Geography from space: Nile at night, a river of light

September 25, 2015

Geography teachers love the Nile Delta because it so well epitomizes what a river delta is — clear demonstration of the delta form, in real photos.

From the International Space Station, the model gets ramped up a bit:

A stunning pic taken by @StationCDRKelly while on @Space_Station shows the Nile River at night

Twitter caption: A stunning pic taken by @StationCDRKelly while on @Space_Station shows the Nile River at night

The Nile becomes a river of light, showing the advance of electrified human settlement along the banks, and providing stark contrast to the unlighted desert on either side of the river.

What other cities, landmarks, or geographical features can you identify in the photo?

Autumnal equinox, September 23, 2015

September 23, 2015

You can only get this shot on two days each year.

I was sad to discover most of my U.S. history students (juniors) didn’t know what an equinox is. So the autumnal equinox always offers a teaching moment that ticks off the teacher raters.

Summer 2015 ended at 4:15 a.m., September 23.

This is what an equinox looks like, from 2013 photos.

From Astronomy Picture of the Day: Earth at Equinox. From the Russian meteorological satellite Elektro-L

From Astronomy Picture of the Day: Earth at Equinox. From the Russian meteorological satellite Elektro-L

Explanation from NASA:

Equinox Earth
Image Credit: Roscosmos / NTSOMZ /
Courtesy: Igor Tirsky, Vitaliy Egorov Explanation: From a geostationary orbit 36,000 kilometers above the equator, Russian meteorological satellite Elektro-L takes high-resolution images our fair planet every 30 minutes. But only twice a year, during an Equinox, can it capture an image like this one, showing an entire hemisphere bathed in sunlight. At an Equinox, the Earth’s axis of rotation is not tilted toward or away from the Sun, so the solar illumination can extend to both the planet’s poles. Of course, this Elektro-L picture was recorded on September 22nd [2013], at the northern hemisphere’s autumnal equinox. For a moment on that date, the Sun was behind the geostationary satellite and a telltale glint of reflected sunlight is seen crossing the equator, at the location on the planet with satellite and sun directly overhead (5MB animated gif).

Wait. Animated .gif?  Cool!

The Earth at equinox, 2013; from Russan space program, via NASA.

The Earth at equinox, 2013; from Russan space program, via NASA.

The autumnal equinox is at 8:22 GMT or 4:22 am EDT on Wednesday. The two satellite images below from the European Meteosat show the sun angle on Earth from June 22 near the summer solstice and then today at the same time.  Notice the sun angle has changed dramatically, and the High Arctic is no longer seeing 24 hour daylight.

June 22 2015 from Meteosat.

Below is today at the same time.

Seviri Sep22


Yes, this is mostly an encore post. Fighting ignorance requires patience.

Yes, this is partly an encore post. Fighting ignorance requires patience.

Annals of Global Warming: Warm the oceans, raise the sea level

September 15, 2015

Svein T veitdal is one of those rare scientists who can explain why science observations are important in effects on people in just living their lives. A good man to listen to (you can follow his Twitter account: @tveitdal).

Recently he sent this notice:

Critics of the science of climate change and the work to slow or halt warming don’t like charts like that. Sea level is something measured by humans, worldwide, for a long time. That’s real data.

And it’s scary.

T veitdal’s Tweet was just a small part of a very large graphic from NASA, explaining the observations that tell us sea levels rise, how the observations are made, and what it means to you and me.

NASA infographic on sea level rise

NASA infographic on sea level rise: We know seas are rising and we know why. The urgent questions are by how much and how quickly. Available to download, this infographic covers the science behind sea level rise, who’s affected, how much melting ice is contributing, and what NASA is doing to help.

Yeah. “Your planet is changing. We’re on it.”

As Ban-ki Moon said the other day, there is no Planet B. We have only one Earth.

General science teachers, geology teachers, physics and chemistry teachers, history, geography and human geography teachers should see if someone at your school has a plotter and can print this thing out for you, poster size.

God uses kitsch to tell conservative Christians to give science a break

February 9, 2015

Look what the Hubble Telescope found!

Look what the Hubble Telescope found!

Photo from Hubble Telescope (via Washington Post) suggests “conservative Christians” can lay off their hatred of science, and especially astronomy, and let funding for NASA increase again.

December 27, Great Beginnings Day 2014: Darwin, Apollo, and more

December 27, 2014

December 27 is one of those days — many of us are off work, but it’s after Boxing Day, and it’s not yet on to New Year’s Eve or Day. We should have celebrated, maybe.

It’s the end of the year, and yet it is also a day of great beginnings.

We should celebrate December 27 as a day of portent: A good embarkation, and a good, safe end to a nation-encouraging trip to almost touch the Moon.

HMS Beagle, Darwin's ship

HMS Beagle, on a voyage of discovery

On December 27, 1831, Charles Darwin and H.M.S. Beagle set sail on an around-the-world voyage of discovery that would change all of science, and especially biology, forever.

December 27 1831
After a few delays, H.M.S. Beagle headed out from Plymouth with a crew of 73 under clear skies and a good wind. Darwin became sea-sick almost immediately.

Darwin never fully overcame his seasickness, but he fought it well enough to become the single greatest collector of specimens in history for the British Museum and British science, a distinction that won him election to science societies even before his return from the trip — and cemented his life in science, instead of in the church.

Darwin’s discoveries would have revolutionized biology in any case. But, in analyzing what he had found, a few years later and with the aid of experts at the British Museum, Darwin realized he had disproved much of William Paley’s hypotheses about life and its diversity, and that another, more basic explanation was possible. This led to his discovery of evolution by natural and sexual selection.

Mini-sheet from the Royal Mail honoring Darwin's discoveries in the Galapagos Islands

Mini-sheet from the Royal Mail in 2009 honoring Darwin’s discoveries in the Galapagos Islands

On December 27, 1968, Apollo 8 splashed down after a successful and heartening trip to orbit the Moon. The three crewmen, Commander Frank Borman, James A. Lovell, Jr., and William A. Anders, had orbited the Moon, a very important milestone in the methodological race to put humans on the Moon (which would be accomplished seven months later).

1968 was a terrible year for the U.S., with the North Korean capture of the U.S.S. Pueblo, assassinations of Rev. Martin Luther King, Jr., and Sen. Robert F. Kennedy during the presidential campaign, riots in dozens of American cities, nasty political conventions with riots at the Democratic Convention in Chicago, a contentious and bitter election making sore the nation’s divide over Vietnam policy, and other problems. On Christmas Eve, Borman, Lovell and Anders broadcast from orbit around the Moon, a triumphant and touching moment for the Apollo Program and Americans around the world. Their safe return on December 27 raised hopes for a better year in 1969. has a great write up from Alex Pasternack, especially concerning the famous photo taken a few days prior to splashdown:

In 1968, NASA engineers were scrambling to meet President Kennedy’s challenge to land a man on the moon by decade’s end. Because delays with the lunar module were threatening to slow the Apollo program, NASA chose to change mission plans and send the crew of Apollo 8 all the way to the moon without a lunar module.

Exactly 43 [46] years ago, the three astronauts of Apollo 8 became the first humans to orbit another celestial object. As they came around the dark side of the Moon for the third time, Frank Borman, the commander, finally turned their capsule around. And then they saw the Earth.

Borman: Oh my God! Look at that picture over there! Here’s the Earth coming up. Wow, is that pretty.
Anders: Hey, don’t take that, it’s not scheduled.
Borman: (laughing) You got a color film, Jim?
Anders: Hand me that roll of color quick, will you…

One of the resulting photos taken by Anders on a Hasselblad camera became one of the world’s most iconic images.

As Bill Anders recalls it:

I just happened to have one with color film in it and a long lens. All I did was to keep snapping… It’s not a very good photo as photos go, but it’s a special one. It was the first statement of our planet Earth and it was particularly impressive because it’s contrasted against this startling horizon . . . After all the training and studying we’d done as pilots and engineers to get to the moon safely and get back, [and] as human beings to explore moon orbit, what we really discovered was the planet Earth.

Plan to raise a glass today, December 27, 2012, to Great Beginnings Day for the human race. December 27 is a day we should remember, for these achievements. (But if you’re raising a glass, consider Carrie Nation, too!)

Also on December 27:


Yes, this is mostly an encore post.  Fighting ignorance requires patience.

Yes, this is mostly an encore post. Fighting ignorance requires patience.

Glorious images of the Sun, from NASA

July 3, 2014

Who’d have thought of such an image, before we used satellites to look?

NASA SDO images of the Sun

From NASA: Image info: This combination of three wavelengths of light from NASA’s Solar Dynamics Observatory shows one of the multiple jets that led to a series of slow coronal puffs on January 17, 2013. The light has been colorized in red, green and blue. Credit: NASA SDO

NASA’s press release, from June 27, 2014:

A suite of NASA’s Sun-gazing spacecraft have spotted an unusual series of eruptions in which a series of fast puffs forced the slow ejection of a massive burst of solar material from the Sun’s atmosphere. The eruptions took place over a period of three days, starting on Jan. 17, 2013. Nathalia Alzate, a solar scientist at the University of Aberystwyth in Wales, presented findings on what caused the puffs at the 2014 Royal Astronomical Society’s National Astronomy Meeting in Portsmouth, England.

The sun’s outermost atmosphere, the corona, is made of magnetized solar material, called plasma, that has a temperature of millions of degrees and extends millions of miles into space. On January 17, the joint European Space Agency and NASA’s Solar and Heliospheric Observatory, or SOHO, spacecraft observed puffs emanating from the base of the corona and rapidly exploding outwards into interplanetary space. The puffs occurred roughly once every three hours. After about 12 hours, a much larger eruption of material began, apparently eased out by the smaller-scale explosions.

By looking at high-resolution images taken by NASA’s NASA Solar Dynamics Observatory (Little SDO), or SDO, and NASA’s Solar Terrestrial Relations Observatory, or STEREO, over the same time period and in different wavelengths, Alzate and her colleagues could focus on the cause of the puffs and the interaction between the small and large-scale eruptions.

“Looking at the corona in extreme ultraviolet light we see the source of the puffs is a series of energetic jets and related flares,” said Alzate. “The jets are localized, catastrophic releases of energy that spew material out from the sun into space. These rapid changes in the magnetic field cause flares, which release a huge amount of energy in a very short time in the form of super-heated plasma, high-energy radiation and radio bursts. The big, slow structure is reluctant to erupt, and does not begin to smoothly propagate outwards until several jets have occurred.”

Because the events were observed by multiple spacecraft, each viewing the sun from a different perspective, Alzate and her colleagues were able to resolve the three-dimensional configuration of the eruptions. This allowed them to estimate the forces acting on the slow eruption and discuss possible mechanisms for the interaction between the slow and fast phenomena.

“We still need to understand whether there are shock waves, formed by the jets, passing through and driving the slow eruption,” said Alzate. “Or whether magnetic reconfiguration is driving the jets allowing the larger, slow structure to slowly erupt. Thanks to recent advances in observation and in image processing techniques we can throw light on the way jets can lead to small and fast, or large and slow, eruptions from the Sun.”

Van Gogh painted rather unusual images of the Sun and stars; Turner painted perhaps more life-like images.   There are many interesting views of the Sun in art, by Monet, and many, many others.

Vincent van Gogh,

Vincent van Gogh, “Sower with the Setting Sun”

But who conceived of any image like this one from NASA, above?

What private entity could ever do that?  

J. M. W. Turner,

J. M. W. Turner, “Caernarvon Castle,” 1799

Claude Monet,

Claude Monet, “Impression Sunrise”

British biologist J. B. S. Haldane said:

I have no doubt that in reality the future will be vastly more surprising than anything I can imagine. Now my own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose.

♦   Possible Worlds and Other Papers (1927), p. 286

Haldane may as well have added, the universe is not only more beautiful that we imagine, but more beautiful than we can imagine.  Reality trumps fiction yet again.

Catch some falling stars (with help from NASA and USA Today)

May 20, 2014

USA Today does some great graphics from time to time.

This set comes as a preview to a special meteor shower — maybe — this weekend.

USA Today chart of meteor showers left in 2014, with star map of how to find Camelopardalid Shower this weekend.

USA Today chart of meteor showers left in 2014, with star map of how to find Camelopardalid Shower this weekend.

And just for this weekend:

Night of Shooting Stars, New meteor shower influenced by Jupiter's gravity -- USA Today starmap showing best place to look for meteoroids this weekend, the Camelopardalid Meteor Shower (first ever).

Night of Shooting Stars, New meteor shower influenced by Jupiter’s gravity — USA Today starmap showing best place to look for meteoroids this weekend, the Camelopardalid Meteor Shower (first ever).

So, early Saturday morning, or early Sunday morning, we could be in for a meteor shower display more intense than we’ve seen in a long time, experts say.

Or maybe not.

NASA’s explanation should help you find them (we found this video via


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