Rare Moon and Earth eclipse of the Sun seen from the SDO

Early in the morning of Sept. 1, 2016, NASA’s Solar Dynamics Observatory, or SDO, caught both Earth and the moon crossing in front of the sun. SDO keeps a constant eye on the sun, but during SDO’s semiannual eclipse seasons, Earth briefly blocks SDO’s line of sight each day – a consequence of SDO’s geosynchronous orbit. On Sept. 1, Earth completely eclipsed the sun from SDO’s perspective just as the moon began its journey across the face of the sun. The end of the Earth eclipse happened just in time for SDO to catch the final stages of the lunar transit.

In the SDO data, you can tell Earth and the moon’s shadows apart by their edges: Earth’s is fuzzy, while the moon’s is sharp and distinct. This is because Earth’s atmosphere absorbs some of the sun’s light, creating an ill-defined edge. On the other hand, the moon has no atmosphere, producing a crisp horizon.

This particular geometry of Earth, the moon and the sun had effects on viewing down on the ground as well: It resulted in a simultaneous eclipse visible from southern Africa. The eclipse was what’s known as a ring of fire, or annular, eclipse, which is similar to a total solar eclipse, except it happens when the moon is at a point in its orbit farther from Earth than average. The increased distance causes the moon’s apparent size to be smaller, so it doesn’t block the entire face of the sun. This leaves a bright, narrow ring of the solar surface visible, looking much like a ring of fire.



Eclipses and Transits – http://www.nasa.gov/topics/solarsystem/features/eclipse/index.html
Download additional imagery at NASA’s Scientific Visualization Studio – http://svs.gsfc.nasa.gov/12292#42786


25 thoughts on “Rare Moon and Earth eclipse of the Sun seen from the SDO

  1. Now that is totally cool. Just wow that AW knows/finds this stuff. WOW. Learn something new every day. Thanks, AW. And WE, and EW, and many other regular contributors.

    • I’m waiting around here for a simultaneous total eclipse of the sun and the moon; well of course viewed from downtown Sunnyvale. I’m not going to any satellite just to see that.


  2. A luminous photosphere of energy radiates from our sun in all directions out across the cosmos. When that sphere expands to the average orbital distance to the earth its dispersed luminous surface radiates a power flux of 1,360 to 1,368 W/m^2. But the earth does not orbit in a nice average circle, but in an ellipse with perihelion being closer and aphelion being farther. So how much difference does that make?

    At perihelion (closer) the power flux is 1,413 W/m^2. At aphelion (farther) the power flux is 1,323 W/m^2. The total annual range/change/fluctuation is 90 W/m^2. Yes, 90 W/m^2.

    According to IPCC AR5 the radiative forcing added to the atmosphere by the CO2 increase in the 261 years between 1750 and 2011 is 2 W/m^2. Yes, 2 W/m^2.

    So if an annual 90 W/m^2 fluctuation does not cause catastrophic climatic consequences what possible reason have we to believe that 2 W/m^2 will?

  3. The radius of the earth is 6,372, 3, 5, 9 km. With four significant figures we’re just guessing at the fourth digit anyway. Let’s say 6,375 km.

    Let’s put some perspective on this.

    6,375 km is 6.375 E6 m. So let’s just scale these numbers, 1 m = E6 m.

    1 m = 3.28’

    On a steel tape 6.375 m is about 20’ 11”.

    The troposphere is 17 km at the equator and 9 km at the poles. 0.017 E6 m and 0.009 E6 m.

    The troposphere would be representative of about 9 mm or 0.35”.

    ToA per NASA is 100 km and where the radiative balance, gozintaz = gozoutaz, has to balance.

    100 km on our scale tape, 100 mm, would be 3.9”.

    Not much stands between us and the void.

    However, the thermal conductivity of this layer is sufficient to keep the surface warm per Q = U A dT, just like the insulated walls of your house or a blanket on a cold day. No hocus-pocus S-B radiation or exemptions to the laws of thermo required.

  4. “However, the thermal conductivity of this layer is sufficient to keep the surface warm per Q = U A dT, just like the insulated walls of your house or a blanket on a cold day. No hocus-pocus S-B radiation or exemptions to the laws of thermo required.”

    Figure 1. As moisture content increases, the thermal conductivity decreases.
    Source: http://www.electronics-cooling.com/2003/11/the-thermal-conductivity-of-moist-air/

    WR: Given the above, moist air and clouds must act as insulation. Clouds in the night feel as a blanket. Clouds raise minimum temperatures at the surface. They seem to be a blanket.

    • Than the rain is the insulation. Following the uptaken moisture from the surface into atmosphere is the insulation.

    • Let’s see thermal conductivity as a function of elevation. As elevation increases density decreases. Fewer molecules mean lower conductivity. So what’s the total thermal conductivity between the surface and the tropopause, say 20 km?

  5. Meanwhile the Earth is buffeted by solar wind from a large coronal hole, cussing two, officially classified as the major solar storms (one step from the severe, the strongest on the scale) in just over 24 hours.

    Electronic communications, satellites, and the high altitude aircraft in polar zone may be affected.

    • “Meanwhile the Earth is buffeted by solar wind from a large coronal hole, cussing two, officially classified as the major solar storms”

      So the solar wind is from the cussing of the large coronal hole?


      Sorry….that just hit my funny bone for imagery.

    • “The Ap-index reached its minimum in October 2009, 10 months after sunspot minimum. Highest monthly Ap-value so far this solar cycle was reached in March 2015 (16,3), slightly higher than March 2012 (16,1) and September 2015 (15,8). In June 2015, the smoothed Ap-value passed 10 for the very first time this solar cycle. Most of the minor geomagnetic storms in 2015 were the result from high speed streams from coronal holes. Table underneath summarizes the highest monthly Ap-value per solar cycle (since 1932). Notice how the highest values almost always happen in spring or autumn, and usually 2-4 years after SC-maximum. So far this solar cycle (June 2015), we still did not experience an extreme geomagnetic storm (Kp=9), however very intense storms (the strongest sofar in SC24) took place on 17 March and 22-23 June 2015 (Dst resp. -223 and -204 nT). See also the updated graph underneath from this STCE Newsitem (26 March 2014), showing the overall weakness of the geomagnetic disturbances in SC24.”

  6. The moon looked very unusual from Perth Western Australia around 7 pm, on evening if 3rd September , appeared low in the sky towards the west … a very faint ring with an orange tinge with a bright silver edging in the bottom half ..I’ve looked up lunar eclipse dates and this is not listed , could it be the same as reported here ?

  7. Figure 10 in Trenberth et al 2011jcli24 is typical of the so called atmospheric heat or energy balances which show 342 +/- W/m^2 entering perpendicular to the entire surface of the ToA, Top of Atmosphere. There is no consideration of day or night, aphelion or perihelion, tropospheric thickness, or the oblique incidence on a spherical surface. This value begins with the TSI, total solar insolation, delivered by the expanding solar photosphere (3.847 E26 W) to the spherical surface of an average orbital distance of 1.496 E8 km yielding a value of 1,368 +/- W/m^2. A sphere of radius r has four times the area of a disc of radius r so 1,368 / 4 = 342 W/m^2.

    As pointed out above the earth’s orbit is not circular, but elliptical and the difference in TSI between perihelion, closest and 1,423 +/- W/m^2, and aphelion, farthest and 1,323 +/- W/m^2, a total annual fluctuation of 90 W/m^2. But there is a second consideration, the 23.5 degree tilt of the earth’s vertical axis which drives the seasons. When the tilt is away from the sun it is winter in the northern hemisphere, summer in the southern hemisphere. When the tilt is towards the sun it is summer in the NH and winter in the SH. At this point in the Malinkovitch cycle the NH winter is around the perihelion. So the coldness of the away tilt is balanced by the hotness of the closer orbit. This will change.

    When the sun is directly overhead TSI at ToA delivers its full amount, but because of the oblique angle at other locations the TSI on a horizontal surface is reduced. Those who design and install solar panels are well aware of this.

    At 40° N latitude and winter solstice the sun is 26.5° above the horizon and the TSI on a ToA horizontal surface is 630.5 +/- W/m^2.

    At 40° N latitude and summer solstice the sun is 73.5° above the horizon the TSI on a ToA horizontal surface is 1,268.5 +/- W/m^2.

    The total TSI variation on a ToA horizontal surface from winter solstice to summer solstice is 638 +/- W/m^2.

    A TSI fluctuation of 638 W/m^2 and the only difference is summer and winter which the earth and mankind have survived every year for millions of years. The 2 W/m^2 and even the RCP 8.5 W/m^2 of IPCC models don’t seem all that significant.

    And the notion that this 2.0 or 8.5 W/m^2 is disturbing some marvelous Zen balance maintained for millennia is religious dogma, not science.

  8. The Earth and Moon are a double planet. The axial tilt wobbles about 1 degree around the 23.5 degree mean and is currently about 23.44 degrees. I think that the tilt angle is in a declining phase.

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