Dwarf planet Ultima Thule flatter than thought


This 8 February 2019 video says about itself:

Ultima Thule is Flatter Than Previously Thought

NASA New Horizons‘ imagery of the Kuiper Belt Object has revealed its true shape.

Ultima Thule is shaped like two lumpy pancakes. New images reveal the skinny side of the Kuiper Belt object. By Emily Conover, 6:00pm, February 8, 2019.

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Saturn’s rings, younger than dinosaurs?


This March 2016 video says about itself:

Saturn’s Moons and Rings May Be Younger Than the Dinosaurs

Some of Saturn‘s icy moons may have been formed after many dinosaurs roamed the Earth. New computer modeling of the Saturnian system suggests the rings and moons may be no more than 100 million years old.

Saturn hosts 62 known moons. All of them are influenced not only by the gravity of the planet, but also by each other’s gravities. A new computer model suggests that the Saturnian moons Tethys, Dione and Rhea haven’t seen the kinds of changes in their orbital tilts that are typical for moons that have lived in the system and interacted with other moons over long periods of time. In other words, these appear to be very young moons.

“Moons are always changing their orbits. That’s inevitable,” Matija Cuk, principal investigator at the SETI Institute and one of the authors of the new research, said in a statement. “But that fact allows us to use computer simulations to tease out the history of Saturn’s inner moons. Doing so, we find that they were most likely born during the most recent 2 percent of the planet’s history.”

The age of Saturn’s rings has come under considerable debate since their discovery in the 1600s. In 2012, however, French astronomers suggested that some of the inner moons and the planet’s well-known rings may have recent origins. The researchers showed that tidal effects — which refer to “the gravitational interaction of the inner moons with fluids deep in Saturn’s interior,” according to the statement — should cause the moons to move to larger orbits in a very short time.

“Saturn has dozens of moons that are slowly increasing their orbital size due to tidal effects. In addition, pairs of moons may occasionally move into orbital resonances. This occurs when one moon’s orbital period becomes a simple fraction of another. For example, one moon could orbit twice as fast as another moon, or three times as fast. Once an orbital resonance takes place, the moons can affect each other’s gravity, even if they are very small. This will eventually elongate their orbits and tilt them from their original orbital plane. By looking at computer models that predict how extended a moon’s orbit should become over time, and comparing that with the actual position of the moon today, the researchers found that the orbits of Tethys, Dione and Rhea are “less dramatically altered than previously thought,” the statement said.

The moons don’t appear to have moved very far from where they were born. To get a more specific value for the ages of these moons, Cuk used ice geysers on Saturn’s moon Enceladus. The researchers assumed that the energy powering those geysers comes from tidal interactions with Saturn and that the level of geothermal activity on Enceladus has been constant, and from there, inferred the strength of the tidal forces from Saturn.

Using the computer simulations, the researchers concluded that Enceladus would have moved from its original orbital position to its current one in just 100 million years — meaning it likely formed during the Cretaceous period. The larger implication is that the inner moons of Saturn and its gorgeous rings are all relatively young. (The more distant moons Titan and Iapetus would not have been formed at the same time.)

“So the question arises — what caused the recent birth of the inner moons?” Cuk said in the statement. “Our best guess is that Saturn had a similar collection of moons before, but their orbits were disturbed by a special kind of orbital resonance involving Saturn’s motion around the sun. Eventually, the orbits of neighboring moons crossed, and these objects collided. From this rubble, the present set of moons and rings formed.” The research is being published in the Astrophysical Journal.

From Space.com:

Saturn’s Rings May Be Younger Than the Dinosaurs

By Charles Q. Choi, Space.com Contributor | January 17, 2019 02:01pm ET

Saturn has not always had rings — the planet’s haloes may date only to the age of dinosaurs, or after it, a new study finds.

The age of Saturn’s rings has long proven controversial. Some researchers had thought the iconic features formed along with the planet about 4.5 billion years ago from the icy rubble left in orbit around it after the formation of the solar system. Others suggested the rings are very young, perhaps originating after Saturn’s gravitational pull tore apart a comet or an icy moon.

One way to solve this mystery is to weigh Saturn’s rings. The rings were initially made of bright ice, but over time have become contaminated and darkened by debris from the outer reaches of the solar system. A few years back, NASA’s Saturn-orbiting Cassini mission determined that the rings are only about 1 percent impure. If scientists could weigh Saturn‘s rings, they could estimate the amount of time it would take for them to accumulate enough contaminants to get 1 percent impure and thus calculate their age, lead study author Luciano Iess, a planetary scientist at the Sapienza University of Rome, told Space.com. [Saturn’s Glorious Rings in Pictures]

Iess and his colleagues relied on more Cassini data. Before the spacecraft plunged to its death into Saturn’s atmosphere in September 2017, it coasted between the planet and its rings and let their gravitational pulls tug it around. The strength of a body’s gravity depends on its mass, and by analyzing how much Cassini was pulled one way or the other during the “grand finale” phase of its mission, the mission team could measure the gravity and mass of both Saturn and its rings.

During six of Cassini’s crossings between Saturn and its rings at altitudes about 1,615 miles to 2,425 miles (2,600 to 3,900 kilometers) above the planet’s clouds, scientists monitored the radio link between the spacecraft and Earth. Much as how an ambulance siren sounds higher pitched as the vehicle drives toward you and lower pitched as it moves away, the radio signals would lengthen in wavelength as their source moved away Earth and shorten as their source moved toward it — an effect called the Doppler shift.

“I’m astonished by the fact that we were able to measure the velocity of a distant spacecraft 1.3 billion kilometers [807 million miles] away from Earth with an accuracy that is a hundredth or a thousandth the speed of a snail — a few hundreds of millimeters per second,” Iess said.

Previous estimates based on data from the Voyager flybys of Saturn suggested the rings’ mass was about 28 million billion metric tons. The new data from Cassini now suggests the rings’ mass is only about 15.4 million billion metric tons. (The largest asteroid, Ceres, has a mass of about 939 million billion metric tons.)

All in all, the researchers suggest the rings formed between 10 million to 100 million years ago. In comparison, the age of dinosaurs ended about 66 million years ago.

Cassini’s grand finale also revealed key details about the internal structure of Saturn. For example, it found that jet streams seen around Saturn’s equator — the strongest measured in the solar system, with winds of up to 930 mph (1,500 km/h) — extend to a depth of at least 5,600 miles (9,000 km), rotating a colossal amount of mass around the planet about 4 percent faster than the layer below it.

“The discovery of deeply rotating layers is a surprising revelation about the internal structure of the planet,” Cassini project scientist Linda Spilker at NASA’s Jet Propulsion Laboratory in Pasadena, California, who did not participate in the study, said in a statement. “The question is, What causes the more rapidly rotating part of the atmosphere to go so deep, and what does that tell us about Saturn’s interior?”

The new findings also suggest that Saturn’s rocky core is about 15 to 18 times the mass of Earth, similar to prior estimates.

The scientists detailed their findings online Jan. 17 in the journal Science.

What Adélie penguins eat, study with spacecraft


This 12 December 2018 video from the USA says about itself:

2018 Fall Meeting Press Conference: Penguins! From space

The science team that led the expedition to document the supercolony of penguins on the remote Danger Islands in Antarctica will present new results from their research conducted on the expedition, including new, unpublished information on the age of the supercolony.

NASA satellite imagery of the penguins’ bright pink poop, or guano, helped the scientists first pinpoint the location of the supercolony of Adélie penguins.

In this press conference, the scientists will report new findings from the refined tools and techniques they’ve developed since the expedition to study penguins from space.

Participants: Heather Lynch, Stony Brook University, Stony Brook, New York, U.S.A.; Michael Polito, Louisiana State University, Baton Rouge, Louisiana, U.S.A.; Casey Youngflesh, University of Connecticut, Storrs, Connecticut, U.S.A.

By Sarah Zielinski, 7:00am, January 2, 2019:

Poop provides a link in determining penguin diet from space

The best way to find out what an Adélie penguin is eating is to catch it and make it regurgitate its meal. This is about as pleasant for bird and researcher as you might think. It’s also invasive, time-consuming and expensive to do on a large scale, so scientists need other ways to determine diet. Now they have one; it relies on images taken by Landsat satellites.

The satellites don’t reveal individual penguins, let alone what they are consuming underwater. What those images do show, though, is poop. Lots of it. Because Adélie penguins cluster together at a predictable rate, researchers have figured out how to count penguin colonies just from their huge poop stains. Last year, for instance, a group led by Stony Brook University ecologist Heather Lynch reported finding a supercolony of 1.5 million Adélie penguins on the Danger Islands, off the coast of the Antarctic Peninsula, from their feces.

Figuring out dietary preferences from those images is a bit more complicated — but it also starts with poop.

Casey Youngflesh is a quantitative ecologist at the University of Connecticut in Storrs. Until a few months ago, he was a graduate student in Lynch’s lab. During that time, he made several trips to the Antarctic Peninsula, visiting Adélie penguin colonies by boat from either the tip of South America or the Falkland Islands. That required crossing some of the roughest waters on the high seas, and, he says, “it can get a little bit hairy sometimes, especially on the smaller vessels.”

Timing was essential. Visit too early and the colonies wouldn’t have started to nest. (The birds spend the dark winters following the sea ice before returning to land to raise chicks during the southern summer.) Visit too late and the colonies would be a mess, with large chicks running amok and poop mixing with mud. “Everything’s a lot cleaner and neater earlier in the season”, he notes.

Youngflesh and the other researchers on these trips gathered lots of data from the penguin colonies they visited. They at times counted birds or checked on packing densities. And sometimes they gathered poop in little smell-proof bags and brought it back to the ship.

To most people, the poop looks pink. (It also stinks, as you might expect.) The guano gets its color from the carotenoids in the carapace of krill the penguins eat. But what a penguin eats can alter that color. And so those subtle changes in color can indicate what a bird has consumed.

Back on the ship, Youngflesh would take each sample and make a “poo patty.” Each patty was “kind of the size of a hamburger patty,” he says (and, from the picture he supplied, looked a bit like one, too). He’d run the patty through a spectrometer, which measures the sample’s colors across the electromagnetic spectrum, even in wavelengths like infrared and ultraviolet that the human eye can’t see. Then the patty went into a dehydrator so it could be shipped back to the lab. There, Youngflesh would measure its nitrogen-15 levels, which correlated with where in the food web the penguin had been eating, higher (fish) or lower (krill).

Once Youngflesh had collected and analyzed poop from a dozen or so colonies along the Antarctic Peninsula, he used statistics to translate the fine spectrometer data to the coarser data in the Landsat imagery. Then each pixel of an image could be connected to the dominant item on the penguin menu: fish or krill. Adélie penguins in West Antarctica tend to eat more krill, and those in East Antarctica eat more fish, Youngflesh reported December 12 at the American Geophysical Union’s fall meeting in Washington, D.C.

Scientists have done diet studies of individual penguin populations, but it’s not easy to do that frequently. The new technique will let researchers get a snapshot of the Adélie penguin diet across the Antarctic continent, year after year, looking both in the past and into the future, Youngflesh notes. Going back through the Landsat archive didn’t reveal any big changes in penguin diet, but now researchers will be able to monitor it as the region changes and provide real data to Antarctic ecosystem managers.

Youngflesh says that researchers might be able to apply this method to other seabirds, “if they’re nesting on the ground and pooping all over the place.” Someone would have to collect more samples, though, to calibrate the satellite data. And if anyone should want more granular data about how a penguin’s diet differs from bird to bird or day to day, there aren’t many good substitutes for going to the bird itself and getting it to give up its lunch.

First ever landing on dark side of moon


This 2 January 2019 video says about itself:

First Photos: China Lands Probe on Dark Side of the Moon

China successfully landed a spacecraft on the far side of the moon Thursday, becoming the first country to ever land on the side of the moon that faces away from Earth.

CHINA LANDS ON THE FAR SIDE OF THE MOON China became the first nation to land a spacecraft on the far side of the moon, the country’s state-run media announced, a milestone that solidifies Beijing’s ambitions to become a world leader in space exploration. [HuffPost]

China’s landing of a scientific probe on the far side of the Moon has led to a rash of media speculation, in the US in particular, about a new international space race amid heightened tensions between the two countries over economic issues, including trade, and a massive American military build-up in Asia against China: here.

Seeds on board China’s Chang’e-4 mission have sprouted, marking the first time any biological matter has grown on the moon.

Dwarf planet Ultima Thule first photos


This 2 January 2018 video from the USA says about itself:

New Horizons probe sends back first images of Ultima Thule

NASA says it will release new images Wednesday of Ultima Thule, the most distant object ever explored by humans, taken by the New Horizons spacecraft. Scientists believe the icy world, more than a billion miles beyond Pluto, will reveal clues about the origins of the solar system. Mark Strassmann reports.

New Horizons shows Ultima Thule looks like a snowman, or maybe BB-8. The Kuiper Belt object is probably two rocks stuck together. By Lisa Grossman, 5:42pm, January 2, 2019.

See also here.

The latest picture of Ultima Thule reveals a remarkably smooth face. The object’s lack of craters suggests the Kuiper Belt isn’t filled with lots of space hazards. By Lisa Grossman, 11:17am, January 29, 2019.

The moon, science and militarisation


This video from the USa says about itself:

Trump Presents ‘Space Force: Episode Dumb’

Today Donald Trump is calling for a space military. Tomorrow he’ll be calling for a space military parade.

By Henry Allan and Bryan Dyne in the USA:

Moon targeted for further exploration, orbiting space stations and militarization

27 December 2018

Earlier this year, NASA announced plans to build a Lunar Orbital Platform-Gateway, which is slated to be humanity’s tenth space station and the first that will orbit the Moon. The Gateway is projected to be operational by the mid-2020s, with the first initial component of the outpost ready to launch in 2022. Congress has already provided $504 million for the initial planning and design of the space station and the project, if it goes forward, is estimated to cost $3 billion a year.

NASA is promoting the Gateway as a lunar-orbiting station with scientific instruments attached externally as well as internally in order to conduct scientific experiments, control lunar rovers, or even act as a jumping off point for further ventures into space, including possible launches towards deep space.

“I envision different partners, both international and commercial, contributing to the gateway and using it in a variety of ways with a system that can move to different orbits to enable a variety of missions”, said William Gerstenmaier, associate administrator for Human Exploration and Operations at NASA Headquarters in Washington, earlier this year. “The gateway could move to support robotic or partner missions to the surface of the moon, or to a high lunar orbit to support missions departing from the gateway to other destinations in the solar system.”

Whatever its potential achievements, however, the development of the Gateway cannot be seen outside the context of the plan to create a “Space Force” as the sixth branch of the US military and the growing militarization of space in general.

When US President Donald Trump announced his intent to form the “Space Force” in June, he made it clear that the move was part of the war plans directed against Russia and China. “Our destiny beyond the Earth is not only a matter of national identity but a matter of national security”, Trump declared, adding that the United States should not have “China and Russia and other countries leading us.” He further emphasized, “It is not enough to merely have an American presence in space; we must have American dominance in space.”

House Space Subcommittee Chairman Brian Babin, a Texas Republican, echoed the national-chauvinist line of Trump, declaring, “Under the president’s leadership, we are now on the verge of a new generation of American greatness and leadership in space—leading us to once again launch American astronauts on American rockets from American soil.”

The Gateway would inevitably be a part of these efforts. A US space station orbiting the Moon immediately raises the possibility of policing of the space between Earth and the Moon, whether by manned or unmanned vehicles. These in turn would need a broader support network of spy satellites and other infrastructure necessary for such an undertaking, including space-based weapons.

It would no doubt also be used as an attempt to counter the influence of China, which is currently planning on building its own base on the surface of the Moon. It is not far-fetched to consider a “freedom of navigation” provocation, like those conducted repeatedly by the US military in the South China Sea, carried out against Chinese vessels in space. The Gateway might also be used as the pretext for attacking a craft that simply went too close to the station, violating its “territorial waters”, so to speak. Any of these could be used to start a war.

Such moves in the direction of new wars of aggression came into sharp focus when Trump announced the unilateral US withdrawal from the Intermediate-Range Nuclear Forces (INF) treaty with Russia, which prohibited Washington and Moscow from developing short- and medium-range missiles capable of carrying nuclear warheads. The withdrawal will set the stage for a further development of the US nuclear arsenal. It also poses the possibility of placing strategic weapons in space, perhaps even as part of the proposed space station.

The Gateway has also drawn criticism from scientists and astronauts who oppose the project as a drain on the already limited resources for space exploration. While the total cost of the Gateway is not fully worked out, it is already known that it will take twenty launches from currently available rockets to get the planned modules for the station to the Moon. This would eliminate twenty launches that could otherwise be dedicated to different unmanned interplanetary missions. While this could be reduced to as little as four if the Gateway was built with either NASA’s Space Launch System or SpaceX’s Super Heavy Starship, [both] of those rocket designs have yet to be built.

Opponents of the Gateway have also pointed out that, unlike the currently operational International Space Station (ISS), because there are no agreements to share any benefits that might be gained from the Gateway, there are no cost-sharing agreements for the station’s operation. If US unilateralism on trade is an example of what will be demanded in space, then other nations will probably stick to the ISS or even begin developing their own, similar projects, with the same inherent risks—the danger of disaster in space and war on Earth.

It is also not clear that the Gateway would actually be a “stepping stone” to missions elsewhere in the Solar System. To arrive at the station, a spacecraft would have to enter orbit around the Moon, which costs fuel. As of now, a trip to the surface of the Moon that first stopped at the Gateway would require thirty percent more fuel. A trip to an asteroid, Mars or elsewhere faces similar problems.

Top Ten 2018 scientific breakthroughs


This 20 December 2018 video from Science magazine in the USA says about itself:

2018 Breakthrough of the Year

Learn about our Breakthrough of the Year: tracking development cell by cell. Nine other advances are recognized as runners-up.

Read more here.

2018 was a busy year in space. We said hello to some spacecraft and good-bye to a few favorites. By Lisa Grossman, 7:00am, December 26, 2018.