. 24/7 Space News .
IRON AND ICE
Rosetta Captures Comet Outburst
by Staff Writers
Paris (ESA) Aug 29, 2016


The majority of Rosetta's instruments were on and pointing at Comet 67P/Churyumov-Gerasimenko at the time of the outburst on 19 February 2016, allowing a clear chain of events to be reconstructed. The graphic highlights some of the measurements from the cameras, dust collectors, and gas and plasma analysers, with each one recording a peak compared with background levels at various times during the outburst. Image courtesy ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; all data from Grun et al (2016). For a larger version of this image please go here.

In unprecedented observations made earlier this year, Rosetta unexpectedly captured a dramatic comet outburst that may have been triggered by a landslide. Nine of Rosetta's instruments, including its cameras, dust collectors, and gas and plasma analysers, were monitoring the comet from about 35 km in a coordinated planned sequence when the outburst happened on 19 February.

"Over the last year, Rosetta has shown that although activity can be prolonged, when it comes to outbursts, the timing is highly unpredictable, so catching an event like this was pure luck," says Matt Taylor, ESA's Rosetta project scientist.

"By happy coincidence, we were pointing the majority of instruments at the comet at this time, and having these simultaneous measurements provides us with the most complete set of data on an outburst ever collected."

The data were sent to Earth only a few days after the outburst, but subsequent analysis has allowed a clear chain of events to be reconstructed, as described in a paper led by Eberhard Grun of the Max-Planck-Institute for Nuclear Physics, Heidelberg, accepted for publication in Monthly Notices of the Royal Astronomical Society.

Which instruments detected the outburst?
A strong brightening of the comet's dusty coma was seen by the OSIRIS wide-angle camera at 09:40 GMT, developing in a region of the comet that was initially in shadow.

Over the next two hours, Rosetta recorded outburst signatures that exceeded background levels in some instruments by factors of up to a hundred. For example, between about 10:00 and 11:00 GMT, ALICE saw the ultraviolet brightness of the sunlight reflected by the nucleus and the emitted dust increase by a factor of six, while ROSINA and RPC detected a significant increase in gas and plasma, respectively, around the spacecraft, by a factor of 1.5-2.5.

In addition, MIRO recorded a 30 C rise in temperature of the surrounding gas.

Shortly after, Rosetta was blasted by dust: GIADA recorded a maximum hit count at around 11:15 GMT. Almost 200 particles were detected in the following three hours, compared with a typical rate of 3-10 collected on other days in the same month.

At the same time, OSIRIS narrow-angle camera images began registering dust grains emitted during the blast. Between 11:10 GMT and 11:40 GMT, a transition occurred from grains that were distant or slow enough to appear as points in the images, to those either close or fast enough to be captured as trails during the exposures.

In addition, the star-trackers, which are used to navigate and help control Rosetta's attitude, measured an increase in light scattered from dust particles as a result of the outburst.

The star-trackers are mounted at 90 to the side of the spacecraft that hosts the majority of science instruments, so they offered a unique insight into the 3D structure and evolution of the outburst.

Astronomers on Earth also noted an increase in coma density in the days after the outburst.

By examining all of the available data, scientists believe they have identified the source of the outburst.

"From Rosetta's observations, we believe the outburst originated from a steep slope on the comet's large lobe, in the Atum region," says Eberhard.

The fact that the outburst started when this area just emerged from shadow suggests that thermal stresses in the surface material may have triggered a landslide that exposed fresh water ice to direct solar illumination. The ice then immediately turned to gas, dragging surrounding dust with it to produce the debris cloud seen by OSIRIS.

"Combining the evidence from the OSIRIS images with the long duration of the GIADA dust impact phase leads us to believe that the dust cone was very broad," says Eberhard.

"As a result, we think the outburst must have been triggered by a landslide at the surface, rather than a more focused jet bringing fresh material up from within the interior, for example."

"We'll continue to analyse the data not only to dig into the details of this particular event, but also to see if it can help us better understand the many other outbursts witnessed over the course of the mission," adds Matt.

"It's great to see the instrument teams working together on the important question of how cometary outbursts are triggered."

"The 19 Feb. 2016 Outburst of Comet 67P/CG: A Rosetta Multi-Instrument Study," E. Grun et al., 2016, to appear in Monthly Notices of the Royal Astronomical Society; doi: 10.1093/mnras/stw2088.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Rosetta at ESA
Asteroid and Comet Mission News, Science and Technology






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
IRON AND ICE
Farewell Philae: Earth severs link with silent comet probe
Paris (AFP) July 27, 2016
Earth bid a final farewell to robot lab Philae on Wednesday, severing communications after a year-long silence from the pioneering probe hurtling through space on a comet. Writing an extraordinary chapter in space history, the washing machine-sized craft was the first to land on a comet - primeval rubble from the formation of the Solar System. Philae sent home reams of data garnered fr ... read more


IRON AND ICE
Space tourists eye $150mln Soyuz lunar flyby

Roscosmos to spend $7.5Mln studying issues of manned lunar missions

Lockheed Martin, NASA Ink Deal for SkyFire Infrared Lunar Discovery Satellite

As dry as the moon

IRON AND ICE
Anomalous grooves on Martian moon Phobos explained by impacts

NASA Awards Launch Services Contract for Mars 2020 Rover Mission

Year-long simulation of humans living on Mars ends in Hawaii

Boredom was hardest part of yearlong dome isolation

IRON AND ICE
The Deep Space Network

Grandpa astronaut breaks US space record

35 years later Voyager's legacy continues at Saturn

Chinese sci-fi prepares to master the universe

IRON AND ICE
China Sends Country's Largest Carrier Rocket to Launch Base

'Heavenly Palace': China to Launch Two Manned Space Missions This Fall

China unveils Mars probe, rover for ambitious 2020 mission

China Ends Preparatory Work on Long March 5 Next-Generation Rocket Engine

IRON AND ICE
US astronauts complete spacewalk for ISS maintenance

Space Station's orbit adjusted Wednesday

Astronauts Relaxing Before Pair of Spaceships Leave

'New port of call' installed at space station

IRON AND ICE
Galileo's Ariane 5 arrives at Europe's Spaceport

Vega's multi-satellite payload integration begins for Arianespace Flight VV07

SpaceX's Dragon cargo ship splashes down in Pacific

Sky Muster II comes to French Guiana for launch on Ariane 5

IRON AND ICE
Discovery one-ups Tatooine, finds twin stars hosting three giant exoplanets

Could Proxima Centauri b Really Be Habitable

Rocky planet found orbiting habitable zone of nearest star

A new Goldilocks for habitable planets

IRON AND ICE
New optical material offers unprecedented control of light and thermal radiation

Copernicus Sentinel-1A satellite hit by space particle

Northrop Grumman gets $375 million G/ATOR radar contract

UNIST to engineer next-generation smart separator membranes









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.