Category Archives: SolarSystem

Information About Eclipses

Here are some of my favorite sites for learning about eclipses (including the upcoming Great American Eclipse!):


“Moon Slide (slim)” from Astronomy Picture of the Day. This “Moon-trail” by Stefan Siep was created by just opening the shutter and keeping it open for about 3 hours. Note the brightness difference between full and eclipsed :)


2016 Planetary Alignment!

As described in class, here are my two favorite articles about this alignment:

Get Up Early, See Five Planets at Once! from Sky and Telescope

How to View Five Planets Aligning in a Celestial Spectacle from The New York Times

I happen to adore the NYT diagram because it shows the Solar System view as well as the view from Earth:

Screen Shot 2016-01-21 at 11.49.15 PM

View of planetary positioning from “above” the Solar System as well as the view from Earth (from the New York Times)

Planet Nine!

Caltech Researchers Find Evidence of a Real Ninth Planet

This is legit folks!  For those who are at a university (like Vanderbilt), this press release has a link to the actual research article in the Astronomical Journal.  It’s a bit heavy at times but well done.

There’s also a pretty good article on Wired: This Isn’t the First Time Astronomers Have “Found” a Planet Nine


(from the press release) The six most distant known objects in the solar system with orbits exclusively beyond Neptune (magenta) all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration.

Saturn’s Titan doesn’t have it’s own magnetosphere!

So whilst finding out some information about Saturn’s orbiter Cassini, I came across this story: Cassini Catches Titan Naked in the Solar Wind.  We’ve been talking a lot about magnetospheres when we discuss the giant worlds so this whole thing is really interesting!

Titan outside of a compressed Saturn magnetosphere

Titan outside of a compressed Saturn magnetosphere. From NASAs Cassini page

The space probe Cassini was going by Titan in 2013 when a big solar storm hit Saturn’s magnetosphere and compressed it.  This left Titan without the protection of that magnetosphere.  According to the newly published data, Titan has no appreciable magnetosphere because particles interacted with its atmosphere just like the particles in the atmospheres of Venus and Mars (no magnetospheres due to not spinning fast enough and solid core, respectively).  The scientists interviewed for the article talk about how this information shows them that computer models developed for closer worlds can still be used for worlds farther away and that’s awesome :)  I love the Universe :)

My favorite tides


From Wikipedia

From Wikipedia

During class today, I talked about tides and how there is a great deal of misinformation out there.

My favorite websites for the astronomical explanation of tides are:

The YouTube videos of the awesome spring and neap tides in Clovelly.

Here’s a great animation about tides from the Nebraska ClassAction collection of Astronomical Simulations and Animations.

The 2017 Nashville Eclipse!

In class yesterday we talked about eclipses and so here’s the post about it!

The totally awesome (and very dedicated) Mr. Eclipse (i.e., The Ultimate Resource for Eclipse Photography) is a favorite of NASA so they use his diagrams on their eclipse website.

The foremost resource for the 2017 eclipse is  The Interactive Google Map they have linked is AMAZING.  The image below is from that map.  The Wikipedia article is pretty good as well.

Path of the 2017 Total Solar Eclipse.  Can't see totality unless within that line.

Path of the 2017 Total Solar Eclipse. Can’t see totality unless within that line.

On the map, you can zoom in and click on a location which will bring up information about time of partial eclipse start/end, totality start/end, duration of totality, and anything else you might need.  The map also has information for areas in the partial eclipse regions.

You should make plans!!

Ooo, you can also see a great map here of total solar eclipses in the US in the next 50 years!!  Make more plans!

The whole asteroid thing!

There have been some pretty amazing things going on with asteroids the past couple of days, namely the passing of Asteroid 2012 DA14 and the Russian Meteor Event.   But they were completely unrelated!  Here is an excellent infographic for you (click to make bigger):

Infographic from The Telegraph (UK)

Infographic from The Telegraph (UK)
– click to make bigger

We weren’t going to be seeing that little 50-foot asteroid coming at us from Sun-ward…  The Sun is the most powerful gravitational slingshot in the Solar System but if we know the trajectories of ALL little rocks in the Solar System, then we could know a bit more.  But it will take a LOT of observing time to see them…  These little ones (like the Russian one) are VERY difficult to see, I just don’t see us catching them all but we can sure try :)  I think we just need a big force field ;)

Here are some of my favorite posts about the Russian event:

Moon Landing Evidence! :)

In class today (Wednesday), I showed some of the lunar landing footage available to we, denizens of the Internet, for FREE!  NASA is a public entity and as such, happily will show us many awesome things and has given us the Apollo Lunar Surface Journal (ALSJ).  Much of the text was written by former astronauts from the missions themselves and many of the best/crowd-favorite clips provide some context.

Whilst meandering the internet last summer looking for great astronaut videos to use in outreach, I came across this great website: Top 10: Videos From the Moon Landings (from How It Works Magazine).  I’d already found some of them in browsing the COPIOUS video clips in the ALSJ but this website really does have some of the very best :)  My favorites almost always involve the Apollo 17 mission it seems (this is a FANTASTIC Wikipedia page – check out the multimedia at the end!!)…  But I suppose that one was the one with the geologist and he seems a bit more jovial than the others sometimes :)

In the end, don’t let anyone tell you we didn’t land on the Moon.  You can find “Bad Astronomer” Dr. Phil Plait’s debunking here along with a page of several links to debunkers (and deniers!).  You can find the Mythbusters episode debunking here (never mind – you have to find that yourself, they keep taking the versions I know down).  You can find an excellent debunking website called here.

Astronomically, it IS an early spring!!

So I read this article and I had to share it with you – I think it’s very good :)

Article:  Spring Arrives With Equinox Tuesday, Earliest in Over a Century
by Joe Rao, Skywatching Columnist

As an introduction, here in Nashville, we’ve been experiencing a really mild spring – personally, I’m pretty happy about it because I go observing with the lab students a lot and it’s been so nice to not have to bundle up ;)  Thus we’ve been having an early spring meteorologically.

But let’s think about what the start of spring means ASTRONOMICALLY.  The start of spring is technically the date of the vernal equinox which technically is when the Sun’s position in the sky goes from being in the southern celestial hemisphere to being in the northern celestial hemisphere.  You can see this with Stellarium!!  Plus you can see how the actual location of the equinox in the sky (comparing it to the constellations) changes over time – this is called the precession of the equinoxes and it is why we are entering the Age of Aquarius!

Heliocentric vernal equinox

The vernal equinox location (see arrow) according to the heliocentric perspective.

Geocentric vernal equinox

The location of the vernal equinox according to a geocentric view

Here’s a lovely graph from Wolfram Alpha that shows the date of the vernal (spring) equinox for certain time periods (see axes ;) ):

Date of the vernal equinox VS time - from Wolfram Alpha

Note that we’re bottoming out for our cycle in the left graph (stupid axes if you ask me so it is kinda hard to see).  The short-period cyclic nature on the left shows the “resetting” every leap year and then the big jumps on the right plot show the effect of not having a leap year during century years (i.e., 1800, 1900, 2100, 2200) unless those years are divisible by 400 (i.e., 2000).  To learn more about this (and to see a better graph), go to Wikipedia :)  Dudes, on Wikipedia, I learned about the Iranian calendar which has 8 leap days in every 33 year time period – it’s more accurate :)

Anyway, the aforementioned article is a good article – Dr. G approved! ;)

Awesome Planetary Formation Videos

Computer Model of Planetary Formation

In class on Monday, I showed a whole bunch of videos that show planetary formation – some showed certain parts better than others but they all are pretty awesome.  Just in case anyone wanted to look at them again, here they are:

  • Short, beginning of formation (from gas cloud to disk) from ESA – here
  • By NASA for the James Webb Space Telescope, uses data from computer models – here
  • Narration by Harrison Ford, I like that it has some timescale information in it, part of a larger series – here
  • From “Space with Sam Neill” Episode: “Star Stuff”, I really like how this one is done (I started it at 1:27) – here
  • If you liked the “Formation of the Moon” video from the end of class (it does happen to be one of my favorites despite the speeding up of some events that they did), it is here


Below is an image of the Orion Nebula (we can see it during our observations this semester ;) ) from the Hubble Space Telescope showing some of the protoplanetary disks that have been found in this nebula.  Look!!!  New baby planetary systems! :)

Click to go to the Astronomy Picture of the Day website for this image.

"Proplyds" (protoplanetary disks) in the Orion Nebula