Latest Jets Stories

2009-09-17 09:21:46

Challenging conventional wisdom, new research finds that the number of sunspots provides an incomplete measure of changes in the Sun's impact on Earth over the course of the 11-year solar cycle. The study, led by scientists at the National Center for Atmospheric Research (NCAR) and the University of Michigan, finds that Earth was bombarded last year with high levels of solar energy at a time when the Sun was in an unusually quiet phase and sunspots had virtually disappeared. "The Sun...

2009-09-14 06:28:01

Scientists using the Cassini spacecraft's  Magnetospheric Imaging instrument (MIMI) have detected a new, temporary radiation belt  at Saturn, located around the orbit of its moon Dione at about 377 000 km from the center of the planet. The discovery will be presented at the European Planetary Science Congress in Potsdam by Dr Elias Roussos on Monday September 14. Radiation belts, like Earth's Van Allen belts, have been discovered at Jupiter, Saturn, Uranus and Neptune. ...

2009-09-10 09:50:00

UCLA atmospheric scientists have discovered a previously unknown basic mode of energy transfer from the solar wind to the Earth's magnetosphere. The research, federally funded by the National Science Foundation, could improve the safety and reliability of spacecraft that operate in the upper atmosphere. "It's like something else is heating the atmosphere besides the sun. This discovery is like finding it got hotter when the sun went down," said Larry Lyons, UCLA professor of atmospheric and...

2009-08-31 14:35:00

Magnetic reconnection could be the Universe's favorite way to make things explode. It operates anywhere magnetic fields pervade space--which is to say almost everywhere. On the sun magnetic reconnection causes solar flares as powerful as a billion atomic bombs. In Earth's atmosphere, it fuels magnetic storms and auroras. In laboratories, it can cause big problems in fusion reactors. It's ubiquitous. The problem is, researchers can't explain it. The basics are clear enough. Magnetic lines of...

2009-08-20 10:00:00

On September 29, the MESSENGER spacecraft will pass by Mercury for the third time, flying 141.7 miles above the planet's rocky surface for a final gravity assist that will enable it to enter orbit about Mercury in 2011. This encounter will also provide new observational opportunities for MESSENGER's Magnetometer, designed to determine the structure and origin of Mercury's intrinsic magnetic field. The comparison of magnetosphere observations from MESSENGER's first flyby in January 2008 with...

2009-07-17 07:10:00

Using data from the Cluster mission scientists have discovered a mechanism that can account for the heating of the solar wind. Cluster data were used to successfully discriminate between a number of theoretical models and, for the time periods analyzed, a remarkable agreement was found with one model in particular. This result may be applicable in other astrophysical contexts such as the heating of the solar corona. This discovery was highlighted in the June 12, 2009 issue of Physical Review...

2009-06-15 08:31:30

400 years of discussion and we're still not sure what creates the Earth's magnetic field, and thus the magnetosphere, despite the importance of the latter as the only buffer between us and deadly solar wind of charged particles (made up of electrons and protons). New research raises question marks about the forces behind the magnetic field and the structure of Earth itself. The controversial new paper published in New Journal of Physics (co-owned by the Institute of Physics and the German...

2009-06-02 11:30:00

As the closest planet to the sun, Mercury is scorching hot, with daytime temperatures of more than 800 degrees Fahrenheit (approximately 450 degrees Celsius). It is also the smallest rocky planet, so its gravity is weak, only about 38 percent of Earth's. These conditions make it hard for the planet to hold on to its atmosphere, which is extremely thin, and invisible to the human eye. However, it can be seen by special instruments attached to telescopes and spacecraft like MESSENGER (MErcury...

2009-04-29 08:55:00

Scientists have found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in near-Earth space. They are now looking to model how these changes affect orbiting satellites, including the GPS system. The results were obtained from coordinated in-situ measurements performed by ESA's four Cluster satellites along with the two Chinese/ESA Double Star satellites. Under normal solar conditions, GPS satellites orbit within the...

2009-04-09 15:45:00

Keeping an unsleeping eye on the phenomena that cause the aurora An international scientific consortium has successfully developed a series of autonomous observatories in Antarctica that for the first time provide critical year-round "space weather" data from the Earth's harshest environment. Recently, data from these observatories were used in conjunction with the National Aeronautics and Space Administration's array of THEMIS satellites to reveal new information about magnetospheric...

Latest Jets Reference Libraries

Ring Current
2004-10-19 04:45:44

Ring Current -- A ring current is an electric current carried by charged particles trapped in a planet's magnetosphere. It is caused by the longitudinal drift of energetic (10-200 keV) particles. Earth's Ring Current Earth's ring current is responsible for geomagnetic storms. The ring current system consists of a band, at a distance of 3-5 RE(1), which lies in the equatorial plane and circulates clockwise around the Earth (when viewed from the north). The particles of this region...

2004-10-19 04:45:41

Microquasar -- Microquasars are smaller cousins of quasars. They are named after quasars, as they have some common characteristics: strong and variable radio emission often seen as radio jets, and an accretion disk surrounding a black hole. In quasars, the black hole is supermassive (millions of solar masses) as in microquasars, the black hole mass is a few solar masses. In microquasars, the accreted mass comes from a normal star and the accretion disk is very luminous in optical regions...

2004-10-19 04:45:41

Aurora -- The Polar Aurora are natural displays of light in the sky that can be seen with the unaided eye only at night. An auroral display in the Northern Hemisphere is called the aurora borealis, or the northern lights; in the Southern Hemisphere it is called the aurora australis. Auroras are the most visible effect of the sun's activity on the earth's atmosphere. The beautiful and often eerie curtains of light in the night time sky have been observed by people for millennia. An aurora...

2004-10-19 04:45:41

Van Allen Radiation Belt -- The Van Allen radiation belt is a torus of energetic charged particles around Earth, trapped by Earth's magnetic field. The presence of a radiation belt had been theorized prior to the Space Age and the belt's presence was confirmed by the Explorer I on January 31, 1958 and Explorer III missions, under Doctor James Van Allen. The trapped radiation was first mapped out by Explorer IV and Pioneer III. Qualitatively, it is useful to view this belt as consisting...

2004-10-19 04:45:41

Solar Wind -- Solar wind, a stream of particles (mostly high-energy protons ~ 500 Kev) that is continually ejected from the surface of the Sun. The composition of this plasma is identical to the Sun's corona, 73% hydrogen and 25% helium with the remainder as trace impurities, and is ionized. Near Earth, the velocity of the solar wind varies from 200km/s-889km/s. The average is 450 km/s. Approximately 3000 tons of material is lost from the Sun every hour as solar wind. Since solar...

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Word of the Day
  • To stammer.
  • Present participle of maffle, to stammer.
  • A simpleton.
The word 'maffle' may come from a Dutch word meaning 'to move the jaws' or a French word meaning 'having large cheeks'.