Category Archives: SolarSystem
Here are some of my favorite sites for learning about eclipses (including the upcoming Great American Eclipse!):
- Mr. Eclipse (the guy NASA uses)
- NASA Eclipse Web Site
- eclipse2017.org (make sure to check out the AMAZING interactive Google map!)
- timeanddate.com (and their eclipse list)
- Of course, one can certainly use the Wikipedia article on Eclipses (you can also go specifically to lunar and solar)
- One of my favorite astronomer-bloggers, Phil Plait (the “Bad Astronomer”) has a nice article with some good diagrams and pictures
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:
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
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!
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 :)
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:
- A rigorously correct but a tiny bit snarky treatment – it’s my favorite: Tidal Misconceptions by Dr. Donald E. Simanek
- One of the links from the page above is a much more mathematically rigorous treatment with equations and animations: Tides and centrifugal force by Paolo Sirtoli
- National Oceanic and Atmospheric Administration (NOAA) Ocean Service Education Tides and Water Levels page
- Dr. Sten Odenwald’s Ask an Astronomer :: 10 FAQ about Lunar Tides
The YouTube videos of the awesome spring and neap tides in Clovelly.
In class yesterday we talked about eclipses and so here’s the post about it!
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!
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):
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:
- Reconstructing the Chelyabinsk meteor’s path, with Google Earth, YouTube and high-school math by Stefan Geens
- I really like his animated GIF – check it out! This is the kind of back-of-the-envelope calculation my undergrad astrophysics professor (who loved back-of-the-envelope calculations) said that Russian scientists did to figure out the power of the first atomic bomb (because the US released time-stamped images)
- From Phil Plait’s Bad Astronomy blog (he’s now a writer but does have a Ph.D. in astrophysics and was a professor) – he has some excellent links (well-vetted)
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 clavius.org here.
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, SPACE.com 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!
Here’s a lovely graph from Wolfram Alpha that shows the date of the vernal (spring) equinox for certain time periods (see axes ;) ):
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! ;)
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! :)