 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 by Staff Writers Paris (ESA) Sep 08, 2020
A permeable heart with a hardened facade -the resting place of Rosetta's lander on Comet 67P/Churyumov-Gerasimenko is revealing more about the interior of the 'rubber duck' shaped-body looping around the Sun. A recent study suggests that the comet's interior is more porous than the material near the surface. The results confirm that solar radiation has significantly modified the comet's surface as it travels through space between the orbits of Jupiter and Earth. Heat from the Sun triggers an ejection and subsequent falling back of material. Location, location, location. That was key for the radar instrument on the Rosetta spacecraft and its Philae lander, which was designed to probe the comet's nucleus. The CONSERT experiment involved two antennas sending precise signals to each other. But when Philae went missing upon landing on November 2014, scientists had to work with estimated values. Philae operated for over two days on the surface - 63 hours, to be precise. "We managed to define the region where the lander was with a margin of about 150 m. The real landing site was in this region," explains Wlodek Kofman, emeritus principal investigator of CONSERT. It took nearly two years to find out where Philae was. In September 2016 the exact position of Philae was retrieved within the area identified by CONSERT. Precise 3D models of the comet with Philae in the picture "allowed us to revisit the measurements and improve our analysis of the interior," says Wlodek. The graphic shows the signal connecting the CONSERT instrument on Philae, on the surface of the comet, to the one on the Rosetta orbiter. The fan like appearance is a result of the motion of Rosetta along its orbit, with the colours marking the separate signal paths as the orbit evolves. The image below shows the signals in more detail, propagating inside the comet from Philae to the points from where they leave the comet to the orbiter. The curving is a result of the projection of its paths on the bumpy surface of the comet. The bluer colour indicates more shallow paths (just a few centimetres), while the redder tones show where the signals penetrated below 100 m in depth. The time for the signal to travel between the two radars offers insights into the comet's nucleus, such as porosity and composition. The team discovered that rays propagated at different velocities, indicating varying densities within the comet. The discussion is still open, but Wlodek believes that "this strongly suggeststhat the less dense interior has kept its pristine nature." Known as the most primitive objects in our cosmic neighbourhood, comets might hold, deep inside, valuable clues about the formation of our Solar System.
Research Report: "The interior of Comet 67P/C-G; revisiting CONSERT results with the exact position of the Philae lander"
A dizzying show by Comet NEOWISE Hilo HI (SPX) Aug 25, 2020 When Comet NEOWISE (C/2020 F3) sped through the inner Solar System during the middle of 2020, astronomers and the general public watched in awe as this "dirty snowball" shed gas and dust into space, producing a striking show visible to the naked eye. Close-up observations, led by Michal Drahus and Piotr Guzik of Jagiellonian University in Krakow, used the international Gemini Observatory, a Program of NSF's NOIRLab, to observe the materials escaping from the comet over time. One set of obser ... read more
|
|||||||||||||
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |
del.icio.us
Digg
Reddit
Google
