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Sonntag, 1. November 2015 - 21:10 Uhr

Astronomie - Weitere Feuerkugel der Tauriden über Deutschland beobachtet

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1.11.2015 / 10.32 MEZ

Über unsere UFO-Meldestelle kam per Email folgende Meldung:

Nachricht: => Guten Abend,
Ich hab gegen 00:10 Uhr, vor ca.40 min, einen auffällig hellen und steil abfallenden Kometen,Asterioiden oder was auch immer gesehen. Dauer im Blickfeld ca 2-3 Sekunden. 
Standort Wickersted im Weimarer Land, Blickrichtung NO-NOO. Klar und sehr hell, ähnelte den Aufnahmen welche Sie aktuell im Netz haben von den Tauriden. Das außergewöhnlichste war der steile Winkel. Ich dachte gleich, der schlägt irgendwo ein.
Besten Gruß 
Achim Hermanns
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Update: 21.10 MEZ

Auch diese Feuerkugel konnte fotografiert werden:

Hier ein Bild vom Keilberg, aufgenommen um 00.13 Uhr von Tomáš Chlibec/Tschechien

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Tags: Astronomie 

1826 Views

Sonntag, 1. November 2015 - 18:00 Uhr

Raumfahrt - NASA Team zeigt Zusammenfassung seiner Bewertung des Orbital ATK Unfall 2014

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Progress is being made toward the resumption of commercial cargo resupply flights to the International Space Station of Orbital’s ATK’s Antares launch vehicle from the Mid-Atlantic Regional Spaceport (MARS) at NASA’s Wallops Flight Facility in Virginia. MARS has completed major repair work at Pad-0A following the Antares launch mishap on Oct. 28, 2014. This work included repairs or replacement to supporting systems and any damaged structures. The pad is now undergoing final system performance testing.
Credits: NASA/Patrick Black
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A NASA team that independently reviewed the unsuccessful launch last year of Orbital ATK’s third commercial resupply services mission intended to deliver cargo to the International Space Station (ISS) has completed its report and publicly released an executive summary of its findings.
Shortly after 6:22 p.m. EDT Tuesday, Oct. 28, 2014, Orbital ATK’s Antares rocket suffered an anomaly during launch from Pad 0A of the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility in Virginia that resulted in the loss of the rocket and its cargo and damage to the launch pad.  No workers or members of the public were injured as a result of the accident. 
 
The launch was conducted under a license from the Federal Aviation Administration (FAA). In accordance with the contingency action plan established between NASA, the FAA, and commercial partners resupplying the space station, the launch operator is responsible for leading an investigation for any accident that does not result in injury to members of the public or public property damage, and where no NASA workers are injured or NASA property is significantly damaged. As a result, Orbital ATK immediately convened an Accident Investigation Board (AIB) that included participants from both the FAA and NASA.
However, to inform and amplify the learning for the NASA team, the agency established an independent review team. The goal of this team was to independently determine the technical root cause of the failure, validate the contractor-led AIB efforts, inform the agency’s risk posture to support Orbital ATK’s return-to-flight efforts, and make recommendations on how to develop, operate, and acquire more reliable systems.
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Orbital ATK’s Antares program remains on schedule to commence flight operations from Wallops in the first half of 2016. The Antares is undergoing integration, with two new RD-181 engines fully installed into the first stage of the rocket. The program is working toward a full-power engine test on the launch pad early next year.
Credits: NASA/Patrick Black
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“The thorough work of the NASA team is essential to ensure the agency continues to learn and improve,” said William Gerstenmaier, associate administrator for the Human Exploration and Operations Mission Directorate at NASA Headquarters. “This unfortunate event provides a tremendous opportunity for the industry and NASA team to improve vehicle development, acquisition, and operations. The findings from this team will provide a basis to begin discussions on future areas for improvement. Even though not all recommendations will be implemented as written, all the recommendations will enable positive lessons for the agency.”
The 12-person team, supported by 31 additional employees, began its work in November 2014 and was given access to the telemetry, data, documents and key personnel. Additionally, as part of its technical investigation efforts, the independent NASA team collected hundreds of documents, briefings, and data packages; conducted site visits and technical reviews with Orbital ATK in Dulles, Virginia, Aerojet Rocketdyne in Sacramento, California, and NASA’s Wallops Flight Facility in Virginia; reviewed vehicle telemetry, photo and video evidence from the launch and previous Antares missions; performed extensive engine system hardware forensic analysis; developed a comprehensive fault tree for the entire Orbital ATK Antares launch system; performed detailed analyses supporting root cause identification; reviewed engine design and qualification data including test history and failures; developed and assessed numerous failure scenarios; and generated multiple independent models and analyses.  As part of its programmatic assessment efforts, the team had discussions with about 20 NASA individuals significantly involved in the development and execution of the Orbital ATK system and resupply missions.
The team determined the proximate cause of the Antares launch vehicle failure was an explosion within the AJ-26 rocket engine and identified three credible technical root causes, any one or combination of which could have resulted in the engine failure. The team outlined six technical findings and made seven recommendations to address those technical findings. In addition, since Orbital ATK was in the process of procuring and testing new engines to replace the AJ-26 for future Antares flights while the investigation was ongoing, the team provided several recommendations for Orbital ATK and the ISS Program that were used to support those testing activities and to reduce overall risk for Antares return-to-flight and follow-on mission efforts. The NASA team’s findings are consistent with the AIB’s findings.
In addition, the team evaluated NASA’s programmatic approach to ensuring the space station is supplied with necessary cargo and the important science and research to be conducted on the unique microgravity laboratory. The team enumerated eight findings and made six programmatic recommendations.
The team praised the Commercial Crew and Cargo Program Office and the ISS Program Office for implementing a program to develop and operate new commercial cargo space transportation systems in support of human exploration endeavors.
Orbital ATK has shown continued progress in its efforts to return to flight and a strong commitment to fulfilling its contract with NASA. To do so, Orbital ATK has contracted with United Launch Alliance for Atlas V rockets to launch two commercial resupply missions that will use an enhanced variant of the company’s Cygnus advanced maneuvering spacecraft.
In 2016 Orbital ATK plans to return to launching Cygnus aboard its Antares rocket from Wallops Flight Facility. Orbital ATK will be required to submit a modification to its existing license to the FAA for review and subsequent approval, prior to conducting future flights from Virginia.
The official report of the independent review team contains information restricted by U.S. International Traffic in Arms Regulations and company-sensitive proprietary information. As a result, the team has prepared an executive summary with an overview of publicly releasable findings and recommendations.
Quelle: NASA

Tags: Raumfahrt 

1654 Views

Sonntag, 1. November 2015 - 17:10 Uhr

Astronomie - Feuerkugel vom Samstagabend in der Presse

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Tags: Astronomie 

1567 Views

Samstag, 31. Oktober 2015 - 19:26 Uhr

Astronomie - Halloween Feuerbälle der Tauriden unterwegs

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30.10.2015

Gestern Abend meldete sich Herr L. aus Naila bei Hof/Bayern bei der UFO-Meldestelle von CENAP da er eine Stunde vorher kurz vor 18 Uhr eine Feuerkugel von Ost nach Südwest linear über den ganzen Himmel fliegen sah. In ca. 45° Grad Höhe sah er sie erst auf sich zufliegen und dann im Südwesten Richtung Würzburg verschwinden. Recht rasch soll sie geflogen sein und in Orange geglüht haben, aber keinen Schweif gebildet haben. Zu diesem Zeitpunkt war es über Bayern klarer Himmel im Gegensatz zu anderen Regionen wo Nebel vorherrschte, daher gab es bis jetzt auch keine weitere Meldungen.

Nach Eingang der Meldungen machte ich mich auf den astronomischen Seiten schlau ob dort sich weitere Zeugen gemeldet hatten, was jedoch Negativ verlief, vielmehr war zu bemerken das "keine aktuellen Beiträge" gerade bei großen astronomischen Seiten vorzhufinden war. Also versuchte ich mit Aufrufen dort auf die Feuerkugel hinzuweisen in der Hoffnung auf weitere Beobachter. Im Laufe der letzten Stunden bekam ich auch aus Österreich dann Negativ Bescheid Betreff Fotoaufnahmen, da auch dort Nebel vorhanden war.

Doch dann kamen Informationen über AKM, das es Aufnahmen in Slowenien von weiterer Feuerkugel gab, welche auch auf Spaceweather erschien:

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HALLOWEEN FIREBALLS: The "Halloween asteroid" is going to miss Earth. The "Halloween fireballs" might not. If forecasters are correct, gravelly debris from Comet Encke could strike our planet's atmosphere this weekend, producing a display of fireballs like this one:

Marko Korosec took the picture last night in Artvize, Slovenia: "This spectacular meteor had two bright flashes," he says. "It caught me a bit unprepared as I was looking in other direction, saw first flash then looked up and--bam!--the second flash was so bright it lit up the ground."
Korosec says the fireball came from the constellation Taurus, which marks it as a meteoroid from Comet Encke. Most debris from Comet Encke is small, dusty and fragile, yielding meteors of ordinary brightness. Taurid fireballs come from a swarm of particles much larger than normal comet dust. They're about the size of pebbles or small stones. The rocky swarm moves within the greater Encke dust stream, sometimes hitting Earth, sometimes not. Will this Halloween be a hit? Korosec's fireball is an encouraging sign. Stay tuned.
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Aber auch eine weitere Aufnahme kam dann von der Wendelsteinbahn-Bergstation welche eine Feuerkugel gegen 19.10 erfasste:
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Auf Grund dieser Aufnahmen gehen wir von mehreren Feuerkugeln der Tauriden aus welche hier am gestrigen Abend zu sehen waren. Daher sind wir gespannt ob weitere Beobachtungen zu diesen Feuerbällen eingehen.
Bitte über Meldestelle-Telefon von CENAP: 0151-18736259 oder per Email: cenap-h-koehler@t-online.de

Tags: Astronomie 

2559 Views

Samstag, 31. Oktober 2015 - 19:00 Uhr

Astronomie - Sonnenfleck AR-2443 im Focus durch Herbstnebel

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Sonnenfleck AR-2443 welcher sich vor Stunden noch am Rande der Sonne befand, kann man nun immer besser beobachten, nachfolgend die SOHO-Aufnahme von Heute,

danach die Aufnahmen durch den Herbstnebel über Odenwald:

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Diese "Nebelwolken-Bedingungen" sind Ideal für Aufnahmen der Sonne, wenn die Sonnenscheibe sich durch die Nebelwolke zeigt...

Fotos: hjkc


Tags: Astronomie 

1474 Views

Samstag, 31. Oktober 2015 - 18:45 Uhr

Raumfahrt - Erfolgreicher Start von Atlas V mit GPS IIF-11 Satelliten

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Atlas V to Launch GPS IIF-11
Rocket/Payload: A United Launch Alliance Atlas V 401 will launch the GPS IIF-11 mission for the U.S. Air Force.
Date/Site/Launch Time: Friday, Oct. 30, 2015, from Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida. 
Mission Description: GPS satellites serve and protect our warfighters by providing navigational assistance for U.S. military operations on land, at sea, and in the air. Civilian users around the world also use and depend on GPS for highly accurate time, location, and velocity information.
GPS IIF-11 is one of the next-generation GPS satellites, incorporating various improvements to provide greater accuracy, increased signals, and enhanced performance for users.
Launch Notes: GPS IIF-11 will be the third GPS mission ULA launches in 2015: GPS IIF-9 launched on a Delta IV in March, and GPS IIF-10 launched in July. This mission will be ULA’s 11th in 2015 and 102nd since the company was founded in 2006.
Quelle: ULA
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Update: 19.10.2015
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Rocket launches expected to ramp up as end of year approaches
United Launch Alliance is preparing its Atlas V rocket for its next launch on October 30 from the Cape Canaveral Air Force Station.
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CAPE CANAVERAL -- 
Rocket launches are expected to ramp up as we end the year on the Space Coast.
SpaceX, Orbital and United Launch Alliance are all planning missions to end 2015 with a bang.
United Launch Alliance is preparing its Atlas V rocket for its next launch on October 30 from the Cape Canaveral Air Force Station.
The company will deliver the 11th in a series of 12 GPS satellites for the US Air Force.
This year alone, ULA has already launched two GPS satellites, including back in July.
Meanwhile, the company's final launch from Florida this year will be historic.
The service module of Orbital ATK's Cygnus spacecraft arrived at Kennedy Space Center last week.
Cygnus will be loaded with 7,700 pounds of food and supplies for astronauts at the International Space Station.
It will launch on ULA's Atlas V rocket on December 3.
It's the first time the spacecraft will launch on an Atlas V and the first time launching from Florida.
The last Orbital mission, a year ago, ended in disaster when an Antares rocket exploded just after liftoff from Virgina.
Orbital isn't the only company banking on a return to flight from Florida.
SpaceX also plans to fly its Falcon 9 rocket again, after it exploded after the launch of NASA cargo from Cape Canaveral back in June.
A faulty strut was to blame.
The company plans to deliver 11 satellites from Orbcomm to space in 6 to 8 weeks.
And aggressive as they are, SpaceX engineers plan another launch, an SES communications satellite, by the end of 2015.
Quelle: NEWS13
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Update: 23.10.2015
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Atlas 5 receives payload for third launch this month

File photo. Credit: ULA
CAPE CANAVERAL — Heading to space next week to replace a 12-year-old satellite in the Global Positioning System navigation network, a modernized spacecraft was placed atop its Atlas 5 launcher.
That completes assembly of the 189-foot-tall United Launch Alliance rocket at Cape Canaveral for liftoff of the GPS 2F-11 craft.
Launch on Oct. 30 will be possible between 12:17 and 12:36 p.m. EDT (1617-1636 GMT) to reach the correct location within the GPS constellation.
The new satellite will take the place of the GPS 2R-10 craft launched aboard Delta 302 on Dec. 21, 2003 into Plane E, Slot 2 of the constellation. The old craft moves to a backup role in the network once the fresh GPS 2F-11 enters service.
The satellite was flown to Florida on June 8 from Boeing’s manufacturing facility in El Segundo, California. After arriving, it was taken to the Cape’s Area 59 were GPS spacecraft undergo their pre-flight preps.
Final testing, loading of hydrazine maneuvering propellant and encapsulation in the rocket’s nose cone was accomplished with the satellite.
Then, a convoy hauled the 3,400-pound satellite north through Cape Canaveral Air Force Station to United Launch Alliance’s Vertical Integration Facility where the Atlas had been stacked beginning Oct. 12.
Already shrouded in the launcher’s 39-foot-tall, 14-foot-diameter aluminum nose cone, the spacecraft was hoisted atop the Centaur upper stage for attachment.
This will be the 11th Block 2F satellite sent into the GPS network since 2010. Boeing in building a dozen spacecraft of this kind featuring greater accuracy, more signals, better anti-jamming and longer design lives than previous models.
For Atlas 5, it is the rocket’s third launch this month. It follows a commercial flight Oct. 2 and a national security mission Oct. 8.
Quelle: SN
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Update: 29.10.2015
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Atlas V rolling to pad for Friday GPS launch

An Atlas V rocket at 10 a.m. today is scheduled to start rolling to its pad for a 12:17 p.m. Friday launch of a Global Positioning System satellite from Cape Canaveral Air Force Station.
The 189-foot rocket and its payload will roll on a transporter over rails about one-third of a mile from a processing tower to the pad at Launch Complex 41.
On top of the rocket is the Air Force's 11th GPS IIF, or 2F, satellite in a series of a dozen built by Boeing, and the third to launch from the Cape this year.
The Atlas V is launching in its most basic configuration known as the "401," with a four-meter (13.1-foot) diameter payload fairing, no solid rocket motors attached to the booster and a single engine powering the Centaur upper stage.
The Air Force's 45th Weather Squadron anticipates a 90 percent chance of favorable weather during Friday's 19-minute launch window.
The mission is ULA's 11th of 2015.
Quelle: Florida Today

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Quelle: ULA

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Update: 30.10.2015

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Atlas V launch pushed back to Saturday

An Atlas V rocket originally scheduled to blast off from Cape Canaveral Air Force Station on Friday has been rescheduled for Saturday after a leak was discovered during final launch preparations.
A ground support equipment valve for the launch pad water suppression system will need to be replaced or repaired, according to the United Launch Alliance.
The rocket is scheduled for a 12:13 p.m. lift-off from Launch Complex 41. There is a 19-minute launch window in case weather or other factors cause a minor delay.
The Air Force's GPS IIF-11 communications satellite is part of a constellation of next-generation GPS technology satellites.
This will be the third such satellite launched this year on a United Launch Alliance Atlas V rocket. Atlas Vs carrying Air Force GPS IIF satellites also went up in March and July. There is one more such satellite planned to complete the constellation.
On Thursday, the Air Force 45th Weather Squadron predicted good weather for Friday’s launch, with light clouds, a slight chance of rain, but no high winds or lightning. There is about a 10 percent chance of weather delaying the launch.
Made by Boeing, the GPS IIF satellites weigh about 3,600 pounds. They have location accuracy of about a meter, and time accuracy of a billionth of a second, providing greater accuracy, increased signals and better performance than old GPS satellites.
This is the last launch scheduled at the cape until Dec. 3, when Orbital ATK will resume its resupply missions to the International Space Station, following a 14-month grounding. The Orbital cargo capsule will group on another Atlas V. Also around that time, though not yet scheduled, Space will resume launching its Falcon 9 rockets, ending a five-month grounding. Both Orbital and SpaceX saw their last rockets blow up.
Space Florida, the state space-industry development corporation, and Florida's Space Coast Office of Tourism are organizing a launch watch party Friday at the Coconuts On The Beach restaurant in Cocoa Beach.
Quelle: Orlando Sentinel

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Update: 31.10.2015 / 8.55 MEZ

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Update: 18.45 MEZ

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Erfolgreicher Start von Atlas V mit GPS IIF-11 Satelliten

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Quelle: ULA


Tags: Raumfahrt 

1621 Views

Samstag, 31. Oktober 2015 - 11:25 Uhr

Astronomie - University of Leicester feiert erfolgreichen Betrieb von Astrosat-Röntgenteleskop

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Scientists from University of Leicester celebrate successful operation of Space Camera
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Event on Friday 30 October in Department of Physics and Astronomy to mark success of Indian satellite mission
Scientists from the Department of Physics and Astronomy at the University of Leicester are finally able to celebrate after an anxious month since the launch of Astrosat, the first Indian satellite dedicated to astronomical observations.
The door, on the x-ray camera which had been assembled at the University by a team led by Dr Gordon Stewart, was opened on Monday 26 October, allowing the soft x-ray telescope to make its first observation of the sky.
Staff from the department and interested parties from outside the University are meeting on Friday 30 October to mark the occasion. The event takes place at 5pm in the Department of Physics and Astronomy.
The target of the first observations is named PKS2155-304 and is one of an enigmatic class of supermassive black holes accelerating jets of material to speeds near the speed of light which point towards and away from the earth, the BL Lac objects.
Analysis of the data show that the camera (and the telescope) are operating perfectly and the data quality is excellent.
Astrosat, which was launched by the Indian Space Research Organisation (ISRO) on 28 September, is designed to make studies of the ultra-violet, optical, low and high-energy x-ray emission from celestial objects at the same time and will be a powerful to tool with which to measure the time variability of compact sources such as neutron stars and black holes, including the supermassive black holes at the centre of galaxies.
The satellite’s instruments have been built by a consortium of institutes in India (the Tata Institute for Fundamental Research, (TIFR), Mumbai, the Indian Institute for Astronomy, (IIA), Bengaluru and the Indian Universities Centre for Astronomy and Astrophysics, (IUCAA), Pune in addition to ISRO), the Canadian Space Agency and the University of Leicester in the UK.
Following a period of calibration and performance verification extending to the end of the year Astrosat will begin its full programme of scientific observations supplying astronomers in Leicester, India and elsewhere with data with which to further develop our understanding of some of the most extreme objects in the Universe.
Dr Stewart said: “ The team are very pleased the camera is operating so well and we look forward to receiving exciting science data in the near future.”
Quelle: The University of Leicester

Tags: Astronomie 

1586 Views

Samstag, 31. Oktober 2015 - 08:44 Uhr

Raumfahrt - Voyager-1 hilft bei der Lösung interstellaren Medium Rätsel

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NASA's Voyager 1 spacecraft made history in 2012 by entering interstellar space, leaving the planets and the solar wind behind. But observations from the pioneering probe were puzzling with regard to the magnetic field around it, as they differed from what scientists derived from observations by other spacecraft.
A new study offers fresh insights into this mystery. Writing in the Astrophysical Journal Letters, Nathan Schwadron of the University of New Hampshire, Durham, and colleagues reanalyzed magnetic field data from Voyager 1 and found that the direction of the magnetic field has been slowly turning ever since the spacecraft crossed into interstellar space. They believe this is an effect of the nearby boundary of the solar wind, a stream of charged particles that comes from the sun.
"This study provides very strong evidence that Voyager 1 is in a region where the magnetic field is being deflected by the solar wind," said Schwadron, lead author of the study.
Researchers predict that in 10 years Voyager 1 will reach a more "pristine" region of the interstellar medium where the solar wind does not significantly influence the magnetic field.
Voyager 1's crossing into interstellar space meant it had left the heliosphere -- the bubble of solar wind surrounding our sun and the planets. Observations from Voyager's instruments found that the particle density was 40 times greater outside this boundary than inside, confirming that it had indeed left the heliosphere.
But so far, Voyager 1's observation of the direction of the local interstellar magnetic field is more than 40 degrees off from what other spacecraft have determined. The new study suggests this discrepancy exists because Voyager 1 is in a more distorted magnetic field just outside the heliopause, which is the boundary between the solar wind and the interstellar medium.
"If you think of the magnetic field as a rubber band stretched around a beach ball, that band is being deflected around the heliopause," Schwadron said.
In 2009, NASA's Interstellar Boundary Explorer (IBEX) discovered a "ribbon" of energetic neutral atoms that is thought to hold clues to the direction of the pristine interstellar magnetic field. The so-called "IBEX ribbon," which forms a circular arc in the sky, remains mysterious, but scientists believe it is produced by a flow of neutral hydrogen atoms from the solar wind that were re-ionized in nearby interstellar space and then picked up electrons to become neutral again.
The new study uses multiple data sets to confirm that the magnetic field direction at the center of the IBEX ribbon is the same direction as the magnetic field in the pristine interstellar medium. Observations from the NASA/ESA Ulysses and SOHO spacecraft also support the new findings.
"All of these different data sets that have been collected over the last 25 years have been pointing toward the same meeting point in the field," Schwadron said.
Over time, the study suggests, at increasing distances from the heliosphere, the magnetic field will be oriented more and more toward "true north," as defined by the IBEX ribbon. By 2025, if the field around Voyager 1 continues to steadily turn, Voyager 1 will observe the same magnetic field direction as IBEX. That would signal Voyager 1's arrival in a less distorted region of the interstellar medium.
"It's an interesting way to look at the data. It gives a prediction of how long we'll have to go before Voyager 1 is in the medium that's no longer strongly perturbed," said Ed Stone, Voyager project scientist, based at the California Institute of Technology in Pasadena, who was not involved in this study.
While Voyager 1 will continue delivering insights about interstellar space, its twin probe Voyager 2 is also expected to cross into the interstellar medium within the next few years. Voyager 2 will make additional observations of the magnetic field in interstellar space and help scientists refine their estimates.
Voyager 1 and Voyager 2 were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft. Voyager 1 is the most distant object touched by human hands.
JPL, a division of Caltech, built the twin Voyager spacecraft and operates them for the Heliophysics Division within NASA's Science Mission Directorate in Washington.
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Quelle: NASA

Tags: Raumfahrt 

1408 Views

Samstag, 31. Oktober 2015 - 08:28 Uhr

Astronomie - Rätsel um Massive Auswirkungen auf Mond Gravitation Karte enthüllt

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The 1,550-mile wide Aitken crater (as seen here by the Apollo 17 crew) appears to be the biggest crater on the moon, according to new data from NASA's gravity-mapping GRAIL mission -- where are all the other massive impact craters?

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New lunar gravity maps point out a stark and unexpected difference between the sizes of ancient asteroids that slammed into the moon billions of years ago and the sizes of the rocky bodies that occupy the in the Main Asteroid Belt today.

Scientists had expected to find buried evidence of several large, potentially “planet killing” asteroid impacts on the moon, as predicted by several computer models. But data collected by NASA’s now-defunct, gravity-mapping GRAIL satellites show only one, previously known, behemoth crater on the moon, the 1,550-mile wide Aitken basin on the lunar south pole, according to a paper published this week Science Advances, a new journal.
Crater size provides an important measure of what was happening in the early days of the solar system. During the so-called Late Heavy Bombardment, which scientists believe occurred about 4 billion years ago -- just a few hundred million years after the solar system’s formation -- Earth and the newly formed inner planets were targets in a celestial shooting gallery.
Computer models suggest the blitz was triggered by Jupiter and the giant planets shifting orbits, causing a barrage of rocky bodies and comets to be gravitationally slingshot inward. But impact basins uncovered by GRAIL don’t fit neatly into those models, astronomer and geophysicist Gregory Neumann, with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, told Discovery News.
“We have more of the medium-size impactors that formed the ‘face’ of the moon, Imbrium (a vast lava-filled crater), and so forth, and we don’t find evidence for larger impactors other than Aitken,” Neumann said. “The implications are enormous.”
“We have been writing this paper since 1996, trying to get an inventory of lunar impact basins from gravity. We haven’t had the gravity field that we’ve needed to do the job until now,” added GRAIL lead scientist Maria Zuber, with the Massachusetts Institute of Technology.
Overall, the number of impact basins uncovered by GRAIL was in the ballpark of what most researchers expected, Zuber told Discovery News.
Now that definitive number, along with the crater sizes, can be used in computer models to glean a better understanding of what was happening not just on the moon, but on Earth and the other inner planets as well.
“Earth was getting bombarded at the same time as the moon was and so if the moon is missing big impacts, so was the Earth,” Zuber said.
“This relates to the number of really large-scale impacts at the time when life was starting to develop. We don’t know how many times life developed and got wiped out from the extreme environments associated with early impacts, but if what we see about the moon holds up -- and I think it will because this is good data -- then it allows us to have a better understanding how many large impacts the Earth could have had during a similar time,” she said.
Quelle: D-News

Tags: Astronomie 

1667 Views

Freitag, 30. Oktober 2015 - 21:00 Uhr

Raumfahrt-History - 1979: Europas Raumlabor Spacelab auf dem Weg ins Weltall

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Aus dem CENAP-Archiv:

Quelle: CENAP-Archiv


Tags: Raumfahrt 

1418 Views


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