NASA observatory captures a rare stretch of our sun without spots

With its usual spots, you can clearly see the sun's rotation. But as a pristine, spotless orb, it's a little harder to see its movement.

Humans foolish enough to gaze directly at the sun will likely perceive a uniformly-colored orb. But this miasma of incandescent plasma isn't actually all that pristine: the star's surface is usually peppered with dark spots created by magnetic activity.

Lines of the sun's magnetic field pop out of its surface in bundles called pores, and when pores get too close to one another they squeeze the plasma between them to form relatively cool spots—3,800 degrees Kelvin in contrast to the rest of the surface's 5,800 K or so temperature. Intense bursts of radiation called solar flares pop out of these plasma squeezes, and that radiation can wreak havoc on various electrical systems on Earth.

Sunspots have been monitored daily since 1849, and all that data has shown that their frequency waxes and wanes in an 11-year cycle. Other kinds of solar activity can still impact Earth while sunspots are sparse, but they serve as a decent index for the overall intensity of space weather.

As you can see from the image below, which was taken by NASA's Solar Dynamics Observatory (SDO), our sun is looking pretty smooth these days. According to NASA, SDO returned spotless images of the star for 15 days straight starting on March 7, which marks the longest stretch of spotlessness since 2010.

sun without sunspots


The image on the left shows sunspot activity from the sun's last "solar maximum"—an extreme period at one end of the solar cycle spectrum. The peak activity of the sun's last cycle occurred in the spring of 2014. We're not at the solar minimum yet, in all likelihood—based on the 11-year cycle schedule, we can expect that to happen sometime during 2019 or 2020. But NASA scientists say that the recent fortnight of sunny-side-up sun indicates that solar activity is winding down towards this low period just as we'd expect.

And the sun acting normal is a very good thing. Between 1645 and 1715 the sun eschewed its usual patterns of activity, casting the 11-year cycle aside in favor of a long stretch of minimal sunspots. This corresponded with a "little ice age" categorized by bitter winters. And you thought the polar vortex was a pain.

Images from NASA on the largest batch of Earth-size, habitable zone planets
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Images from NASA on the largest batch of Earth-size, habitable zone planets
This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. The TRAPPIST-1 planets orbit their star extremely closely, with periods ranging from 1.5 to only about 20 days. This is much shorter than the period of Mercury, which orbits our sun in about 88 days.
This poster imagines what a trip to TRAPPIST-1e might be like.
This artist's concept allows us to imagine what it would be like to stand on the surface of the exoplanet TRAPPIST-1f, located in the TRAPPIST-1 system in the constellation Aquarius.
This data plot shows infrared observations by NASAs Spitzer Space Telescope of a system of seven planets orbiting TRAPPIST-1, an ultracool dwarf star. Over 21 days, Spitzer measured the drop in light as each planet passed in front of the star. Spitzer was able to identify a total of seven rocky worlds, including three in the habitable zone where liquid water might be found.
The TRAPPIST-1 system contains a total of seven planets, all around the size of Earth. Three of them -- TRAPPIST-1e, f and g -- dwell in their star’s so-called “habitable zone.” The habitable zone, or Goldilocks zone, is a band around every star (shown here in green) where astronomers have calculated that temperatures are just right -- not too hot, not too cold -- for liquid water to pool on the surface of an Earth-like world. 

This artist's concept appeared on the February 23rd, 2017 cover of the journal Nature announcing that the TRAPPIST-1 star, an ultra-cool dwarf, has seven Earth-size planets orbiting it. Any of these planets could have liquid water on them. Planets that are farther from the star are more likely to have significant amounts of ice, especially on the side that faces away from the star.


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