Venus AND Earth from Mars

I missed something in the last post--the image is Venus and Earth from Mars. Venus is the bright point in the center, and Earth is the faint object moving to the lower right of Venus.


This is from fredk at http://www.unmannedspaceflight.com/index.php?showtopic=6042&st=60&start=60

Venus from Mars

Via Emily Lakdawalla @ facebook.

http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=18408

UPDATE: I realize I missed something in this animation--Earth!

Crescent Venus movie

I took this Wednesday evening. Venus is close to the Earth, big in angular size, close to the Sun and getting lower every day. Turbulence, turbulence, turbulence. And an orange filter.

Earth and Jupiter from Mars

An older image, but cool nonetheless. Earth and Jupiter visible from Mars, taken by the now-deceased Mars Global Surveyor. Make sure you see the orbital diagram.

You have the chance to see Saturn and Venus close together, from right here on Earth, on Saturday evening, the same evening as the Full Moon.

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.

See the Shuttle and ISS again tonight, Wednesday, in Chicago

Last night was a fantastic pass--photos will be up in the next post. Tonight, see them again, this time starting at 9:52:07PM in the NW, reaching up about halfway to the zenith in the SW at 9:54:54PM, and entering the Earth's shadow a minute later.

Pass details from Heavens Above.

They look like a moving bright star--about as bright as Jupiter, which is low in the southeastern sky, but not quite as bright as Venus, which is in the west.

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

Mercury, the Moon, and Venus

As I mentioned in my last post, more images from the evening of May 17th.

You can see the Moon--but look closely at the support wires on the left side of the crane--see Mercury?


Through the telescope, the autofocus picks up the high contrast of the crane--and makes Mercury a round blur.


Forcing the focus to Mercury.


Venus, much higher up in the sky, but still subject to atmospheric dispersion.


You can see the turbulence by viewing this video of Venus here (753kB, 0:17 WMV).

The wide view.

The moon and Venus

The waxing crescent Moon and Venus appeared in the unusually clear evening skies at Chicago on Tuesday.