All posts by Tom

SDO Coming Back Online

On 02 August 2016 the SDO was witness to a lunar transit. The moon passed between the SDO and the Sun in a transit lasting nearly an hour from 11:13 UTC until 12:08 UTC (07:13 EDT to 8:08 EDT). When the transit over the SDO did not return to science mode.


Returning to science mode wasn’t quite as simple as I thought it would be. Two of the three instruments (the Helioseismic and Magnetic Imager, or HMI, and the Extreme Ultraviolet Variability Experiment, or EVE) were returning data two days later. The A1A instrument came back online and was returning data on 06 August.

Here’s a sample from A1A:

A few more issues should be cleared up starting today according to Dean Pesnell over at the SDO blog: You Never Miss Them ‘TIl They’re Gone!

Images: SDO/NASA

This Week At NASA

An especially good episode this week. Very interesting bit on the atmosphere of the Jupiter moon Io, the sulfur dioxide atmosphere freezes onto the moons surface during the period where Jupiter shades the moon and then is restored as the shading goes away.


A Long Dead Star


The original caption:
This NASA/ESA Hubble Space Telescope image captures the remnants of a long-dead star. These rippling wisps of ionised gas, named DEM L316A, are located some 160 000 light-years away within one of the Milky Way’s closest galactic neighbours — the Large Magellanic Cloud (LMC).

The explosion that formed DEM L316A was an example of an especially energetic and bright variety of supernova, known as a Type Ia. Such supernova events are thought to occur when a white dwarf star steals more material than it can handle from a nearby companion, and becomes unbalanced. The result is a spectacular release of energy in the form of a bright, violent explosion, which ejects the star’s outer layers into the surrounding space at immense speeds. As this expelled gas travels through the interstellar material, it heats it up and ionise it, producing the faint glow that Hubble’s Wide Field Camera 3 has captured here.

The LMC orbits the Milky Way as a satellite galaxy and is the fourth largest in our group of galaxies, the Local Group. DEM L316A is not alone in the LMC; Hubble came across another one in 2010 with SNR 0509 (heic1018), and in 2013 it snapped SNR 0519 (potw1317a).

Copyright ESA/Hubble & NASA, Y. Chu

Saturn’s Atmosphere


Cassini gives us this close-up view of Saturn’s swirling atmosphere. The Juno mission to Jupiter may help us understand what is going on inside Saturn as well.  You will notice a “ring” on the right side in the dark band.  This is an artifact, quite possibly a bit of dust.

This image was obtained by Cassini (Image Credit: NASA/JPL-Caltech/Space Science Institute) on 20 July 2016.

Sample 15415

Sample 15415 or the Genesis Rock was collected by Apollo 15 astronauts James Irwin and David Scott on the surface of the moon. The date was 01 August 1971 and it was the second EVA for the astronauts when Sample 15415 was collected from Spur crater.


The early idea was the Genesis Rock was lunar primordial crust, however it turn out not to be so. The rock is anorthosite.

More about the oldest moon rocks.

Scientific data on Sample 15415.

The name Genesis Rock is stored at the Lunar Sample Laboratory Facility.

Here’s a written transcript of the astronaut radio transmissions at the time of the finding and below (should be) the audio file.



Juno At Apojovi


The Juno spacecraft will reach its farthest point in the initial orbit, ‘apojovi’ as NASA calls it.

Juno will be be 8.1 million km / 5 million miles from Jupiter at 16:41 UTC / 12:41 EDT, when Jupiter’s gravity will draw the spacecraft back towards it. The spacecraft will finish this first orbit on 27 August and will make one more “long orbit” before settling into the science orbits of the mission.

Credits: NASA/JPL-Caltech

What’s Up For August

A great month of sky watching! I will save you the trouble of running to your calendar, 12 August is on a Friday. I plan on taking the day off work to allow for a nap so I can get up extra early for the showers. I will be trying out a new reclining chair I am getting for the occasion. If I can find a screen filter for my phone or tablet so I don’t ruin my night vision I might see who is doing the same on Twitter. Rain of course will change everything.

The video mentions the Perseid Double Cluster; it is one of the most beautiful sights in the sky especially with binoculars or a small telescope.