A giant lava lamp inside the Earth might be flipping the planet's magnetic field. If you could travel back in time 41,000 years to the last ice age, your compass would point south instead of north.
That’s because for a period of a few hundred years, the Earth’s magnetic field was reversed. These reversals have happpened repeatedly over the planet’s history, sometimes lasting hundreds of thousands of years. We know this from the way it affects the formation of magnetic minerals, that we can now study on the Earth’s surface. Several ideas exist to explain why magnetic field reversals happen. One of these just became more plausible. Around 3,000km below our feet – 270 times further down than the deepest part of the ocean – is the start of the Earth’s core, a liquid sphere of mostly molten iron and nickel.
On the mantle side of this boundary, solid rock gradually flows over millions of years, driving the plate tectonics that cause continents to move and change shape. New explanation These regions might be less dense simply because they are hotter. Brown Dwarfs: Failed Stars Resembling Planets. Sometimes collapsing clouds of gas and dust don't quite manage to make it as stars.
These objects, known as brown dwarfs, have many of the elements of their more famous siblings but lack the mass needed to jumpstart nuclear fusion in their core. Because brown dwarfs never burn fusion at their core, scientists sometimes refer to them as "failed stars. " Brown dwarfs start out just like their main-sequence siblings. A cloud of dust and gas collapses, gravity piling the components in tightly and forming a young protostar at its center. For main sequence stars, the gravity pushes inward until hydrogen fusion is jump-started in their core. "Brown dwarfs are the missing link between gas giant planets like Jupiter and small stars like red dwarfs," Ian McLean, an astronomer at the University of California, Los Angeles, said in a statement. Brown dwarfs come in a variety of masses and temperatures. Stars are classified by their spectral type, or the energy they radiate.
Coldest Known Star Is a Real Misfit. Astronomers have detected a new candidate for the coldest known star – one whose temperature is roughly equivalent to a fresh cup of tea.
The object is part of a double system and is a type of star known as a brown dwarf, which is essentially a failed star. Brown dwarfs lack enough mass for gravity to trigger the nuclear reactions that make stars shine, but they’re more massive than what’s typically considered to be a planet. This newly discovered brown dwarf is identified as CFBDSIR 1458+10B, and is the dimmer member of the binary brown dwarf system, which is located only 75 light-years from Earth.
Stars are hot, right? Not this star. Astronomers have found the coolest star – temperature-wise, that is – although some would argue it should not be called a star.
Star Colors and Temperatures. Stars appear to be exclusively white at first glance.
But if we look carefully, we can notice a range of colors: blue, white, red, and even gold. What is the Hottest Star? - Universe Today. [/caption] Stars can range in temperature, from the relatively cool red dwarfs to superhot blue stars.
So what is the hottest star in the Universe? First, let’s talk a bit about temperature. The color of a star is a function of its temperature. If a star looks red, that means its surface temperature is approximately 2,500 Kelvin. Just for comparison, our Sun, which actually looks white from space, measures about 6,000 Kelvin. So the hottest stars in the Universe are going to be a blue star, and we know they’re going to be massive. Sunquakes, siesmic activity on the sun and solar flares. Sunquakes and solar flare activity are two of the great remaining mysteries of the sun.
This "Granddaddy" solar flare prominence was recorded in 1945 and remains the largest recorded flare on video record. Sometimes a sunquake results in the solar flare, but a sunquake is not necessarily the only thing that can trigger a solar flare. The continuous erosion from the electrical arcing at the surface of the sun occasionally weakens the surface along large fault lines resulting in sunquakes. These fault lines eventually rupture and generate solar flare activity, releasing huge amounts of heat and energy from the hot, dense magma-like layers below the surface of the sun.
This can often set off spectacular solar flares. Fiery Looping Rain on the Sun. Hypnotic Solar Explosions in 4k. Magnificent Eruption in Full HD. Thermonuclear Art – The Sun In Ultra-HD (4K) Secrets of the Sun PBS Nova HD 1080p. Space Weather Model Helps Simulate Solar Storms. Related multimedia at NASA Goddard's Scientific Visualization Studio Scientists from NASA and three universities have presented new discoveries about the way heat and energy move and manifest in the ionosphere, a region of Earth’s atmosphere that reacts to changes from both space above and Earth below.
Far above Earth’s surface, within the tenuous upper atmosphere, is a sea of particles that have been split into positive and negative ions by the sun’s harsh ultraviolet radiation. NSO/GONG: Helioseismology. Solar Eruptions Cause Sunquakes. A study led by UCL's Mullard Space Science Laboratory has shown for the first time that sunquakes can be produced during eruptions of magnetic field and charged particles, as the immense magnetic structure blasts off into the Solar System.
The results will be presented by Dr Sergei Zharkov at the National Astronomy Meeting 2012 in Manchester on Friday 30th March 2012. The first observation of a sunquake was reported by Kosovichev & Zharkova in the late 1990s. During the last decade it has become well established that explosions in the Sun's atmosphere, known as solar flares, can create sunquakes through the impact of powerful beams of particles which travel into the Sun. This new study shows that eruptions of material known as coronal mass ejections are also able to produce sunquakes.
"Sunquakes were first predicted in 1972 by Wolff and are seen at the Sun's surface as circular ripples emanating outward, looking much like those produced as a stone is dropped into to a pond. Room 3.214.