Tag: science

Changing seasons on Titan

9:15 am

Since entering Saturn orbit in 2004, Cassini has seen the seasons on Titan shift through half a Saturn year.

As Titan approaches its northern summer solstice, NASA’s Cassini spacecraft has revealed dramatic seasonal changes in the atmospheric temperature and composition of Saturn’s largest moon. Winter is taking a grip on the southern hemisphere and a strong vortex, enriched in trace gases, has developed in the upper atmosphere over the south pole. These observations show a polar reversal in Titan’s atmosphere since Cassini arrived at Saturn in 2004, when similar features were seen in the northern hemisphere.

Sadly, there will not be any spacecraft at Saturn during the second half of this Saturn year. After Cassini ends its mission in 2017 it will likely be many decades before another spacecraft arrives, since at this moment none has even been proposed.

9 comments

Science conference accepts fake paper

11:30 pm

I’m so glad it was peer-reviewed! A fake physics paper written entirely in gibberish using autocomplete function has been accepted by a science conference.

Christoph Bartneck, an associate professor at the Human Interface Technology laboratory at the University of Canterbury in New Zealand, received an email inviting him to submit a paper to the International Conference on Atomic and Nuclear Physics in the US in November. “Since I have practically no knowledge of nuclear physics I resorted to iOS autocomplete function to help me writing the paper,” he wrote in a blog post on Thursday. “I started a sentence with ‘atomic’ or ‘nuclear’ and then randomly hit the autocomplete suggestions. The text really does not make any sense.”

It only took the conference three hours to review the work and to accept it. They then asked the author to confirm his oral presentation and register for the conference for a mere $1099.

13 comments

Saturn’s changing north pole

10:38 pm

A comparison of images taken by Cassini in 2012 and then in 2016 of Saturn’s north polar region shows a significant change in color.

Scientists are investigating potential causes for the change in color of the region inside the north-polar hexagon on Saturn. The color change is thought to be an effect of Saturn’s seasons. In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.

Leave a comment

Moon found orbiting one of the larger known Kuiper belt object

6:22 pm

Astronomers have found a moon circling 2007 Or10, one of the Kuiper Belts eight largest objects and the only one as yet unnamed.

Astronomers Gábor Marton and Csaba Kiss (Konkoly Observatory, Hungary), and Thomas Müller (Max Planck Institute, Germany) have identified a moon orbiting 2007 OR10. They spotted it in Hubble Space Telescope images taken in September 2010 as part of a survey of trans-Neptunian objects. Marton announced the discovery this week at a joint meeting of the AAS’s Division for Planetary Sciences and the European Planetay Science Congress.

Although 2007 OR10 itself has been known for almost a decade, only recently have researchers realized that it’s surface is quite dark and therefore that it must be quite sizable, with an estimated diameter of 1,535 km (955 miles). This makes it the third-largest dwarf planet, after Pluto and Eris. It also ranks third for distance — 13 billion km or 87 astronomical units away — drifting among the stars of central Aquarius at a dim magnitude 21.

Of the eight largest Kuiper Belt objects, only Sedna has not yet been found to have a moon.

Leave a comment

Something in the Kremlin is jamming GPS

6:14 pm

It appears that any GPS unit that approaches the Kremlin in Moscow can no longer pinpoint accurately its location.

A programmer for Russian internet firm Yandex, Grigory Bakunov, said Thursday his research showed a system for blocking GPS was located inside the Kremlin, the heavily guarded official residence of Russian President Vladimir Putin. Users of GPS have complained on social media in recent months that when they are near the Kremlin their GPS-powered apps stop working or show them to be in Moscow’s Vnukovo airport, 29 kilometers (18 miles) away.

The problem has frustrated those requesting taxis via services such as Uber or looking to catch Pokemons in the popular game played on mobile devices. Large numbers of people running the Moscow marathon last month complained that their jogging apps lost track of how far they had run when they passed the Kremlin.
“I got 40 kilometers added on to my distance. It happened by the Kremlin,” marathoner Andrey Yegorov wrote on Facebook as part of a discussion by runners.

Not surprisingly, the agency in charge of security at the Kremlin declined to comment.

3 comments

Expansion rate of the universe might not be accelerating

6:06 pm

The uncertainty of science: A new review of the data suggests that the expansion of the universe might not be accelerating as posited based on research done in the 1990s.

Making use of a vastly increased data set – a catalogue of 740 Type Ia supernovae, more than ten times the original sample size – the researchers have found that the evidence for acceleration may be flimsier than previously thought, with the data being consistent with a constant rate of expansion.

The study is published in the Nature journal Scientific Reports.

Professor Sarkar, who also holds a position at the Niels Bohr Institute in Copenhagen, said: ‘The discovery of the accelerating expansion of the universe won the Nobel Prize, the Gruber Cosmology Prize, and the Breakthrough Prize in Fundamental Physics. It led to the widespread acceptance of the idea that the universe is dominated by “dark energy” that behaves like a cosmological constant – this is now the “standard model” of cosmology.

‘However, there now exists a much bigger database of supernovae on which to perform rigorous and detailed statistical analyses. We analysed the latest catalogue of 740 Type Ia supernovae – over ten times bigger than the original samples on which the discovery claim was based – and found that the evidence for accelerated expansion is, at most, what physicists call “3 sigma”. This is far short of the 5 sigma standard required to claim a discovery of fundamental significance.

I am not surprised. In fact, I remain continually skeptical about almost all cosmological theories. They might be the best we have, based on the facts available, but they are also based upon incredibly flimsy facts.

2 comments

MRO images Schiaparelli on Mars

12:06 pm

before and after Schiaparelli

A comparison of images taken by Mars Reconnaissance Orbiter before and after Schiaparelli’s failed attempt to land on Mars have revealed changes that are likely the lander on the surface. The image on the right is a composite that I’ve made showing the two images. The black spot near the top and the white spot near the bottom are not in the first image.

It is thought that the white spot is likely Schiaparelli’s parachute, while the dark spot is thought to be the lander’s impact point.

The larger dark spot near the upper edge of the enlargement was likely formed by the Schiaparelli lander. The spot is elliptical, about 50 by 130 feet (15 by 40 meters) in size, and is probably too large to have been made by the impact of the heat shield.

The large size of the dark spot suggests that the lander hit the ground hard enough to create this large scar.

3 comments

Did Viking discover life on Mars?

11:30 am

Link here. The article provides a very detailed review of the conflicting results from the various 1970s Viking lander experiments, one of which strongly suggested the presence of microorganisms.

Overall, these life-detection experiments produced surprising and contradictory results. One experiment, the Labeled Release (LR) experiment, showed that the Martian soil tested positive for metabolism—a sign that, on Earth, would almost certainly suggest the presence of life. However, a related experiment found no trace of organic material, suggesting the absence of life. With no organic substances, what could be, or seem to be, metabolizing?

In the forty years since these experiments, scientists have been unable to reconcile the conflicting results, and the general consensus is that the Viking landers found no conclusive evidence of life on Mars. However, a small minority of scientists argues that the Viking results were positive for life on Mars.

The contradictory Viking results have never been fully explained. Many theories have been proposed, ranging from the chemical to the biological, but none have satisfied anyone.

2 comments

TMT hearing a fiasco

8:00 pm

The initial hearing in Hawaii for the second permit application of the Thirty Meter Telescope today appears to have been a complete fiasco, designed to extend the proceedings as long as possible, ad infinitum.

Confusion reigned as Thursday’s hearing got underway in a Hilo hotel banquet room. Various telescope opponents complained about the scheduling and location of the hearing. One lawyer wanted to know the process for making objections. More than an hour went by before the first witness, environmental planner Perry White, was called to testify.

All witnesses will be allowed to provide a 10-minute summary of written testimony already submitted. But before White could provide his summary, there were various objections about qualifying him as an expert. Nearly two dozen people— many who are individual telescope opponents who don’t have lawyers representing them — will have a chance to cross-examine each witness.

Cross-examination of White will resume Monday.

It is very clear to me that Hawaii is stalling, designing the hearings so that they will last forever. TMT will never get built in Hawaii. It is time to say bye-bye and go somewhere where knowledge and technology is treasured.

7 comments

Did Opportunity see Schiaparelli?

9:43 am

Opportunity image of Schiaparelli?

Because Schiaparelli was aimed at a landing site somewhat close to the Mars rover Opportunity, the science team aimed the rover’s panoramic camera at the sky yesterday, taking fourteen pictures in the hope of capturing the lander as it came down. Of those fourteen images, the image on the right, reduced in resolution, is the only one that shows that bright streak in the upper right.

close-up of streak

Though this streak might be an artifact, I do not think so. To the left is a close-up from the full resolution image, showing the streak in detail. That doesn’t look like an artifact. It still could be a meteorite, but I also think that doubtful. The coincidence of a meteorite flashing across the sky at the same exact moment Opportunity is looking to photograph Schiaparelli’s landing is too unlikely.

If this is Schiaparelli, expect a press release from NASA in the next few days.

4 comments

Schiaparelli landing apparently a failure

8:32 am

This report from russianspaceweb.com provides some details about the apparent landing failure of the European Mars probe Schiaparelli on Wednesday.

The very preliminary analysis of the data revealed a number of serious problems in the final phase of the parachute descent. The telemetry showed that the back heat shield holding the parachute had been ejected earlier than scheduled — 50 seconds instead of 30 seconds before the touchdown. Also, the lander was apparently descending at a speed higher than planned. There were also indications that the soft-landing engines had fired for only three or four seconds and all communications from the lander were cut 19 seconds later, or shortly before touchdown. By that time, Schiaparelli’s landing radar had been activated.

It appears the parachutes were released too soon so that they did not function properly and slow the spacecraft down enough. When the retro-rockets fired the spacecraft was probably also closer to the ground than planned and falling too fast, so they failed to stop it from impacting the surface hard and prematurely.

13 comments

Fate of Schiaparelli remains unknown

4:06 pm

While Europe’s Trace Gas Orbiter has successfully gone into orbit around Mars, it remains unknown whether the lander Schiaparelli was able today to land successfully on the surface.

The carrier signal from Schiaparelli recorded by Mars Express abruptly ended shortly before landing, just as the beacon tone received by a ground-based radio telescope in India stopped in real-time earlier today.

Paolo Ferri, head of ESA’s mission operations department, just gave an update on the situation. “We saw the signal through the atmospheric phase — the descent phase. At a certain point, it stopped,” Ferri said. “This was unexpected, but we couldn’t conclude anything from that because this very weak signal picked up on the ground was coming from an experimental tool.

“We (waited) for the Mars Express measurement, which was taken in parallel, and it was of the same kind. It was only recording the radio signal. The Mars Express measurement came at 1830 (CEST) and confirmed exactly the same: the signal went through the majority of the descent phase, and it stopped at a certain point that we reckon was before the landing.

“There could be many many reasons for that,” Ferri said. “It’s clear these are not good signs, but we will need more information.”

11 comments

Juno enters safe mode prior to Jupiter close approach

1:25 pm

Because Juno entered safe mode prior to its close approach of Jupiter today, no science data was gathered.

NASA’s Juno spacecraft entered safe mode Tuesday, Oct. 18 at about 10:47 p.m. PDT (Oct. 19 at 1:47 a.m. EDT). Early indications are a software performance monitor induced a reboot of the spacecraft’s onboard computer. The spacecraft acted as expected during the transition into safe mode, restarted successfully and is healthy. High-rate data has been restored, and the spacecraft is conducting flight software diagnostics. All instruments are off, and the planned science data collection for today’s close flyby of Jupiter (perijove 2), did not occur. “At the time safe mode was entered, the spacecraft was more than 13 hours from its closest approach to Jupiter,” said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We were still quite a ways from the planet’s more intense radiation belts and magnetic fields. The spacecraft is healthy and we are working our standard recovery procedure.”

This problem, combined with the thruster valve problem that prevented engineers from putting the spacecraft into its proper 14-day science orbit today, is significantly delaying science operations. They will not be able to adjust the orbit again until its next close approach December 11 (assuming the thruster problem has been solved by then), and until then it will also not be able to do much science.

Leave a comment

Landslides on Charon

8:40 am

Landslide on Charon

Images from New Horizons have detected evidence of past avalanches on Pluto’s largest moon, Charon. The image on the right is a reduced version of a perspective view created using data from various instruments.

This perspective view of Charon’s informally named “Serenity Chasm” consists of topography generated from stereo reconstruction of images taken by New Horizons’ Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC), supplemented by a “shape-from-shading” algorithm. The topography is then overlain with the PIA21128 image mosaic and the perspective view is rendered. The MVIC image was taken from a distance of 45,458 miles (73,159 kilometers) while the LORRI picture was taken from 19,511 miles (31,401 kilometers) away, both on July 14, 2015.

close-up of landslide

To the left is a close-up taken from the annotated image. You can see the slump materials at the base of the mountain left behind after the material slide down the mountain. It is not clear whether it is Charon’s lower gravity and alien composition and environment (very very very cold) that makes this look more muddy than one would expect, or whether it is because of the limited resolution of the original image and the modeling to create the oblique version.

One comment

Comet 67P/C-G slowly breaking apart

5:56 pm

A comparison of Rosetta images before and after Comet 67P/C-G’s close approach to the sun last year found new fractures and an enlargement of older fractures.

The fractures appear to be developing as forces subtly bend the comet to and fro, Stubbe Hviid, a planetary scientist at the German Aerospace Center Institute of Planetary Research in Berlin, reported October 17 in a press conference at a meeting of the American Astronomical Society’s Division for Planetary Sciences. Hviid and colleagues combined maps from Rosetta with computer simulations of all the forces at work within the comet to determine how the cracks develop. They found that the two bulbous ends rock in opposite directions as the comet spins, flexing the neck and creating severe stress. Because the comet isn’t held together strongly — it’s a conglomeration of dust and ice not much stickier than snow, Hviid said — the neck is starting to break. After a few hundred more years, he said, the comet could fold itself in half as the two lobes snap apart and smoosh together.

Leave a comment

Active volcano on Venus?

5:18 pm

The uncertainty of science: A new analysis of past data from a variety of Venus orbiters suggests that at least one volcano is active there.

The review of old data from the Magellan and Venus Express orbiters suggests that some lava flows on the volcano’s slopes are fresh, though how fresh remains unknown. However, computer models and the detection of excess heat by Venus Express on the mountain’s eastern slopes adds weight to the theory that the volcano is spewing out lava.

Leave a comment

The clouds of hot Jupiter exoplanets

11:24 am

Exoplanet clouds

Cool image time! The image on the right, reduced to show here, provides an overall summary of what astronomers know about the atmospheres of many gas giant exoplanets that also orbit very close to their suns and are tidally locked. The view is of the planet hemisphere facing away from the star, which is also where most of the clouds are thought to be. These results come from Kepler data combined with computer modeling, and show what scientists thinks happens with different cloud compositions at different temperatures.

Link fixed!

2 comments

Mars rover update

10:49 am

Emily Lakdawalla at Sky & Telescope today provides an update of the two Mars rovers, but takes a different approach than I have. While I have been focusing on tracking where the rovers are going and what they are doing, she gives a very nice overview of each rovers’ condition, what instruments continue to work and what have failed.

I myself have not done a new rover update since October 6 for several reasons. First and foremost, neither rover has gone anywhere since my last report. Opportunity is still sitting on Spirit Mound, studying the rocks there. Curiosity is still in the flats south of Murray Buttes, preparing to drill another hole.

Secondly, there was a delay this past weekend in downloading data, especially from Curiosity. I strongly suspect that the delay was simply because the Deep Space Network was being used to help with communications between Europe and its ExoMars probes, now set to arrive at Mars tomorrow. When the lander Schiaparelli separated from the orbiter on Sunday they had had some initial communications problems, and it is likely that though ESA was using its own deep space network, they also enlisted ours to help.

Thirdly, I have been very tied up trying to finish my cave project monograph. This is done now, so I finally have more time to work on Behind the Black.

Leave a comment

New object found beyond Kuiper belt

10:20 am

Worlds without end: Astronomers have discovered another object far beyond Pluto and in an elliptical orbit whose farthest point is 1,450 astronautical units, or about 135 billion miles from the Sun.

This is not the same object recently discovered in a somewhat similar elliptical orbit.

Astronomers right now do not understand the formation process that put these objects in these distant orbits. Some think the objects might have originally come from the Oort cloud that is even farther out from the Sun, their orbits shifted by the as-yet undiscovered Planet X that astronomers love to talk about, but others are skeptical. Since no one has ever actually detected anything in the the theorized Oort Cloud, it is also possible that it does not exist as presently theorized, and might actually be a more scattered collection of objects, like these new discoveries, that travel both farther and closer to the Sun.

One comment

Mars in ultraviolet

9:47 am

Data from the Mars orbiter MAVEN have given scientists their first detailed look at the red planet in ultraviolet wavelengths.

New global images of Mars from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission being led by CU Boulder show the ultraviolet glow from the Martian atmosphere in unprecedented detail, revealing dynamic, previously invisible behavior.

They include the first images of “nightglow” that can be used to show how winds circulate at high altitudes. Additionally, dayside ultraviolet imagery from the spacecraft shows how ozone amounts change over the seasons and how afternoon clouds form over giant Martian volcanoes. The images were taken by the Imaging UltraViolet Spectrograph (IUVS) on MAVEN.

The build-up of clouds over Mars’ four big volcanoes is especially interesting, since it is thought this water vapor likely comes from underground ice left over from glaciers that were once on the mountains’ slopes. A very short video of that build up can be seen, below the fold.
» Read more

Leave a comment

ExoMars 2016 in detail

8:14 am

This Nature article provides a nice summary of the European/Russian ExoMars 2016 mission that on Wednesday will try to place a lander on Mars as well as put an orbiter in orbit.

Neither probe is going to provide many exciting photos. The orbiter, dubbed boringly the Trace Gas Orbiter, is designed to study Mars’ atmosphere, while the lander, Schiaparelli, is essentially a technology test mission for planning and designing what Europe and Russia hope will be a more ambitious lander/orbiter mission in 2020.

Anyone expecting spectacular pictures from Schiaparelli itself might be disappointed — photos will be limited to 15 black-and-white shots of the Martian surface from the air, intended to help piece together the craft’s trajectory. No photos will be taken on the surface, because the lander lacks a surface camera.

Schiaparelli’s instruments will study the Martian atmosphere, including the possible global dust storm that might happen this month but so far has not yet appeared. The instruments will also be able to detect lightning, should it exist on Mars.

One comment

Problems with Juno’s main engine

6:18 pm

Valve problems detected during Juno’s orbital insert around Jupiter has caused engineers to delay the October 19 engine burn that would have lowered the probe’s orbit around Jupiter.

Mission managers for NASA’s Juno mission to Jupiter have decided to postpone the upcoming burn of its main rocket motor originally scheduled for Oct. 19. This burn, called the period reduction maneuver (PRM), was to reduce Juno’s orbital period around Jupiter from 53.4 to 14 days. The decision was made in order to further study the performance of a set of valves that are part of the spacecraft’s fuel pressurization system. The period reduction maneuver was the final scheduled burn of Juno’s main engine. “Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft’s main engine did not operate as expected during a command sequence that was initiated yesterday,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine.”

Because of this, they will instead use this next close approach to Jupiter to do pure science, something that they would not have done during the engine burn. Though this is a good example of turning lemons into lemonade, it will not be a good thing if Juno can never reduce its orbit to 14 days. A 53 day orbit will mean that they can only do good research every two months, and will seriously limit what they can learn over the long run.

One comment

Kaguya data released at last

9:06 am

Seven years after the mission ended Japan has finally released the full catalog of images and videos taken by its lunar orbiter Kaguya.

No explanation for the long delay has been provided. Overall, this is just another example of what to me appears to be a bloated, bureaucratic, and slow to move Japanese space program. Their rockets are expensive, their planetary probes have had repeated problems, and they seem to be very uninterested in stepping up their game to compete in the increasingly competitive international race to explore and settle the solar system. That it took them more than seven years to release this data is quite shameful.

Leave a comment

ExoMars 2016 bearing down on Mars

8:59 am

This article provides a detailed look at Sunday’s arrival of ExoMars 2016 at Mars.

If all goes right the Schiaparelli lander will soft land on the surface while the Trace Gas Orbiter will enter an initial 185 by 60,000 mile orbit, which will slowly be adjusted so that by January it can begin its atmospheric research.

Though the Russian contribution to this mission was only the rocket that sent it to Mars, if the mission succeeds it will be the first time any Mars mission with major Russian participation has succeeded. The failure rate for any Russian effort to go to Mars has been 100%. And it hasn’t been because the missions have been particularly difficult. The majority of their failures occurred in the 1960s and 1970s, even as they were very successfully completing much harder lander missions to Venus.

It has almost as if there is a curse against any Russian attempt to visit the Red Planet. Hopefully, that curse will finally be broken on Sunday.

One comment

New power source for planetary missions?

9:53 am

Research at JPL has developed new materials called skutterudites that have the potential of increasing the efficiency and power output of the radioisotope electric generators used on deep space missions where solar power will not work.

The new eMMRTG would provide 25 percent more power than Curiosity’s generator at the start of a mission, according to current analyses. Additionally, since skutterudites naturally degrade more slowly that the current materials in the MMRTG, a spacecraft outfitted with an eMMRTG would have at least 50 percent more power at the end of a 17-year design life than it does today.

“Having a more efficient thermoelectric system means we’d need to use less plutonium. We could go farther, for longer and do more,” Bux said.

This being NASA research, they are moving somewhat slowly in testing and confirming whether these new materials will work. They hope that after passing further reviews in 2017 and 2018 the agency might finally approve their use in subsequent missions.

3 comments

Ten times more galaxies than previously believed

9:44 am

The uncertainty of science: A new analysis from Hubble and other telescope data suggests that the universe actually contains ten times more galaxies than previously estimated, several trillion instead of the past estimate of 100 to 200 billion.

I would not bet much money on this conclusion. I suspect that further research will find even more galaxies, since our deep observations of the universe are at the moment confined to a mere handful of Hubble deep field images that cover only a few tiny specks of space.

This new analysis however did confirm previous estimates that suggest the universe has evolved and changed significantly over time.

In analysing the data the team looked more than 13 billion years into the past. This showed them that galaxies are not evenly distributed throughout the Universe’s history. In fact, it appears that there were a factor of 10 more galaxies per unit volume when the Universe was only a few billion years old compared with today. Most of these galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way.

These results are powerful evidence that a significant evolution has taken place throughout the Universe’s history, an evolution during which galaxies merged together, dramatically reducing their total number. “This gives us a verification of the so-called top-down formation of structure in the Universe,” explains Conselice.

5 comments
1 … 150 151 152 153 154 … 279