Tag Archives: solar system

First Geologic Map of Jupiter’s Moon Io Details an Otherworldly Volcanic Surface

FLAGSTAFF, Ariz. – More than 400 years after its discovery by Galileo, the innermost large moon of Jupiter – Io – can finally rest on its geologic laurels. A group of scientists led by Dr. David A. Williams of Arizona State University has produced the first global geologic map of the Jovian satellite. The map, which was published by the U. S. Geological Survey, technically illustrates the geologic character of some of the most unique and active volcanoes ever documented in the solar system.

Since its discovery in January 1610, Io has been the focus of repeated observation, first by Earth-based telescopes, and later by fly-by and orbiting spacecraft. These studies depict an otherworldly celestial body whose gravitational relationships with Jupiter and sister moons Europa and Ganymede cause massive, rapid flexing of its surface and interior. This flexing generates tremendous heat in Io’s interior, which is relieved through surface volcanism, resulting in 25 times more volcanic activity than occurs here on Earth. (more…)

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What Do Sunsets Look Like From Other Planets?

A University of Exeter astrophysicist has shown what sunsets look like on planets outside our solar system.

He has worked out the colour of sunsets on two planets: HD 209458 b and HD 189733 b, known as ‘extrasolar planets’ because they are outside our solar system.

Extrasolar planets orbit stars, in a similar way to the Earth orbiting the Sun. Professor Frédéric Pont of the University of Exeter has used the extrasolar planets’ ‘transmission spectrum’, taken by the Hubble Space Telescope, to work out the colour of the ‘sunsets’ created by these stars.

Writing on the website ExoClimes.com, where he has posted the two sunset images he has produced, Professor Pont said: “Unlike its sister planet HD ’189, the planet HD ’209 (‘Osiris’) has a sunset that looks truly alien. The star is white outside the atmosphere, since its temperature is close to that of the Sun. It then acquires a bluish tinge as it sinks deeper, because the absorption by the broad wings of the neutral sodium lines (the spectral lines responsible for the gloomy orange of sodium street lighting) remove the red and orange from the star light. (more…)

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NASA Discovers First Earth-Size Planets Beyond Our Solar System

PASADENA, Calif. — NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet’s surface, but they are the smallest exoplanets ever confirmed around a star like our sun.

The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1,000 light-years away in the constellation Lyra. (more…)

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Meteorite Shockwaves Trigger Dust Avalanches on Mars

Dust avalanches around impact craters on Mars appear to be the result of the shock wave preceding the actual impact, according to a study led by an undergraduate student at the UA.

When a meteorite careens toward the dusty surface of the Red Planet, it kicks up dust and can cause avalanching even before the rock from outer space hits the ground, a research team led by an undergraduate student at the University of Arizona has discovered.

“We expected that some of the streaks of dust that we see on slopes are caused by seismic shaking during impact,” said Kaylan Burleigh, who led the research project. “We were surprised to find that it rather looks like shockwaves in the air trigger the avalanches even before the impact.” (more…)

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Pair of Black Holes ‘Weigh In’ At 10 Billion Suns, The Most Massive Yet

AUSTIN, Texas — A team of astronomers including Karl Gebhardt and graduate student Jeremy Murphy of The University of Texas at Austin have discovered the most massive black holes to date — two monsters weighing as much as 10 billion suns and threatening to consume anything, even light, within a region five times the size of our solar system.

The research is published in the Dec. 8 issue of the journal Nature in a paper headlined by  graduate student Nicholas McConnell and professor Chung-Pei Ma of the University of California, Berkeley. (more…)

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NASA Probe Data Show Liquid Water Evidence on Europa

PASADENA, Calif. — Data from a NASA planetary mission have provided scientists evidence of what appears to be a body of liquid water, equal in volume to the North American Great Lakes, beneath the icy surface of Jupiter’s moon, Europa.

The data suggest there is significant exchange between Europa’s icy shell and the ocean beneath. This information could bolster arguments that Europa’s global subsurface ocean represents a potential habitat for life elsewhere in our solar system. The findings are published in the scientific journal Nature. (more…)

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Voyager 2 Completes Switch to Backup Thruster Set

PASADENA, Calif. — NASA’s Voyager 2 has successfully switched to the backup set of thrusters that controls the roll of the spacecraft. Deep Space Network personnel sent commands to the spacecraft to make the change on Nov. 4 and received confirmation today that the switch has been made.

The change allows engineers to reduce the amount of power that the 34-year-old spacecraft needs to operate by turning off the heater that keeps the fuel to the primary thrusters warm. Although the rate of energy generated by Voyager 2’s nuclear power source continues to decline, by reducing its power requirements, engineers expect the spacecraft can continue to operate for another decade. (more…)

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NASA Says Comet Elenin Gone and Should Be Forgotten

Comet Elenin is no more.

Latest indications are this relatively small comet has broken into even smaller, even less significant, chunks of dust and ice. This trail of piffling particles will remain on the same path as the original comet, completing its unexceptional swing through the inner solar system this fall.

“Elenin did as new comets passing close by the sun do about two percent of the time: It broke apart,” said Don Yeomans of NASA’s Near-Earth Object Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Elenin’s remnants will also act as other broken-up comets act. They will trail along in a debris cloud that will follow a well-understood path out of the inner solar system. After that, we won’t see the scraps of comet Elenin around these parts for almost 12 millennia.” (more…)

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