Tag: science

Radar images of Titan taken in 2013 by Cassini show a twelve-mile patch appear in one of the moon’s methane lakes, then disappear.

9:14 am

The mysteries of science: Radar images of Titan taken in 2013 by Cassini show a twelve-mile patch appear in one of the moon’s methane lakes, then disappear.

They really don’t know what this patch is.

Prior to the July 2013 observation, that region of Ligeia Mare had been completely devoid of features, including waves. Titan’s seasons change on a longer time scale than Earth’s. The moon’s northern hemisphere is transitioning from spring to summer. The astronomers think the strange feature may result from changing seasons.

In light of the changes, Hofgartner and the other authors speculate on four reasons for this phenomenon:

  • Northern hemisphere winds may be kicking up and forming waves on Ligeia Mare. The radar imaging system might see the waves as a kind of “ghost” island.
  • Gases may push out from the sea floor of Ligeia Mare, rising to the surface as bubbles.
  • Sunken solids formed by a wintry freeze could become buoyant with the onset of warmer temperatures during the late Titan spring.
  • Ligeia Mare has suspended solids, which are neither sunken nor floating, but act like silt in a terrestrial delta.

“Likely, several different processes – such as wind, rain and tides – might affect the methane and ethane lakes on Titan,” [says Hofgarnter]

It is very important to remember that Titan is a very alien planet to the Earth. While some features, its methane lakes, have a superficial resemblance to lakes on Earth, the materials and environment are completely different. For example, on Earth the only thing that generally floats on water is ice, so that when winter arrives the surface freezes while the water below remains liquid. On Titan, if the methane freezes the ice will sink.

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Groundbreaking — the literally blasting off of a mountaintop — took place today in Chile at the eventual site of the European Extremely Large Telescope (E-ELT).

2:45 pm

Groundbreaking — the literally blasting off of a mountaintop — took place today in Chile at the eventual site of the European Extremely Large Telescope (E-ELT).

Once completed in 2024 this telescope will have a segmented mirror with a total diameter of 39 meters or 128 feet, the largest ever built.

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Two low-cost, car battery-sized Canadian space telescopes were launched successfully in Russia today

10:14 am

Two low-cost, car battery-sized Canadian space telescopes were launched successfully in Russia today.

The important detail here is this quote:

“BRITE-Constellation will exploit and enhance recent Canadian advances in precise attitude control that have opened up for space science the domain of very low cost, miniature spacecraft, allowing a scientific return that otherwise would have had price tags 10 to 100 times higher,” [emphasis mine]

Most nanosats and cubesats have not had the kind of precise attitude control of larger satellites, which is one of their limitations. If the technology is now maturing so that these tiny satellites can be pointed as accurately as bigger payloads, it will mean that unmanned satellites are going to get smaller very quickly. This lowers cost and increases the customer base, creating more business for launch companies.

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Rosetta’s comet has unexpectedly gone to sleep.

10:04 am

Rosetta’s comet has unexpectedly gone to sleep.

An image snapped earlier this month by ESA’s Rosetta spacecraft shows its target comet has quietened, demonstrating the unpredictable nature of these enigmatic objects. The picture was captured on 4 June by Rosetta’s scientific camera, and is the most recent full-resolution image from the narrow-angle sensor. It has been used to help fine-tune Rosetta’s navigation towards comet 67P/Churyumov–Gerasimenko, which was 430 000 km away at the time.

Strikingly, there is no longer any sign of the extended dust cloud that was seen developing around nucleus at the end of April and into May, as shown in our last image release. Indeed, monitoring of the comet has shown a significant drop in its brightness since then.

Rosetta’s approach for the next few months and arrival at the comet in August should be quite exciting.

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Is the Sun’s strange double-peaked solar maximum finally ending?

11:42 am

Last week NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in April. As I do every month, I am posting it here, with annotations to give it context.

May Solar Cycle graph

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.

For the third month in a row the Sun continued its drop in sunspots, with the total finally slipping below the 2009 prediction for this moment in the solar cycle. If this decline continues through to solar minimum, the shape of the solar maximum will essentially have been established, double-peaked with the second peak stronger than the first, something that solar scientists have never seen before.

At the moment I await word from the scientists that the Sun has completed the flip of its magnetic field polarity in the southern hemisphere. This flip has already occurred in the northern hemisphere, and when the south follows, the maximum will be officially over and we will officiallybegin the ramp down to solar minimum.

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The astronomers who allocate time on the Hubble Space Telescope have decided to devote a large block for finding a Kuiper Belt object that the probe New Horizons might fly past.

5:52 pm

The astronomers who allocate time on the Hubble Space Telescope have decided to devote a large block for finding a Kuiper Belt object that the probe New Horizons might fly past.

This allocation is still contingent upon a test observation to see if Hubble will be able to spot enough objects to make the long observations worthwhile.

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Engineers have returned to full operation the x-ray instrument on the Swift gamma-ray burst space telescope.

11:58 pm

Engineers have returned to full operation the x-ray instrument on the Swift gamma-ray burst space telescope.

They are still investigating what went wrong this week, but have figured out how to get the instrument back in full automatic robotic mode so that it can gather x-ray data on gamma ray bursts within seconds of their occurence.

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For the past four years the glaciers in Glacier National Park have stopped shrinking.

10:00 pm

The uncertainty of science: For the past four years the glaciers in Glacier National Park have stopped shrinking.

“We had this sort of pause,” Fagre said of shrinking at Sperry Glacier and, by extrapolation, other glaciers. “They pretty much got as much snow as they needed.” Sperry covered 0.86 square kilometers in 2005, 0.83 in 2009 and 0.82 in 2013, illustrating the “pause” in its retreat as there was a 0.03 square kilometer loss from 2005 to 2009, but only 0.01 in the last four years, from 2009 to 2013, Fagre said.

The article spends a lot of time talking about how the shrinkage is about to resume and the glaciers are certain to disappear, but this pause in glacier shrinkage corresponds nicely with the 17 plus year pause in warming that has been going on.

And then there’s this: Great moments in climate forecasting.

And this, also from Steve Goddard: In 1971 the world’s top climate scientists said fossil fuels would cause an ice age by 2020.

I especially like the quote from the last article, where these experts say that there is “no need to worry about the carbon dioxide fuel-burning puts in the atmosphere.” These are the same experts who have have spent the past three decades since 1988 telling us that CO2-caused global warming was going to kill us all.

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A new analysis of Apollo lunar rocks provides strong new evidence for the theory that the Moon was formed when the Earth was hit by a Mars’ sized planet.

9:14 am

A new analysis of Apollo lunar rocks provides strong new evidence for the theory that the Moon was formed when the Earth was hit by a Mars’ sized planet.

The abstract from this just released science paper summarizes the scientific problem.

Earth formed in a series of giant impacts, and the last one made the Moon. This idea, an edifice of post-Apollo science, can explain the Moon’s globally melted silicate composition, its lack of water and iron, and its anomalously large mass and angular momentum. But the theory is seriously called to question by increasingly detailed geochemical analysis of lunar rocks. Lunar samples should be easily distinguishable from Earth, because the Moon derives mostly from the impacting planet, in standard models of the theory. But lunar rocks are the same as Earth in O, Ti, Cr, W, K, and other species, to measurement precision. Some regard this as a repudiation of the theory; others say it wants a reformation. Ideas put forward to salvage or revise it are evaluated, alongside their relationships to past models and their implications for planet formation and Earth.

The new analysis has found that lunar rocks do differ from Earth in certain ways. Not surprisingly, however, the results have uncertainties.

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The rupture of a drum at a nuclear waste site in New Mexico has shut down a neutrino experiment.

9:00 am

The rupture of a drum at a nuclear waste site in New Mexico has shut down a neutrino experiment.

This article, from Nature, focuses on the harm done to the science experiment, which is considerable and very unfortunate. However, scroll to the end of the article to learn a little about the drum rupture, which has serious implications for the storage of nuclear waste anywhere.

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A place on Mars that was possibly habitable only 200 million years ago.

9:43 pm

A place on Mars that was possibly habitable only 200 million years ago.

This article discusses the possibility of liquid water from the melting of the glaciers that scientists think once covered the western slopes of the giant volcano Arsia Mons. I have also written about this area in an article I wrote for Sky & Telescope last year on exploring caves in space. It is thought that there might be caves here in which some of that water from those glaciers might still be found.

As one scientist is quoted as saying in this article, “Arsia Mons would be the next place I would want to go.” Like the south pole of the Moon, it likely has all the ingredients for establishing a habitable colony.

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An summary of the past week’s private effort at Aceibo to reactivate ISEE-3.

9:59 am

A summary of the past week’s private effort at Aceibo to reactivate ISEE-3.

They have discovered that the spacecraft is approximately 150,000 miles away from its expected position. This complicates the rescue effort significantly, as all their course corrections have to be recalculated based on this new position and they don’t yet have it refined enough to do those recalculations.

This has become extremely important as there is a solid statistical chance that the spacecraft could impact the moon or even be off course enough to threaten other spacecraft in Earth orbit. We are working with Mike Loucks of Space Exploration Engineering (SEE) our trajectory guy on this issue. An east coast company, Applied Defense (ADS) has also offered their help and engineering support to derive a new ephemeris from our new position reports. ADS and SEE did the trajectories for NASA’s just completed LADEE mission.

Hopefully by the end of this weekend they will have more to report.

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The predicted new meteor shower last night was less than hoped but intriguing nonetheless.

9:18 am

The predicted new meteor shower last night was less than hoped but intriguing nonetheless.

Based on a few reports via e-mail and my own vigil of two and a half hours centered on the predicted maximum of 2 a.m. CDT (7 UT) Saturday morning the Camelopardalid meteor shower did not bring down the house. BUT it did produce some unusually slow meteors and (from my site) one exceptional fireball with a train that lasted more than 20 minutes.

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Short of money for astrophysics because of the overruns on the James Webb Space Telescope as well as federal budget woes, NASA has decided to shut down the Spitzer Space Telescope.

9:11 am

Short of money for astrophysics because of the overruns on the James Webb Space Telescope as well as federal budget woes, NASA has decided to shut down the Spitzer Space Telescope.

Other missions, such as Kepler, Chandra, Hubble, NuStar, and Swift got extensions, however.

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The Sun settling down?

3:43 pm

Two weeks ago NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in April. I have been remiss about doing my monthly post about this, so here it is now, posted below with annotations.

April Solar Cycle graph

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.

The Sun continued the drop in sunspots seen the previous month, though the total number remains above the 2009 prediction for this moment in the solar cycle. As already noted, that the second peak of this double peaked solar maximum has been much stronger than the first remains unprecedented.

Overall, the maximum continues to be the weakest seen in a hundred years. Whether this is an indicator of future events or an anomaly can only be discovered after the Sun completes this solar solar cycle and begins the ramp up to its next solar maximum, at least five years away.

The next update is only a few weeks away. Stay tuned.

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Designed and funded on the premise that it would fly past a Kuiper belt asteroid after it flew past Pluto, the New Horizons team has so far failed to find such an asteroid and is running out of time.

9:29 am

Designed and funded on the premise that it would fly past a Kuiper belt object (KBO) after it flew past Pluto, the New Horizons team has so far failed to find such an asteroid and is running out of time.

In theory, project scientists should have identified a suitable KBO long ago. But they postponed their main search until 2011, waiting for all the possible KBO targets to begin converging on a narrow cone of space that New Horizons should be able to reach after its Pluto encounter. Starting to look for them before 2011 would have been impossible, says Grundy, because they would have been spread over too much of the sky.

Now that the hunt for KBOs is on, the New Horizons researchers have mainly been using the 8.2-metre Subaru Telescope in Hawaii and the 6.5-metre Magellan Telescopes in Chile. They have found about 50 new KBOs; none is close enough for New Horizons to reach.

I always thought it unlikely that they would be able to, on the fly, find a suitable candidate that New Horizons could reach in the very empty vastness beyond Pluto. In fact, it seemed absurd and to me seemed instead a transparent public relations ploy to get the funding for the fly-by mission to Pluto. Sadly, my cynical perspective here appears to be turning out to be true.

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The first preliminary list of candidate landing sites for NASA’s next Mars rover have been proposed.

9:59 am

The first preliminary list of candidate landing sites for NASA’s next Mars rover have been proposed.

At the conclusion of the workshop, attendees voted informally on the nearly 30 candidate sites that researchers had presented—ranking the sites as being of high, medium, or low scientific interest. Floating to the top was a site called Northeast Syrtis Major, a terrain at the edge of the Isidis Basin, the remnant of one of Mars’s biggest and most ancient asteroid impacts. Jack Mustard, a planetary scientist at Brown University and an advocate for the site, says material from the impact could offer a precise date for that event. Scientists also want a piece of nearby lava flows, thought to have oozed out and cooled several hundred million years later.

Nothing is even close to being decided yet, however.

In related news, a new study suggests that dozens of microbes might have stowed away on Curiosity when it left for Mars.

Emphasis must be placed on the word “suggests” however.

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