New evidence from an ancient lunar rock suggests that the moon once harbored a long-lived dynamo — a molten, convecting core of liquid metal that generated a strong magnetic field 3.7 billion years ago. The findings, ...
Space Exploration
Jan 27, 2012
3
0
Mars had a global magnetic field much earlier—and much later—in the planet's history than scientists have previously known.
Astronomy
May 1, 2020
14
1719
A conventional compass would be of little use on the moon, which today lacks a global magnetic field.
Space Exploration
Jan 3, 2020
7
1085
(PhysOrg.com) -- Mercury, the smallest of the eight planets with a diameter of 4900 kilometres and the closest to the Sun, looks more like the Moon than the Earth from the outside. It is the only rocky planet that has a global ...
Space Exploration
Dec 23, 2011
27
2
One of the big questions in solar physics is why the sun's activity follows a regular cycle of 11 years. Researchers from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), an independent German research institute, now present ...
Space Exploration
May 28, 2019
7
1447
When the Apollo astronauts returned to Earth, they brought with them some souvenirs: rocks, pebbles, and dust from the moon's surface. These lunar samples have since been analyzed for clues to the moon's past. One outstanding ...
Space Exploration
Dec 4, 2014
19
1
A dynamo mechanism could explain the incredibly strong magnetic fields in white dwarf stars according to an international team of scientists, including a University of Warwick astronomer.
Astronomy
Apr 30, 2021
16
472
Researchers at CU Boulder have discovered hints that humanity's favorite star may have a dual personality, with intriguing discrepancies in its magnetic fields that could hold clues to the sun's own "internal clock."
Astronomy
Jun 12, 2019
6
876
(PhysOrg.com) -- A University of California, Berkeley, geophysicist has made the first-ever measurement of the strength of the magnetic field inside Earth's core, 1,800 miles underground.
Earth Sciences
Dec 16, 2010
10
0
The Earth's global magnetic field is generated in its metallic core, located nearly 3,000 kilometers beneath the planet’s surface. The field has existed on Earth for at least 3.5 billion years and offers clues about how ...
Space Exploration
Mar 25, 2010
4
0
A dynamo (from the Greek word dynamis; meaning power), originally another name for an electrical generator, generally means a generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter. Today, the simpler alternator dominates large scale power generation, for efficiency, reliability and cost reasons. A dynamo has the disadvantages of a mechanical commutator. Also, converting alternating to direct current using power rectification devices (hollow state or more recently solid state) is effective and usually economic.
The word still has some regional usage as a replacement for the word generator. A small electrical generator built into the hub of a bicycle wheel to power lights is called a Hub dynamo, although these are invariably AC devices.[citation needed]
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