Disturbance in Saturn’s outermost ring
Cool image time! The picture below, taken by Cassini in April, looks down at Saturn’s vast rings and shows a disruption in Saturn’s outermost F ring, likely caused by an interaction of objects within the ring.
Tag: science
Pluto’s jagged shores
Cool image time! The picture on the right, taken by New Horizons during its July 2015 flyby and cropped and reduced here, shows the reddish hues of the Krun Macula dark region along the shore of Pluto’s vast nitrogen ice plains. The hillsides here rise about a mile and a half above both the plains and the valleys, making them deeper than the Grand Canyon. The hills are “believed to get its dark red color from tholins, complex molecules found across Pluto.”
Mars’ seasonal dust storms
Data from the many Martian orbiters since 1997 have allowed scientists to roughly outline a seasonal pattern of dust storms on Mars.
Most Martian dust storms are localized, smaller than about 1,200 miles (about 2,000 kilometers) across and dissipating within a few days. Some become regional, affecting up to a third of the planet and persisting up to three weeks. A few encircle Mars, covering the southern hemisphere but not the whole planet. Twice since 1997, global dust storms have fully enshrouded Mars. The behavior of large regional dust storms in Martian years that include global dust storms is currently unclear, and years with a global storm were not included in the new analysis.
They have also found three types of regional dust storms, all of which appear to occur each Martian year.
A sunspot returns to the Sun
After four blank days without sunspots, the longest such string since 2010 during the middle of the solar minimum, the Sun got a new sunspot today.
Four new names proposed for periodic table
Scientists in Russia, Japan, and the United States have proposed four new names for the elements they helped discover.
The periodic table will soon have four new names added to its lower right-hand corner. Element 113 should be named nihonium (Nh); element 115 moscovium (Mv); element 117 tennessine (Tc) and element 118 oganesson (Og), according to proposals outlined on 8 June by chemistry’s governing body, the International Union of Pure and Applied Chemistry (IUPAC).
The laboratories who were credited with the discovery of the elements – in Russia, the United States and Japan – got to propose the names under the constraint that elements can only be named after one of their chemical or physical properties, a mythological concept, a mineral, a place or country, or a scientist.
The last choice, oganesson, is only the second element named after a living person. It will one of a more than a dozen elements named after individuals, overall.
The post originally said that ogranesson was only the second named after a person. My readers noted that many elements had been named for people, which implied the article was wrong. In truth, I was wrong. The article was more specific and correct, noting that this was only the second element to be named for a living person, as the editor of Nature wrote to explain. I have thus corrected the post, and noted my error here.
National Science Foundation considers shuttering Arecibo
Faced with tight budgets, the National Science Foundation (NSF) is considering several options for the future operation of the Arecibo Observatory, the world’s largest single radio telescope dish, including its complete removal.
[T]he NSF could mothball the site, shutting it down in such a way that it could restart (sometime in the future). Or it could dismantle the telescope altogether and restore the area to its natural state, as required by law if the agency fully divests itself of the observatory and closes it. Previous studies have said such a process could cost around $100 million—more than a decade’s worth of its current funding for telescope operations. Jim Ulvestad, director of the NSF Division of Astronomical Sciences, says the agency is still investigating, not concluding. “No alternative has been selected at this juncture,” he says. And much consideration will go into the final financial decision, whatever it may be. Some outside the agency see writing on the wall. “NSF is dead serious about offloading Arecibo funding to someone else—anyone else,” says Ellen Howell, a former staff scientist at Arecibo and now a faculty member at the Lunar and Planetary Laboratory (LPL) in Tucson, Arizona.
The article spends a lot of time talking about how wonderful Arecibo is, but never tells us how many astronomers actually demand to use it. Is it oversubscribed, like Hubble, where five times the number of astronomers request time than can be handled, or does it often sit unused because not enough astronomers require its use? NSF and the government do not have unlimited funds, and need to focus their spending where the demand is. If Arecibo is not in demand, then they are wise to consider closing it, or handing it off to someone who wants it.
LISA Pathfinder proves space-based gravity wave detection technology
Engineers have announced that the gravity wave detection technology being tested in orbit by Europe’s LISA Pathfinder works.
To show that the necessary sensitivity is possible, LISA Pathfinder measures the distance between two masses, both of which are inside the spacecraft. “We’ve shrunk the arm of a large gravitational wave antenna to 35 centimeters so we could show it works properly,” Paul McNamara, LISA Pathfinder project scientist, told the press conference.
LISA Pathfinder was launched in December 2015 to a spot 1.5 million kilometers from Earth. When its test masses where first released to float free in February, “the relief was unbelievable,” McNamara says. Science operations began on 1 March and on that first day the team was able to measure distance variations between the masses much smaller than LISA Pathfinder’s mission requirements, Stefano Vitale, the mission’s principle investigator, told reporters. After a month, the variations were even smaller, “very close to [eLISA] requirements,” he says.
They now hope to launch an array of at least three such spacecraft by the mid-2030s.
Sunspot cycle update
NOAA today released its monthly update of the solar cycle, showing the Sun’s sunspot activity in May. It is annotated and posted below.
The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.
Though sunspot activity increased in May, the increase was not significant. The ramp down from solar maximum continues to track the 2007 low prediction for this maximum.
Meanwhile, the Sun continues its first multi-day string of blank days since 2011, now up to 3 days with all indications suggesting it will continue at least one more day. This early blank string, combined with the relatively fast decline in sunspots in the past two years, suggests that the solar maximum is ending sooner than predicted by the 2009 prediction (the red curve above), and that the next minimum will possibly be longer as well.
Titan over Saturn’s rings
Cool image time! The picture on the right, taken on January 26, 2016 by Cassini and reduced and cropped to show here, captures Titan above Saturn’s rings, which are themselves partly obscured by the shadow of Saturn (unseen on the right) that falls across them.
Make sure you go to look at the full image. This is the kind of vista that artists in the 1950s imagined we’d see once we began to explore the solar system.
No sunspots for two days
For the first time since the beginning of solar maximum in 2011, the Sun has been blank of sunspots for two consecutive days.
As there continue to be no signs of any sunspots, this string could continue for several more days, which would then be the longest blank stretch since 2010, when we were in the tail end of the last very prolonged solar minimum.
No sunspots for the first time in two years
For the first time since July 17, 2014, and only the second time since 2011 at the beginning of the solar maximum, the Sun was blank today, with no sunspots visible on its surface.
I expect the next monthly update of the solar cycle will arrive early next week, and though I expect it will show a slight increase during the past month, it will also show that the ramp down to solar minimum is continuing unabated.
The Rosetta science team wants your help!
The scientists running Rosetta are asking the public to help them pour through the more than 20,000 images of Comet 67P/C-G to identify any changes the comet has undergone since the spacecraft’s arrival.
A faster Hubble constant?
The uncertainty of science: New data from the Hubble Space Telescope suggests the universe’s expansion rate is 5%-9% faster than previously thought.
They say they have refined the expansion rate to a margin of error of only 2.4%, but forgive me if I remain skeptical. When it comes to cosmology, the uncertainties dominate, despite these claims.
California moves to ban climate dissent
Climate fascists: The California legislature is considering a bill that would make it illegal to express skepticism about human-caused global warming.
The bill declares that there is no legitimate disagreement on the causes and extent of climate change, stating that, “There is broad scientific consensus that anthropogenic global warming is occurring and changing the world’s climate patterns, and that the primary cause is the emission of greenhouse gases from the production and combustion of fossil fuels, such as coal, oil, and natural gas.”
What I find frightening about this is that the liberal Democrats who are writing and pushing this bill, with the full support of numerous liberal environmentalist groups, no longer feel the slightest shame about their oppressive and tyrannical preferences. They are now out in the open, suggesting that they sense a wide support for their actions. I fear that they are right.
Pluto: the world’s largest lava lamp
In comparing the New Horizons’ data with computer simulations, scientists have determined that the frozen nitrogen in the heart-shaped Sputnik Planum region rises and sinks as the nitrogen is heated from below.
McKinnon and colleagues believe the pattern of these cells stems from the slow thermal convection of the nitrogen-dominated ices that fill Sputnik Planum. A reservoir that’s likely several miles deep in some places, the solid nitrogen is warmed by Pluto’s modest internal heat, becomes buoyant and rises up in great blobs – like a lava lamp – before cooling off and sinking again to renew the cycle. The computer models show that ice need only be a few miles deep for this process to occur, and that the convection cells are very broad. The models also show that these blobs of overturning solid nitrogen can slowly evolve and merge over millions of years. Ridges that mark where cooled nitrogen ice sinks back down can be pinched off and abandoned, resulting in Y- or X-shaped features in junctions where three or four convection cells once met.
New data challenges consensus on galaxy formation
The uncertainty of science: A new study has found that the accepted consensus for the formation of large elliptical galaxies does not work, and that, rather than forming from the merger of smaller spiral galaxies, ellipticals formed in place from the material at hand.
From the press release [pdf].
“We started from the data, available in complete form only for the closer galaxies and in incomplete form for the more distant ones, and we filled the ‘gaps’ by interpreting and extending the data based on a scenario we devised” comments Mancuso. The analysis also took into account the phenomenon of gravitational lensing, which allows us to observe very distant galaxies belonging to ancient cosmic epochs.
In this “direct” manner (i.e., model-independent) the SISSA group obtained an image of the evolution of galaxies even in very ancient epochs (close, in a cosmic timescale, to the epoch of reionization). This reconstruction demonstrates that elliptical galaxies cannot have formed through the merging of other galaxies, “simply because there wasn’t enough time to accumulate the large quantity of stars seen in these galaxies through these processes”, comments Mancuso. “This means that the formation of elliptical galaxies occurs through internal, in situ processes of star formation.
The important take-away of this result is that it shows that the present theory of galaxy formation, where smaller spiral galaxies merge to form larger elliptical galaxies, does not fit the data. And if a theory does not fit the data, it must be abandoned.
Rosetta almost lost during weekend
Because Rosetta’s star tracker became confused by dust particles, the spacecraft lost contact with Earth, went into safe mode, and required the entire weekend for engineers to regain control.
“We lost contact with the spacecraft on Saturday evening for nearly 24 hours,” says Patrick Martin, ESA’s Rosetta mission manager. “Preliminary analysis by our flight dynamics team suggests that the star trackers locked on to a false star – that is, they were confused by comet dust close to the comet, as has been experienced before in the mission.” This led to spacecraft pointing errors, which triggered the safe mode. Unfortunately the star trackers then got hung in a particular sub mode requiring specific action from Earth to recover the spacecraft.
“It was an extremely dramatic weekend,” says Sylvain Lodiot, ESA’s Rosetta spacecraft operations manager.”
The spacecraft has been diving to within only a few miles of the surface of Comet 67P/C-G, which means it is flying close to the comet’s coma. The increased dust in that region has confused the star tracker in the past, but this appears to have been the most serious event yet.
Rosetta finds organic compounds at Comet 67P/C-G
Rosetta’s scientists have detected the amino acid glycine as well as other organic molecules in the atmosphere of Comet 67P/C-G.
Glycine is very hard to detect due to its non-reactive nature: it sublimates at slightly below 150°C, meaning that little is released as gas from the comet’s surface or subsurface due to its cold temperatures. “We see a strong correlation of glycine to dust, suggesting that it is probably released from the grains’ icy mantles once they have warmed up in the coma, perhaps together with other volatiles,” says Altwegg. At the same time, the researchers also detected the organic molecules methylamine and ethylamine, which are precursors to forming glycine. Unlike other amino acids, glycine is the only one that has been shown to be able to form without liquid water. “The simultaneous presence of methylamine and ethylamine, and the correlation between dust and glycine, also hints at how the glycine was formed”, says Altwegg.
New Horizons’ best Pluto close-up
The New Horizons science team has released the highest resolution image across Pluto’s face, taken by the spacecraft during its flyby last year.
This mosaic strip, extending across the hemisphere that faced the New Horizons spacecraft as it flew past Pluto on July 14, 2015, now includes all of the highest-resolution images taken by the NASA probe. With a resolution of about 260 feet (80 meters) per pixel, the mosaic affords New Horizons scientists and the public the best opportunity to examine the fine details of the various types of terrain the mosaic covers, and determine the processes that formed and shaped them.
The view extends from the “limb” of Pluto at the top of the strip, almost to the “terminator” (or day/night line) in the southeast of the encounter hemisphere, seen at the bottom of the strip. The width of the strip ranges from more than 55 miles (90 kilometers) at its northern end to about 45 miles (75 kilometers) at its southern end. The perspective changes greatly along the strip: at its northern end, the view looks out horizontally across the surface, while at its southern end, the view looks straight down onto the surface.
Go to the full image, go to its top, center your browser on the image, and then pan down slowly to see it in all its glory. The image above is cropped from about two-thirds of the way down, about when the terrain is transitioning from what they call cellular nitrogen ice plains to pitted non-cellular nitrogen ice plains. It includes what looks like a cluster of cave pits on the left.
They have also provided a video which does the same as panning down yourself, but adds a scale and labeling.
Juno enters Jupiter’s gravity well
After a five year journey the Jupiter science probe Juno today entered the gas giant’s gravity well.
It will fire its engines on July 4 to enter orbit.