Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

History’s greatest comet hunter approaches major milestone

07.07.2005


SOHO see two comets plunging into the Sun


SOHO spacecraft


As of 6 July 2005, 990 comets have been discovered using the ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft, which is expected to discover its 1000th comet this summer.

The SOHO spacecraft, a joint effort between NASA and the European Space Agency, has been so prolific that it has accounted for almost half of all comet discoveries for which orbits have been computed in the history of astronomy.

Before SOHO was launched, only 16 ‘sungrazing’ comets had been discovered by space observatories. Based on that experience, who could have predicted that SOHO would discover more than sixty times that number, and in only nine years?



Comets are chunks of ice and dust that zoom around the Solar System in elongated orbits. These ‘dirty snowballs’ are the nucleii of the comets. Comet nuclei are thought to be cosmic ‘leftovers’, the condensed remains of the gas and dust cloud that formed the Solar System.

About 85 percent of the comets discovered so far by SOHO belong to the Kreutz group of ‘sungrazing’ comets, so named because their orbits take them very close to the Sun.

The Kreutz sungrazers come within 800 000 km of the Sun’s visible surface. In comparison, Mercury, the planet closest to the Sun, is about 57.6 million km from the solar surface.

SOHO has also been used to discover three other well-populated comet groups: the Meyer (at least 55 members), Marsden (at least 21 members), and Kracht (24 members) groups. Comet groups are named after the astronomer who determined that they are related because they have similar orbits.

Many SOHO comet discoveries have been by amateurs using SOHO images on the internet. SOHO comet hunters come from all over the world; the United States, United Kingdom, China, Japan, Taiwan, Russia, Ukraine, France, Germany and Lithuania are among the many countries whose citizens have used SOHO to chase comets.

Almost all SOHO’s comets are discovered using images from its Large Angle and Spectrometric Coronagraph (LASCO) instrument. LASCO is used to observe the faint, multimillion-degree outer atmosphere of the Sun, called the corona.

A disk in the instrument is used to make an artificial eclipse, blocking direct light from the Sun so the much fainter corona can be seen. Sungrazing comets are discovered when they enter LASCO’s field of view as they pass close by the Sun.

SOHO successfully completed its primary mission in April 1998, and it has enough fuel to remain on station and keep hunting comets for decades, assuming the LASCO instrument continues to function.

For more information:

Bernhard Fleck, ESA SOHO Project Scientist
E-mail: bfleck @ esa.nascom.nasa.gov

Bernhard Fleck | EurekAlert!
Further information:
http://www.esa.int/esaSC/SEMJ086DIAE_index_0.html

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>