Four-image mosaic comprising images taken by Rosetta’s navigation camera from a distance of 9.8 km from the centre of comet 67P/C-G – about 7.8 km from the surface. The corresponding image scale is about 66 cm/pixel, and the mosaic covers roughly 1200 x 1350 metres.
Four-image montage comprises images taken by Rosetta’s navigation camera from a distance of 9.8 km from the centre of comet 67P/C-G – about 7.8 km from the surface. The corresponding image scale is about 66 cm/pixel, so each 1024 x 1024 pixel frame is about 676 m across. In this orientation the larger lobe occupies the upper frames, with the neck filling the lower frames. The smaller lobe of the comet is out of view towards the right.
For the first time, researchers using ALMA have detected a streamer of gas flowing from a massive outer disc toward the inner reaches of a binary star system. This never-before-seen feature may be responsible for sustaining a second, smaller disc of planet-forming material that otherwise would have disappeared long ago. Half of Sun-like stars are born in binary systems, meaning that these findings will have major consequences for the hunt for exoplanets. The results are published in the journal Nature on 30 October 2014.
This artist’s impression shows the dust and gas around the double star system GG Tauri-A. Researchers using ALMA have detected gas in the region between two discs in this binary system. This may allow planets to form in the gravitationally perturbed environment of the binary. Half of Sun-like stars are born in binary systems, meaning that these findings will have major consequences for the hunt for exoplanets.
Like a wheel in a wheel, GG Tau-A contains a large, outer disc encircling the entire system as well as an inner disc around the main central star. This second inner disc has a mass roughly equivalent to that of Jupiter. Its presence has been an intriguing mystery for astronomers since it is losing material to its central star at a rate that should have depleted it long ago.
While observing these structures with ALMA, the team made the exciting discovery of gas clumps in the region between the two discs. The new observations suggest that material is being transferred from the outer to the inner disc, creating a sustaining lifeline between the two .
“Material flowing through the cavity was predicted by computer simulations but has not been imaged before. Detecting these clumps indicates that material is moving between the discs, allowing one to feed off the other,” explains Dutrey. “These observations demonstrate that material from the outer disc can sustain the inner disc for a long time. This has major consequences for potential planet formation.”
Planets are born from the material left over from star birth. This is a slow process, meaning that an enduring disc is a prerequisite for planet formation. If the feeding process into the inner disc now seen with ALMA occurs in other multiple-star systems the findings introduce a vast number of new potential locations to find exoplanets in the future.
The first phase of exoplanet searches was directed at single-host stars like the Sun . More recently it has been shown that a large fraction of giant planets orbit binary-star systems. Now, researchers have begun to take an even closer look and investigate the possibility of planets orbiting the individual stars of multiple-star systems. The new discovery supports the possible existence of such planets, giving exoplanet discoverers new happy hunting grounds.
Emmanuel Di Folco, co-author of the paper, concludes:
“Almost half the Sun-like stars were born in binary systems. This means that we have found a mechanism to sustain planet formation that applies to a significant number of stars in the Milky Way. Our observations are a big step forward in truly understanding planet formation.”
This wide-field view shows the sky around the young multiple star system GG Tauri, which appears very close to the centre of this picture. This view also shows a dust cloud and evidence of star formation near the top of the picture. This, like GG Tauri itself, is part of the Taurus Dark Cloud complex, one of the closest star-forming regions to Earth. Credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin
An announcement about the High Frontier space settlement simuator:
New Video Game Blends Science, Fun
FORT COLLINS, Colo. – Oct. 27, 2014 – A small family business launched a KickStarter campaign today for a space settlement simulation game. The game, called “High Frontier“, allows the player to design their own free-floating orbital colony. Players will then be able to go “inside” their colony, and manage the city in detail.
The game is being developed by Strout and Sons, a small company based in Fort Collins, Colorado (USA). Joe Strout, the lead developer, has previously coauthored two scientific papers on real space settlement designs. That experience is now being applied to the new video game, which features a custom physics engine to accurately simulate how large rotating bodies behave in space. Other parts of the simulation cover energy balance and population dynamics.
“High Frontier is already the most accurate, detailed space colony simulator ever made,” Strout said in a statement Monday. Work on the game has led to several relevant scientific insights, including the realization that inverted endcaps (like the bottom of a soda can) improve the stability of cylindrical space colonies, and recognition of the advantages of building early space colonies in low-Earth orbit.
“The idea of orbital space colonies has been around since the 1970s,” Strout explains, “but hasn’t received much attention in recent years. With High Frontier, we hope to change that.”
High Frontier has been following the incremental release model popularized by such games as Minecraft and Kerbal Space Program. The team has released ten versions so far, completing the “design” and “build” phases of the game. The third phase of the game, managing the colony, is still in progress; so far only an external view is available. To support the internal city-management view, the company has launched a KickStarter campaign (www.kickstarter.com/projects/1045364912/high-frontier). The team hopes to raise $10,000, which will be used primarily to fund custom artwork for the city simulation.
“We hope this game will help people realize the vast potential of the solar system,” Strout says. “High Frontier is designed to both entertain and inspire.”
The KickStarter campaign continues until November 26.