Category Archives: General

Happy Solstice!

summersolsctice

Today the Sun reaches its most northern point in the sky in the northern hemisphere and the lowest in the southern hemisphere.

Put another way,  for the northern hemisphere: the June solstice is when the subsolar point or that point where the sun is perceived to be directly over head, is at the northern most latitude it will attain before due to the tilt of the Earth on its axis and is on the Tropic of Cancer (23.44 deg). After the June Solstice the Sun will day by day become lower in the northern sky until the December solstice when it rises to its lowest point of the year.

The southern hemisphere experiences the opposite, so today the Sun is at its lowest point and after today will gradually reach higher in sky until the December solstice.

The moment of the June Solstice occurred  today concurrent with the publishing of this post at 16:38 UTC.  US Naval Observatory.

Note: I am going by the USNO time, it’s being reported in other media the time is 16:39 UTC – see timeanddate.com

My typical June solstice tradition is to take a nice long walk at sunrise, heavy rain made me skip the walk.

#SummerSolstice

Image: Creative Commons

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Did You Miss Towel Day

Gee, 25 May was Towel Day and I completely missed it. Sad.

A towel, is about the most massively useful thing an interstellar hitchhiker can have. –  “The Hitchhiker’s Guide to the Galaxy” (Doug Adams)

Wait until next year :mrgreen:

Video

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Comparisons

plutochartsm
Kuiper and Asteroid belt objects compared. Credit: NASA via Space Ref

 

NASA produced this image as part of a televised event back on 25 August the same day New Horizons passed the orbit of Neptune and 25 years after the Neptune/Voyager encounter with Neptune in 1989.

Since Voyager we have made signifcant discoveries in the Kuiper Belt. The image shows objects from both the Kuiper and Asteroid Belts. The Asteroids include little Vesta that was examined in detail by Dawn up to the largest asteroid Ceres the asteroid where Dawn is heading to now. The Kuiper Belt objects include Pluto, the destination of New Horizons spacecraft and it’s getting very close.

NASA set the objects to scale to show how they compare to each other. I wanted to compare then to something more provincial, so if you click the image I have added the moon. I’m not saying it is exactly to scale, it is close enough to get the idea.

Have a look.

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Happy Birthday RAS

Mineral flow on the asteroid Vesta, from Feb 2014.  Credit: NASA/JPL-Caltech/UCLAMPS/DLR/IDA via RAS
Mineral flow on the asteroid Vesta, from Feb 2014. Credit: NASA/JPL-Caltech/UCLAMPS/DLR/IDA via RAS

There are a few things going on these days and among them:

The Dawn spacecraft is about to start Ceres approach imaging very soon – last I heard was tomorrow, 13 January 2015.

The image above was created by researchers from the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany, have used the multiwavelength filters on NASA’s Dawn spacecraft to create compositional maps of the surface of the asteroid Vesta. More about the image from RAS.

I found the image at the Royal Astronomical Society and as it happens as of today has been around 195 years. Here’s to many more!

At one time (link) “New Horizon’s Distant Encounter Operations” (approaching Pluto) were to begin today, I’m sure there is much to do before the “Closest Enounter Operations” being in just 30 days.

And finally at 06:00 EST / 11:00 UTC the SpaceX Dragon cargo ship should arrive at the International Space Station – I will be away briefly at that time and will update this a little later.

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