This artist’s concept shows a possible model of Titan’s internal structure that incorporates data from NASA’s Cassini spacecraft. In this model, Titan is fully differentiated, which means the denser core of the moon has separated from its outer parts. This model proposes a core consisting entirely of water-bearing rocks and a subsurface ocean of liquid water. The mantle, in this image, is made of icy layers, one that is a layer of high-pressure ice closer to the core and an outer ice shell on top of the sub-surface ocean.
A model of Cassini is shown making a targeted flyby over Titan’s cloudtops, with Saturn and Enceladus appearing at upper right.
The model, developed by Dominic Fortes of University College London, England, incorporates data from Cassini’s radio science experiment.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at Wellesley College, Wellesley, Mass.
The close proximity of COROT-7b to its star (just 1.6 million miles) keeps it gravitationally locked in place just as the moon is to the Earth, meaning the same side of always faces the star. As such, it stays very, very hot there (about 4,220 degrees Fahrenheit). That kind of heat vaporizes rocks, and that’s exactly what happens on COROT-7b. Using computer modeling, the team at Washington ran through four different scenarios with four different starting compositions (since the exact makeup of the planet is unknown) with the same result each time.
Just as water vaporizes in our atmosphere only to condense at higher, cooler altitudes and fall back to the Earth as rain, so do the sodium, potassium, silicon monoxide, magnesium, aluminum, calcium and iron of COROT-7b. When they condense, however, they condense into rock clouds that rain little pebbles of different types of rocks. What’s more, the type of rock is dependent on altitude. The atmosphere gets colder the higher up the rock vapor goes. Since each rock or mineral has a different boiling point, the materials with the highest boiling points will condense out at lower altitudes, while the ones with lower boiling points can rise higher as vapor before condensing back into rocks.
Uranus, photographed by the Hubble Space Telescope through various filters. Of note is what appears to be a cloud centre-right; Uranus looked almost completely featureless in Voyager’s pictures, but at least at some wavelengths, there is something going on in the atmosphere. The rings are also clearly visible in the last few frames (892nm methane filter). Assuming I made no interpretational blunders with HORIZONS data, Miranda is the small moon at the bottom of the frame, and Ariel is near the top.
Last week, this Tumblr went on a Hubble binge. This week: Keck! (Yes, in a desperate bid to keep the daily updates going, I’ve started using ground-based observations.) We start with Jupiter, seen from the Keck Observatory at Mauna Kea in Hawaii on 4 June 2010, at wavelengths of 1.95-2.3 microns (i.e., infrared). The gif covers about 30 minutes of real time. (Program ID C304N2L.)
Plants under the confocal microsope:Seeing is believing.
The last twenty years have seen a revolution in the application of optical techniques to the study of biological systems. Largely due to the development of highly specific fluorescent labelling methods, and optical techniques such as confocal laser scanning microscopy.
Different coloured fluorescent proteins are used routinely to decorate cells and subcellular structures in living tissues, and optical sectioning techniques allow visualisation of these labels.Meaning we can observe the different parts of any tissue and watch their movements.
1) An algae from the genus Cosmarium at 100x magnification, 2) the visual system of a pupal fruit fly at 1500x magnification showing the retina (brown), photoreceptors (blue), and brain (green),and 3) a bone cancer cell at 63x magnification showing protein filaments (purple), mitochondria (yellow), and DNA (blue).
The latest analysis of data from the Kepler planet-hunting spacecraft reveals that almost all stars have planets, and about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury. Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there, according to Francois Fressin of the Harvard-Smithsonian Center for Astrophysics (CfA), who presented new findings today in a press conference at the American Astronomical Society meeting in Long Beach, California. Moreover, he said, almost all Sun-like stars have planetary systems.
The holy grail of planet-hunting is finding a twin of Earth – a planet of about the same size and in the habitable zone around similar star. The odds of finding such a planet is becoming more likely Fressin said, as the latest analysis shows that small planets are equally common around small and large stars.
While the list of Kepler planetary candidates contains majority of the knowledge we have about exoplanets, Fressin said the catalog is not yet complete, and the catalog is not pure. “There are false positives from events such as eclipsing binaries and other astrophysical configurations that can mimic planet signals,” Fressin said.
By doing a simulation of the Kepler survey and focusing on the false positives, they can only account for 9.5% of the huge number of Kepler candidates. The rest are bona-fide planets.
Each star in the Milky Way shines its light upon at least one companion planet, according to a new analysis that suddenly renders exoplanets commonplace, the rule rather than the exception. This means there are billions of worlds just in our corner of the cosmos. This is a major shift from just a few years ago, when many scientists thought planets were tricky to make, and therefore special things. Now we know they’re more common than stars themselves.
“Planets are like bunnies; you don’t just get one, you get a bunch,” said Seth Shostak, a senior astronomer at the SETI Institute who was not involved in this research. “So really, the number of planets in the Milky Way is probably like five or 10 times the number of stars. That’s something like a trillion planets.”
Of course there’s no way to know, at least not yet, how many of these worlds could be hospitable to forms of life as we know it. But the odds alone are tantalizing, Shostak said.
“It’s not unreasonable at this point to say there are literally billions of habitable worlds in our galaxy, probably as a lower limit,” he said. “Maybe they’re all sterile as an autoclave, but it doesn’t seem very likely, does it? That would make us very odd.”
Other astronomers maintain that we are odd indeed, and that increasing the known planet population does not increase the odds of finding intelligent life on any of them.
“The numbers are huge by any human standard, but we are still looking at only a tiny bit of our galaxy,” said John Gribbin, an astronomer and science writer who just published a book called “Alone in the Universe.” “[This research] does further our understanding of how things like planets form and how stars form, but there is a long way to go before we can say there is life on any of these planets, and further to go before we get to civilization.”
Image 2 |A Plethora of Planets:This artist’s impression shows how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using a technique called microlensing concluded that every star has at least one planet orbiting around it. ESO/M. Kornmesser
Image 3 | A new analysis examined the frequencies of planets of different sizes based on findings from NASA’s Kepler spacecraft, correcting for both incompleteness and false positives. The results show that one in six stars has an Earth-sized planet in a tight orbit. Credit: F. Fressin (CfA)
Image 4 | This artist’s illustration represents the variety of planets being detected by NASA’s Kepler spacecraft. Credit: C. Pulliam & D. Aguilar (CfA)