galaxyscope

Though the galaxy is 11.6 million light-years away, the vision of the NASA/ESA Hubble Space Telescope is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas.

The spiral arms, which wind all the way down into the nucleus, are made up of young, bluish, hot stars formed in the past few million years. They also host a population of stars formed in an episode of star formation that started about 600 million years ago.

The galaxy’s central bulge -significantly larger than the Milky Way's- contains much older, redder stars. The central black hole is 70 million solar masses, or 15 times the mass of the Milky Way's black hole.

Source:
http://www.innovations-report.com/html/reports/physics_astronomy/report-84944.html

Humans might not be walking the face of the Earth were it not for the ancient fusing of two prokaryotes — tiny life forms that do not have a cellular nucleus. Endosymbiosis refers to a cell living within another cell. If the cells live together long enough, they will exchange genes; they merge but often keep their own cell membranes and sometimes their own genomes.

"We have been overlooking how important cooperation is," UCLA molecular biologist James A. Lake said. "If two prokaryotes get together, they can change the world. They restructured the atmosphere of the Earth. It's a message that evolution is giving us: Cooperation is a way to get ahead."

Lake discovered the first exclusively prokaryote endosymbiosis. All other known endosymbioses have involved a eukaryote — a cell that contains a nucleus. Eukaryotes are found in all multicellular forms of life, including humans, animals and plants.

"This relationship resulted in a totally different type of life on Earth," said Lake, a UCLA distinguished professor of molecular, cell and developmental biology and of human genetics. "We thought eukaryotes always needed to be present to do it, but we were wrong."

Lake reported that two groups of prokaryotes — actinobacteria and clostridia — came together and produced "double-membrane" prokaryotes.

"Higher life would not have happened without this event," Lake said. "These are very important organisms. At the time these two early prokaryotes were evolving, there was no oxygen in the Earth's atmosphere. Humans could not live. No oxygen-breathing organisms could live."

The oxygen on the Earth is the result of a subgroup of these double-membrane prokaryotes, Lake said. This subgroup, the cyanobacteria, used the sun's energy to produce oxygen through photosynthesis. They have been tremendously productive, pumping oxygen into the atmosphere; we could not breathe without them. In addition, the double-membrane prokaryotic fusion supplied the mitochondria that are present in every human cell, he said.

"This work is a major advance in our understanding of how a group of organisms came to be that learned to harness the sun and then effected the greatest environmental change the Earth has ever seen, in this case with beneficial results," said Carl Pilcher, director of the NASA Astrobiology Institute, headquartered at the NASA Ames Research Center in Moffett Field, Calif., which co-funded the study with the National Science Foundation.

"Along came these organisms — the double-membrane prokaryotes — that could use sunlight," Lake said. "They captured this vast energy resource. They were so successful that they have more genetic diversity in them than all other prokaryotes.

"We have a flow of genes from two different organisms, clostridia and actinobacteria, together," he said. "Because the group into which they are flowing has two membranes, we hypothesize that that was an endosymbiosis that resulted in a double membrane. It looks as if a single-membrane organism has engulfed another. The genomes are telling us that the double-membrane prokaryotes combine sets of genes from the two different organisms."

For this study whuch will be published in Nature, Lake has looked back more than 2.5 billion years. He conducted an analysis of the genomics of the five groups of prokaryotes.

Posted by Casey Kazan

Source: University of California - Los Angeles

NASA is looking at bringing nuclear power to other planets.  It's an intelligent option, perfectly suited to off-world exploration, and is being rigorously tested - so look forward to headlines screaming "NASA NUKING SPACE SHOCKER OUTRAGE!"

The thing to remember is NASA aren't idiots - they are literally an organization of rocket scientists, and nuclear power is an excellent option for offworld energy.  The technology is well known, it's the most power bang per fuel mass buck available, and the small size and off-world nature of any space reactors means that's the only "bang" there could actually be.  And in case you haven't noticed, off-world exploration is the most incredible and envelope-pushing mission mankind is capable of.  It would be imbecilic to rule anything out.

The system works off a Stirling engine, one of the original heat engines (built as a rival to steam designs) which operates off the difference between a hot and cold location.  The small nuclear fission pile provides the heat, conducted by liquid metal, and the cold is conveniently provided by being in space - or at the very least, being on a planet that's not as hot as nuclear reactions.  The liquid metal is a sodium potassium mixture, and yes, this does mean that NASA are not only cooler than the T1000 but are actually using it to do work.

The system still needs a radiator, a forty-by-sixty meter cooling fin which will get rid of excess heat.  It's important to remember that a heat engine doesn't convert hot into electricity - "hot" isn't actually a thing, and the point of the nuclear power is to provide a constant high temperature region.  If you let the temperature get to high you'll run into all sorts of awful melting things, especially in space - it's extremely capable of cold, but there's no conduction or convection, so it's extremely easy to overheat if you don't work to radiate.

Solar power is perfect for some space applications but not everything we want to do lives in the light (or can afford the weight of batteries to store excess power for night-side operations). Until we come up with something better, nuclear power is our only option if we don't want to become reverse-vampires who have to hide in the sunshine.  The Fission Surface Power (FSP) project has tested all the parts of this power source individually and is gearing up for full scale trials in 2014.

But don't let little things like logic, strict controls, or rigorous testing of proven hardware distract you.  Look forward to lunacy as soon as news of nuclear hits the anti-everything crowd, and use it to discriminate between intelligent environmental activists and those who hear buzzwords and start screaming.  Nuclear weaponry is undeniably the scariest thing we've ever achieved, and power plants need the very strictest of standards, it's true - but surely even if you hate nuclear material you'd be in favor of getting it off the planet?

A Lunar Nuclear Reactor http://www.technologyreview.com/energy/23247/

Fission Surface Power http://www.grc.nasa.gov/WWW/TECB/fsp.htm