Partial solar eclipse on January 4th

The eclipse season continues, as the Moon's nodes--the intersection line of the Moon's orbital plane and the Earth's orbital plane--continue to point in the direction of the Sun and anti-Sun. After the winter solstice lunar eclipse Europe, Northern Africa, and the Middle East will get a partial solar eclipse on January 4th. The maximum eclipse reaches nearly 86% in Scandinavia, although I wouldn't really trust a low-altitude solar eclipse at the Arctic Circle this time of year to be likely visible.

Since we know the Moon's orbital plane right now, we can extrapolate to the appearance of the Moon in upcoming months and phases. We know that the first and third quarter Moons will be either higher or lower away from the ecliptic, since at new the moon was obviously at the ecliptic (to produce the eclipse). So we need one other piece of information to give us the appearance of the Moon in the sky: is the node ascending or descending? Recall the Moon passing Jupiter about two weeks ago.
Was it above or below Jupiter in the sky?

Sadly, I had to check via a planetarium program because I couldn't remember. It passed above Jupiter. So the node is ascending, and the First Quarter Moon in January will be higher than usual in the sky and the Third Quarter Moon lower (but keep in mind only in deviation from the ecliptic, not in absolute elevation in the sky). In three months (aka March-April) the full Moon will be lower in the sky than usual and rise and set further south than normal.



http://eclipse.gsfc.nasa.gov/OH/OH2011.html

The star next to the moon tonight

The bright "star" next to the nearly Full Moon tonight was Jupiter, in case you were wondering.

Pits on the Moon

Phil Plait points out pits on the Moon!



Click to enlarge. Images via NASA/GSFC/Arizona State University/LROC

Moonrise from the ISS today

The orange object next to the full moon tonight

The bright orange "star" next to the Full Moon tonight and Friday is the planet Mars, which happens to be closest to Earth tonight (ok last night) during this current cycle (Mars and Earth come close to each other every 2 years and 2 months). And closest in only the sense of currently: it's still 99 million kilometers away.

Two awesome things you have already heard about

The LRO imaged most of the Apollo landing site on the Moon. Things will get better as the orbital parameters are modified.

There appears to have been an impact of some sort on Jupiter, first seen by an Australian amateur.

Lunar Reconaissance Orbiter first images

The first test images are back from the LRO.





I've annotated a previous image of the moon with the location of the image: The orange markers are at the crater Hell E, which is listed in the press release as being just a few kilometers west of the image site. Hell E is listed as 10km across, so the images are just a touch to the right of that crater. Click on the image for a large original.



Credit for the LRO images are NASA/GSFC/ASU.

Kayuga impact and the videos you should watch

The Japanese Space Agency JAXA just deorbited their lunar orbiting spacecraft Kayuga.

Watch this, this, this (embedded below), or this, turn on the HD for sure, and raise a toast to the mission.



UPDATE: Oh heck, you should see one taken from the ISS while passing over Japan. Again, don't forget to hit the HD version.

Another moon mosaic

This was taken on Thursday.

Click to enlarge. 2427x2599. A composite of 6 sets of images. Each set is approximately 30 subexposures of 1/1000 seconds. Processed with Registax, Autostitch, and Photoshop.

Moon mosaic

A moon mosaic from last night. I didn't take the images or process them; Will did all that. The only thing I've done is run it through Autolevel in Photoshop. For processing, we took about thirty images each of each section of the Moon with the SXV-H9 camera at 1/1000s, and then ran each set through Registax to get the sharpest ones, then used Autostitch to put the sets together.


Click to enlarge.

Moon, Icicles, and the observatory

Click to enlarge

Kaguya: Color on the Moon

I was perusing (as best as possible without reading Japanese) the currently released images of the Moon from the Japanese spacecraft Kaguya when I encountered this one. You nearly forget all the images are in color when all you are looking at is the nearly monochrome Moon.

Click to enlarge to HDTV resolution

The winter moon

There is no doubt that the northern winter continues on at full strength, ignoring the cold and wind chill. The full moon rose last night well to the north of east, roughly opposite in the sky to where the sun is. The full moon will be precisely opposite the Sun on February 20th, just a month from now, as proven by a total lunar eclipse. I placed the camera directly on an east-west fence line; the moon is the white circle in the sky to the left.

The Mars asteroid thingy

http://www.space.com/scienceastronomy/071220-asteroid-mars.html

Speaking of 2007 WD5, the orbit is weakly constrained because the observations extend to only 29 days. The object was discovered on November 20th after it passed Earth some 4.5 million miles away on November 2th. It's currently only magnitude 22 and fading, and the moon is getting brighter in the same part of the sky, so there will be no observations for at least a week. In fact, the moon will be two moon diameters away from 2007 WD5 on Saturday evening, if you'd like an idea of where the minor planet is now in the sky. Mars is unmistakable at opposition in the East in the constellation Gemini in the evening. At time of possible impact, Mars will be in the horns of Taurus.

Usually these sorts of things tend to clear up after just a few more observations constrain the orbit better. Since it's so faint, a number of the observatories doing this sort of work (and a lot of them are amateurs doing it for free) won't be able to see it.

http://neo.jpl.nasa.gov/news/news151.html
A good press release, with the error ellipse, which you can see is very, very long.


Play with this java orbit visualizer: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007%20WD5&orb=1

My old-fashioned planetarium program has a miss by quite a distance, but I wouldn't really be shocked at that.

Anyways, go out and see the Moon and Mars close together on Sunday night. It'll be beautiful. In the right place on Earth, the Moon will occult it.

P.S. This wouldn't be the first impact seen on Mars. The Mars Global Surveyor found 20 new craters over the course of it's mission.

The Earth and Moon from Kaguya

Kaguya is a Japanese moon orbiter that is sending back HD video.
And awesome images.

Phil Plait talks about the Moon's orbital plane

Phil Plait looks at the low southern moon here that I mentioned last month

Fall equinox

It's the autumnal equinox today, the day when the Sun appears to cross over into the southern sky. The stirrings of winter are beginning--little reminders of the fragile nature of our comfort zone on this planet. This last week in the evening twilight the first-quarter moon barely peeked above the trees and buildings to the south, showing roughly where the Sun would be in three months time. It seemed a little low for the winter noon, though, so I checked and indeed the Moon is at its greatest distance from the ecliptic, some 5 degrees south. I have some discussion of the tilt at this previous post. And, to confirm it, there was a lunar eclipse in late August, meaning the nodes (the points where the Moon's orbit meet the ecliptic) of the Moon's orbit were aligned in the Earth-Sun line, which meant my first-quarter moon should have been above or below the ecliptic.

And it now occurs to me the root of eclipse and ecliptic are the same, a point I never realized. This will require another post.

One more good ISS pass in Chicago

The last good pass of the International Space Station for Chicago in the near future will be tomorrow, June 22nd. You may be asking, why is that? To see the space station pass, you have to pass several criteria, each of which can derail easy viewing.

To first order:
1. The satellite must be above your local horizon.
2. The satellite must be sunlit while you are not.

On #1, a satellite's orbit around the Earth is a invariate thing--that is, it orbits the Earth and the ellipse it defines stays the same in an absolute reference. The Earth may rotate below it, but the object stays in the same fixed plane. Since the Earth rotates every 24 hours, you will roughly be under where the satellite orbits twice a day. The satellite also needs to be in the part of the orbit near you. Generally, this is not a problem, because 1. low earth orbit satellites have an orbital period of only 90 minutes and 2. you can see them several hundred miles away from their ground track. See this Java applet to see the Shuttle's visible ground track.

You also need the pass to occur when the satellite is lit by the sun, and have it dark where you are. This leads to satellites generally being most visible just after evening twilight and before dawn. In the summer, sunlight streaming over the pole can illuminate satellites for most of the night--many people remember staying up and watching the Perseids and seeing more satellites than meteors.

But because the satellite's orbit is fixed in space, and the Earth rotates around the Sun, at any one location the visibility factors come in and out of phase. The satellite's orbit hasn't really changed, but where the terminator is on Earth has. And tonight's ISS pass is the last good one for a few weeks.


So tomorrow, if it's clear, at 8:58 the ISS will start becoming visible in the WNW; pass well above Venus in the west; pass well above the moon, and reach a maximum altitude of 54 degrees at 9:01PM in the SW, and pass by Jupiter at 9:04PM in the SE.

Details at Heavens-Above

Animation and images of ISS and Shuttle pass in Chicago

A fine night in Chicago, the Moon near Regulus, with Saturn halfway between the Moon and Venus.



Space Shuttle Atlantis and the International Space Station passed Chicago last night. Rising in the NW, the newly brightened ISS shone orange against the Chicago light pollution, its solar panels dominating the light. In binoculars the Shuttle was visible trailing by half a degree. As they got higher, the Shuttle became visible to the naked eye and the ISS changed color into a pure white.

Check out this awesome animation of the pass:


A single image of that animation is here, with an additional airplane trail.

See them tonight as well.

Some useful astronomy charts

For the current Mercury and Venus evening apparitions, here are two useful graphics from Curt Renz, plus the lunar phases for June:

June moon calendar
Mercury evening apparition
Venus evening apparition

See via Chicago Astronomer's forum