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 Basque researchers turn light upside down
23.02.2018 | Elhuyar Fundazioa

nachricht Attoseconds break into atomic interior
23.02.2018 | Max-Planck-Institut für Quantenoptik

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>