Tag: science

Plan of New Horizons’ fly-by of 2014 MU69 announced

11:31 pm

The New Horizons science team has announced its detailed plan for the January 1, 2019 fly-by of Kuiper Belt object 2014 MU69.

If all goes as planned, New Horizons will come to within just 2,175 miles (3,500 kilometers) of MU69 at closest approach, peering down on it from celestial north. The alternate plan, to be employed in certain contingency situations such as the discovery of debris near MU69, would take New Horizons within 6,000 miles (10,000 kilometers) — still closer than the 7,800-mile (12,500-kilometer) flyby distance to Pluto.

…If the closer approach is executed, the highest-resolution camera on New Horizons, the telescopic Long Range Reconnaissance Imager (LORRI) should be able to spot details as small as 230 feet (70 meters) across, for example, compared to nearly 600 feet (183 meters) on Pluto.

MU69 is thought to either be two objects orbiting very close to each other or an object similar to Comet 67P/C-G, two objects in contact but barely so.

In a related New Horizons story, the International Astronautical Union (IAU) has officially accepted 14 names chosen by the New Horizons team for features on Pluto.

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Juno finds mystery in Jupiter’s aurora

1:34 pm

The uncertainty of science: Scientists analyzing the data sent back by Juno have found that the system for generating Jupiter’s aurora does not appear to be same as the process that creates auroras on Earth.

The science here is a bit complicated. Suffice it to say that Jupiter’s aurora seems produced by a much more complex process, which actually should not have surprised anyone, considering how much larger Jupiter is and more powerful its magnetic field.

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Mars rover update: September 6, 2017

9:56 am

Summary: Curiosity ascends up steepest part of Vera Rubin Ridge, getting just below the ridgetop, while Opportunity inspects its footprint in Perseverance Valley.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity panorama, Sol 1807

Curiosity's location, Sol 1802

Since my last update on August 11, Curiosity has been slowly working its way along the base of Vera Rubin Ridge, and up its slope. Today’s update from the science team describes how the rover is now on the steepest part of that slope, which is also just below the ridgetop. The panorama above looks east at the ridge, at the sand-duned foothills in the Murray Formation that Curiosity has been traversing since March 2016, and the crater plains beyond.

The image on the right shows Curiosity’s approximate position, with the point of view of the panorama indicated. The image also shows their planned upcoming route across the Hematite Unit. As they note in their update:

Curiosity now has great, unobstructed views across the lowlands of Gale crater to the rear of the rover. The view is improving as the air becomes clearer heading into the colder seasons. The first image link below shows a Navcam view into the distance past a cliff face just to the left of the rover. The image is tilted due to the to the unusually high 15.5 degree tilt of the rover as it climbs the ridge. Part of Mount Sharp is in the background. The second link shows an image looking ahead, where we see much more rock and less soil. The foreground shows that some of the pebbles are relatively well rounded. The rock face up ahead is smooth, which will mean easier driving.

That report I think is somewhat optimistic.
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Sunspot update for August 2017

10:52 am

Yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for August. That graph is posted below, with annotations.

August 2017 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 long slow decline to solar minimum has now shown itself. Up until now, the ramp down from solar maximum had been fast and steep, unlike past solar cycles where the ramp down is slow and steady. The last few months the ramp down had practically ceased. In this August graph the ramp down turned into a temporary ramp up. Considering the strong activity going on right now as well as the past week, I expect the September numbers to also show this increase.

None of this means that the ramp down has ended, or that we will not see a solar minimum. All it means is that it takes awhile for the Sun to slowly calm down after each solar maximum. The sunspots we are seeing right now, all near the equator, are from the solar cycle now slowly ending. We will know the minimum is coming as well as the next solar maximum when the first tiny and rare sunspots appear in high latitudes. These high latitude sunspots will belong to the next cycle, and will have reversed polarity.

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First images released from Juno’s seventh close fly-by of Jupiter

9:17 am

Jupiter's South pole, August 2017

Cool image time! The raw images taken during Juno’s seventh close fly-by of Jupiter have been released. The image on the right, reduced in resolution to post here, was reprocessed by Gerald Eichstädt and shows the gas giant’s south polar region.

It is worthwhile comparing this with previous south pole images, as well as other images from this fly-by reprocessed by Eichstadt. I want to know whether anyone can identify specific storms and show how they have changed over time. Unfortunately, Juno’s orbit is large, and so it only drops in close every 53 days, allowing for these storms to change a great deal, and thus making it more difficult to link images of the same changing storm. Moreover, the images don’t necessarily show the same longitudes on Jupiter, making this even more difficult.

Nonetheless, to gain a real understanding of Jupiter’s atmosphere will require a clear understanding of the pace in which its storms and atmosphere change. These images might give us our first glimpse of this process.

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Senate/House budget conflicts over science and space

8:52 am

Link here. The article gives a good overview, from a pro-science, pro-big spending perspective, of some of the significant budget differences between the proposed House and Senate budgets for 2018.

Except for NASA’s planetary program, the House generally wants to cut more than the Senate. This once again reflects the overall political trends. Because House membership changes more frequently (its members must face the voters every two years), the positions of its membership tend to reflect more closely the wishes of the voters. The Senate meanwhile (with only one-third of its membership facing re-election every two years and with six year terms for all senators) has historically trailed behind, defending past positions that are no longer popular with the voters.

If you want to predict the political future, look at what the House proposes. The budget proposals here reflect the increasing desire of the voters to trim back the federal government. Congress (and the establishment Republican leadership) might not yet realize this, but the trends show it. Soon (I hope after 2018), the resistance by that leadership and within the Senate will break, and we shall finally see some major budget cutting.

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New study claims global warming caused 2015 spike in road deaths

9:41 am

This is why global warming activists have little credibility: A new study has concluded that global warming, not increased use of cell phones, caused the increased number of road deaths in 2015.

Combining government data for the 100 most densely-populated U.S. counties for miles driven, vehicle fatalities and weather, researcher Leon Robertson found that motorists clock up extra miles as temperatures and precipitation rates rose. When temperature rose by a degree Fahrenheit (0.5 Celsius), vehicles were driven an additional 60 miles (95 kms) per person over a year, Robertson said in the study, which was published in the academic journal Injury Prevention.

Using mathematical models, the retired Yale University epidemiologist also found that for every additional inch (2.5 cm) of rainfall, cars and trucks racked up an average of 66 more miles (105 kms) per motorist for a year. Hotter than normal outdoors temperatures likely accounted for most of the extra deaths in 2015, Robertson said.”If millions more people drive cars because the temperature is getting warmer … then that adds up to a lot of miles,” he told the Thomson Reuters Foundation.

“Mainly it’s a simple multiplication.”

Since road deaths apparently dropped in 2016, does this mean that global warming has ceased?

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Mars or a bacterial cell?

8:48 am

Mars's southern polar regions

Cool image time! The image on the right, reduced and cropped to show here, was taken by Mars Reconnaissance Orbiter and shows just one spot in Mars’s southern polar regions. The surface only looks like bacteria because the basic structure of both is based on fractals. Scientists call this area “swiss-cheese terrain” because of the many holes that have opened up there.

The texture is very alien, bearing more of a resemblance to the universe of the very small, rather than the universe far, far away. But if this is a polar cap, then why does it not look like the polar caps on Earth? Indeed, there is no equivalent terrain observed here on Earth.

The so-called “Swiss cheese terrain,” referencing the numerous holes of the region, is a product of seasonal exchange between the surface and the Martian atmosphere. With a predominantly carbon dioxide content at 98 percent, the colder temperatures condense the gas out of the atmosphere to produce dry ice. The prevalence of water is more concentrated in the north, leaving the South polar region more carbon dioxide rich, and it’s this difference in composition that generates the unusual texture of the Swiss cheese terrain.

Be sure and take a look at the full resolution image. It is quite wild.

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Cassini movie flying past Saturn’s rings

8:37 am

movie of Cassini flying past Saturn's rings

Cool image time! The Cassini science team has assembled a short movie from 21 images taken by the spacecraft during its August 20th dive between the rings and Saturn. That animation is to the right.

Only two weeks remain in the Cassini mission. The spacecraft dives into Saturn on September 15.

The spacecraft is expected to lose radio contact with Earth within about one to two minutes after beginning its descent into Saturn’s upper atmosphere. But on the way down, before contact is lost, eight of Cassini’s 12 science instruments will be operating. In particular, the spacecraft‘s ion and neutral mass spectrometer (INMS), which will be directly sampling the atmosphere’s composition, potentially returning insights into the giant planet’s formation and evolution. On the day before the plunge, other Cassini instruments will make detailed, high-resolution observations of Saturn’s auroras, temperature, and the vortices at the planet’s poles. Cassini’s imaging camera will be off during this final descent, having taken a last look at the Saturn system the previous day (Sept. 14).

The second link above gives a detailed moment-by-moment breakdown of the final six days.

I would have posted this earlier this week, but my limited internet access made it impossible. Sorry about that.

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Astronomers search for water on Trappist-1 ecoplanets

10:54 am

The uncertainty of science: New research suggests that the Earth-sized exoplanets circling Trappist-1 might have water, or might not.

The data suggests the inner planets likely have lost all their water, but the outer planets, some of which are in the habitable zone, could have water. The key word is “could.” They actually don’t yet have any data that says for sure whether water is there..

Posted as we drive through Kayenta in the Navaho Reservation.

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Akatsuki finds super-rotating equatorial jet on Venus

4:56 pm

Japan’s Venus orbiter Akatsuki has discovered a previously unseen equatorial jet with wind speeds that often exceed 200 miles per hour.

The winds, named “equatorial jet” by the research team, were found from July to August 2016 when an infrared camera captured images of areas about 45 to 60 kilometers above the planet’s surface. The areas are invisible at optical wavelengths due to extremely dense clouds of sulfuric acid. The camera spotted thick clouds traveling at a speed of 288 kph to 324 kph near the planet’s equator.

Based on the news reports, it appears the significance of this discovery is that they identified a particular jet stream at a specific latitude. Previous observations did not have that resolution.

This would have been posted in the morning, but the internet access here in this Torrey hotel is almost as slow as what I experienced in Glacier. I had it written, but I sinply couldn’t get it to post this morning.

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Global warming and Glacier National Park

10:05 pm

One of the main activities for almost everyone visiting Glacier National Park is to drive across the park on Going-to-the-Sun Road, which crosses the mountains and probably has some of the most spectacular scenery of any road in the United States. During our visit this week we entered the park from the west side, spent several days there hiking trails, then took this road across to the east side, where we did more hiking.

The highest point on Going-to-the-Sun Road is Logan Pass. The park service has built a visitor center there, where everyone stops to do a short hike and admire the views. The trail head for the more challenging Highline Trail, which we did soon after arrival, is also here.

Outside the Logan Pass visitor center are a variety of displays. One focused on the changing environment at Glacier, and not surprisingly, it made a point of talking about the documented shrinkage of the glaciers during the past century. Below is an image of the pertinent quote from that display:

Display outside Logan Pass visiter center

When I saw this I was quite amused. The glaciers in the park are expected to be gone in only three more years, by 2020? Not a chance. I thought, they are going to have to change this sign soon. In fact, based on my experience with past failed global warming predictions, I was actually surprised they had let this display stay there this long, and hadn’t already made it vanish to be replaced with a new doomsday prediction that was far enough in the future that they could use if for awhile to generate new fear (and funding) before it too turned out to be wrong.

Anyway, in driving east and down from Logan Point, Diane and I eventually reached the east entrance to the park, where there was another visitor center. Like Logan Pass, this center also had a collection of outdoor displays, with one display once again focused on the park’s changing environment. Below is the pertinent quote from that display:
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Astronomers produce best image yet of a star

2:11 pm

The uncertainty of science: Astronomers have produced the best image so far of the surface face of a star.

The star is Antares, and it provides some details of the star’s complex outer layers. If I was home and had good internet access, I’d post it here.

At the same time, it should be noted that this is not a real image. It is recreated from four telescopes, using interferometry to combine the images, and also includes it a great deal of assumptions and uncertainties in its creation.

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The Eclipse

9:24 pm

The eclipse approaching totality

Just arrived at Glacier, where the internet access is bad, and there is no cell service. Thus, this might be my last post for the week. I will try to post in the evening, but this is a vacation, so it will not be my first priority. If I could do it in my room that would okay, but I have to go down to the lobby of the Lake McDonald Lodge.

Anyway the image to the right was taken by me by holding my hand filter out at arm’s length, blocking the sun, and snapping a picture with my camera. It came out far better than I expected, as you can actually see the sun in the filter, partly blocked.

Totality was amazing. I was amazed by two things. First, how quiet it became. There were about hundred people scattered about the hotel lawn, with dogs and kids playing around. The hotel manager’s husband set up speakers for music and to make announcements, but when totality arrived he played nothing. People stopped talking. A hush fell over everything. Moreover, I think we somehow imagine a subconscious roar from the full sun. Covered as it was, with its soft corona gleaming gently around it, it suddenly seemed still.

Secondly, the amazing unlikeliness of the Moon being at just the right distance and size to periodically cause this event seemed almost miraculous. Watching it happen drove this point home to me. And since eclipses themselves have been a critical event in the intellectual development of humanity, helping to drive learning and our understanding of the universe, it truly makes me wonder at the majesty of it. I do not believe in any particular religion or their rituals (though I consider the Bible, the Old Testament especially, to be a very good manual for creating a good life and society), but I do not deny the existence of a higher power. Something made this place, and set it up in this wonderous way. Today’s eclipse only served to demonstrate this fact to me again.

Posting will be light for the rest of the week. If I get a chance I will add some more pictures to this post tomorrow.
» Read more

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Trump administration to end climate panel

8:16 am

The Trump administration has decided to not renew a pro-global warming climate panel set to expire this week.

The panel is part of the National Climate Assessment, a group aimed at helping officials and policy makers integrate the US Government’s climate change analysis into their long-term planning. A mandate for the 15-member Advisory Committee for the Sustained National Climate Assessment is set to expire on Sunday, and will not be renewed.

The press will paint this panel as an objective collection of climate scientists put together to provide the president with good advice on the climate. In truth, it is a part of the propaganda machine for the global warming part of the climate science community, designed to push their conclusions while excluding any skeptical input.

Once again it appears that while Trump might be wishy-washy on many issues, on climate he is serious about dismantling the corruption that has worked its way into that field while eliminating the over-regulation that this corruption has imposed on American society.

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To protect students from eclipse some schools will close Monday, or will keep their students indoors

9:54 am

The coming dark age: Fearful of the thunder gods, some school administrators have decided to close their schools or to keep their students indoors so they can’t see the eclipse on Monday.

CBS Miami reports some local schools in South Florida are giving kids an excused absence or even the day off to enjoy the eclipse, while others have decided to keep students inside for their safety.

The Scottsdale Unified School District in Arizona decided it was just too dangerous to let kids view the eclipse, especially after some reports of fake eclipse glasses on the market that might put eyes at risk, CBS Phoenix affiliate KPHO reports. “So without us being able to control the equipment that’s being used, if it’s donated or something, and also when you’re talking about a large amount of children it’s also very difficult to convince all of the kids to not look up. That’s not to say our kids won’t be very well behaved but if there’s even a question that there could be something unsafe, Scottsdale’s not going to take the chance,” said Erin Helm with Scottsdale Unified.

The quote is from the second link above. The first link describes the decision of Ohio schools to close.

It is horrifying that there are school officials out there who would actually act to prevent children from experiencing the eclipse out of fear. Kids are smart enough to know not to look at the Sun, if you tell them not to. And it is the responsibility of the school to provide them the right kinds of eclipse glasses, which do not cost a lot and can easily be purchased.

In fact, it is revealing that the schools doing this are all public schools, and thus provides more evidence that the public schools might be the worst place to send kids to get educated.

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“One of the greatest discoveries of the century is based on these things and we don’t even know what they are, really.”

9:42 am

The uncertainty of science: New research suggests that astronomers have little understanding of the supernovae that they use to estimate the distance to most galaxies, estimates they then used to discover dark energy as well as measure the universe’s expansion rate.

The exploding stars known as type Ia supernovae are so consistently bright that astronomers refer to them as standard candles — beacons that are used to measure vast cosmological distances. But these cosmic mileposts may not be so uniform. A new study finds evidence that the supernovae can arise by two different processes, adding to lingering suspicions that standard candles aren’t so standard after all.

The findings, which have been posted on the arXiv preprint server and accepted for publication in the Astrophysical Journal, could help astronomers to calibrate measurements of the Universe’s expansion. Tracking type Ia supernovae showed that the Universe is expanding at an ever-increasing rate, and helped to prove the existence of dark energy — advances that secured the 2011 Nobel Prize in Physics.

The fact that scientists don’t fully understand these cosmological tools is embarrassing, says the latest study’s lead author, Griffin Hosseinzadeh, an astronomer at the University of California, Santa Barbara. “One of the greatest discoveries of the century is based on these things and we don’t even know what they are, really.”

The key to understanding this situation is to maintain a healthy skepticism about any cosmological theory or discovery, no matter how enthusiastically touted by the press and astronomers. The good astronomers do not push these theories with great enthusiasm as they know the feet of clay on which they stand. The bad ones try to use the ignorant mainstream press to garner attention, and thus funding.

For the past two decades the good astronomers have been diligently checking and rechecking the data and the supernovae used to discover dark energy. Up to now this checking seems to still suggest the universe’s expansion is accelerating on large scales. At the same time, our knowledge of supernovae remains sketchy, and thus no one should assume we understand the universe’s expansion rate with any confidence.

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Water ice found near Martian equator

8:27 am

A review of old Mars Odyssey data has revealed the presence on Mars of water ice near the planet’s equator.

The article makes a big deal about the importance of this discovery for the possibility of past or even present life on Mars. I say that its real importance relates to future colonists, and cannot be understated.

I should add one caveat: The resolution of the data is not great, 290 kilometers, which leaves a lot of room for error.

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Ten planetary probes track a solar eruption through the solar system

9:02 am

The path of an October 2014 solar eruption was tracked by ten different spacecraft, including Curiosity on the surface of Mars, as its blast moved outward through the solar system.

The measurements give an indication of the speed and direction of travel of the CME [Coronal Mass Ejection], which spread out over an angle of at least 116 degrees to reach Venus Express and STEREO-A on the eastern flank, and the spacecraft at Mars and Comet 67P Churyumov–Gerasimenko on the western flank.

From an initial maximum of about 1000 kilometers per second (621 miles per second) estimated at the sun, a strong drop to 647 kilometers per second (402 miles per second) was measured by Mars Express three days later, falling further to 550 kilometers per second (342 miles per second) at Rosetta after five days. This was followed by a more gradual decrease to 450–500 kilometers per second (280-311 miles per second) at the distance of Saturn a month since the event.

The CME was first detected by solar observatories Proba-2, SOHO, Solar Dynamics Observatory, and STEREO-A.It was then tracked as it moved outward by Venus Express, Mars Express, MAVEN, Mars Odyssey, Curiosity, Rosetta, Cassini, and even New Horizons and Voyager 2.

On my last appearance on Coast to Coast, I was specifically asked if the probes to Venus, Mars, and other planets have the capability to track solar events. I knew that the Voyager spacecraft had equipment to do this, but was unsure about other planetary probes. This article answers that question.

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The gentle storms of Saturn

10:03 am

Saturn's gentle storms

Cool image time! The Cassini image above, cropped and reduced slightly, shows a close-up view of Saturn’s cloud tops, taken during Cassini’s May 18, 2017 fly-by.

Clouds on Saturn take on the appearance of strokes from a cosmic brush thanks to the wavy way that fluids interact in Saturn’s atmosphere. Neighboring bands of clouds move at different speeds and directions depending on their latitudes. This generates turbulence where bands meet and leads to the wavy structure along the interfaces.

What I see is a much less turbulent storm pattern, when compared with Jupiter. This is not to say that the weather of Saturn is quiet or peaceful, for it certainly cannot be, considering the gas giant’s size and the depth of the atmosphere. Still, this image suggests that the turbulence is less violent here, possibly because Saturn is farther from the Sun and is hit with less solar energy, and because Saturn is smaller and thus produces less of its own internal energy.

Either way, it is beautiful and mysterious, in the way are all such images of alien places.

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New research challenges theories on Earth formation

9:47 am

The uncertainty of science: New research about the Earth’s core contradicts the presently accepted theories about the Earth’s formation.

New geochemical research indicates that existing theories of the formation of the Earth may be mistaken. The results of experiments to show how zinc (Zn) relates to sulphur (S) under the conditions present at the time of the formation of the Earth more than 4 billion years ago, indicate that there is a substantial quantity of Zn in the Earth’s core, whereas previously there had been thought to be none. This implies that the building blocks of the Earth must be different to what has been supposed.

The research suggests that the Earth is made up of materials different than expected, which means that the materials from the solar system from which it formed are different than presently believed, which also means that present formation theories will need to be revised.

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Cassini’s last close look at Titan

9:44 am

Titan's magic lake district

The Cassini science team has released the last radar swath that the spacecraft will take of Titan, imaged on April 22.

You can see the full swath up close here. The image above is my crop of the section on the swath’s right portion, showing the shoreline of the hydrocarbon lake Ligeia Mare, where periodically an island has been seen by radar to intermittently appear and disappear.

No “island” feature was observed during this pass. Scientists continue to work on what the transient feature might have been, with waves and bubbles being two possibilities.

The fly-by also took the first, and last, depth measurement of 8 other lakes, finding that they all had the same depth, suggesting they are connected by an underground “water” table. In this case, it ain’t water, but liquid hydrocarbons like methane.

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Unexpected big storm on Neptune

9:17 am

The uncertainty of science: Astronomers have spotted a new very big storm on Neptune, occurring unexpectedly near the plane’s equator.

A large, high-pressure vortex system deep within Neptune’s atmosphere is thought to drive the white storm clouds. As methane gases rise up in the vortex, they cool below the condensation temperature, forming clouds in the same way that water vapor does on Earth.

The location of the vortex caught astronomers by surprise, though. “Historically, bright clouds have occasionally been seen on Neptune, but usually at latitudes closer to the poles, around 10 to 60 degrees north or south” says de Pater. “Never before has a cloud been seen at, nor close to the equator, or anything so bright.”

Neptune is the windiest planet in the solar system, with observed equatorial wind speeds of up to 1,000 miles per hour (450 m/s). Since wind speeds vary drastically with latitude, a storm crossing more than 30° of latitude should quickly break apart. Something, such as an underlying vortex, must be holding it together. But a long-lasting vortex right at the equator would be hard to reconcile with our current understanding of the planet’s atmosphere.

I think any theory about Neptune’s weather should treated with a great deal of skepticism. I am sure the theories are based on what is known, but what is known is very little. Until we have been able to observe this gas giant up close and for decades, our understanding of its weather is going to be sketchy, at best.

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Chinese engineers and astronomers fight over new telescope design

9:10 am

A dispute over the design of a new Chinese optical telescope has broken out between the astronomers who will use it and the engineers who will build it.

In April, an international committee convened by [Chinese Academy of Science’s] Center for Astronomical Mega-Science, which is responsible for the project, reviewed the competing designs and recommended the three-mirror option [the preference of astronomer Jiansheng Chen and China’s astronomers]. On 10 July, [Xiangqun Cui, the instrument’s chief engineer] organized her own review committee that picked the SYZ design as better. Cui’s panel “leaned toward one side,” Chen says. And one member says that the three-mirror design was not sufficiently presented, partly because no one from the Huazhong team was there. Cui and Su explain in their open letter that a member of their own group who knows it well introduced the Huazhong design. “Members were repeatedly reminded they could abstain from voting,” they write. One-third of the 21 committee members did abstain.

Meanwhile, to date, more than 130 young astronomers have signed an open letter to the astronomical community urging that the recommendations of the international panel be respected.

The fundamental disagreement, according to Chen, is “whether a large science project should be technically or scientifically oriented.” Cui and Su say the choice is between incorporating “rapidly developing new technologies” that ensure a long life for the facility, or “simply replicating a 10-meter telescope built 30 years ago.”

This spat reinforces the impression gained from the recent other story about China’s inability to find a manager for its newly built radio telescope. Its top-down management approach (where decisions are made by well-connected powerful bureaucrats at the top of the chain of command) produces office politics that generally does not lead to good technical decisions.

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Mars rover update: August 11, 2017

12:34 pm

Summary: After a two week hiatus because the Sun was between the Earth and Mars and blocking communications, both rovers are once again on the move.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity panorama, Sol 1782

Vera Rubin Ridge close-up

Since my last update on July 12,, Curiosity spent most of the month waiting out the solar conjunction that placed the Sun between the Earth and Mars and blocked communications. In the past few days, however, the rover has begun to send down images again while resuming its journey up Mt. Sharp. The panorama above, reduced to show here, was taken by the rover’s left navigation camera, and shows the mountain, the ridge, and the route the rover will take to circle around the steepest sections to get up onto the ridge. To see the full resolution panorama click on the picture.

To the right is a full resolution section of the area in the white box. As you can see, the geology of the ridge is many-layered, with numerous vertical seams or cracks. In order to track the geological changes across these layers as the rover climbs, the science team is as expected taking a systematic approach.

Lately, one of our biggest science objectives is to conduct bedrock APXS measurements with every 5-meter climb in elevation. This allows us to systematically analyze geochemical changes in the Murray formation as we continue to climb Mount Sharp. Yesterday’s drive brought us 6 meters higher in elevation, so another touch and go for today it is!

Below is a cropped and reduced resolution image of the most recent orbital traverse image, dated sol 1754. The dotted line shows where I think the rover’s has traveled in the last 28 sols. I have also annotated what I think is the point of view of the panorama above.
» Read more

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First very short movie from Jupiter

7:37 am

Using two Juno images of the same area, taken at slightly different times, scientists have produced what might be the first very short gif animation showing the changing circulation patterns in Jupiter’s atmosphere.

The animation is only two images long, so in a sense it isn’t a movie but a blink comparison. Moreover, the difference in circulation patterns between the two images is not strongly evident, partly because the two images have different resolution and somewhat different lighting. Nonetheless, this animation foretells what will should become possible with time, as Juno’s mission continues. Eventually its images will show the changes in the gas giant’s storms.

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Cassini’s last five orbits of Saturn

10:14 pm

Cassini is about to begin its last of five orbits of Saturn, before it is sent into the planet’s atmosphere to burn up.

Cassini will make the first of these five passes over Saturn at 12:22 a.m. EDT Monday, Aug. 14. The spacecraft’s point of closest approach to Saturn during these passes will be between about 1,010 and 1,060 miles (1,630 and 1,710 kilometers) above Saturn’s cloud tops.

The spacecraft is expected to encounter atmosphere dense enough to require the use of its small rocket thrusters to maintain stability – conditions similar to those encountered during many of Cassini’s close flybys of Saturn’s moon Titan, which has its own dense atmosphere. “Cassini’s Titan flybys prepared us for these rapid passes through Saturn’s upper atmosphere,” said Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory (JPL) in California. “Thanks to our past experience, the team is confident that we understand how the spacecraft will behave at the atmospheric densities our models predict.”

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A Martian Journey

10:56 am

The exploration of the solar system has barely begun. Though we regularly get to see some spectacular images taken by the fleet of unmanned planetary probes that now circle or rove the various planets throughout the solar system, we mustn’t think we have seen very much. In truth, we have only gotten a very distant glimpse of only a few tiny spots, most of which have been viewed from very far away. Even at the highest resolution the images do not really tell us what it really will be like when we can stroll across those surfaces routinely.

To give you an idea of how much remains hidden, let’s take a journey inward from Mars orbit. The image below looks down on a good portion of the Martian globe, with the giant volcano Olympus Mons on the left, its three companion volcanoes in line to the east, and the vast valley of Valles Marineris east of these. This valley would cover the continental United States almost entirely, and extend significantly beyond into the oceans on either side.

Olympus Mons and Valles Marineris

This was essentially our first good look at Mars, taken from orbit by Mariner 9 in 1971.
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Sunspot update for July 2017

10:06 am

NOAA today posted its monthly update of the solar cycle, covering sunspot activity for July. As I have done every month since 2010, the graph is posted below, with annotations.

July 2017 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.

Sunspot activity in July remained almost exactly the same as in both May and June. This is the first indication that this cycle’s ramp down from solar maximum will follow the standard pattern of a slow and extended decline to minimum. Up until now the drop in sunspot activity has been as fast as the increase during ramp up. Historically the ramp down has instead been slower, sloping downward gently and over a much longer time period. The last few months suggest that this cycle’s end is beginning to resemble past cycles.

Meanwhile, a review of past solar cycles by German scientists suggests that a cyclical cooling period in the Sun’s output is coming, and that such ups and downs can be tracked in the solar record.

In order to elucidate the solar influence, we have used a large number of temperature proxies worldwide to construct a global temperature mean G7 over the last 2000 years. The Fourier spectrum of G7 shows the strongest components as ~1000-, ~460-, and ~190 – year periods whereas other cycles of the individual proxies are considerably weaker. The G7 temperature extrema coincide with the Roman, medieval, and present optima as well as the well-known minimum of AD 1450 during the Little Ice Age. We note that the temperature increase of the late 19th and 20th century is represented by the harmonic temperature representation, and thus is of pure multiperiodic nature. It can be expected that the periodicity of G7, lasting 2000 years so far, will persist also for the foreseeable future. It predicts a temperature drop from present to AD 2050, a slight rise from 2050 to 2130, and a further drop from AD 2130 to 2200. [emphasis mine]

Note that this prediction is not based on any real understanding of the Sun’s sunspot cycle or what causes any variations in its brightness. All they have done is extrapolate into the future the patterns of past fluctuations. This is as if a weatherman averaged how many times it normally rains in your town, and then predicted rain in the next few days merely by those averages. “It rains on average every three days, so because it rained yesterday expect no rain for the next two days!”

Nonetheless, the past fluctuations seem to follow a cyclical pattern, and thus also appear to confirm other studies that suggest we are heading towards another grand minimum, with no sunspots for decades, which also in the past corresponded with cooler global temperatures.

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Looking down at Saturn’s rings

9:19 am

Looking down at Saturn's rings

Cool image time! The image on the right, reduced in resolution to show here, was taken by Cassini in May and looks down at the outer rings of Saturn. The moon Prometheus can also be seen in the large gap between the main rings and the outermost F ring.

Most of the small moon’s surface is in darkness due to the viewing geometry here. Cassini was positioned behind Saturn and Prometheus with respect to the sun, looking toward the moon’s dark side and just a bit of the moon’s sunlit northern hemisphere.

Also visible here is a distinct difference in brightness between the outermost section of Saturn’s A ring (left of center) and rest of the ring, interior to the Keeler Gap (lower left).

The image clearly shows the gravitational influence of the moon on the outer ring. As Prometheus orbits past the F ring its mass creates waves through the ring’s materials.

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