Orbiter.ch Space News: 2022-10-09

samedi 15 octobre 2022

SpaceX - Falcon 9 launches Eutelsat Hotbird 13F

SpaceX - Falcon 9 / Eutelsat Hotbird 13F patch.

Oct 15, 2022

Falcon 9 carrying Eutelsat Hotbird 13F liftoff

A SpaceX Falcon 9 launch vehicle launched the Eutelsat Hotbird 13F communications satellite from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida, on 15 October 2022, at 05:22 UTC (01:22 EDT). Following stage separation, Falcon 9’s first stage landed on the “Just Read the Instructions” droneship, stationed in the Atlantic Ocean. Falcon 9’s first stage (B1069) previously launched CRS-24 and one Starlink mission.

Falcon 9 launches Eutelsat Hotbird 13F & Falcon 9 first stage landing

The separation of the all-electric satellite occurred after a 35-minute flight and the spacecraft systems initialisation was successfully completed over a period of 3 hours.

EUTELSAT HOTBIRD 13F is one of two satellites built by manufacturer Airbus Defence and Space. EUTELSAT HOTBIRD 13F is based on the Eurostar Neo telecommunications satellite platform, developed under an ESA Partnership Project with Airbus designed to foster innovation and competitiveness in the European space industry.

Eutelsat Hotbird 13F & Eutelsat Hotbird 13G

Once into orbit and positioned, the satellite EUTELSAT HOTBIRD 13F will, with its twin EUTELSAT HOTBIRD 13G, reinforce and enhance the broadcast of more than a thousand television channels into homes across Europe, Northern Africa and the Middle East. Moreover, the satellites will offer advanced features in terms of uplink signal protection and resilience.

The two satellites will be replacing three older satellites at Eutelsat’s 13° East flagship neighbourhood position.

Related links:

SpaceX: https://www.spacex.com/

Eutelsat: https://www.eutelsat.com/en/home.html

Images, Video, Text, Credits: Airbus/Eutelsat/SpaceX/SciNews/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of October 10, 2022

ISS - Expedition 68 Mission patch.

Oct 15, 2022

Crew members aboard the International Space Station conducted scientific investigations during the week of Oct. 10 that included collecting data to support studies of how the body adapts to space, comparing properties of soil microbes in space and on the ground, and mapping radiation doses inside the space station. Crew-4, including Kjell Lindgren, Bob Hines, and Jessica Watkins of NASA and Samantha Cristoforetti of ESA (European Space Agency), departed the station for return to Earth aboard the SpaceX Dragon Freedom on Friday, Oct. 14.

Image above: This image shows the big island of Hawaii as the space station orbits overhead. Image Credit: NASA.

Here are details on some of the microgravity investigations currently taking place aboard the orbiting lab:

Adapting to space

Many new crew members arriving at the space station participate in ongoing studies that evaluate how their bodies adapt. During the week, crew members conducted sessions for three such investigations from ESA.

GRASP examines the effect on coordination of the hand and visual environment to control reaching for and grasping an object. Astronauts perform sessions pre- and post-flight, as well as within the first 15 days and at other points during flight to help researchers evaluate how the brain adapts to microgravity.

GRIP studies the long-duration effects on a person’s ability to regulate the force of their grip and trajectory of upper limbs when manipulating objects. Data could identify potential hazards for astronauts as they move between gravitational environments, as well as contribute to the design of systems for controlling rovers, robots, and other tools used to explore planets, moons, and asteroids.

Animation above: NASA astronaut Josh Cassada conducts a seated session for GRIP, an ESA investigation into how microgravity affects a person’s ability to regulate the force of their grip and trajectory of upper limbs when manipulating objects. GRIP is one of several ongoing studies that evaluate how the human body adapts to space. Animation Credit: NASA.

Myotones monitors changes in the properties of muscles during spaceflight, comparing data from preflight sessions to those conducted early in flight. Results could support development of better countermeasures for future space missions as well as alternative rehabilitation treatments for those experiencing the effects of aging and restricted mobility on Earth.

Microbes in microgravity

Image above: A preflight view of soil samples for the DynaMoS investigation, which examines how microgravity affects metabolic interactions in communities of soil microbes. Image Credit: Pacific Northwest National Laboratory

DynaMoS compares metabolic interactions in a community of soil microbes on the space station and a control sample on the ground. Communities of microorganisms carry out key functions in soil, including carbon and nutrient cycling and supporting plant growth. Results could improve understanding of function of soil microorganisms in space and support the design of life-support systems for future missions that use the natural processes carried out by soil microorganisms. Improved understanding of the function of soil microorganism communities also could support improvements in agricultural production on Earth. During the week, crew members conducted a scheduled sample collection, placing the sealed tubes in MELFI, one of the station’s cold storage units.

Mapping radiation doses

Image above: This bright orange sensor is part of data collection for DOSIS 3D, an investigation from ESA that measures the nature and distribution of the radiation field inside the space station. Image Credit: NASA.

DOSIS-3D, an investigation from ESA, uses several active and passive detectors that determine the nature and distribution of the radiation field inside the space station to create a three-dimensional radiation map of its sections. Specific detectors measure various radiation components and absorbed doses, averaged over the mission. A comprehensive understanding of the space radiation environment could help scientists develop better ways to protect crews. On Earth, commercial and military flight crews and nuclear plant workers are exposed to greater-than-average radiation levels, and results could improve protection for them as well. The DOSIS-3D experiment also provides insight into combining different devices for dosage monitoring and provides lessons in how to monitor real-time data. Crew members deployed dosimeters for the investigation during the week.

Other investigations involving the crew:

- Wireless Compose-2, an investigation from ESA, demonstrates an infrastructure for wireless transmission of data and a smart shirt for measuring forces generated by the heart as it pumps blood. This technology could help monitor the health of astronauts on future missions and this investigation also could improve use of the medical monitoring technology on the ground.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8563

- Robo Pro Challenge 3 from the Japan Aerospace Exploration Agency (JAXA) is an educational program where students solve various problems using NASA’s Astrobee and JAXA’s Internal Ball Camera robots. The experience helps to inspire the next generation of scientists, engineers, and leaders.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8705

- Standard Measures collects a set of core measurements, including data on behavioral health and performance, cellular profiles and immunology, the microbiome, biochemistry markers, sensorimotor changes, and cardiovascular health. These data help researchers characterize adaptive responses to living and working in space and monitor the effectiveness of countermeasures.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711

- ISS Ham Radio sessions engage students, teachers, parents, and other members of the community in direct communication with astronauts via ground-based amateur radio units. This experience helps inspire interest in science, technology, engineering, and math.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337

- Rhodium Space Microbiome Isolates characterizes changes induced by spaceflight in individual bacterial species from the human gut microbiome, a complex community of diverse bacterial species. Results could provide a better understanding of how spaceflight affects the human gut microbiome and lead to strategies to improve human health and function during future missions.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8802

- XROOTS uses the Veggie facility to test hydroponic (liquid-based) and aeroponic (air-based) techniques to grow plants without soil or other traditional growth media, potentially enabling production of crops on a larger scale for future space exploration.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8088

Space to Ground: A Full House: 10/14/2022

Best regards, Orbiter.ch

NASA’s Swift, Fermi Missions Detect Exceptional Cosmic Blast

NASA - Goddard Space Flight Center logo.

Oct 15, 2022

Image above: Astronomers think GRB 221009A represents the birth of a new black hole formed within the heart of a collapsing star. In this illustration, the black hole drives powerful jets of particles traveling near the speed of light. The jets pierce through the star, emitting X-rays and gamma rays as they stream into space. Image Credits: NASA/Swift/Cruz deWilde.

Astronomers around the world are captivated by an unusually bright and long-lasting pulse of high-energy radiation that swept over Earth Sunday, Oct. 9. The emission came from a gamma-ray burst (GRB) – the most powerful class of explosions in the universe – that ranks among the most luminous events known.

On Sunday morning Eastern time, a wave of X-rays and gamma rays passed through the solar system, triggering detectors aboard NASA's Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and Wind spacecraft, as well as others. Telescopes around the world turned to the site to study the aftermath, and new observations continue.

Image above: Swift’s X-Ray Telescope captured the afterglow of GRB 221009A about an hour after it was first detected. The bright rings form as a result of X-rays scattered from otherwise unobservable dust layers within our galaxy that lie in the direction of the burst. Image Credits: Credit: NASA/Swift/A. Beardmore (University of Leicester).

Called GRB 221009A, the explosion provided an unexpectedly exciting start to the 10th Fermi Symposium, a gathering of gamma-ray astronomers now underway in Johannesburg, South Africa. “It’s safe to say this meeting really kicked off with a bang – everyone’s talking about this,” said Judy Racusin, a Fermi deputy project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who is attending the conference.

The signal, originating from the direction of the constellation Sagitta, had traveled an estimated 1.9 billion years to reach Earth. Astronomers think it represents the birth cry of a new black hole, one that formed in the heart of a massive star collapsing under its own weight. In these circumstances, a nascent black hole drives powerful jets of particles traveling near the speed of light. The jets pierce through the star, emitting X-rays and gamma rays as they stream into space.

The burst also provided a long-awaited inaugural observing opportunity for a link between two experiments on the International Space Station – NASA’s NICER X-ray telescope and a Japanese detector called the Monitor of All-sky X-ray Image (MAXI). Activated in April, the connection is dubbed the Orbiting High-energy Monitor Alert Network (OHMAN). It allows NICER to rapidly turn to outbursts detected by MAXI, actions that previously required intervention by scientists on the ground.

Animation above: This sequence constructed from Fermi Large Area Telescope data reveals the sky in gamma rays centered on the location of GRB 221009A. Each frame shows gamma rays with energies greater than 100 million electron volts (MeV), where brighter colors indicate a stronger gamma-ray signal. In total, they represent more than 10 hours of observations. The glow from the midplane of our Milky Way galaxy appears as a wide diagonal band. The image is about 20 degrees across. Animation Credit: NASA/DOE/Fermi LAT Collaboration.

“OHMAN provided an automated alert that enabled NICER to follow up within three hours, as soon as the source became visible to the telescope,” said Zaven Arzoumanian, the NICER science lead at Goddard. “Future opportunities could result in response times of a few minutes."

The light from this ancient explosion brings with it new insights into stellar collapse, the birth of a black hole, the behavior and interaction of matter near the speed of light, the conditions in a distant galaxy – and much more. Another GRB this bright may not appear for decades.

According to a preliminary analysis, Fermi’s Large Area Telescope (LAT) detected the burst for more than 10 hours. One reason for the burst’s brightness and longevity is that, for a GRB, it lies relatively close to us.

Animation above: images taken in visible light by Swift’s Ultraviolet/Optical Telescope show how the afterglow of GRB 221009A (circled) faded over the course of about 10 hours. The explosion appeared in the constellation Sagitta and occurred 1.9 billion years ago. The image is about 4 arcminutes across. Animation Credits: NASA/Swift/B. Cenko.

“This burst is much closer than typical GRBs, which is exciting because it allows us to detect many details that otherwise would be too faint to see,” said Roberta Pillera, a Fermi LAT Collaboration member who led initial communications about the burst and a doctoral student at the Polytechnic University of Bari, Italy. “But it’s also among the most energetic and luminous bursts ever seen regardless of distance, making it doubly exciting.”

Related links:

Fermi Gamma-Ray Space Telescope: http://www.nasa.gov/mission_pages/GLAST/main/index.html

NICER (Neutron star Interior Composition ExploreR): http://www.nasa.gov/nicer

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

NASA’s Goddard Space Flight Center (GSFC): https://www.nasa.gov/goddard

Images (mentioned), Animation (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Francis Reddy.

Greetings, Orbiter.ch

NASA’s Lucy Spacecraft Prepares to Swing by Earth

NASA - LUCY Mission patch.

Oct 15, 2022

On Oct. 16, at 7:04 a.m. EDT, NASA’s Lucy spacecraft, the first mission to the Jupiter Trojan asteroids, will skim the Earth’s atmosphere, passing a mere 220 miles (350 kilometers) above the surface. By sling-shotting past Earth on the first anniversary of its launch, Lucy will gain some of the orbital energy it needs to travel to this never-before-visited population of asteroids.

The Trojan asteroids are trapped in orbits around the Sun at the same distance as Jupiter, either far ahead of or behind the giant planet. Lucy is currently one year into a twelve-year voyage. This gravity assist will place Lucy on a new trajectory for a two-year orbit, at which time it will return to Earth for a second gravity assist. This second assist will give Lucy the energy it needs to cross the main asteroid belt, where it will observe asteroid Donaldjohanson, and then travel into the leading Trojan asteroid swarm. There, Lucy will fly past six Trojan asteroids: Eurybates and its satellite Queta, Polymele and its yet unnamed satellite, Leucus, and Orus. Lucy will then return to Earth for a third gravity assist in 2030 to re-target the spacecraft for a rendezvous with the Patroclus-Menoetius binary asteroid pair in the trailing Trojan asteroid swarm.

Image above: This illustration shows the Lucy spacecraft passing one of the Trojan Asteroids near Jupiter. Image Credit: Southwest Research Institute.

For this first gravity assist, Lucy will appear to approach Earth from the direction of the Sun. While this means that observers on Earth will not be able to see Lucy in the days before the event, Lucy will be able to take images of the nearly full Earth and Moon. Mission scientists will use these images to calibrate the instruments.

Lucy’s trajectory will bring the spacecraft very close to Earth, lower even than the International Space Station, which means that Lucy will pass through a region full of earth-orbiting satellites and debris. To ensure the safety of the spacecraft, NASA developed procedures to anticipate any potential hazard and, if needed, to execute a small maneuver to avoid a collision.

“The Lucy team has prepared two different maneuvers,” says Coralie Adam, Lucy deputy navigation team chief from KinetX Aerospace in Simi Valley, California. “If the team detects that Lucy is at risk of colliding with a satellite or piece of debris, then--12 hours before the closest approach to Earth --the spacecraft will execute one of these, altering the time of closest approach by either two or four seconds. This is a small correction, but it is enough to avoid a potentially catastrophic collision.”

Lucy will be passing the Earth at such a low altitude that the team had to include the effect of atmospheric drag when designing this flyby. Lucy’s large solar arrays increase this effect.

“In the original plan, Lucy was actually going to pass about 30 miles closer to the Earth,” says Rich Burns, Lucy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “However, when it became clear that we might have to execute this flyby with one of the solar arrays unlatched, we chose to use a bit of our fuel reserves so that the spacecraft passes the Earth at a slightly higher altitude, reducing the disturbance from the atmospheric drag on the spacecraft’s solar arrays.”

Lucy Spacecraft Will Slingshot Around Earth

Video above: NASA’s Lucy spacecraft will make an exceptionally close flyby of Earth on October 16, 2022. Video Credits: NASA's Goddard Space Flight Center.

At around 6:55 a.m. EDT, Lucy will first be visible to observers on the ground in Western Australia (6:55 p.m. for those observers). Lucy will quickly pass overhead, clearly visible to the naked eye for a few minutes before disappearing at 7:02 a.m. EDT as the spacecraft passes into the Earth’s shadow. Lucy will continue over the Pacific Ocean in darkness and emerge from the Earth’s shadow at 7:26 a.m. EDT. If the clouds cooperate, sky watchers in the western United States should be able to get a view of Lucy with the aid of binoculars.

“The last time we saw the spacecraft, it was being enclosed in the payload fairing in Florida,” said Hal Levison, Lucy principal investigator at the Southwest Research Institute (SwRI) Boulder, Colorado office. “It is exciting that we will be able to stand here in Colorado and see the spacecraft again. And this time Lucy will be in the sky.”

Lucy will then rapidly recede from the Earth’s vicinity, passing by the Moon and taking a few more calibration images before continuing out into interplanetary space.

“I’m especially excited by the final few images that Lucy will take of the Moon,” said John Spencer, acting deputy project scientist at SwRI. “Counting craters to understand the collisional history of the Trojan asteroids is key to the science that Lucy will carry out, and this will be the first opportunity to calibrate Lucy’s ability to detect craters by comparing it to previous observations of the Moon by other space missions.”

The public is invited to join the #WaveToLucy social media campaign by posting images of themselves waving towards the spacecraft and tagging the @NASASolarSystem account. Additionally, if you are in an area where Lucy will be visible, take a photograph of Lucy and post it to social media with the #SpotTheSpacecraft hashtag. Instructions for observing Lucy from your location are available here:

http://lucy.swri.edu/SpotTheSpacecraft-EGA1.html

Hal Levison of Southwest Research Institute (SwRI), in the Boulder Colorado office is the principal investigator. SwRI, headquartered in San Antonio, also leads the science team and the mission’s science observation planning and data processing. NASA Goddard provides overall mission management, systems engineering and the safety and mission assurance for Lucy. Lockheed Martin Space in Littleton, Colorado built the spacecraft, principally designed the orbital trajectory and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the Lucy spacecraft. Lucy is the thirteenth mission in NASA’s Discovery Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

For more information about the Lucy mission, visit:

https://www.nasa.gov/lucy or http://lucy.swri.edu

Image (mentioned), Video (mentioned), Text, Credits: NASA/Bill Steigerwald/Southwest Research Institute/By: Katherine Kretke.

Best regards, Orbiter.ch

CASC - Long March-2D launches Yaogan-36

CASC - China Aerospace Science and Technology Corporation logo.

Oct 15, 2022

Long March-2D carrying Yaogan-36 liftoff

A Long March-2D launch vehicle launched the Yaogan-36 satellite from the Xichang Satellite Launch Center, Sichuan Province, China, on 14 October 2022, at 19:12 UTC (15 Octobet, at 03:12 local time).

Long March-2D launches Yaogan-36

According to official sources, the satellite (遥感三十六号, Yaogan-36) has entered the planned orbit successfully.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Image, Video, Text, Credits: Credits: China Central Television (CCTV)/China Aerospace Science and Technology Corporation (CASC)/SciNews/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

NASA Dust Detective Delivers First Maps From Space for Climate Science

ISS - Earth Surface Mineral Dust Source Investigation (EMIT) patch.

Oct 15, 2022

Measurements from EMIT, the Earth Surface Mineral Dust Source Investigation, will improve computer simulations researchers use to understand climate change.

Image above: Installed on the space station in July 2022, EMIT orbits Earth about once every 90 minutes, to map the world’s mineral-dust sources. This includes the Sahara, where it recently gathered data on three minerals – goethite, hematite, and kaolinite – in an area of southwest Libya marked by the red box. Image Credits: NASA/JPL-Caltech.

NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) mission aboard the International Space Station has produced its first mineral maps, providing detailed images that show the composition of the surface in regions of northwest Nevada and Libya in the Sahara Desert.

Windy desert areas such as these are the sources of fine dust particles that, when lifted by wind into the atmosphere, can heat or cool the surrounding air. But scientists haven’t been able to assess whether mineral dust in the atmosphere has overall heating or cooling effects at local, regional, and global scales. EMIT’s measurements will help them to advance computer models and improve our understanding of dust’s impacts on climate.

EMIT scientists at NASA’s Jet Propulsion Laboratory in Southern California and the U.S. Geological Survey created the maps to test the accuracy of the instrument’s measurements, a crucial first step in preparing for full science operations.

Image above: This image cube shows the true-color view of an area in northwest Nevada observed by NASA’s EMIT imaging spectrometer. The side panels depict the spectral fingerprint for each point in the image. The cube shows the presence of kaolinite, a light-colored clay mineral that reflects sunlight. Image Credits: NASA/JPL-Caltech/USGS.

Installed on the space station in July, EMIT is the first of a new class of high-fidelity imaging spectrometers that collect data from space and produce better-quality data at greater volumes than previous instruments.

“Decades ago, when I was in graduate school, it took 10 minutes to collect a single spectrum from a geological sample in the laboratory. EMIT’s imaging spectrometer measures 300,000 spectra per second, with superior quality,” said Robert Green, EMIT’s principal investigator and senior research scientist at JPL.

“The data we’re getting from EMIT will give us more insight into the heating and cooling of Earth, and the role mineral dust plays in that cycle. It’s promising to see the amount of data we’re getting from the mission in such a short time,” said Kate Calvin, NASA’s chief scientist and senior climate advisor. “EMIT is one of seven Earth science instruments on the International Space Station giving us more information about how our planet is affected by climate change.”

EMIT analyzes light reflected from Earth, measuring it at hundreds of wavelengths, from the visible to the infrared range of the spectrum. Different materials reflect light in different wavelengths. Scientists use these patterns, called spectral fingerprints, to identify surface minerals and pinpoint their locations.

Image above: NASA’s EMIT mission recently gathered mineral spectra in northwest Nevada that match what the agency’s AVIRIS instrument found in 2018, helping to confirm EMIT’s accuracy. Both instruments found areas dominated by kaolinite, a reflective clay mineral whose particles can cool the air when airborne. Image Credits: NASA/JPL-Caltech/USGS.

Mapping Minerals

The Nevada map focuses on a mountainous area about 130 miles (209 kilometers) northeast of Lake Tahoe, revealing locations dominated by kaolinite, a light-colored mineral whose particles scatter light upward and cool the air as they move through the atmosphere. The map and spectral fingerprint closely match those collected from aircraft in 2018 by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), data that was verified at the time by geologists. Researchers are using this and other comparisons to confirm the accuracy of EMIT’s measurements.

The other mineral map shows substantial amounts of kaolinite as well as two iron oxides, hematite and goethite, in a sparsely populated section of the Sahara about 500 miles (800 kilometers) south of Tripoli. Darker-colored dust particles from iron-oxide-rich areas strongly absorb energy from the Sun and heat the atmosphere, potentially affecting the climate.

Image above: The image cube’s front panel is a true-color view of part of southwestern Libya observed by NASA’s EMIT mission. The side panels depict the spectral fingerprints for every point in the image, showing kaolinite, a reflective clay mineral, and goethite and hematite, iron oxides that absorb heat. Image Credits: NASA/JPL-Caltech.

Currently there is little or no information on the composition of dust originating in parts of the Sahara. In fact, researchers have detailed mineral information of only about 5,000 soil samples from around the world, requiring that they make inferences about the composition of dust.

EMIT will gather billions of new spectroscopic measurements across six continents, closing this gap in knowledge and advancing climate science. “With this exceptional performance, we are on track to comprehensively map the minerals of Earth’s arid regions – about 25% of the Earth’s land surface – in less than a year and achieve our climate science objectives,” Green said.

EMIT’s data also will be freely available for a wide range of investigations, including, for example, the search for strategically important minerals such as lithium and rare-earth elements. What’s more, the instrument’s technology is laying the groundwork for the future Surface Biology and Geology (SBG) satellite mission, which is part of NASA’s Earth System Observatory, a set of missions aimed at addressing climate change.

Pioneering Technology

EMIT traces its roots to imaging spectrometer technology that NASA’s Airborne Imaging Spectrometer (AIS) first demonstrated in 1982. Designed to identify minerals on Earth’s surface from a low-altitude research aircraft, the instrument delivered surprising results almost immediately. During early test flights near Cuprite, Nevada, AIS detected the unique spectral signature of buddingtonite, a mineral not seen on any previous geological maps of the area.

Paving the way for future spectrometers when it was introduced in 1986, AVIRIS – the airborne instrument that succeeded AIS – has studied geology, plant function, and alpine snowmelt, among other natural phenomena. It has also mapped chemical pollution at Superfund sites and studied oil spills, including the massive Deepwater Horizon leak in 2010. And it flew over the World Trade Center site in Manhattan following the Sept. 11 attacks, locating uncontrolled fires and mapping debris composition in the wreckage.

Image above: The mineral map shows a part of southwestern Libya, in the Sahara, observed by NASA’s EMIT mission. It depicts areas dominated by kaolinite, a reflective clay mineral that scatters light, and goethite and hematite, iron oxides that absorb heat and warm the surrounding air. Image Credits: NASA/JPL-Caltech.

Over the years, as optics, detector arrays, and computing capabilities have progressed, imaging spectrometers capable of resolving smaller targets and subtler differences have flown with missions across the solar system.

A JPL-built imaging spectrometer on the Indian Space Research Organization’s Chandrayaan-1 probe measured signs of water on the Moon in 2009. NASA’s Europa Clipper, which launches in 2024, will rely on an imaging spectrometer to help scientists assess if the icy Jovian moon has conditions that could support life.

Highly advanced JPL-developed spectrometers will be part of NASA’s forthcoming Lunar Trailblazer – which will determine the form, abundance, and distribution of water on the Moon and the nature of the lunar water cycle – and on satellites to be launched by the nonprofit Carbon Mapper, aimed at spotting greenhouse gas point-sources from space.

“The technology took directions that I would never have imagined,” said Gregg Vane, the JPL researcher whose graduate studies in geology helped inspire the idea for the original imaging spectrometer. “Now with EMIT, we’re using it to look back at our own planet from space for important climate research.”

More About the Mission

EMIT was selected from the Earth Venture Instrument-4 solicitation under the Earth Science Division of NASA Science Mission Directorate and was developed at NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California. It launched aboard a SpaceX Dragon resupply spacecraft from NASA’s Kennedy Space Center in Florida on July 14, 2022. The instrument’s data will be delivered to the NASA Land Processes Distributed Active Archive Center (DAAC) for use by other researchers and the public.

To learn more about the mission, visit: https://earth.jpl.nasa.gov/emit/

Related links:

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

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Wang/Jane J. Lee.

Greetings, Orbiter.ch

Hubble Spots Ultra-Speedy Jet Blasting From Star Crash

NASA - Hubble Space Telescope patch.

Oct 15, 2022

Astronomers using NASA's Hubble Space Telescope have made a unique measurement that indicates a jet, plowing through space at speeds greater than 99.97% the speed of light, was propelled by the titanic collision between two neutron stars.

The explosive event, named GW170817, was observed in August 2017. The blast released the energy comparable to that of a supernova explosion. It was the first combined detection of gravitational waves and gamma radiation from a binary neutron star merger.

Hubble Reveals Ultra-Relativistic Jet

Video above: Two neutron stars, the surviving cores of massive stars that exploded, collided sending a ripple through the fabric of time and space in a phenomenon called gravitational waves. In the aftermath, a blowtorch jet of radiation was ejected at nearly the speed of light, slamming into material surrounding the obliterated pair. Astronomers used Hubble to measure the motion of a blob of material the jet slammed into. Video Credits: NASA's Goddard Space Flight Center; Lead Producer: Paul Morris.

This was a major watershed in the ongoing investigation of these extraordinary collisions. The aftermath of this merger was collectively seen by 70 observatories around the globe and in space, across a broad swath of the electromagnetic spectrum in addition to the gravitational wave detection. This heralded a significant breakthrough for the emerging field of Time Domain and Multi-Messenger Astrophysics, the use of multiple "messengers" like light and gravitational waves to study the universe as it changes over time.

Scientists quickly aimed Hubble at the site of the explosion just two days later. The neutron stars collapsed into a black hole whose powerful gravity began pulling material toward it. That material formed a rapidly-spinning disk that generated jets moving outward from its poles. The roaring jet smashed into and swept up material in the expanding shell of explosion debris. This included a blob of material through which a jet emerged.

While the event took place in 2017, it has taken several years for scientists to come up with a way to analyze the Hubble data and data from other telescopes to paint this full picture.

The Hubble observation was combined with observations from multiple National Science Foundation radio telescopes working together for very long baseline interferometry (VLBI). The radio data were taken 75 days and 230 days after the explosion.

"I'm amazed that Hubble could give us such a precise measurement, which rivals the precision achieved by powerful radio VLBI telescopes spread across the globe," said Kunal P. Mooley of Caltech in Pasadena, California, lead author of a paper being published in the October 13 journal of Nature magazine.

The authors used Hubble data together with data from ESA's (the European Space Agency) Gaia satellite, in addition to VLBI, to achieve extreme precision. "It took months of careful analysis of the data to make this measurement," said Jay Anderson of the Space Telescope Science Institute in Baltimore, Maryland.

Image above: This is an artist's impression of two neutron stars colliding. The smashup between two dense stellar remnants unleashes the energy of 1,000 standard stellar nova explosions. In the aftermath of the collision a blowtorch jet of radiation is ejected at nearly the speed of light. The jet is directed along a narrow beam confined by powerful magnetic fields. The roaring jet plowed into and swept up material in the surrounding interstellar medium. Image Credits: Artwork: Elizabeth Wheatley (STScI).

By combining the different observations, they were able to pinpoint the explosion site. The Hubble measurement showed the jet was moving at an apparent velocity of seven times the speed of light. The radio observations show the jet later had decelerated to an apparent speed of four times faster than the speed of light.

In reality, nothing can exceed the speed of light, so this "superluminal" motion is an illusion. Because the jet is approaching Earth at nearly the speed of light, the light it emits at a later time has a shorter distance to go. In essence the jet is chasing its own light. In actuality more time has passed between the jet's emission of the light than the observer thinks. This causes the object's velocity to be overestimated – in this case seemingly exceeding the speed of light.

"Our result indicates that the jet was moving at least at 99.97% the speed of light when it was launched," said Wenbin Lu of the University of California, Berkeley.

The Hubble measurements, combined with the VLBI measurements, announced in 2018, greatly strengthen the long-presumed connection between neutron star mergers and short-duration gamma-ray bursts. That connection requires a fast-moving jet to emerge, which has now been measured in GW170817.

This work paves the way for more precision studies of neutron star mergers, detected by the LIGO, Virgo, and KAGRA gravitational wave observatories. With a large enough sample over the coming years, relativistic jet observations might provide another line of inquiry into measuring the universe's expansion rate, associated with a number known as the Hubble constant.

At present there is a discrepancy between Hubble constant values as estimated for the early universe and nearby universe – one of the biggest mysteries in astrophysics today. The differing values are based on extremely precise measurements of Type Ia supernovae by Hubble and other observatories, and Cosmic Microwave Background measurements by ESA's Planck satellite. More views of relativistic jets could add information for astronomers trying to solve the puzzle.

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

The Hubble Space Telescope is a project of international cooperation between NASA and ESA. 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.

Related links:

Nature: https://www.nature.com/articles/s41586-022-05145-7

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

ESA's Gaia satellite: https://www.esa.int/Science_Exploration/Space_Science/Gaia

LIGO: https://www.ligo.caltech.edu/

Virgo: https://www.virgo-gw.eu/

KAGRA: https://gwcenter.icrr.u-tokyo.ac.jp/en/

ESA's Planck satellite: https://www.esa.int/Enabling_Support/Operations/Planck

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Andrea Gianopoulos/GSFC/Claire Andreoli/STSi/Ray Villard/California Institute of Technology/Kunal P. Mooley.

Best regards, Orbiter.ch

vendredi 14 octobre 2022

NASA’s SpaceX Crew-4 Astronauts Safely Splash Down in Atlantic

SpaceX - Dragon Crew-4 Mission patch.

Oct 14, 2022

NASA’s SpaceX Crew-4 astronauts aboard the Dragon spacecraft safely splashed down Friday off the coast of Jacksonville, Florida, completing the agency’s fourth commercial crew mission to the International Space Station. The international crew of four spent 170 days in orbit.

Image above: The SpaceX Crew Dragon Freedom spacecraft is seen as it lands with NASA astronauts Kjell Lindgren, Robert Hines, Jessica Watkins, and ESA (European Space Agency) astronaut Samantha Cristoforetti aboard in the Atlantic Ocean off the coast of Jacksonville, Florida, Friday, Oct. 14, 2022. Image Credits: NASA/Bill Ingalls.

NASA astronauts Bob Hines, Kjell Lindgren, and Jessica Watkins and ESA (European Space Agency) astronaut Samantha Cristoforetti returned to Earth in a parachute-assisted splashdown at 4:55 p.m. EDT. Teams aboard SpaceX recovery vessels retrieved the spacecraft and astronauts. After returning to shore, all astronauts will fly to NASA’s Johnson Space Center in Houston. Cristoforetti then will board a plane to Europe.

Image above: The SpaceX Dragon Freedom crew ship with four Crew-4 astronauts aboard undocks from the space station to begin its return to Earth. Image Credit: NASA TV.

“Welcome home Crew-4! This international crew has spent nearly six months on the International Space Station conducting science for the benefit of all. Their work aboard the orbiting laboratory will help prepare future explorers for future space missions,” said NASA Administrator Bill Nelson. “Working and living on the space station is the opportunity of a lifetime, but it also requires these explorers to make sacrifices, especially time away from loved ones. Kjell, Bob, Jessica and Samantha, thank you for your contributions over the past six months to science, innovation, and discovery!"

SpaceX Crew-4 hatch closure

The Crew-4 mission launched at 3:52 a.m. EDT April 27 on a Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. Less than 16 hours later, Dragon docked to the Harmony module’s space-facing port. The astronauts undocked from the same port at 12:05 p.m. Friday, to begin the trip home.

Hines, Lindgren, Watkins, and Cristoforetti traveled 72,168,935 miles during their mission, spent 170 days aboard the space station, and completed 2,720 orbits around Earth. Lindgren has logged 311 days in space over his two flights, and with the completion of their flight today, Cristoforetti has logged 369 days in space on her two flights, making her second on the all-time list for most days in space by a woman. The Crew-4 mission was the first spaceflight for Hines and Watkins.

SpaceX Crew-4 splashdown

Throughout their mission, the Crew-4 astronauts contributed to a host of science and maintenance activities and technology demonstrations. Cristoforetti completed two spacewalks with Roscosmos cosmonaut Oleg Artemyev to perform station maintenance and upgrades.

Crew-4 continued work on investigations documenting how improvements to the space diet affect immune function and the gut microbiome, determining the effect of fuel temperature on the flammability of a material, exploring possible adverse effects on astronaut hearing from equipment noise and microgravity, and studying whether additives increase or decrease the stability of emulsions. The astronauts also investigated microgravity-induced changes in the human immune system similar to aging, tested a novel water-reclamation membrane, and examined a concrete alternative made with a material found in lunar and Martian dust.

SpaceX Crew-4 recovery operations and astronauts egress

The spacecraft, named Freedom by Crew-4, will return to Florida for inspection and processing at SpaceX’s Dragon Lair, where teams will examine the spacecraft’s data and performance throughout the flight.

The Crew-4 flight is part of NASA’s Commercial Crew Program and its return to Earth follows on the heels of NASA’s SpaceX Crew-5 launch, which docked to the station Oct. 6, beginning another science expedition.

The goal of NASA’s Commercial Crew Program is safe, reliable, and cost-effective transportation to and from the International Space Station. This already has provided additional research time and has increased the opportunity for discovery aboard humanity’s microgravity testbed for exploration, including helping NASA prepare for human exploration of the Moon and Mars.

Related article:

NASA’s SpaceX Crew-4 Space Station Departure Delayed for Weather
https://orbiterchspacenews.blogspot.com/2022/10/nasas-spacex-crew-4-space-station.html

Learn more about NASA’s Commercial Crew program at: https://www.nasa.gov/commercialcrew

Related links:

Improvements to the space diet: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7870

Fuel temperature on the flammability: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8266

Adverse effects on astronaut hearing: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7898

Increase or decrease the stability of emulsions: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7963

Changes in the human immune system similar to aging: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8343

Water-reclamation membrane: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8369

Examined a concrete alternative: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8634

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

Images (mentioned), Videos, Text, Credits: NASA/Gerelle Dodson/Joshua Finch/KSC/Kathleen Ellis/JSC/Leah Cheshier/Sandra Jones/NASA TV/SciNews.

Best regards, Orbiter.ch

Heaviest element yet detected in an exoplanet atmosphere

ESO - European Southern Observatory logo.

Oct. 14, 2022

Artist’s impression of an ultra-hot Jupiter transiting its star

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered the heaviest element ever found in an exoplanet atmosphere — barium. They were surprised to discover barium at high altitudes in the atmospheres of the ultra-hot gas giants WASP-76 b and WASP-121 b — two exoplanets, planets which orbit stars outside our Solar System. This unexpected discovery raises questions about what these exotic atmospheres may be like.

“The puzzling and counterintuitive part is: why is there such a heavy element in the upper layers of the atmosphere of these planets?” says Tomás Azevedo Silva, a PhD student at the University of Porto and the Instituto de Astrofísica e Ciências do Espaço (IA) in Portugal who led the study published today in Astronomy & Astrophysics.

Artist’s impression of the night side of WASP-76 b

WASP-76 b and WASP-121 b are no ordinary exoplanets. Both are known as ultra-hot Jupiters as they are comparable in size to Jupiter whilst having extremely high surface temperatures soaring above 1000°C. This is due to their close proximity to their host stars, which also means an orbit around each star takes only one to two days. This gives these planets rather exotic features; in WASP-76 b, for example, astronomers suspect it rains iron.

But even so, the scientists were surprised to find barium, which is 2.5 times heavier than iron, in the upper atmospheres of WASP-76 b and WASP-121 b. “Given the high gravity of the planets, we would expect heavy elements like barium to quickly fall into the lower layers of the atmosphere,” explains co-author Olivier Demangeon, a researcher also from the University of Porto and IA.

Detecting barium in an exoplanet atmosphere

“This was in a way an ‘accidental’ discovery,” says Azevedo Silva. “We were not expecting or looking for barium in particular and had to cross-check that this was actually coming from the planet since it had never been seen in any exoplanet before.”

The fact that barium was detected in the atmospheres of both of these ultra-hot Jupiters suggests that this category of planets might be even stranger than previously thought. Although we do occasionally see barium in our own skies, as the brilliant green colour in fireworks, the question for scientists is what natural process could cause this heavy element to be at such high altitudes in these exoplanets. “At the moment, we are not sure what the mechanisms are,” explains Demangeon.

In the study of exoplanet atmospheres ultra-hot Jupiters are extremely useful. As Demangeon explains: “Being gaseous and hot, their atmospheres are very extended and are thus easier to observe and study than those of smaller or cooler planets”.

A ‘fly to’ WASP-76, the star around which WASP-76 b orbits

Determining the composition of an exoplanet’s atmosphere requires very specialised equipment. The team used the ESPRESSO instrument on ESO’s VLT in Chile to analyse starlight that had been filtered through the atmospheres of WASP-76 b and WASP-121 b. This made it possible to clearly detect several elements in them, including barium.

These new results show that we have only scratched the surface of the mysteries of exoplanets. With future instruments such as the high-resolution ArmazoNes high Dispersion Echelle Spectrograph (ANDES), which will operate on ESO’s upcoming Extremely Large Telescope (ELT), astronomers will be able to study the atmospheres of exoplanets large and small, including those of rocky planets similar to Earth, in much greater depth and to gather more clues as to the nature of these strange worlds.

More information:

This research was presented in the paper “Detection of Barium in the atmospheres of ultra-hot gas giants WASP-76b & WASP-121b” to appear in Astronomy & Astrophysics (doi: 10.1051/0004-6361/202244489).

The team is composed of T. Azevedo Silva (Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, Portugal [IA/UPorto, CAUP] and Departamento de Física e Astronomia Faculdade de Ciências, Universidade do Porto, Portugal [FCUP]), O. D. S. Demangeon (IA/UPorto, CAUP and FCUP), N. C. Santos (IA/UPorto, CAUP and FCUP), R. Allart (Department of Physics, and Institute for Research on Exoplanets, Université de Montréal, Canada and Observatoire astronomique de l’Université de Genève, Switzerland [UNIGE]), F. Borsa (INAF – Osservatorio Astronomico di Brera, Italy), E. Cristo (IA/UPorto, CAUP and FCUP), E. Esparza-Borges (Instituto de Astrofísica de Canarias, Spain [IAC] and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain [IAC-ULL]), J. V. Seidel (European Southern Observatory, Chile [ESO Chile]), E. Palle (IAC), S. G. Sousa (IA/UPorto), H. M. Tabernero (Centro de Astrobiología, CSIC-INTA, Spain [CSIC-INTA]), M. R. Zapatero Osorio (CSIC-INTA), S. Cristiani (INAF – Osservatorio Astronomico di Trieste, Italy [INAF Trieste]), F. Pepe (UNIGE), R. Rebolo (IAC and IAC-ULL), V. Adibekyan (IA/UPorto and FCUP), Y. Alibert (Physikalisches Institut, University of Bern, Switzerland), S. C. C. Barros (IA/UPorto and FCUP), V. Bourrier (UNIGE), P. Di Marcantonio (INAF Trieste), V. D’Odorico (INAF Trieste, Scuola Normale Superiore, Italy and Institute for Fundamental Physics of the Universe, Trieste, Italy [IFPU]), D. Ehrenreich (UNIGE and Centre Vie dans l’Univers, Faculté des sciences de l’Université de Genève, Switzerland), P. Figueira (UNIGE and IA/UPorto), J. I. González Hernández (IAC and Universidad de La Laguna, Departamento de Astrofísica, Spain), C. J. A. P. Martins (UA/UPorto and Centro de Astrofísica da Universidade do Porto, Portugal), A. Mehner (ESO Chile), G. Micela (INAF – Osservatorio Astronomico di Palermo, Italy), P. Molaro (INAF Trieste and IFPU), D. Mounzer (UNIGE), N. J. Nunes (Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa and Departamento de Física, Faculdade de Ciências da Universidade de Lisboa, Portugal), A. Sozzetti (INAF - Osservatorio Astrofisico di Torino, Italy), A. Suárez Mascareño (IAC and IAC-ULL), and S. Udry (UNIGE).

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.

Links:

Heaviest Element yet Detected in an Exoplanet Atmosphere (ESOcast 257 Light):
https://www.eso.org/public/videos/eso2213a/

Research paper: https://www.eso.org/public/archives/releases/sciencepapers/eso2213/eso2213a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

ESO's Very Large Telescope (VLT): http://www.eso.org/public/teles-instr/paranal-observatory/vlt/

ESPRESSO instrument:
https://www.eso.org/public/usa/teles-instr/paranal-observatory/vlt/vlt-instr/espresso/

Find out more about ESO's Extremely Large Telescope: https://elt.eso.org/

For journalists: subscribe to receive our releases under embargo in your language: https://www.eso.org/public/outreach/pressmedia/#epodpress_form

For scientists: got a story? Pitch your research: http://www.eso.org/sci/publications/announcements/sciann17463.html

Images Credits: ESO/M. Kornmesser/Videos Credits: ESO/L. Calçada/M. Kornmesser/spaceengine.org/Text Credits: ESO/Juan Carlos Muñoz Mateos/University of Geneva/Baptiste Lavie/INAF Osservatorio Astronomico di Trieste/Paolo Molaro/Instituto de Astrofísica de Canarias/Alejandro Suárez Mascareño/Jonay González Henández/Centro de Astrobiología (CSIC-INTA)/Hugo Tabernero/María Rosa Zapatero Osorio/Instituto de Astrofisica e Ciências do Espaço, Faculdade de Ciências, Universidade do Porto/Nuno Santos/Olivier Demangeon/Tomás Azevedo Silva.

Best regards, Orbiter.ch

30 000 near-Earth asteroids discovered and rising

Planetary Defence logo.

October 13, 2022

In brief

We have now discovered 30 039 near-Earth asteroids in the Solar System – rocky bodies orbiting the Sun on a path that brings them close to Earth’s orbit. The majority of these were discovered in the last decade, showing how our ability to detect potentially risky asteroids is rapidly improving.

Artist's impression of asteroid 21 Lutetia

In-depth

What is a near-Earth asteroid?

An asteroid is called a near-Earth asteroid (NEA) when its trajectory brings it within 1.3 Astronomical Units (au) of the Sun. 1 au is the distance between the Sun and Earth, and so NEAs can come within at least 0.3 au, 45 million km, of our planet’s orbit.

Currently, near-Earth asteroids make up about a third of the roughly one million asteroids discovered so far in the Solar System. Most of them reside in the asteroid belt between Jupiter and Mars.

Asteroids have been catalogued by astronomers for more than two centuries since the very first asteroid, Ceres, was discovered in 1801 by Giuseppe Piazzi. The first near-Earth asteroid, (433) Eros, was discovered nearly one hundred years later, on 13 August 1898.

Asteroid Eros, as seen by NEAR Shoemaker

The roughly 30 km Eros asteroid was discovered by Carl Gustav Witt and Felix Linke at the Urania Observatory in Berlin and independently by Auguste Charlois at the Nice Observatory. The stony asteroid’s orbit brings it to within around 22 million km of Earth – 57 times the distance of the Moon.

Not only is Eros the first known NEA, but the first asteroid to be orbited by a spacecraft and the first to have a spacecraft land on it. Early calculations of the space rock’s orbit also enabled a precise determination of the then imperfectly known distance between the Sun and Earth.

How to un-Earth a near-Earth asteroid

Naturally, large asteroids were discovered first as they are so much easier to see. They were thought of as minor planets, a term still used today. As telescopes get more sensitive, we are finding many more and at a great rate, even those down to tens of metres in size.

Ground-based survey telescopes such as the Catalina Sky Survey in Arizona, in the United States, discover new asteroids every week. They are designed to scan large sections of the sky, looking for new objects moving in front of the backdrop of ‘motionless’ stars.

Dramatic moonset behind ESO's Very Large Telescope (VLT), Chile

More focussed, large telescopes, such as the European Southern Observatory’s Very Large Telescope (VLT), can then be used for follow-up observations, helping us better understand a ‘new’ asteroid’s path, size and even composition.

Gaia, ESA’s space observatory on a mission to catalogue one billion stars in the galaxy, has also helped us better understand the asteroid risk.

Gaia’s first asteroid survey

“Because of Gaia, we know more about the stars in the galaxy which act as a backdrop to asteroid observations,” explains Tineke Roegiers, community support for the Gaia mission.

“Asteroid’s positions are obtained against these background stars, so, the better one knows where the stars are, the more precisely the orbits of asteroids can be computed.”

With the use of ‘Gaia’s stars’, even the orbits of already-known near-Earth asteroids have been improved, and some asteroids that were “lost” were found again.

ESA’s asteroid risk list

“Of course, any asteroid discovered near Earth qualifies as a near-Earth asteroid, but many are found far from home,” explains Marco Micheli, Astronomer at ESA’s Near-Earth Object Coordination Centre.

A new home for Planetary Defence in Europe

“New objects are observed over time, their movements are studied and with just a handful of data points from different nights their future positions can be predicted. Depending on the number and quality of observations, this can extend decades, even hundreds of years into the future.”

New radar observations of Apophis rule out future impact

ESA’s Near-Earth Object Coordination Centre (NEOCC) in ESRIN, Italy, is home to the Agency’s asteroid experts and risk assessors. The team activates its network of telescopes around the globe to get observations of new asteroids discovered and determine their impact risk, while also chasing up ‘old’ asteroids that haven’t yet been deemed safe.

Currently, 1 425 asteroids with a ‘non-zero’ chance of impact are under their watchful eye, organised in the NEOCC’s Asteroid Risk List which is constantly updated and freely available for anyone to see. You can even sign up to ESA’s monthly ‘Asteroid Newsletter’, and the asteroid news will come direct to you.

Will any of these asteroids strike Earth?

DART's moment of impact

Currently, none of the near-Earth asteroids discovered so far are a concern, for at least one hundred years. Some of the smaller objects will and do impact Earth – but the most common are also the smallest and have little effect, except for creating trails of shooting stars as they burn up in the night sky.

When it comes to large and potentially devastating asteroids larger than 1 km across and above, the majority have been discovered and none show an impact risk for at least a century. For those that could impact later, we have plenty of time to study them and prepare a deflection mission.

Image above: Flyeye spies with many little eyes – ESA’s cutting-edge Flyeye telescope will scan the sky for new asteroids. Using a compound, fly-inspired eye it will break up the sky into smaller chunks and analyse each one.

The current priority are the medium-sized asteroids a few hundred metres in diameter. Many are still out there, waiting to be discovered, and at smallish sizes they’re not quite as easy to find.

“The good news is that more than half of today’s known near-Earth asteroids were discovered in the last six years, showing just how much our asteroid eyesight is improving,” explains Richard Moissl, ESA’s Head of Planetary Defence.

“As this new 30 000 detection milestone shows, and as new telescopes and methods of detection are built, it’s only a matter of time until we’ve found them all.”

Related links:

Planetary Defence: https://www.esa.int/Space_Safety/Planetary_Defence

Space Safety: https://www.esa.int/Space_Safety

Catalina Sky Survey: https://catalina.lpl.arizona.edu/

European Southern Observatory’s Very Large Telescope (VLT): https://www.eso.org/public/

Gaia: https://www.esa.int/Science_Exploration/Space_Science/Gaia

ESA’s Near-Earth Object Coordination Centre: https://www.esa.int/Space_Safety/Planetary_Defence/Scaling_up_ESA_s_asteroid_facilities

NEOCC’s Asteroid Risk List: https://neo.ssa.esa.int/risk-list

ESA’s monthly ‘Asteroid Newsletter’: https://neo.ssa.esa.int/subscribe-to-services

Images, Videos, Text, Credits: ESA/C. Carreau/A. Baker/NASA/JPL/JHUAPL/ESO/G.Gillet/NASA/JPL-Caltech and NSF/AUI/GBO.

Greetings, Orbiter.ch