Tag Archives: solar system

Comet to Make Close Flyby of Red Planet in October 2014

Comet 2013 A1 (Siding Spring) will make a very close approach to Mars in October 2014.

The latest trajectory of comet 2013 A1 (Siding Spring) generated by the Near-Earth Object Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., indicates the comet will pass within 186,000 miles (300,000 kilometers) of Mars and there is a strong possibility that it might pass much closer. The NEO Program Office’s current estimate based on observations through March 1, 2013, has it passing about 31,000 miles (50,000 kilometers) from the Red Planet’s surface. That distance is about two-and-a-half times that of the orbit of outermost moon, Deimos.

Scientists generated the trajectory for comet Siding Spring based on the data obtained by observations since October 2012. Further refinement to its orbit is expected as more observational data is obtained. At present, Mars lies within the range of possible paths for the comet and the possibility of an impact cannot be excluded. However, since the impact probability is currently less than one in 600, future observations are expected to provide data that will completely rule out a Mars impact. (more…)

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Cassini Spies Bright Venus from Saturn Orbit

PASADENA, Calif. – A distant world gleaming in sunlight, Earth’s twin planet, Venus, shines like a bright beacon in images taken by NASA’s Cassini spacecraft in orbit around Saturn.

One special image of Venus and Saturn was taken last November when Cassini was placed in the shadow of Saturn. This allowed Cassini to look in the direction of the sun and Venus, and take a backlit image of Saturn and its rings in a particular viewing geometry called “high solar phase.” This observing position reveals details about the rings and Saturn’s atmosphere that cannot be seen in lower solar phase. (more…)

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Life Possible on Extrasolar Moons

In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets.

The research, conducted by Rory Barnes of the University of Washington and the NASA Astrobiology Institute and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam, will appear in the January issue of Astrobiology. Heller is lead author of the paper. (more…)

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Exploding Star Missing From Formation of Solar System

A new study published by University of Chicago researchers challenges the notion that the force of an exploding star prompted the formation of the solar system.

In this study, published online last month in Earth and Planetary Science Letters, authors Haolan Tang and Nicolas Dauphas found the radioactive isotope iron 60 — the telltale sign of an exploding star—low in abundance and well mixed in solar system material. As cosmochemists, they look for remnants of stellar explosions in meteorites to help determine the conditions under which the solar system formed. (more…)

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NASA’s GRAIL Creates Most Accurate Moon Gravity Map

PASADENA, Calif. — Twin NASA probes orbiting Earth’s moon have generated the highest resolution gravity field map of any celestial body.

The new map, created by the Gravity Recovery and Interior Laboratory (GRAIL) mission, is allowing scientists to learn about the moon’s internal structure and composition in unprecedented detail. Data from the two washing machine-sized spacecraft also will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

The gravity field map reveals an abundance of features never before seen in detail, such as tectonic structures, volcanic landforms, basin rings, crater central peaks and numerous simple, bowl-shaped craters. Data also show the moon’s gravity field is unlike that of any terrestrial planet in our solar system. (more…)

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UCLA Researchers Find Evidence for Water Ice Deposits and Organic Material on Mercury

Planetary scientists have identified water ice and unusually dark deposits within permanently shadowed areas at Mercury’s north pole.

Using data collected by NASA’s MESSENGER spacecraft, a team from UCLA crafted the first accurate thermal model of the solar system’s innermost planet, successfully pinpointing the extremely cold regions where ice has been found on or below the surface.

The researchers say the newly discovered black deposits are a thin crust of residual organic material brought to the planet over the past several million years through impacts by water-rich asteroids and comets. (more…)

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NASA Observations Point to ‘Dry Ice’ Snowfall on Mars

PASADENA, Calif. — NASA’s Mars Reconnaissance Orbiter data have given scientists the clearest evidence yet of carbon-dioxide snowfalls on Mars. This reveals the only known example of carbon-dioxide snow falling anywhere in our solar system.

Frozen carbon dioxide, better known as “dry ice,” requires temperatures of about minus 193 degrees Fahrenheit (minus 125 Celsius), which is much colder than needed for freezing water. Carbon-dioxide snow reminds scientists that although some parts of Mars may look quite Earth-like, the Red Planet is very different. The report is being published in the Journal of Geophysical Research. (more…)

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NASA, Texas Astronomers Find First Multi-Planet System Around a Binary Star

FORT DAVIS, Texas — NASA’s Kepler mission has found the first multi-planet solar system orbiting a binary star, characterized in large part by University of Texas at Austin astronomers using two telescopes at the university’s McDonald Observatory in West Texas. The finding, which proves that whole planetary systems can form in a disk around a binary star, is published in today’s issue of the journal Science.

“It’s Tatooine, right?” said McDonald Observatory astronomer Michael Endl. “But this was not shown in Star Wars,” he said, referring to the periodic changes in the amount of daylight falling on a planet with two suns. Measurements of the star’s orbits showed that daylight on the planets would vary by a large margin over the 7.4-Earth-day period as the two stars completed their mutual orbits, each moving closer to, then farther from, the planets (which are themselves moving). (more…)

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