Early Tidal and Rotational Forces Helped Shape Moon

by Shannon Hall on July 30, 2014

Using a precision formation-flying technique, the twin GRAIL spacecraft will map the moon's gravity field, as depicted in this artist's rendering. Radio signals traveling between the two spacecraft provide scientists the exact measurements required as well as flow of information not interrupted when the spacecraft are at the lunar farside, not seen from Earth. The result should be the most accurate gravity map of the moon ever made. The mission also will answer longstanding questions about Earth's moon, including the size of a possible inner core, and it should provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed. GRAIL is a part of NASA's Discovery Program. Image credit: NASA/JPL-Caltech

An artist’s conception of how the twin GRAIL spacecraft map the moon’s gravity field. Image credit: NASA / JPL-Caltech

The shape of the moon deviates from a simple sphere in a way that scientists have struggled to explain. But new research shows that tidal forces during the moon’s early history can explain most of its large-scale topography. As the moon cooled and solidified more than four billion years ago, the sculpting effects of tidal and rotational forces became frozen in place. [click to continue…]

Mysterious Molecules in Space Named?

by Shannon Hall on July 30, 2014

The diffuse interstellar bands. Image Credit: P. Jenniskens, F. X. Desert

The diffuse interstellar bands. Image Credit: P. Jenniskens, F. X. Desert

It’s a well-kept secret that the vacuum of space is not — technically speaking — a vacuum. Strong winds generated from supernova explosions push material into the interstellar medium, tainting space with the heavier elements generated by nuclear fusion. These lonely molecules account for a significant amount of all the hydrogen, carbon, silicon, and other atoms in the Universe.

Although these molecules remain mysterious, since we don’t know their exact chemical composition or atomic arrangements, they’re likely the cause of diffuse interstellar bands: unknown fingerprints within the spectra of distant astronomical objects.

New research, however, offers a tantalizing new possibility: these mysterious molecules may be silicon hydrocarbons. [click to continue…]

ALMA Observes Binary Star System with Wacky Disks

by Shannon Hall on July 30, 2014

ALMA data of HK Tau shown in a composite image with Hubble infrared and optical data. Credit: B. Saxton (NRAO/AUI/NSF); K. Stapelfeldt et al. (NASA/ESA Hubble)

ALMA data of HK Tau shown in a composite image with Hubble infrared and optical data. Image Credit: B. Saxton / K. Stapelfeldt et al. / NASA / ESA

When it comes to exoplanets, we’ve discovered an array of extremes — alien worlds that seem more like science fiction than reality. But there are few environments more extreme than a binary star system in which planet formation can occur. Powerful gravitational perturbations from the two stars can easily grind a planet to dust, let alone prevent it from forming in the first place.

A new study has uncovered a striking pair of wildly misaligned planet-forming disks in the young binary star system HK Tau. It’s the clearest picture ever of protoplanetary disks around a double star, shedding light on the birth and eventual orbit of the planets in a multiple star system.

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The last of Europe’s five automated transfer vehicles made a flawless launch to orbit yesterday (July 30). So far, all is going well with ATV Georges Lemaître as it brings a load of cargo to the International Space Station. You can watch the launch above. The ship is not only acting as a freighter, but a testbed for technology to help with docking and re-entry.

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Astronaut Mike Massimino on a spacewalk during shuttle mission STS-109 in March 2002. Credit: NASA

Astronaut Mike Massimino on a spacewalk during shuttle mission STS-109 in March 2002. Credit: NASA

The first astronaut who tweeted from space is leaving NASA, the agency announced yesterday. Mike Massimino (best known to his 1.29 million followers as @astro_mike) — and also one of several astronauts to repair the Hubble Space Telescope — will now bring his skills to a full-time position with Columbia University in New York.

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