Asteroid Research – Orbits

One of the fun things about writing science fiction is learning about science!  My current work in progress is set in the asteroid belt, so I’ve had fun studying it. 

In my story, the aliens travel from the asteroid they live on to visit several asteroids humans live on before returning to their own asteroid.  I wanted to find a set of real asteroids where this made sense.  

In order to find a real set of asteroids, I had to answer two questions: 1) which asteroids would it make sense for humans and aliens to live on?  And 2) how do asteroids move relative to one another and what would it take to travel between them?

For the first question, I thought that humans (and aliens) would establish bases on asteroids big enough to support them.  I thought the most important resources for an asteroid to have are water and organics.  I discovered that many asteroids are members of families, groups of asteroids that have similar orbits (semi-major axis [maximum distance from the sun], inclination [angle from the ecliptic plane], and eccentricity [a measure of how circular the orbit is]).  Asteroid families can be created by collisions, so most of the asteroids in the family were once part of the same parent body and would likely be composed of similar materials.  One such family is the Themis family.  I found multiple papers arguing there is evidence that the Themis asteroids contain water ice and organics (among them: 1, 2, 3, 4).  So, if I use members of the Themis family for the asteroids that my story humans and aliens live on, I can assume they have water, organics, and metal resources to be extracted.  

For the second question, I hoped that having asteroids in the same family might mean the asteroids travel together.  Over the long term (months and longer), orbital dynamics does not work that way (unless the asteroids happen to be at different points in the same orbit and one “follows” the other).  Asteroids closer to the sun have a shorter “year” than asteroids further away, so even with a small difference in semimajor axis, the closer-to-the-sun asteroids will eventually “lap” the further out ones.  So they will be close, and then far away, and then close again.  Plotting a course in the asteroid belt is going to be a challenge!  Happily for me, my story takes place within a short period of time, and I can put my asteroid bases wherever is convenient, so I just needed to find a handful of Themis-family asteroids that are “near” each other at a point in time.  

I found a really cool asteroid simulator on line (Catalina Sky Survey (CSS) Orbit View) where you can enter the asteroids and date of your choice and see where they are and how they move relative to one another. The pictures in this blog post were generated by this awesome tool. It’s really fun just to watch the asteroids move around!

I filtered the Minor Planet Center Orbit (MPCORB) database for Themis family asteroids, put the top 60 into the simulator, let it run starting at 2150, and followed 24 Themis.  In 2243, I found what I was looking for: 6 Themis family asteroids “reasonably” close to one another.  

Note: I am well aware that “reasonably” close together at 3.14 AU is still really far apart.  However, my alien spacecraft does not need to break the laws of physics and exceed the speed of light to get from one to another, which is enough for me.

My next step will be to determine what we know about these asteroids, so I can make these tiny worlds more realistic.

Comet Lovejoy and the Pleiades

Comet Lovejoy and the Pleiades


Comet Lovejoy – Change in Position in One Day



Sunday and Monday evening it was clear, so it was time to find Comet Lovejoy again. This time it was near the beautiful Pleiades. Of course, that is worth a picture.

I thought it would also be fun to see how much the comet had moved over one day – the change is quite visible. I was hoping to go for a three-day comparison, but now it’s cloudy again.

Camera geek info:

  •            Canon EOS 60D in manual mode set at f/4.0, 3.2 second exposure, ISO 6400
  •            Canon EF 70 – 200 mm f/4L lens, set at 94 mm for Pleiades and comet and 200 mm for comet, manual focus at infinity
  •            Tripod
  •            Cable release

In choosing which picture is the best, I find that I am using the following criteria: good focus (automatic toss for out of focus picture unless happen upon cool “artistic” effect), no visible star trails (stars should look like a point, not a line), visibility of comet, color of objects, color of sky, and noise of sky. While I have pictures with darker, less noisy sky, they don’t show the comet as well.

I am also finding that the image quality is far better when I zoom to my desired field of view instead of cropping in post-processing to get there.

Astrophotography – Planets

Conjunction of Moon and Saturn

Saturn (“One of the These Things is Not Like the Others”)

Jupiter and four Galilean Moons

You know you enjoy a hobby when you get up early and go out into the dark cold for it. This morning there was a conjunction of the Moon and Saturn, so I got up and went out. And while I was at it, I took some pictures of Jupiter and its moons, too. I checked – yes all four moons were on the same side of Jupiter this morning. I think it would be fun to make a time lapse of their motion. Might have to try it.

I learned a new astrophotography trick last night. I knew I needed to manually focus for star pictures, but it’s hard to do with dim sources and a camera designed for autofocus. But my camera has a nifty real-time view on the LCD screen with a 10x view … so I could zoom in on the moon or a planet and use the real-time view to help me manually focus. Neat! And *much* sharper pictures.

The real-time view also showed me that, in spite of the solid tripod, the 200 mm is actually quite shaky if I want to crop further in. So I get out my cable release so I could watch the image settle down on the 10x screen and then trigger the camera without actually touching it.

I also already knew that although I could easily see both the Moon and Saturn, Saturn would disappear or the Moon would wash out without some filtering. Graduated neutral density filters to the rescue! I used two (wish I had more and stronger ones) to dim down the Moon so you can see both bodies in the same photo.

Camera geek info:

  •            Canon EOS 60D in manual mode set at f/4.0, 1/60 second exposure for Moon and Saturn, 1/13 second exposure for Jupiter, ISO 2000
  •             Canon EF 70 – 200 mm f/4L lens, set at 200 mm, manual focus at infinity
  •             Singh-Ray Galen Rowell Filter ND-1G-SS + ND-2G-SS for Moon
  •             Tripod
  •             Cable release

Comet Lovejoy

Can you spot the comet?  (Hint: it’s green!)CometLovejoy20150107-1

Zooming in … how about now?


It’s been a long time since there’s been a comet that I could successfully see and photograph! Comet Lovejoy is a star hop from Rigel (Orion’s foot) into Eridanus, where it can easily be seen (at least in the suburbs in the northern hemisphere) with binoculars, a telephoto lens, or a telescope.  It looked gray through the binoculars, but in the pictures it is a beautiful green.

I am glad that our winter clouds cleared away and I got a clear night last night to spot it. I was hoping for a second clear night in a row so I could show that the comet is moving relative to the stars. Alas, the weather did not cooperate, and it looks like it’s going to be cloudy for a while. But I’ll keep looking up!

Orion EFT1 Mission


I got up early yesterday and again today to watch the launch of NASA’s newest spacecraft, Orion. This flight, Experimental Flight Test 1 (EFT1), is, as its name suggests, a flight test to check out critical Orion systems before we send it further away with people on board.

I cheered when it successfully launched this morning and did not get any writing done because I was too intrigued with the Orion TV feed.

Here were the thoughts I had while watching:

– I’m conditioned to watch Space Shuttle launches and know the event timing, and it was odd for me to watch a launch with different timing and steps. Shouldn’t the side rockets fall off after two minutes? Apparently, no.

– I saw some insulation popcorning off the Delta IV in the rocket cam video feed, but I didn’t have to worry about anything hitting Orion since it’s on top of the stack. That’s a big benefit to the top of the stack design.

– I was furious with the idiots who kept tweeting Orion had blown up.  Can I tunnel through the internet and terminate their connections?  Please?

– I cheered when we started getting good telemetry off Orion via its own communication system and the Tracking and Data Relay Satellites (TDRSs).

– I loved the views of Earth from the Orion cameras.

– I was happy when I saw the Orion animation showing Orion was passing the Texas Gulf Coast. Unfortunately, I hadn’t thought to use my screen capture program to catch it. And it was raining here at the time, so there was no point in going out to wave.

– Once Orion was up in its elliptical orbit, the view of the Earth was a tri-color Earth much like my tri-color Moon from my lunar eclipse photos: white limb, blue middle, and black in shadow. I need to figure out if that’s just an effect of the camera’s dynamic range because if not I want to capture the tri-color effect in the story I’m currently writing.


– Orion did, as expected, experience a communication blackout when the reentry plasma got too thick.

– The video of the landing and splashdown – from the Ikhana drone and Orion itself – were awesome. I loved the infrared point of the approaching Orion and getting to see all the parachutes deploy.

– It was great that NASA TV and ustream broadcast the entire mission, and I enjoyed sharing the event with the twitter community. I don’t tweet often, but this event seemed made for it.

I spent the whole morning watching the flight. What an awesome day!

Congratulations to the NASA and Lockheed Martin Orion teams on a flawless flight! I am such a NASA fangirl! Luckily for me, I work for a NASA contractor and occasionally get to do work for Orion. But today I just got to be a fan.  🙂

[1] Ground track picture from NASA Flickr.

[2] Tri-color Earth picture screen shot from ustream NASA TV feed.

Saturn hovers over Mercury


As Murphy would have it, we’ve had heavy clouds and rain this week, so we weren’t able to look for Comet ISON.  The clouds finally blew away this morning, so we braved the cold morning to see if we could spot the comet through the colors of the sunrise.  We didn’t spot the comet, but we did see Saturn hovering above Mercury.  It was quite striking, don’t you think?

Apollocon 2013 Report

I just got home from Apollocon 2013, which I consider my “local” science fiction convention.  I’ve been going for a number of years, and I always enjoy it.  As usual, I wished I could borrow Hermione’s time turner so I could attend multiple panels at the same time.

I enjoyed all the typical con things: meeting other authors, expanding my thinking on various issues at the panels, and coming home with new books and a list of more books and blogs that I want to read.

One of the neat things about this particular con is that because it is in Houston, home of NASA/Johnson Space Center, it has some great space science presentations and panels.  This year, the highlights for me were:

– Dr. Paul Abell‘s presentation on the Chelyabinsk meteor that exploded over Russia in February (the audio recordings of this thing are just amazing)

– Astronaut Stanley Love‘s presentation on searching for meteorites in Antarctica (with lots of observations about the physical space spent on logistics and time spent on non-science work which are as invaluable to science fiction authors trying to get it right as it is to NASA mission planners)

– Dr. Paul Abell, Dr. Al Jackson, and Dr. Stanley Love’s panel on Planetary Defense and the work being done to find and categorize near earth objects with the potential to impact our planet and cause local to knock-us-back-to-the-stone-age destruction as well as the work being done to find ways to prevent such an event from occurring should a NEO be found that is predicted to impact the Earth

Of course, I am fascinated by meteorites, so I enjoyed all these talks immensely.

But even if one is not fascinated by meteorites, these guys make their subjects compelling.  I highly recommend going to one of their talks if you ever get the opportunity.