynamic descent to the surface and obtained sounds from Jezero Crater on Feb. 20. About 10 seconds into the 60-second recording, a Martian breeze is audible for a few seconds, as are mechanical sounds of the rover operating on the surface.

Perseverance’s First Sounds from Mars

Video above: The microphone on the side of NASA’s Perseverance Rover recorded these sounds on 20 February 2021. Wind is audible in the filtered section. This is the first time a Mars rover has been equipped with a microphone. Video Credit: Audio and image courtesy of NASA/JPL-Caltech/SciNews.


Image above: This is the first high-resolution, color image to be sent back by the Hazard Cameras on the underside of NASA’s Perseverance Mars rover after its landing on Feb. 18, 2021. Image Credits: NASA/JPL-Caltech.

Perseverance’s first panorama on Mars

Video above: Panorama composed of six individual images taken by the Navigation Cameras (Navcams) on NASA’s Perseverance rover, 20 February 2021. The Navcams also captured a view of the rover’s deck. Video Credit: NASA/JPL-Caltech/SciNews.

More About the Mission

A key objective of Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.

For more about Perseverance:

https://www.nasa.gov/perseverance and https://mars.nasa.gov/mars2020

Image (mentioned), Videos (mentioned), Text, Credits: NASA/Sean Potter/Alana Johnson/Grey Hautaluoma/JPL/DC Agle.

Best regards, Orbiter.ch

Reclusive Neutron Star May Have Been Found in Famous Supernova

 







NASA - Chandra X-ray Observatory logo.


Feb 23, 2021


Since astronomers captured the bright explosion of a star on February 24, 1987, researchers have been searching for the squashed stellar core that should have been left behind. A group of astronomers using data from NASA space missions and ground-based telescopes may have finally found it.

As the first supernova visible with the naked eye in about 400 years, Supernova 1987A (or SN 1987A for short) sparked great excitement among scientists and soon became one of the most studied objects in the sky. The supernova is located in the Large Magellanic Cloud, a small companion galaxy to our own Milky Way, only about 170,000 light-years from Earth.

While astronomers watched debris explode outward from the site of the detonation, they also looked for what should have remained of the star’s core: a neutron star.

Data from NASA’s Chandra X-ray Observatory and previously unpublished data from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR), in combination with data from the ground-based Atacama Large Millimeter Array (ALMA) reported last year, now present an intriguing collection of evidence for the presence of the neutron star at the center of SN 1987A.

“For 34 years, astronomers have been sifting through the stellar debris of SN 1987A to find the neutron star we expect to be there,” said the leader of the study, Emanuele Greco, of the University of Palermo in Italy. “There have been lots of hints that have turned out to be dead ends, but we think our latest results could be different.”

When a star explodes, it collapses onto itself before the outer layers are blasted into space. The compression of the core turns it into an extraordinarily dense object, with the mass of the Sun squeezed into an object only about 10 miles across. These objects have been dubbed neutron stars, because they are made nearly exclusively of densely packed neutrons. They are laboratories of extreme physics that cannot be duplicated here on Earth.

Rapidly rotating and highly magnetized neutron stars,called pulsars, produce a lighthouse-like beam of radiation that astronomers detect as pulses when its rotation sweeps the beam across the sky. There is a subset of pulsars that produce winds from their surfaces – sometimes at nearly the speed of light – that create intricate structures of charged particles and magnetic fields known as “pulsar wind nebulae.”

With Chandra and NuSTAR, the team found relatively low-energy X-rays from SN 1987A’s debris crashing into surrounding material. The team also found evidence of high-energy particles using NuSTAR’s ability to detect more energetic X-rays.

There are two likely explanations for this energetic X-ray emission: either a pulsar wind nebula, or particles being accelerated to high energies by the blast wave of the explosion. The latter effect doesn’t require the presence of a pulsar and occurs over much larger distances from the center of the explosion.

The latest X-ray study supports the case for the pulsar wind nebula – meaning the neutron star must be there – by arguing on a couple of fronts against the scenario of blast wave acceleration. First, the brightness of the higher energy X-rays remained about the same between 2012 and 2014, while the radio emission detected with the Australia Telescope Compact Array increased. This goes against expectations for the blast wave scenario. Next, authors estimate it would take almost 400 years to accelerate the electrons up to the highest energies seen in the NuSTAR data, which is over 10 times older than the age of the remnant.

“Astronomers have wondered if not enough time has passed for a pulsar to form, or even if SN 1987A created a black hole,” said co-author Marco Miceli, also from the University of Palermo. “This has been an ongoing mystery for a few decades and we are very excited to bring new information to the table with this result.”

The Chandra and NuSTAR data also support a 2020 result from ALMA that provided possible evidence for the structure of a pulsar wind nebula in the millimeter wavelength band. While this “blob” has other potential explanations, its identification as a pulsar wind nebula could be substantiated with the new X-ray data. This is more evidence supporting the idea that there is a neutron star left behind.

If this is indeed a pulsar at the center of SN 1987A, it would be the youngest one ever found.

“Being able to watch a pulsar essentially since its birth would be unprecedented,” said co-author Salvatore Orlando of the Palermo Astronomical Observatory, a National Institute for Astrophysics (INAF) research facility in Italy. “It might be a once-in-a-lifetime opportunity to study the development of a baby pulsar.”

Chandra X-ray Observatory. Animation Credits: NASA/CXC

The center of SN 1987A is surrounded by gas and dust. The authors used state-of-the-art simulations to understand how this material would absorb X-rays at different energies, enabling more accurate interpretation of the X-ray spectrum, that is, the amount of X-rays at different energies. This enables them to estimate what the spectrum of the central regions of SN 1987A is without the obscuring material.

As is often the case, more data are needed to strengthen the case for the pulsar wind nebula. An increase in radio waves accompanied by an increase in relatively high-energy X-rays in future observations would argue against this idea. On the other hand, if astronomers observe a decrease in the high-energy X-rays, then the presence of a pulsar wind nebula will be corroborated.

The stellar debris surrounding the pulsar plays an important role by heavily absorbing its lower energy X-ray emission, making it undetectable at the present time. The model predicts that this material will disperse over the next few years, which will reduce its absorbing power. Thus, the pulsar emission is expected to emerge in about 10 years, revealing the existence of the neutron star.

A paper describing these results is being published this week in The Astrophysical Journal and a preprint is available online. The other authors of the paper are Barbara Olmi and Fabrizio Bocchino, also from INAF-Palermo; Shigehiro Nagataki and Masaomi Ono from the Astrophysical Big Bang Laboratory, RIKEN in Japan; Akira Dohi from Kyushu University in Japan, and Giovanni Peres from the University of Palermo.

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.

NuSTAR is a Small Explorer mission led by Caltech and managed by NASA’s Jet Propulsion Laboratory for the agency’s Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corporation in Dulles, Virginia (now part of Northrop Grumman). NuSTAR's mission operations center is at UC Berkeley, and the official data archive is at NASA's High Energy Astrophysics Science Archive Research Center. ASI provides the mission's ground station and a mirror archive. JPL is a division of Caltech.

Image credit: Chandra (X-ray): NASA/CXC/Univ. di Palermo/E. Greco; Illustration: INAF-Osservatorio Astronomico di Palermo/Salvatore Orlando.

Read more from NASA's Chandra X-ray Observatory: https://chandra.harvard.edu/photo/2021/pwn1987a/

The Astrophysical Journal: https://arxiv.org/abs/2101.09029

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Lee Mohon.

Greetings, Orbiter.ch

lundi 22 février 2021

NASA’s Mars Perseverance Rover Provides Front-Row Seat to Landing, First Video Recording of Red Planet

 







NASA - Mars 2020 Perseverance Rover logo.


February 22, 2021

New video from NASA’s Mars 2020 Perseverance rover chronicles major milestones during the final minutes of its entry, descent, and landing (EDL) on the Red Planet on Feb. 18 as the spacecraft plummeted, parachuted, and rocketed toward the surface of Mars. A microphone on the rover also has provided the first audio recording of sounds from Mars.

From the moment of parachute inflation, the camera system covers the entirety of the descent process, showing some of the rover’s intense ride to Mars’ Jezero Crater. The footage from high-definition cameras aboard the spacecraft starts 7 miles (11 kilometers) above the surface, showing the supersonic deployment of the most massive parachute ever sent to another world, and ends with the rover’s touchdown in the crater.

First panorama taken from Jezero Crater by Perseverance rover. Image Credits: NASA/JPL-Caltech

A microphone attached to the rover did not collect usable data during the descent, but the commercial off-the-shelf device survived the highly dynamic descent to the surface and obtained sounds from Jezero Crater on Feb. 20. About 10 seconds into the 60-second recording, a Martian breeze is audible for a few seconds, as are mechanical sounds of the rover operating on the surface.

“For those who wonder how you land on Mars – or why it is so difficult – or how cool it would be to do so – you need look no further,” said acting NASA Administrator Steve Jurczyk. “Perseverance is just getting started, and already has provided some of the most iconic visuals in space exploration history. It reinforces the remarkable level of engineering and precision that is required to build and fly a vehicle to the Red Planet.”


Perseverance Rover’s Descent and Touchdown on Mars. Image Credits: NASA/JPL-Caltech


Also released Monday was the mission’s first panorama of the rover’s landing location, taken by the two Navigation Cameras located on its mast. The six-wheeled robotic astrobiologist, the fifth rover the agency has landed on Mars, currently is undergoing an extensive checkout of all its systems and instruments.

“This video of Perseverance’s descent is the closest you can get to landing on Mars without putting on a pressure suit,” said Thomas Zurbuchen, NASA associate administrator for science. “It should become mandatory viewing for young women and men who not only want to explore other worlds and build the spacecraft that will take them there, but also want to be part of the diverse teams achieving all the audacious goals in our future.”

The world’s most intimate view of a Mars landing begins about 230 seconds after the spacecraft entered the Red Planet’s upper atmosphere at 12,500 mph (20,100 kph). The video opens in black, with the camera lens still covered within the parachute compartment. Within less than a second, the spacecraft’s parachute deploys and transforms from a compressed 18-by-26 inch (46-by-66 centimeter) cylinder of nylon, Technora, and Kevlar into a fully inflated 70.5-foot-wide (21.5-meter-wide) canopy – the largest ever sent to Mars. The tens of thousands of pounds of force that the parachute generates in such a short period stresses both the parachute and the vehicle.

“Now we finally have a front-row view to what we call ‘the seven minutes of terror’ while landing on Mars,” said Michael Watkins, director of NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission for the agency. “From the explosive opening of the parachute to the landing rockets’ plume sending dust and debris flying at touchdown, it’s absolutely awe-inspiring.”

The video also captures the heat shield dropping away after protecting Perseverance from scorching temperatures during its entry into the Martian atmosphere. The downward view from the rover sways gently like a pendulum as the descent stage, with Perseverance attached, hangs from the back shell and parachute. The Martian landscape quickly pitches as the descent stage – the rover’s free-flying “jetpack,” which decelerates using rocket engines and then lowers the rover on cables to the surface – breaks free, its eight thrusters engaging to put distance between it and the now-discarded back shell and the parachute.

Then, 80 seconds and 7,000 feet (2,130 meters) later, the cameras capture the descent stage performing the sky crane maneuver over the landing site – the plume of its rocket engines kicking up dust and small rocks that have likely been in place for billions of years.

Perseverance Rover’s Descent and Touchdown on Mars (Official NASA Video)

Video above: NASA's Mars 2020 Perseverance mission captured thrilling footage of its rover landing in Mars' Jezero Crater on Feb. 18, 2021. The real footage in this video was captured by several cameras that are part of the rover's entry, descent, and landing suite. The views include a camera looking down from the spacecraft's descent stage (a kind of rocket-powered jet pack that helps fly the rover to its landing site), a camera on the rover looking up at the descent stage, a camera on the top of the aeroshell (a capsule protecting the rover) looking up at that parachute, and a camera on the bottom of the rover looking down at the Martian surface. The audio embedded in the video comes from the mission control call-outs during entry, descent, and landing. Video Credits: NASA/JPL-Caltech.

“We put the EDL camera system onto the spacecraft not only for the opportunity to gain a better understanding of our spacecraft’s performance during entry, descent, and landing, but also because we wanted to take the public along for the ride of a lifetime – landing on the surface of Mars,” said Dave Gruel, lead engineer for Mars 2020 Perseverance’s EDL camera and microphone subsystem at JPL. “We know the public is fascinated with Mars exploration, so we added the EDL Cam microphone to the vehicle because we hoped it could enhance the experience, especially for visually-impaired space fans, and engage and inspire people around the world.”

The footage ends with Perseverance’s aluminum wheels making contact with the surface at 1.61 mph (2.6 kilometers per second), and then pyrotechnically fired blades sever the cables connecting it to the still-hovering descent stage. The descent stage then climbs and accelerates away in the preplanned flyaway maneuver.

“If this were an old Western movie, I’d say the descent stage was our hero riding slowly into the setting Sun, but the heroes are actually back here on Earth,” said Matt Wallace, Mars 2020 Perseverance deputy project manager at JPL. “I’ve been waiting 25 years for the opportunity to see a spacecraft land on Mars. It was worth the wait. Being able to share this with the world is a great moment for our team.”

Five commercial off-the-shelf cameras located on three different spacecraft components collected the imagery. Two cameras on the back shell, which encapsulated the rover on its journey, took pictures of the parachute inflating. A camera on the descent stage provided a downward view – including the top of the rover – while two on the rover chassis offered both upward and downward perspectives.

The rover team continues its initial inspection of Perseverance’s systems and its immediate surroundings. Monday, the team will check out five of the rover’s seven instruments and take the first weather observations with the Mars Environmental Dynamics Analyzer instrument. In the coming days, a 360-degree panorama of Jezero by the Mastcam-Z should be transmitted down, providing the highest resolution look at the road ahead.

More About the Mission

A key objective of Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.

For more about Perseverance:

https://www.nasa.gov/perseverance and https://mars.nasa.gov/mars2020

For more information about NASA’s Mars missions, go to: https://www.nasa.gov/mars

Images (mentioned), Video (mentioned), Text, Credits: NASA/Alana Johnson/Grey Hautaluoma/JPL/DC Agle.

Best regards, Orbiter.ch

NASA’s Swift Helps Tie Neutrino to Star-shredding Black Hole

 







NASA - Swift Mission patch.


Feb 22, 2021

For only the second time, astronomers have linked an elusive particle called a high-energy neutrino to an object outside our galaxy. Using ground- and space-based facilities, including NASA’s Neil Gehrels Swift Observatory, they traced the neutrino to a black hole tearing apart a star, a rare cataclysmic occurrence called a tidal disruption event.

Swift observatory. Image Credit: NASA

“Astrophysicists have long theorized that tidal disruptions could produce high-energy neutrinos, but this is the first time we’ve actually been able to connect them with observational evidence,” said Robert Stein, a doctoral student at the German Electron-Synchrotron (DESY) research center in Zeuthen, Germany, and Humboldt University in Berlin. “But it seems like this particular event, called AT2019dsg, didn’t generate the neutrino when or how we expected. It’s helping us better understand how these phenomena work.”

The findings, led by Stein, were published in the Feb. 22 issue of Nature Astronomy and are available online: https://www.nature.com/articles/s41550-020-01295-8

Swift Links Neutrino to Star-destroying Black Hole

Video above: Watch how a monster black hole ripping apart a star may have launched a ghost particle toward Earth. Astronomers have long predicted that tidal disruption events could produce high-energy neutrinos, nearly massless particles from outside our galaxy traveling close to the speed of light. One recent event, named AT2019dsg, provides the first proof this prediction is true but has challenged scientists’ assumptions of where and when these elusive particles might form during these destructive outbursts. Video Credits: NASA’s Goddard Space Flight Center.

Neutrinos are fundamental particles that far outnumber all the atoms in the universe but rarely interact with other matter. Astrophysicists are particularly interested in high-energy neutrinos, which have energies up to 1,000 times greater than those produced by the most powerful particle colliders on Earth. They think the most extreme events in the universe, like violent galactic outbursts, accelerate particles to nearly the speed of light. Those particles then collide with light or other particles to generate high-energy neutrinos. The first confirmed high-energy neutrino source, announced in 2018, was a type of active galaxy called a blazar.

Tidal disruption events occur when an unlucky star strays too close to a black hole. Gravitational forces create intense tides that break the star apart into a stream of gas. The trailing part of the stream escapes the system, while the leading part swings back around, surrounding the black hole with a disk of debris. In some cases, the black hole launches fast-moving particle jets. Scientists hypothesized that tidal disruptions would produce high-energy neutrinos within such particle jets. They also expected the events would produce neutrinos early in their evolution, at peak brightness, whatever the particles’ production process.  

AT2019dsg was discovered on April 9, 2019, by the Zwicky Transient Facility (ZTF), a robotic camera at Caltech’s Palomar Observatory in Southern California. The event occurred over 690 million light-years away in a galaxy called 2MASX J20570298+1412165, located in the constellation Delphinus.

As part of a routine follow-up survey of tidal disruptions, Stein and his team requested visible, ultraviolet, and X-ray observations with Swift. They also took X-ray measurements using the European Space Agency’s XMM-Newton satellite and radio measurements with facilities including the National Radio Astronomy Observatory’s Karl G. Jansky Very Large Array in Socorro, New Mexico, and the South African Radio Astronomy Observatory's MeerKAT telescope.

Peak brightness came and went in May. No clear jet appeared. According to theoretical predictions, AT2019dsg was looking like a poor neutrino candidate.

Then, on Oct. 1, 2019, the National Science Foundation’s IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station in Antarctica detected a high-energy neutrino called IC191001A and backtracked along its trajectory to a location in the sky. About seven hours later, ZTF noted that this same patch of sky included AT2019dsg. Stein and his team think there is only one chance in 500 that the tidal disruption is not the neutrino’s source. Because the detection came about five months after the event reached peak brightness, it raises questions about when and how these occurrences produce neutrinos.

“Tidal disruption events are incredibly rare phenomena, only occurring once every 10,000 to 100,000 years in a large galaxy like our own. Astronomers have only observed a few dozen at this point,” said Swift Principal Investigator S. Bradley Cenko at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Multiwavelength measurements of each event help us learn more about them as a class, so AT2019dsg was of great interest even without an initial neutrino detection.”

For example, tidal disruptions generate visible and UV light in the outer regions of their hot accretion disks. In AT2019dsg, these wavelengths plateaued shortly after they peaked. That was unusual because such plateaus typically appear only after a few years. The researchers suspect the galaxy’s monster black hole, with a mass estimated at 30 million times the Sun’s, could have forced the stellar debris to settle into a disk more quickly than it might have around a less massive black hole.

AT2019dsg is one of only a handful of known X-ray-emitting tidal disruptions. Scientists think the X-rays come from either the inner part of the accretion disk, close to the black hole, or from high-speed particle jets. The outburst’s X-rays faded by an unprecedented 98% over 160 days. Stein’s team doesn’t see clear evidence indicating the presence of jets and instead suggests rapid cooling in the disk most likely explains the precipitous drop in X-rays.

Not everyone agrees with this analysis. Another explanation, authored by DESY’s Walter Winter and Cecilia Lunardini, a professor at Arizona State University in Tempe, proposes that the emission came from a jet that was swiftly obscured by a cloud of debris. The researchers published their alternative interpretation in the same issue of Nature Astronomy: https://www.nature.com/articles/s41550-021-01305-3


Image above: The Zwicky Transient Facility captured this snapshot of tidal disruption event AT2019dsg, circled, on Oct. 19, 2019. Image Credits: ZTF/Caltech Optical Observatories.

Astronomers think radio emission in these phenomena comes from the black hole accelerating particles, either in jets or more moderate outflows. Stein’s team thinks AT2019dsg falls into the latter category. The scientists also discovered that the radio emission continued steadily for months and did not fade along with the visible and UV light, as previously assumed.

The neutrino detection, combined with the multiwavelength measurements, prompted Stein and his colleagues to rethink how tidal disruptions might produce high-energy neutrinos.

The radio emission shows that particle acceleration happens even without clear, powerful jets and can operate well after peak UV and visible brightness. Stein and his colleagues suggest those accelerated particles could produce neutrinos in three distinct regions of the tidal disruption: in the outer disk through collisions with UV light, in the inner disk through collisions with X-rays, and in the moderate outflow of particles through collisions with other particles.

Stein’s team suggests AT2019dsg’s neutrino likely originated from the UV-bright outer part of the disk, based on the fact that the particle’s energy was more than 10 times greater than can be achieved by particle colliders.

“We predicted that neutrinos and tidal disruptions could be related, and seeing that for the first time in the data is just very exciting,” said co-author Sjoert van Velzen, an assistant professor at Leiden University in the Netherlands. “This is another example of the power of multimessenger astronomy, using a combination of light, particles, and space-time ripples to learn more about the cosmos. When I was a graduate student, it was often predicted this new era of astronomy was coming, but now to actually be part of it is very rewarding.”

Goddard manages the Swift mission in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico, and Northrop Grumman Innovation Systems in Dulles, Virginia. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory, and the Italian Space Agency in Italy.

Related links:

Zwicky Transient Facility (ZTF): https://www.ztf.caltech.edu/

Caltech’s Palomar Observatory: https://www.astro.caltech.edu/palomar/homepage.html

National Science Foundation’s IceCube Neutrino Observatory: https://icecube.wisc.edu/

German Electron-Synchrotron (DESY): https://www.desy.de/index_eng.html

Humboldt University: https://www.hu-berlin.de/en?set_language=en

Arizona State University: https://www.asu.edu/

Leiden University: https://www.universiteitleiden.nl/en

Swift: http://www.nasa.gov/mission_pages/swift/main/index.html

Image (mentioned), Video (mentioned), Text, Credits: NASA/Jeanette Kazmierczak/GSFC/Claire Andreoli, by Jeanette Kazmierczak.

Best regards, Orbiter.ch