6.10.2022
NASA asteroid crash leaves trail of debris more than 6,000 miles long
Astronomers captured images of the comet-like trail using a telescope located in Chile.
Astronomers using the NSF’s NOIRLab’s SOAR telescope in Chile captured the vast plume of dust and debris blasted from the surface of the asteroid Dimorphos by NASA’s DART spacecraft when it impacted on Sept. 26, 2022.
CTIO/NOIRLab/SOAR/NSF/AURA/T. Ka
NASA's $325 million mission last week to intentionally crash a spacecraft into an asteroid to throw it off its course has created a more than 6,000-mile-long trail of debris across space. An image released Monday shows that after the NASA Double Asteroid Redirection Test (DART) spacecraft slammed into the asteroid Dimorphos on Sept. 26, dust and debris that was blown off the surface of the space rock from the impact had formed a comet-like tail.
An image of the vast plume of dust and debris was captured by astronomers Teddy Kareta from the Lowell Observatory and Matthew Night from the U.S. Naval Academy using the 4.1-meter Southern Astrophysical Research (SOAR) Telescope at the National Science Foundation-funded NOIRLab's Cerro Tololo Inter-American Observatory in Chile just two days after the crash test. The plume has been pushed away by the sun's radiation, not unlike the tail of a comet. Astronomers estimated the tail was around 6,200 miles long. Prior to the impact, scientists estimated that Dimorphos was about 525 feet wide.
"It is amazing how clearly we were able to capture the structure and extent of the aftermath in the days following the impact," Kareta said in a news release.
"Now begins the next phase of work for the DART team as they analyze their data and observations by our team and other observers around the world who shared in studying this exciting event," Knight said, adding that the team plans to use SOAR to continue monitoring the debris trail in the coming weeks and months. The SOAR team said these observations will provide insight about the surface of Dimorphos, how much material was ejected by the crash, how fast it was ejected, and the size of the particles ejected.
"Analyzing this information will help scientists protect Earth and its inhabitants by better understanding the amount and nature of the ejecta resulting from an impact, and how that might modify and asteroid's orbit," the release said.
DART was humanity's first planetary defense test in which an impact of a spacecraft attempted to change the orbit of an asteroid by crashing into it. The test, which was streamed live, was deemed a success after the spacecraft directly made impact with the small asteroid after taking 10 months to reach its target.
NASA to Provide Update on DART, World’s First Planetary Defense Test
Editor's Note: This advisory was updated October 7 to include participating speakers.
NASA will host a media briefing at 2 p.m. EDT, Tuesday, Oct. 11, to discuss the agency’s Double Asteroid Redirection Test (DART) mission and its intentional collision with its target asteroid, Dimorphos.
The briefing will air on NASA TV, the NASA app, and the agency’s website.
Participants include:
- NASA Administrator Bill Nelson
- Italian Space Agency President Giorgio Saccoccia
- DART update panel:
- Lori Glaze, director of the Planetary Science Division at NASA Headquarters in Washington
- Tom Statler, DART program scientist at NASA Headquarters
- Nancy Chabot, DART coordination lead at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland
To attend the briefing in person, or to participate remotely and ask questions, media must RSVP no later than two hours before the start of the briefing to Josh Handal at: joshua.a.handal@nasa.gov. NASA’s media accreditation policy is available online.
The media briefing will take place in the Webb Auditorium of NASA Headquarters Mary W. Jackson building, 300 E. Street, SW in Washington.
On Monday, Sept. 26, DART successfully impacted its asteroid target in the world’s first planetary defense technology demonstration. As a part of NASA’s overall planetary defense strategy, DART’s impact with the asteroid Dimorphos will help to determine whether asteroid deflection using a kinetic impactor spacecraft is a viable mitigation technique for protecting the planet from an Earth-bound asteroid or comet, if one were discovered. Johns Hopkins APL manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office. Neither DART’s target asteroid, Dimorphos, nor its larger asteroid parent, Didymos, poses a hazard to Earth.
Quelle: NASA
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Update: 12.10.2022
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NASA Confirms DART Mission Impact Changed Asteroid’s Motion in Space
Analysis of data obtained over the past two weeks by NASA’s Double Asteroid Redirection Test (DART) investigation team shows the spacecraft's kinetic impact with its target asteroid, Dimorphos, successfully altered the asteroid’s orbit. This marks humanity’s first time purposely changing the motion of a celestial object and the first full-scale demonstration of asteroid deflection technology.
“All of us have a responsibility to protect our home planet. After all, it’s the only one we have,” said NASA Administrator Bill Nelson. “This mission shows that NASA is trying to be ready for whatever the universe throws at us. NASA has proven we are serious as a defender of the planet. This is a watershed moment for planetary defense and all of humanity, demonstrating commitment from NASA's exceptional team and partners from around the world.”
Prior to DART’s impact, it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. Since DART’s intentional collision with Dimorphos on Sept. 26, astronomers have been using telescopes on Earth to measure how much that time has changed. Now, the investigation team has confirmed the spacecraft’s impact altered Dimorphos’ orbit around Didymos by 32 minutes, shortening the 11 hour and 55-minute orbit to 11 hours and 23 minutes. This measurement has a margin of uncertainty of approximately plus or minus 2 minutes.
Before its encounter, NASA had defined a minimum successful orbit period change of Dimorphos as change of 73 seconds or more. This early data show DART surpassed this minimum benchmark by more than 25 times.
“This result is one important step toward understanding the full effect of DART’s impact with its target asteroid” said Lori Glaze, director of NASA’s Planetary Science Division at NASA Headquarters in Washington. “As new data come in each day, astronomers will be able to better assess whether, and how, a mission like DART could be used in the future to help protect Earth from a collision with an asteroid if we ever discover one headed our way.”
The investigation team is still acquiring data with ground-based observatories around the world – as well as with radar facilities at NASA Jet Propulsion Laboratory’s Goldstone planetary radar in California and the National Science Foundation’s Green Bank Observatory in West Virginia. They are updating the period measurement with frequent observations to improve its precision.
Focus now is shifting toward measuring the efficiency of momentum transfer from DART’s roughly 14,000-mile (22,530-kilometer) per hour collision with its target. This includes further analysis of the "ejecta” – the many tons of asteroidal rock displaced and launched into space by the impact. The recoil from this blast of debris substantially enhanced DART’s push against Dimorphos – a little like a jet of air streaming out of a balloon sends the balloon in the opposite direction.
To successfully understand the effect of the recoil from the ejecta, more information on of the asteroid’s physical properties, such as the characteristics of its surface, and how strong or weak it is, is needed. These issues are still being investigated.
“DART has given us some fascinating data about both asteroid properties and the effectiveness of a kinetic impactor as a planetary defense technology,” said Nancy Chabot, the DART coordination lead from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. “The DART team is continuing to work on this rich dataset to fully understand this first planetary defense test of asteroid deflection.”
For this analysis, astronomers will continue to study imagery of Dimorphos from DART’s terminal approach and from the Light Italian CubeSat for Imaging of Asteroids (LICIACube), provided by the Italian Space Agency, to approximate the asteroid’s mass and shape. Roughly four years from now, the European Space Agency’s Hera project is also planned to conduct detailed surveys of both Dimorphos and Didymos, with a particular focus on the crater left by DART’s collision and a precise measurement of Dimorphos’ mass.
Johns Hopkins APL built and operated the DART spacecraft and manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office. Telescopic facilities contributing to the observations used by the DART team to determine this result include: Goldstone, Green Bank Observatory, Swope Telescope at the Las Campanas Observatory in Chile, the Danish Telescope at the La Silla Observatory in Chile, and the Las Cumbres Observatory global telescope network facilities in Chile and in South Africa.
Neither Dimorphos nor Didymos poses any hazard to Earth before or after DART’s controlled collision with Dimorphos.
Quelle: NASA
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STORISCHER ERFOLG
NASA-Sonde änderte erfolgreich Bahn von Asteroid
Die erste absichtlich herbeigeführte Kollision einer Raumsonde mit einem Asteroiden war nach Angaben der US-Weltraumagentur NASA ein Erfolg: Durch den Einschlag der DART-Sonde im September sei die Umlaufbahn des Asteroidenmondes Dimorphos verkleinert worden, berichtete am Dienstag NASA-Chef Bill Nelson.
Die Analyse der Daten, die das Untersuchungsteam für den Double Asteroid Redirection Test (DART) der NASA in den vergangenen zwei Wochen seit dem Aufprall erhalten hat, zeige, dass der kinetische Aufprall des Raumfahrzeugs auf seinen Zielasteroiden Dimorphos dessen Orbit erfolgreich verändert hat, so die US-Raumfahrtbehörde.
„Wir alle haben die Verantwortung, unseren Heimatplaneten zu schützen. Schließlich ist er der einzige, den wir haben“, wird Nelson auf der Website der NASA zitiert. „Diese Mission zeigt, dass die NASA versucht, auf alles vorbereitet zu sein, was das Universum uns entgegenwirft. Die NASA hat bewiesen, dass wir es als Verteidiger des Planeten ernst meinen.“
Vor dem Einschlag von DART benötigte Dimorphos elf Stunden und 55 Minuten, um seinen größeren Elternasteroiden Didymos zu umkreisen. Seit der absichtlichen Kollision von DART mit Dimorphos am 26. September haben Astronomen verschiedene Teleskope auf der Erde verwendet, um zu messen, wie sehr sich der Orbit verändert hat.
Umlaufbahn wurde deutlich verkürzt
Jetzt hat das Untersuchungsteam bestätigt, dass der Aufprall der Sonde mit mehr als 23.000 Stundenkilometern die Umlaufbahn von Dimorphos um Didymos verändert hat. Benötigte Dimorphos bisher elf Stunden und 55 Minuten für eine Umrundung seines großen Bruders Didymos, sind es demnach jetzt elf Stunden und 23 Minuten (mit einer Unsicherheit von plus/minus zwei Minuten), berichtet die NASA auf ihrer Website. Geplant war gewesen, die Umlaufbahn von Dimorphos um bis zu zehn Minuten zu verkürzen. Dieses Ziel wurde nun deutlich übertroffen.
Es war das erste Manöver im Weltall überhaupt, mit dem die Abwehr eines die Erde bedrohenden Asteroiden getestet werden sollte. Um im Ernstfall einen gefährlichen Asteroiden an der Erde vorbeizulenken, wären bei einem frühzeitigen Eingreifen auch nur minimale Kursänderungen nötig.
Quelle: Kronen Zeitung
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Update: 23.10.2022
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NASA’s Hubble Spots Twin Tails in New Image After DART Impact
Two tails of dust ejected from the Didymos-Dimorphos asteroid system are seen in new images from NASA’s Hubble Space Telescope, documenting the lingering aftermath of NASA’s Double Asteroid Redirection Test (DART) impact.
The DART spacecraft impacted Dimorphos, a small moonlet of Didymos, on Sept. 26 in a planetary defense test to change Dimorphos’ orbit by crashing into it. Current data show that DART shortened Dimorphos’ original 11 hour and 55 minute orbit around Didymos by about 32 minutes.
Following impact, Hubble made 18 observations of the system. Imagery indicates the second tail formed between Oct. 2 and Oct. 8.
In this image, DART impacted the Didymos-Dimorphos system from the 10 o’clock direction.
The relationship between the comet-like tail and other ejecta features seen at various times in images from Hubble and other telescopes is still unclear, and is something the Investigation Team is currently working to understand. The northern tail is newly developed. In the coming months, scientists will be taking a closer look at the data from Hubble to determine how the second tail developed. There are a number of possible scenarios the team will investigate.
The Hubble data were collected as part of Cycle 29 General Observers Program 16674.
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 and Webb science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
Early Results from NASA’s DART Mission
Since NASA’s Double Asteroid Redirection Test (DART) spacecraft intentionally slammed into the asteroid moonlet Dimorphos on Sept. 26 – altering its orbit by 33 minutes – the investigation team has been digging into the implications of how this planetary defense technique could be used in the future, if such a need should ever arise. This has included further analysis of the “ejecta” — the many tons of asteroidal rock displaced and launched into space by the impact – the recoil from which substantially enhanced DART’s push against Dimorphos.
Continued observations of that evolving ejecta have given the investigation team better understanding of what the DART spacecraft achieved at the impact site. DART team members provided a preliminary interpretation of their findings during the American Geophysical Union’s Fall Meeting on Thursday, Dec. 15, in Chicago.
“What we can learn from the DART mission is all part of a NASA’s overarching work to understand asteroids and other small bodies in our Solar System,” said Tom Statler, the program scientist for DART at NASA headquarters in Washington, and one of the presenters at the briefing. “Impacting the asteroid was just the start. Now we use the observations to study what these bodies are made of and how they were formed – as well as how to defend our planet should there ever be an asteroid headed our way.”
Central to this effort are detailed, post-impact science and engineering analyses of data from the world’s first planetary defense technology demonstration. In the weeks after impact, scientists turned their focus toward measuring the momentum transfer from DART’s roughly 14,000 mile per hour (22,530 kilometer per hour) collision with its target asteroid.
Scientists estimate DART’s impact displaced over two million pounds (one million kilograms) of the dusty rock into space – enough to fill six or seven rail cars. The team is using that data – as well as new information on the composition of the asteroid moonlet and the characteristics of the ejecta, gained from telescope observations and images from DART’s ride-along Light Italian CubeSat for Imaging of Asteroids (LICIACube) contributed by the Italian Space Agency (ASI) – to learn just how much DART’s initial hit moved the asteroid, and how much came from the recoil.
“We know the initial experiment worked. Now we can start to apply this knowledge,” said Andy Rivkin, DART investigation team co-lead at the Johns Hopkins Applied Physics Lab (APL). “Studying the ejecta made in the kinetic impact – all of it derived from Dimorphos – is a key way of gaining further insights into the nature of its surface.”
Observations before and after impact, reveal that Dimorphos and its larger parent asteroid, Didymos, have similar makeup and are composed of the same material – material that has been linked to ordinary chondrites, similar to the most common type of meteorite to impact the Earth. These measurements also took advantage of the ejecta from Dimorphos, which dominated the reflected light from the system in the days after impact. Even now, telescope images of the Didymos system show how solar radiation pressure has stretched the ejecta stream into a comet-like tail tens of thousands of miles in length.
Putting those pieces together, and assuming that Didymos and Dimorphos have the same densities, the team calculates that the momentum transferred when DART hit Dimorphos was roughly 3.6 times greater than if the asteroid had simply absorbed the spacecraft and produced no ejecta at all – indicating the ejecta contributed to moving the asteroid more than the spacecraft did.
Accurately predicting momentum transfer is central to planning a future kinetic impact mission if one is ever needed, including determining the size of the impactor spacecraft and estimating the amount of lead-time necessary to ensure that a small deflection would move a potentially dangerous asteroid off its path.
“Momentum transfer is one of the most important things we can measure, because it is information we would need to develop an impactor mission to divert a threating asteroid,” said Andy Cheng, DART investigation team lead from Johns Hopkins APL. “Understanding how a spacecraft impact will change an asteroid’s momentum is key to designing a mitigation strategy for a planetary defense scenario.”
Neither Dimorphos nor Didymos poses any hazard to Earth before or after DART’s controlled collision with Dimorphos.
Johns Hopkins APL built and operated the DART spacecraft and manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office.
Banner image: This image is constructed from several images taken on November 30, 2022 by astronomers at Magdalena Ridge Observatory in New Mexico, USA. It holds Didymos still in the frame, and thus the background stars are seen as linear trails of dots. Average images like this can provide additional details to astronomers studying faint structures in the ejecta tail. This image is roughly 32,000 kilometers across the field of view at the distance of Didymos. Credit: Magdalena Ridge Observatory/NM Tech
Quelle: NASA