Distant volcano could turn latest lunar eclipse dark red

Distant volcano could turn latest lunar eclipse dark red

 

 

 

 

 

 

 On the evening of January 20 to 21, the entire Western Hemisphere will be treated to a more-than-hour-long sky show: a total eclipse of the moon. The eruption of a volcano half a world  away could make this particular event especially colorful-as a deep red.

Total lunar eclipses aren't rare. They happen somewhere across the globe once a year or so. But not everybody can see them. People have to be on the night side of  Earth to catch the dark shadow fall over  the moon face.

A lunar eclipse occurs when Earth moves between the sun and a full moon. At first the moon appears to darken a bit as the shadow cast by Earth sweeps across the lunar surface. At what's known as totality. Earth blocks out most moon-bound sunlight. This  casts the darkest shadow. With only a fraction of the light passing through Earth's razor-thin atmosphere, the moon plunges into sudden darkness.

But it does not vanish entirely. The blanket of shadow,known as an umbra, lights up the moon enough that it remains slightly visible. It also turns the moon red. The reason has to do with optical physics. Most of the sunlight passing through our atmosphere will be scattered. Only the long-wavelength radiation-red light- penetrates.

You might call this eclipse Big Red

This eclipse also will be supersized. That's due to what some are calling a super moon. That too is due to physics. The moon appears larger because it has been getting  closer to Earth. At 357,342 kilometers away it's approaching its perigee-that point in its orbit when the moon will be nearest our planet. 

The January  total lunar eclipse will be special  for another reason its color. One can never predict the specific red hue that will develop. But there reason to suspect that this year's will be deep. This volcano in Indonesia erupted with explosive force on December 22, 2018. The shock was so powerful  that it sent a tsunami-a wall of water-racing ashore the beaches of the Sundas Strait.

The volcano also lost 110,000,000 cubic meters  in volume, dropping 229 meters in height. That's according to Indonesia's Center for Volcano logy and Geological Hazard Mitigation. All that ash and other debris had to go somewhere. Much of it shot high into the atmosphere. Along with it came copious smoke and airborne particles spewed by erupting lava itself.

Turning to history 

  The late Richard B. Stothers worked at NASA's Institute for Space Studies at the Goddard Space Flight Center in New York. He reviewed data on volcanic eruptions that had altered the color of eclipses. In 2005, he reported finding that recent volcanic activity seemed to darken a lunar eclipse. Indeed he noted, "A dark eclipse on a clear night usually implies the presence of significant turbidity in the Earth's stratosphere arising from a recent volcanic eruption."

One of the darkest eclipses on record occurred on June 10, 1816. This was shortly after the eruption of Mount Tambora, another Indonesian volcano. Henrik B. Claus sen was at astronomer at the University of Copenhagen in Denmark. This let them gauge the amount of acid in different air pockets with in the ice. They found an "acid signal" that came from sulfate pollution. Volcanoes often release lots of sulfates. And this sulfate was abundant in the ice that formed in 1816. That's a year after Tambora's  1815 eruption. And that makes sense: It would have taken volcanic pollutants that long to make it to the Northern Hemisphere and settle out in Greenland.

So when the moon goes red or brown on Sunday night, keep a watchful eye. It may be as informative about our planet as it is beautiful.

Power  Words 

Astronomy  The area of science that deals with celestial objects, space and the physical universe. People who work in this field are called astronomy.

Atlantic   One of the world's five oceans, it is second in size only to the Pacific. It separates Europe and Africa to the east from North and South America to the west.

Atmosphere   The envelope of gases surrounding Earth or other planet.

Debris  Scattered fragments, typically of trash or of something that has been destroyed. Space debris, for instance, includes the wreckage of defunct satellites and spacecrafts.

Eclipse   This occurs when two celestial bodies line up in space so that one totally or partially obscures the other. In a solar eclipse, the sun, moon and Earth line up in that order. The moon casts its shadow on the Earth. From Earth, it look like the moon is blocking out the sun. In a lunar eclipse, the three bodies line up a in a different order - sun, Earth, moon -and the Earth casts its shadow on the moon, turning the moon a deep red.

Eruption   The sudden bursting or spraying of hot material from deep inside a planet or moon and out through its surface. Volcanic eruptions on Earth usually send hot lava, hot gases or ash into the air and across surrounding land. In colder parts of the solar system, eruptions often involve liquid water spraying out through cracks in an icy crust. This happen on Enchiladas, a moon of Saturn that is covered in ice.

Filter   A screen, plate or layer of a substance that absorbs light or other radiation or selectively prevents the transmission of some of its components.

Gauge    A device to measure the size or volume of something. The act of measuring or estimating the size of something.

Greenland     The world's largest island, Greenland sits between the Arctic Ocean and North Atlantic. Ice covers roughly 80 percent of Greenland.

Jet Stream      A fast-flowing, high-altitude air current. On Earth, the major jet streams flow from west to east in the mid-latitude regions of the Northern and Southern Hemispheres.

Lava          Molten rock that comes up from the mantle, through Earth's crust, and out of a volcano.

Lunar       Of or relating to Earth's moon.

Orbit        The curved path of a celestial object or spacecraft around a star, planet or moon. One complete circuit around a celestial body.

Perigee       That point when some orbiting satellite or celestial object will be nearest the center of the object that it is  orbiting.


Planet       A celestial object that orbits a star, is big enough for gravity to have squashed it into a roundish ball and has cleared other objects out of the way in its orbital neighborhood. 

Plume       The movement of some gas or liquid, under the direction of gravity, winds or currents. It may be in air, soil or water. It gets its name from the fact that it tends to be long and relatively thin, shaped like a large feather. Fluids that move, largely intact, in a feather-like shape over long distances.

Pollutant       A substance that taints something - such as the air, water, our bodies or products.Some pollutants are chemicals, such as pesticides. Other may be radiation, including excess heat or light. Even weeds and other invasive species can be considered a type of biological pollution.

 Radiation       One of the three major ways that energy is transferred. In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.


Stratosphere      The second layer of the Earth's atmosphere, just above the troposphere or ground layer. The stratosphere stretches from 10 to 50 kilometers above sea level.

Sulfate            A family of chemical compounds that are related to sulfuric acid.

Super cool           To cool liquid water below its freezing point without it turning into a solid or crystallizing.