November 28, 2016

Carnival of Space 485

The Carnival of Space 485 is up at Urban Astronomer

Universe Today - ‘Global Warming Hiatus’ Not Good News For Planet Earth

Universe Today - How Do We Colonize Jupiter’s Moons?

Establishing colonies on the Galilean moons has many potential benefits for humanity. For one, the Jovian system is incredibly rich in terms of volatiles – which include water, carbon dioxide, and ammonia ices – as well as organic molecules. In addition, it is believed that Jupiter’s moons also contain massive amounts of liquid water.

For example, volume estimates placed on Europa’s interior ocean suggest that it may contain as much as 3 × 10^18 m3 – three quadrillion cubic kilometers, or 719.7 trillion cubic miles – of water. This is slightly more than twice the combined volume of all of Earth’s oceans. In addition, colonies on the moons of Jupiter could enable missions to Jupiter itself, where hydrogen and helium-3 could be harvested as nuclear fuel.

Only Callisto is far enough from Jupiter that it is not dominated by its magnetic environment. Here, radiation levels only reach about 0.01 rems per day, just a fraction of what we are exposed to here on Earth. However, its distance from Jupiter means that it experiences its fair share of problems as well (not the least of which is a lack of tidal heating in its interior).



Chandra Xray space telescope blog - Cygnus X-3 and its Little Friend

In 2000, Chandra made an observation of Cygnus X-3 to study its X-ray spectrum, that is, the X-ray intensity measured at different energies. In this observation an X-ray source was found 16 arcseconds away from Cygnus X-3 (this separation is roughly the angular size of a penny observed from the distance of three football fields). Chandra is the only X-ray telescope we have right now that has high enough resolution to see both of these close objects. In 2006, another Chandra observation was made to study its X-ray spectrum during a brighter state and make a more detailed study of the nearby source to Cygnus X-3. We found the source to be extended (not a point source) and that it varied in X-ray intensity with the same 4.8-hour period of Cygnus X-3 (but delayed in time). Because of the location of the feature relative to Cygnus X-3 and the similar variability, we started calling it the "Little Friend".

From an analysis of the Little Friend's X-ray spectrum, variability and intensity we arrived at the conclusion that what we were seeing was an X-ray mirror where the Little Friend is reflecting the X-rays from Cygnus X-3. We are seeing X-ray scattering by dust in a small cloud that is very close to the line-of-sight to Cygnus X-3. The delay in the X-rays gives us the location of the Little Friend relative to Cygnus X-3. Using this information we can deduce the size, density and mass of the Little Friend. From this we concluded that the Little Friend was a small dense cloud called a Bok globule. This represents the first detection of a Bok globule in X-rays



Planetaria - ‘Cracked and tipped over’ Pluto has a subsurface ocean: New evidence from New Horizons


iew of Sputnik Planitia on Pluto. This vast region of nitrogen ice provides clues that a subsurface ocean of liquid water exists on Pluto. Photo Credit: NASA/JHUAPL/SwRI



Nextbigfuture - DARPA is developing robotic support and maintenance of geosynchronous Earth orbit satellites with the Phoenix and GEO programs

The traditional process of designing, developing, building and deploying space systems is long, expensive and complex. These difficulties apply especially to the increasing number of expensive, mission-critical satellites launched every year into geosynchronous Earth orbit (GEO), approximately 22,000 miles above the Earth. Unlike objects in low Earth orbit (LEO), such as the Hubble Space Telescope, satellites in GEO are essentially unreachable with current technology.

DARPA's Phoenix program seeks to change this paradigm and reduce the cost of space-based systems by developing and demonstrating new satellite assembly architectures and delivery systems. Phoenix is currently focusing on two primary technical areas of research

Nextbigfuture - Donald Trump is poised to eliminate all climate change research conducted by Nasa as part of a crackdown on “politicized science”, his senior adviser on issues relating to the space agency has said.

Nasa’s Earth science division is set to be stripped of funding in favor of exploration of deep space, with the president-elect having set a goal during the campaign to explore the entire solar system by the end of the century.

This would mean the elimination of Nasa’s world-renowned research into temperature, ice, clouds and other climate phenomena. Nasa’s network of satellites provide a wealth of information on climate change, with the Earth science division’s budget set to grow to $2 billion next year. By comparison, space exploration has been scaled back somewhat, with a proposed budget of $2.8 billion in 2017.

Nextbigfuture - Frozen beneath a region of cracked and pitted plains on Mars lies about as much water as what's in Lake Superior, largest of the Great Lakes, researchers using NASA's Mars Reconnaissance Orbiter have determined.

Scientists examined part of Mars' Utopia Planitia region, in the mid-northern latitudes, with the orbiter's ground-penetrating Shallow Radar (SHARAD) instrument. Analyses of data from more than 600 overhead passes with the onboard radar instrument reveal a deposit more extensive in area than the state of New Mexico. The deposit ranges in thickness from about 260 feet (80 meters) to about 560 feet (170 meters), with a composition that's 50 to 85 percent water ice, mixed with dust or larger rocky particles.

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