As Comet McNaught heads towards its closest approach to the Sun on 12 January 2007, it will disappear from view for earthbound observers, becoming lost in the Sun's glare. That's where SOHO comes in. Poised in space between the Earth and Sun, SOHO ceaselessly watches the Sun and objects that pass nearby.
Comet McNaught will pass within a fifth of the distance between the Earth and the Sun. As the comet approaches the Sun, the amount of dust and gas it releases will increase dramatically, causing the comet to become extremely bright. "This might become the brightest comet SOHO has ever seen," says Bernhard Fleck, SOHO Project Scientist.
The material ejected from the comet forms the tails. There are two tails, the dust tail and the gas – or ion – tail. The dust tail is the brighter and is formed by the intense sunlight forcing dust particles away from the comet. The solar wind, a constant stream of material flowing from the Sun, drags ionized gas from the comet to create the ion-tail.
Researchers Karl Battams and Jeff Morrill at the Naval Research Laboratory in Washington, DC are planning colour filter observations of these two comet tails. "Close to the Sun the ion and dust tails move apart, a phenomenon that is often difficult to observe from the Earth. By measuring the ion-tail angle we can get information about the solar wind speed very close to the Sun," says Morrill.
Comet McNaught is moving through space on an inclined orbit. This will carry it above the Sun’s north pole and across the Sun’s equator, a place where there is a reversal of the magnetic properties of the solar wind. Crossing this boundary could cause the comet’s ion-tail to fragment. Observations of such events are generally very rare, so SOHO's images of comet McNaught constitute an exciting opportunity for scientists.
After SOHO's work is finished, the comet will emerge from the Sun’s glare and become visible again to earthbound sky watchers in the Southern Hemisphere. "It could become a really bright object in the twilight sky," says Fleck. The ghostly veils of a bright comet are amongst the most spectacular of sights that can be seen in the night sky.
Between 12 and 15 January, Comet McNaught will not be visible from Earth but everyone can still track the comet's passage near the Sun by looking at the SOHO images at http://soho.esac.esa.int/hotshots/.
Bernhard Fleck | alfa
From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison
Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science
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...
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
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”...
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...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
28.02.2017 | Health and Medicine
28.02.2017 | Earth Sciences
27.02.2017 | Materials Sciences