Category Archives: Science

Juno Red Spot Images

If you’re going to go all the way out to Jupiter, and spend months snapping pix, you really, really ought to get some pictures of the Red Spot. The Great Red Spot has been observed since 1830, but never from this close.

This week’s close flyby picked up the best pictures ever from this giant hurricane.

The visual imagery was rapidly processed to produce a pretty picture. The entire data collection will be analyzed and described soon (presumably by the end of the year conferences).

This enhanced-color image of Jupiter’s Great Red Spot was created by citizen scientist Jason Major using data from the JunoCam imager on NASA’s Juno spacecraft. The image was taken on July 10, 2017 at 07:10 p.m. PDT (10:10 p.m. EDT), as the Juno spacecraft performed its 7th close flyby of Jupiter. At the time the image was taken, the spacecraft was about 8,648 miles (13,917 kilometers) from the tops of the clouds of the planet. JunoCam’s raw images are available for the public to peruse and process into image products at: http://www.missionjuno.swri.edu/junocam More information about Juno is at: https://www.nasa.gov/juno and http://missionjuno.swri.edu Credits: NASA/JPL-Caltech/SwRI/MSSS/Jason Major

The composite image gives us the impression of this massive storm. Visually, it is clearly a really complicated “hurricane of hurricanes”.

The more detailed analysis may suggest a more refined understanding of how this storm developed and has persisted for at least 150 Earth years.

Cool.

There will be another close pass on 1 September, just before Cassini’s finial dive at Saturn. The Juno mission will end in February with a deliberate dive into the atmosphere.


  1. Agle, DC, Dwayne Brown, and Laurie Cantillo, NASA’s Juno Spacecraft Spots Jupiter’s Great Red Spot, in NASA Latest, M. Perez, Editor. 2017. https://www.nasa.gov/feature/jpl/nasa-s-juno-spacecraft-spots-jupiter-s-great-red-spot

 

Space Saturday

Life After the Dinosaurs

Everyone knows about the mass extinction that ended the age of dinosaurs. This is often said to have opened the way for the age of mammals and eventually us.

Of course, it wasn’t exactly like that.

In the wake of the mass extinction, there was an explosive radiation of all the surviving species, not just mammals.

This month saw two articles about this exciting period.

First of all, the dinosaurs didn’t actually all die out. One whole wing of the family survived and thrived until today: the birds.

Ksepka, Daniel T., Thomas A. Stidham, and Thomas E. Williamson report on new findings which document the rapid diversification of birds after the extinction event.[2].  Specifically, they report a small bird that is dated from the very early Paleocene, i.e., soon after the end of the dinosaurs. They argue that dating this species implies that four major groups of birds arose soon after that.

The authors comment that this observation puts the diversification of birds on approximately the same time line as the expansion of mammals.


In a different study, Yan-Jie Feng and collagues analyzed DNA from 156 living species of frogs to construct a putative taxonimic history, anchored by 20 representative fossils [1]. The results suggest that “three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification” right after the end of the dinosaurs. ([1], p. 1)

They argue that the “mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities.” There is a very telling diagram in the full article, with a gigantic fan out of species just past the red line of the Cretaceous extinction event.

The researchers comment that their molecular study is important because the fossil record of frogs is sparse. This is one of the clearest pictures, albeit indirectly, that documents the evolutionary history of frogs during this period.

Again, this is the same time scale as mammals and birds, suggesting that there was a mad evolutionary scramble to fill the huge void left by the mass extinction at the end of the Cretaceous.

Cool!


After the Dinosaurs came not the “Age of Mammals” but the “Age of Pretty Much Everything Except Non-Avian Dinosaurs”! 🙂


  1. Yan-Jie Feng, David C. Blackburn, Dan Liang, David M. Hillis, David B. Wake, David C. Cannatella, and Peng Zhang, Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous–Paleogene boundary. Proceedings of the National Academy of Sciences, July 3, 2017 2017. http://www.pnas.org/content/early/2017/06/26/1704632114.abstract
  2.  Daniel T. Ksepka, Thomas A. Stidham, and Thomas E. Williamson, Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K–Pg mass extinction. Proceedings of the National Academy of Sciences, July 10, 2017 2017. http://www.pnas.org/content/early/2017/07/05/1700188114.abstract

 

Where are the bees?

In the past decade, scientists have raised alarms about the decline in pollinators, including the semi-domestic honey bee.

There seems little doubt that honey bees are dying off at alarming rates. It would be surprising if similar trends were not occurring across many species of bee, wasp, beetle, and butterfly.

Data point: in my pollinator friendly yard, we get lots of insects. Up to two years ago, we had honey bees and at least three other species of bees, as well as butterflies, and numerous identified insects. Every day, all summer.

Last year, there were no honey bees. None this year, either. From hundreds to zero in one year. I assure you that the flowers are the same, so where are the bees?

Suspicions fall on agricultural chemicals, insecticides intended to protect crops from being eaten by insects. But with a bazillion dollar industry and possibly huge crop losses at stake, trivial ideas like, “just stop using pesticides” are neither reasonable nor feasible. We need to know exactly what is happening to bees, and we need to know as soon as possible.

For one thing, there are a number of stressors for bees, including the familiar refrains of habitat loss and climate shift. For that matter, there are a lot of human introduced chemicals that might be involved. And, in the end, the bees must contend with the combination of all these.

But out of all the troubles plaguing our bees, fingers have pointed to neonicotinoid chemicals which are applied as a coating on crop seeds. Bees don’t have much to do with seeds, but the worry is that these chemicals persist for months, and small quantities are on the flowers that bees and other insects visit. Visiting hundreds of flowers, a bee may be exposed to tiny amounts of chemical many times. Furthermore, insects may carry the chemicals to other flowers and back to nests, spreading small amounts of the toxins.

An assessment of the problem requires examining how tiny amounts of chemicals persist and spread, as well as how much pollinators pick up from these sources. Investigating this in real settings is a non-trivial challenge, because the amounts of chemicals are small and must be measured over long periods of time. There are many possible variables, including how the chemicals are used, weather and soil conditions, and who know what else.

This month a European team reports a large scale study of these effects, comparing the effects over two years of neonicotinoid with control [3]. The careful study found a rather complicated set of results, different for different countries in the study. In some cases, there was clear losses of the bees, in others there were no differences between conditions. In the case of the UK, so many bees died in all conditions that there could be no statistical comparison of the effects. The study also found traces of the chemicals in the nests of wild bees, which appears to be related to reduced populations.

Overall, their results seem to show that there definitely are losses of bees, and these chemicals may contribute to the losses, at least in some cases. Most likely, neonicotinoids weaken some of the bees, making them more vulnerable to other challenges.

This study also confirms that the chemicals persist for months, and seem to accumulate in the nests of wild bees, far from the location of the deployment, and far from the intended target. This is consistent with other studies [2].

There is certainly cause for concern here. The EU and Canada are moving to stop using these chemicals, with a calculus that even with uncertainty, the benefits don’t outweigh the risks [1].

With the current administration, the US EPA will almost certainly not act to restrict these chemicals, study or no study. Sigh.

If you still have bees, be sure to say goodbye to them this summer. There won’t be very many left in a few years.


  1. Rebecca Morelle, Large-scale study ‘shows neonic pesticides harm bees’, in BBC News – Science & Environment. 2017. http://www.bbc.com/news/science-environment-4038208
  2. Erik Stokstad, Controversial pesticides can decimate honey bees, large study finds, in Science – News. 2017. http://www.sciencemag.org/news/2017/06/controversial-pesticides-can-decimate-honey-bees-large-study-finds
  3. B. A. Woodcock J. M. Bullock, R. F. Shore, M. S. Heard, M. G. Pereira, J. Redhead, L. Ridding, H. Dean, D. Sleep, P. Henrys, J. Peyton, S. Hulmes, L. Hulmes, M. Sárospataki, C. Saure, M. Edwards, E. Genersch, S. Knäbe, and R. F. Pywell, Country-specific effects of neonicotinoid pesticides on honey bees and wild bees. Science, 356 (6345):1393, 2017. http://science.sciencemag.org/content/356/6345/1393.abstract

 

Dinosaurs Rising From The Ashes

We’re all fascinated with the story of the end of the Dinosaurs, which corresponds with a really big impact, and possibly other catastrophes. The death of the dinosaurs is not only a puzzle, it is the event that made room for mammals and puny humans to evolve.

But there was also a mass extinction that cleared the way for the great adaptive radiation of dinosaurs. At the end of the Triassic period, about 200M years ago, there was a massive extinction of animals. The dinosaurs rose after this catastrophe.

This month a team of British scientists published new evidence that there was a huge sequence volcanic eruptions at that time, which would have been devastating for living things. This event has been suspected from other evidence of huge lava flows, global cooling (due to volcanic material in the atmosphere), and, of course, mass extinctions.

The new study uses a new techniques which measures mercury (Hg) in the rocks. This element is highly correlated with volcanic activity, which spews Hg into the air.  The mercury falsl out and is incorporated into rock, where it persists for long periods of time–hundreds of millions of years.

Careful measurements indicate high levels of mercury in the period between the extinctions at the end of the Triassic, and the beginning of the Jurassic. In other words, a very clear suggestion that the volcanic disaster caused the extinctions, and the end of the episode was followed by the rise of the dinosaurs.

A key aspect of this work is to trace mercury deposits to many locations around the world. Furthermore, the deposits should be temporally aligned, rising and falling at the same time.   These signatures are consistent with large volcanic “pulses”.

The researchers report that the “Hg excursions are recorded in five of the six sections studied”, and that “The onset of Hg enrichment occurred synchronously across the globe, coincident with the end-Triassic extinction and associated global carbon cycle perturbation.“ (p.5)

In other words, there is clear evidence of very widespread effects of volcanism at the precise time of the mass extinctions.

As Rebecca Morelle puts it, “The onset of Hg enrichment occurred synchronously across the globe, coincident with the end-Triassic extinction and associated global carbon cycle perturbation.

And, evidently, ancestors of the dinosaurs survived this catastrophe, and “once the volcanoes had simmered down, few of their competitors were left, allowing the age of the dinosaurs to begin.”

The dinosaur age began and ended in world-wide catastophe that wiped out most living species, clearing the way for another burst of speciation.

The “age of mammals” started with the catastrophe that killed off the dinosaurs.  It is ending now with the sixth extinction, and, most likely, a spike in global temperature.


  1. Rebecca Morelle, Volcanoes ‘triggered dawn of dinosaurs’, in BBC News: Science & Environment. 2017. http://www.bbc.com/news/science-environment-40333902
  2. Lawrence M. E Percival, Micha Ruhl, Stephen P. Hesselbo, Hugh C. Jenkyns, Tamsin A. Mather, and Jessica H. Whiteside, Mercury evidence for pulsed volcanism during the end-Triassic mass extinction. Proceedings of the National Academy of Sciences, June 19, 2017 2017. http://www.pnas.org/content/early/2017/06/13/1705378114.abstract

Celibrate World Giraffe Day: June 21

June 21 is World Giraffe Day!

Visit a Zoo or explore information on the web.

I think the closest giraffes to me are in Peoria:

This celebration is organized by The Giraffe Conservation Foundation, which seeks funding to help preserve this iconic and beloved species. Their website has lots of images of giraffes, and invites people to “stick their necks out” to save the giraffes.

I have to say that I would not want to live on an Earth without giraffes.

 

Remote Sensing Penguin Guano

There is so much we don’t know about the Earth and the biosphere. Even for relatively big and easy to see species such as birds, it is hard to know how and where they live, or even how many individuals exist. There are only so many biologists, and humans can only go and see so much.

Remote sensing of the planet from space has gives important insights about large scale processes that can’t be seen easily form a human perspective. For instance, a few images from space make absolutely clear how important dust storms in Africa are for the Amazon forests in South America.

In the past, it has been difficult to learn much about animal populations, because individuals are small and elusive. Biologists are getting better at detecting and tracking animals, especially mass movements of them.

This month NASA calls attention to a successful long term project that uses satellite imagery to locate colonies of Penguins [3]. Penguins are, of course, far too small to be reliably detected from most satellite imagery. However, Penguins live in colonies, and produce immense amounts of guano, which can be seen from space.

In fact, Penguin colonies could be seen from space 30 years ago [2], and space imagery and analysis have gotten a lot better since then.

The basic technique is to detect the color of guano covered rocks, and to infer how many Penguins live there from the area covered. Cross checking on the ground has confirmed that this indirect and remote measure is a pretty good estimate of and many Penguins there are and where they nest.

As the researchers note, Penguins live on sea ice, which means that they are a sensitive indicator of how ice conditions change. As sea ice is melting in parts of Antarctica, we can document how Penguins relocate in response. Penguins are also eat krill and fish, so they are a visible indicator of the health of these foods in an area.

Mathew Schwaller, Heather Lynch and colleagues have completed a global census of Adelie Penguins using imagery from several satellites [1]. They use machine learning techniques to identify the visual signature of nesting areas. Based on the very characteristic nesting habits of Adelies, it is possible to estimate the number of Penguins based on the area. Naturally, the satellite data is combined with on-site investigations and other reports, in order to validate the remote sensing and the estimation.

From [1] FIGURE 1. Map of extant Adélie Penguin colonies, as well as penguin colonies not found in imagery and presumed extinct. Solid bars represent sections of coastline in which populations are generally increasing in abundance, and dashed lines those in which populations are generally decreasing. Areas with no bar are either a mix of increasing and decreasing populations, are not changing in abundance, or do not have sufficient data to assess population change (see Supplemental Material Appendix A). Right: example of high-resolution imagery from Devil Island (−63.797°, −57.290°; location indicated by black arrow). Areas identified in the analysis as guano are shaded in light green. Imagery © 2014 by DigitalGlobe, Inc.
One huge advantage of the satellite data is that there is continued coverage of the whole world, so it is possible to track the changes in Penguin populations. For instance, the 2014 report indicates that over the last twenty some years, nesting sites in West Antarctica have dwindled. This is where sea ice is shrinking. In the same period, new nesting sites have appeared in East Antarctica, where sea ice has increased. Overall, the total population of Adelies seems to have increased in recent years, even as the birds have migrated to more favorable ice.

Ideally, the census can be maintained for a number of years to accumulate a much more detailed baseline, to improve the technique, and refine the understanding of the Penguin population. This census is only one species, so it remains to be seen how similar techniques might track other species.


  1. Heather J. Lynch and M. A. LaRue, First global census of the Adélie Penguin. The Auk, 131 (4):457-466, 2014/10/01 2014. https://doi.org/10.1642/AUK-14-31.1
  2. Heather J.  Lynch,  and Mathew R. Schwaller, Mapping the Abundance and Distribution of Adélie Penguins Using Landsat-7: First Steps towards an Integrated Multi-Sensor Pipeline for Tracking Populations at the Continental Scale. PLOS ONE, 9 (11):e113301, 2014. https://doi.org/10.1371/journal.pone.0113301
  3. Adam Voiland, Penguin Droppings Are Fertile Ground for Science : Image of the Day. NASA Earth Observatory.2017,  https://earthobservatory.nasa.gov/IOTD/view.php?id=90372

PS.  Wouldn’t “Penguin Guano” be a good name for a band? How about ‘Adelie Census’?

 

 

Space Saturday

New Study: Tyrannosaurs Not Furry

One rule of thumb for blogging is, “when in doubt, go with Dinosaurs!”.  And, for preference, T. rex, of course.  🙂

As I have said, this is the great age of Dinosaur science. Aided in part by the opening of rich fossil beds in China, but also by better and better technology that lets us see much more from the fossils we find.

No controversy has been more controversial than the kerfluffle over feathered Dinosaurs. It’s not that many Dinosaurs couldn’t or shouldn’t have feathers—they did.  They are the ancestors of birds, after all.

But it’s very hard to accept a feathery T. rex. The very paragon of bad ass, top of the top predators, T. rex really should not be fluffy. I mean you’re dead anyway, but you don’t want to be saying, “ooh, look at that gorgeous thing” just as you are snarfed down by the most ferocious land animal ever. It’s just not dignified.

This month Phil Bell and colleagues from around the world published a new detailed study of the skin of Tyrannosaurus rex and family [1]. They conclude that T. rex was not feathered, though it might have had a some feathers on its back. It remains possible that baby rexes may have had features that shed as the animals matured. (We don’t know much at all about baby rexes.)

This finding makes sense form the point of view of thermoregulation. Large, active animals don’t really need a coat of feathers to keep warm. It also might indicate T. rex migrated to live a warmer climate, or out into hot open spaces.

Ancestors of T. rex definitely had a lot of hair-like feathers, and some of them grew to be fairly large, as large as some Tyrannosaurs. So there is still a lot to be learned about the evolution of these animals, and what may have influenced the evolution of feathers and scales.

It is important to note that this is one of the most comprehensive studies of fossils that preserve the skin, but it is nevertheless a pretty tiny dataset (a dozen or two samples). In addition, feathers are a lot less likely to be preserved than skin, so the absence of fossil feathers isn’t necessarily evidence of absence [2].

But for now, I’m not going to visualize T. rex as being fluffy.


  1. Phil R. Bell, Nicolás E. Campione, W. Scott Persons, Philip J. Currie, Peter L. Larson, Darren H. Tanke, and Robert T. Bakker, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution. Biology Letters, 13 (6) 2017. http://rsbl.royalsocietypublishing.org/content/13/6/20170092.abstract
  2. Helen Briggs, Study casts doubt on the idea of ‘big fluffy T. rex’, in BBC News – Science & Environment. 2017. http://www.bbc.com/news/science-environment-40172587