Only 4.6 square miles in area, the Palmyra Atoll offers scientists the opportunity to compare largely intact ecosystems within shouting distance of recently disturbed habitats. A riot of life—huge grey reef sharks, rays, snapper and barracuda—plies the clear waters while seabirds flock from thousands of miles away to roost in the verdant forests of this tropical idyll.

This past fall, Stanford students Douglas McCauley and Paul DeSalles tracked manta rays’ movements around the atoll for a predator-prey interaction study. Swimming with the rays and charting their movements with acoustic tags, the scientists noticed the graceful creatures kept returning to the same particular coastlines. At the same time, Harvard’s Hillary Young was studying the coconut palm trees’ effects on bird communities and native habitats.

Over meals and sunset chats at the small research station, McCauley, DeSalles, Young, and other scientists discussed their work and traded theories about their observations. “As the frequencies of these different conversations mixed together, the picture of what was actually happening out there took form in front of us,” McCauley says.

The picture seems to look like this: seabirds prefer the native trees’ larger and more complex canopies to the human-planted coconut palms on the Palmyra Atoll. The birds feed on nitrogen-rich fish and squid and tend to leave their droppings, or guano, on the soil around those native trees. Rainfall washes these droppings into the nearby sea, enriching the phytoplankton (algae) in the water. The zooplankton (animals) feed on the enriched phytoplankton in these areas, attracting the giant manta rays.

Giant manta rays were abundant on the coasts where there were native trees nearby, but were not spotted at all where there were coconut palms.

This incredible food chain leads from sea to land to sea again. Carl Zimmer reports in Yale Environment 360 that:

The new study is a particularly striking illustration of a pattern that scientists are finding around the world. Life on land and life in the ocean are bonded in unexpectedly powerful ways. While they may seem like separate realms, the well being of one depends on the other.

(Zimmer offers more examples of this interdependence, as does the New York Times.)

The researchers also say that these findings shed light on how human disturbance of the natural world may lead to widespread, yet largely invisible, disruptions of ecological interaction chains. This, in turn, highlights the need to build non-traditional alliances—among marine biologists and foresters, for example—to address whole ecosystems across political boundaries.

“This is an incredible cascade,” says researcher Rodolfo Dirzo, of the Stanford Woods Institute for the Environment. “As an ecologist, I am worried about the extinction of ecological processes. This dramatically illustrates the significance of such extinctions.”

Image: Gareth Williams

Solar eclipses occur when the Moon passes directly between the Sun and Earth. In contrast to total solar eclipses, when the disk of the Moon completely covers the disk of the Sun, as seen from Earth, annular solar eclipses occur when the Moon lies slightly farther away, appearing slightly smaller than the Sun.  As a result, the Moon doesn’t completely block the Sun and instead leaves a bright ring of the solar disk visible around it—like a dime laid on top of a penny.  This ring is called an “annulus,” and it will be bright enough to wash the Sun’s outer atmosphere, or corona, from view.

While solar eclipses occur about every six months, it’s a rare treat to see it from your own backyard—you have to be in the right place, at the right time. The next time an eclipse will cast its shadow on the western US is a total solar eclipse on August 21, 2017.

Sunday’s eclipse will begin in Asia around 2:19 p.m. our time. You can watch its progress live online.

In the western United States, it will follow a narrow line from Eureka and Redding through Reno, Carson City, Albuquerque, and Lubbock. Observers will see the silhouette of the New Moon slowly passing directly in front of the Sun’s disk.

While we won’t see the entire event here in the San Francisco Bay Area, we’ll still get a great view! For us, the eclipse begins at 5:16 p.m. and ends at 7:40 p.m., with maximum eclipse occurring at 6:33 p.m., when the Moon will cover 89% of the Sun’s diameter, turning the Sun into a thin, graceful crescent.  The change in illumination won’t plunge us into darkness, but with most of the Sun’s disk blocked from view, people should notice something odd or different about the quality of daylight.

Looking directly at the Sun is never safe, and it is especially important with all the excitement this weekend that everyone remains cautious. We’ve produced a fun, informative video on how to view the eclipse safely.

If you’re in the area and we’re fog-free, join us in front of the Academy Sunday evening to view this spectacular event!

Bing Quock and Alyssa Keimach contributed to this article.

Image: sancho_panza/Wikipedia

Solar flares are generated by an abrupt release of magnetic energy around sunspots, a process that Nature News describes quite vividly:

Solar flares occur when magnetic-field loops threading through sunspots get twisted and break, releasing massive amounts of radiation and accelerating charged particles into space.

Although large flares from our own Sun can wreak havoc on satellites and power grids on Earth, it could be worse. Distant stars observed by the Kepler mission are emitting “superflares,” which carry 10 to 10,000 times more energy than average solar flares. If our Sun had these outbursts, they would damage the ozone, kill off species, and cause a change in the amount of sunlight emitted.

Fortunately, superflares are rare. Observing 83,000 Sun-like stars, a team of Japanese researchers, poring over Kepler data, determined that only 148 emitted superflares. The astronomers studied fluctuations in the stars’ overall light.

Could our Sun emit a deadly superflare? No.

Most of the superflare stars rotate quickly, unlike our slow-rotating Sun. ScienceNOW describes why this increases the stakes for superflares:

Most of these feisty stars spin fast, intensifying magnetic fields that spawn spots and flares.

Additionally, most of the superflare-emitting stars are quite young, unlike our middle-aged Sun.

What causes these superflares? It’s a mystery. One theory suggests that hot Jupiters are to blame. These Jupiter-sized planets rotate so close to their parent stars that the two massive objects might interact to supercharge the stellar flares.

Many scientists, including Lucianne Walkowicz of the Kepler team at Princeton University, find the hot Jupiter theory hard to believe. Walkowicz told Nature News:

It seems extremely unlikely that a planet is causing these flares. More likely, it means that even when [stars are rotating slowly], they are occasionally able to store up their magnetic energy and release it in these big flares. It’s really a mystery as to how and why that happens.

The study was published earlier this week in the journal Nature.

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and volunteers for the Morrison Planetarium.

Image: SOHO/ESA/NASA