The give and take of orbital mechanics

Orbital mechanics giveth and orbital mechanics taketh away, and sometimes orbital mechanics giveth back, at least for a while.

The bright, glowing dot of the International Space Station has been gone from the early evening skies for several weeks due to the way it orbits Earth being visible only in the very early hours of the day.

However, for the last couple of weeks there have been some rather fantastic passes visible from here in Southwest Nebraska, Southeast Colorado and Northwest Kansas.

Passes where the ISS was visible from horizon to horizon traveling right overhead for all to see. Alas, for the next couple of weeks we will be limited to very short duration visibility options in the late evening.

For me it was fascinating to watch as the spacecraft passed silently overhead against the background of the stars. To realize that each component of the station was blasted aloft by rocket and assembled by workers in clumsy-gloved space suits in a very hostile environment.

We were recently treated to several days of watching those astronauts as they repaired and replaced components on the aging Hubble Space Telescope. That workhorse of engineering that has returned some absolutely astounding photographs of our universe.

As of now there are six individuals from various countries of the world aboard the station conducting work and experiments to enable not only the ordinary everyday person to live a better life but to provide tools that science and medicine can use to further our understanding and well being.

Take for instance that little thing the doctor sticks in your ear to take your temperature when you visit his office. Where do you think that came from? If you stop to think, there are hundred, perhaps thousands of things that touch our everyday life that came as a result of work and research in space engendering.

OK, I will get off the soapbox now. Now, where was I. Oh yes, the ISS. Beginning today, July 16, go outside at 11:11 p.m. MDT (you may want to go out a little earlier so you can find where to look) and look to the north.

The ISS will pass very, very low to the horizon traveling from north-northwest to north. Look quick.

On Friday, July 17 at 10:01 p.m. MDT north to north-northeast; July 18 10:25 from north-northwest to north-northeast; and July 19 at 9:14 p.m. MDT from northwest to north-northeast. (For those in Central Daylight Time, add one hour)

All of these passes will be extremely low on the northern horizon so find someplace that is very clear and unobstructed. If you want more information on other viewing times, point your favorite web browser to www:heavens-above.com. There you will be asked to enter your latitude and longitude (available on that site by often just entering your zip-code) and choose the ISS option. There are other satellite options there too.

Space shuttle mission STS-127, launched Wednesday evening, is another fun opportunity, to watch both the ISS and the space shuttle flying together, two small dots against the blackness of space.

Starting on Sunday, July 19, the Great Nebraska Star Party starts at Merritt Reservoir near Valentine, Neb. Dark skies and telescopes, what better combination?

SKY WATCH:

Third-quarter moon today. Nice conjunction of a very slender crescent moon, the Pleiades star cluster, and bright Venus at about 4:30 am MDT in the east on Saturday, July 18.

The moon will join Venus the next morning at about the same time.

NEXT TIME:

More astronomical blathering.