Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NRL Instrument on NASA Satellite Sees Solar Hurricane Detach Comet Tail

05.10.2007
Scientists at the Naval Research Laboratory report they have captured the first images of a collision between a comet and a solar hurricane. It is the first time scientists have witnessed such an event on another cosmic body. One of NASA's pair of Solar Terrestrial Relations Observatory satellites, known as STEREO, recorded the event on April 20, 2007.

The phenomenon was caused by a coronal mass ejection, a large cloud of magnetized gas cast into space by the sun. The collision resulted in the complete detachment of the plasma tail of Encke's comet. Observations of the comet reveal the brightening of its tail as the coronal mass ejection swept by and the tail's subsequent separation as it was carried away by the front of the ejection. The researchers combined the images into a movie.

"We were awestruck when we saw these images," says Angelos Vourlidas, lead author and researcher at NRL. "This is the first time we've witnessed a collision between a CME and a comet and the surprise of seeing the disconnection of the tail was the icing on the cake"

Encke's comet was traveling within the orbit of Mercury when a coronal mass ejection first crunched the tail then ripped it completely away. The comet is only the second repeating, or periodic, comet ever identified. Halley's comet was the first.

Scientists at NRL made the observations using the Heliospheric Imager in its Sun Earth Connection Coronal and Heliospheric Investigation telescope suite aboard the STEREO-A spacecraft. The results will be published in the October 10 print issue of the Astrophysical Journal Letters (ApJL) but are online now at the ApJL website (http://www.journals.uchicago.edu/ApJ/journal/contents/ApJL/v668n1.html).

Coronal mass ejections are violent eruptions with masses greater than a few billion tons. They travel from 60 to more than 2,000 miles per second. They have been compared to hurricanes because of the widespread disruption they can cause when directed at Earth. These solar hurricanes cause geomagnetic storms that can present hazards for satellites, radio communications and power systems. However, coronal mass ejections are spread over a large volume of space, mitigating their mass and power to create an impact softer than a baby's breath.

Scientists have been aware of the disconnection of the entire plasma tail of a comet for some time, but the conditions that lead to these events remained a mystery. It was suspected that coronal mass ejections could be responsible for some of the disconnected events, but the interaction between a coronal mass ejection and a comet never had been observed.

Preliminary analysis suggests the disconnection likely is triggered by what is known as magnetic reconnection, in which the oppositely directed magnetic fields around the comet are crunched together by the magnetic fields in the coronal mass ejection. The comet fields suddenly link together, reconnecting, to release a burst of energy that detaches the comet's tail. A similar process takes place in Earth's magnetosphere during geomagnetic storms, powering the aurora borealis and other phenomena.

Comets are icy leftovers from the solar system's formation billions of years ago. They usually reside in the cold, distant regions of the solar system. Occasionally, the gravitational tug from a planet, another comet or a nearby star sends a comet into the inner solar system, where the sun's heat and radiation vaporizes gas and dust from the comet to form its tail. Comets typically have two tails: one of dust and a fainter one of electrically conducting gas called plasma.

"Even though STEREO is primarily designed to study coronal mass ejections, particularly their impact on Earth, we hope this impact will provide many insights to scientists studying comets," said Michael Kaiser, STEREO project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md.

STEREO is the third mission in NASA's Solar Terrestrial Probes program, sponsored by NASA's Science Mission Directorate, Washington. Goddard manages the mission, instruments, and science center. The Heliospheric Imager was built in the United Kingdom by Rutheford Appleton Laboratory and the University of Birmingham with major contributions from NRL and the Centre Spatial de Liege, Belgium. Other international partners in the STEREO mission include the European Space Agency and France, Germany, Hungary and Switzerland.

Donna McKinney | EurekAlert!
Further information:
http://www.nrl.navy.mil

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>