The Key Project Team of the Hubble Space Telescope has completed work on an eight year project that was the primary purpose of the telescope. They have completed efforts to measure precise distances to far-flung galaxies. This is an essential ingredient to determining the age, size, and fate of the universe.

“Before Hubble, astronomers could not decide if the universe was 10 billion or 20 billion years old,” said team leader Wendy Freedman of the Observatories of the Carnegie Institution of Washington. “The size scale of the universe had a range so vast that it didn’t allow astronomers to confront with any certainty many of the most basic questions about the origin and eventual fate of the cosmos. After all these years, we are finally entering an era of precision in cosmology. Now we can reliably address the broader picture of the universe’s origin, evolution, and destiny.”

The team’s precise measurements are the key to learning about the universe’s rate of expansion, called the Hubble constant. Measuring Hubble’s constant was one of the three major goals for NASA’s Hubble Space Telescope when it was launched in 1990.

For the past 70 years astronomers have sought a precise measurement of Hubble’s constant, ever since astronomer Edwin Hubble realized that galaxies were rushing away from each other at a rate proportional to their distance, i.e. the farther away, the faster the recession. For many years, right up until the launch of the Hubble telescope — the range of measured values for the expansion rate was from 50 to 100 kilometers per second per megaparsec (a megaparsec, or mpc, is 3.26 million light years).

The team measured the Hubble constant to be 70 km/sec/mpc, with an uncertainty of 10%. This means that a galaxy appears to be moving away 160,000 miles per hour faster for every 3.3 million light-years away from Earth.

“The truth is out there, and we will find it,” said Dr. Robert Kirshner of Harvard University. “We used to disagree by a factor of two; now we are just as passionate about 10%. A factor of two is like being unsure if you have one foot or two. Ten percent is like arguing about one toe. It’s a big step forward.” Added Robert Kennicutt of the University of Arizona, a co-leader of the team: “Things are beginning to add up. The factor of two controversy is over.”

This article is excerpted from a NASA press release. To read the whole release with links try http://science.nasa.gov/newhome/headlines/ast25may99_1.htm For those interested in more information on cosmology there is a new web site just for you, try going to http://www.hubbleconstant.com

You can read this issue of the newsletter with clearer color pictures on the web site. Our copier doesn’t always get the images clear, and if it’s cranky you will get streaks and bloches. We can’t afford to get them printed commercially so come see us on the web. There will usually be more pictures on the website as well, and usually links to more information related to our programs.

The response has been so positive to our last two Backyard astronomy series that we are planning to have another set in September. Gary Lazich from the Davis Planetarium in Jackson will again be our principal speaker, and though some of the topics may sound the same, there will be some new wrinkles. The dates for these programs will be every Monday evening from 7:00 p.m. till 8:30 These are meant for the whole family to come and enjoy learning about the sky.

There will be more information later, but for now, reserve Mondays from September 13 until October 4. There will be an informal Star Party and picnic to wrap up the series on either Friday October 8 or Saturday October 9. Titles of the programs will be “Summer Starbirds”, “Many Moons”, “The Farthest Shore”, and “Growing Up in the Milky Way”.

We all know what a pain light pollution is to astronomers. A new study reveals that lights at night are hazardous to future eyesight for infants. A child that sleeps in the dark has only a 10% chance of being nearsighted when they are older. If they sleep in a room with a nightlight, the odds triple. If they sleep with a regular light on, they have better than a 60% chance of ending up nearsighted.

In my house the street lights are so bright coming in the windows that you don’t need to turn on the lights to let the dog out. When they put up a new light, we had to move our bedroom to another room to get some sleep. I don’t think that it adds to security to flood our second floor window with wasted energy all night.

If you want to know more about what you can do to help preserve dark skies and the glory of the night sky for our children, contact the International Dark Sky Association, 3223 N. First Avenue, Tucson, AZ 85719 ($30 dues per year). We have a lot of their materials and slides in our materials center. They have an informative and useful web site at www.darksky.org

Why don’t you learn about this movement. You could volunteer to give a talk about it to your civic club, or have them invite Jim, and he’ll do it for you.

Looking back on the 1999 version of the MSSG it seems as if a lot of things came together just right. Some folks started coming in on Tuesday afternoon to get a headstart. We ended up with a total of 175 participants from 14 states. Rex made a lot of folks poorer and happier with his Astrostuff, the food was good, and the fellowship better. The weather was a bit chilly, but the last couple of nights gave us some fantastic seeing.

Great thanks again are due for the hours of work by Craig Hodges, our registrar. He kept nearly everything organized. Our speakers and talks were outstanding. Everyone wants to do video astronomy now. Scott Degenhardt should get a commission from Astrovid. How is Gerrit Verschuur going to top his stories of Bernard Lovell and the Russians and bonking in the midlands delaying radio astronomy?

Next month we will have a gallery of photos from the star gaze in the newsletter, and on the web site as well. The copy machine was out of order this time. Thanks for all the good pictures we received.

If you’ve done much observing, you know that satellites are regularly seen in the sky just after dark and before sunrise. At those times they are high enough to be in sight of the Sun while we are still in the dark. They look like slow-moving stars, and you can tell them from aircraft because they don’t have the flashing strobe lights. Some of these man made moons seem to vary in brightness because they are tumbling. Others seem to fade out as they move across the sky because they are going into the Earth’s shadow.

With the coming of the International Space Station you might want to know when and where to look for some of the thousands of satellites in the sky. You can use NASA’s J-Pass to track them. For a story and how you can use this free program look at http://science.nasa.gov/newhome/headlines/ast06may99_1.htm

There is a new way to find out what’s going on at Rainwater and around the sky. Our web site now has a new feature, thanks to webmaster Craig. If you look on the web page you will see under programs and services a “Subscribe/unsubscribe to e-mail announcements” link. Click there, fill in the info., then click submit. We can send one e-mail and it will automatically go to everyone who has subscribed. We’ll remind everyone on the list about meetings, new comets, etc.

Smiley Faced Mars

Those of you who missed the Mid-South Star Gaze also missed a chance to see the god of war in a different light. Scott Degenhardt and Chris Reese of Murfreesboro, TN and Ric Honey of Memphis, TN were videoing Mars through the observatory’s C-14 with a 2X Barlow and a #25 red filter when Mars presented a happy face to the Earth. They were using an Astrovid 2000 camera with an effective magnification of 1300X.

The night was chilly, but the seeing was about as good as it gets. Nearly everyone felt that they had never seen surface features on Mars as well. I know it was as good through the 6” Astrophysics as it was in the 23” refractor at Roper Mountain.

If this image doesn’t come out very well on our copy machine, then you can get the original image on Scott’s web site http://nashville.com/~dega/daufhome.htm

Question: When solar system objects are first discovered they are given a name like 1996 CB6. What do these letters and numbers mean?

RR - NY, NY

Answer: This is a specific question, and easier to answer than more general ones like “what do astronomers do?”

The designation referred to is the temporary catalog device for asteroids. The 1996 refers to the fact that it was discovered in the year 1996. The first letter is the half month of discovery. (In this case the second half of March.) The second letter refers to the ordinal number of the object’s discovery (Up to 25 - where I and J aren’t both used - too much alike.)

The subscript is only used if there are so many objects discovered in that half month that you run out of letters. If more than 25 are discovered you begin to double up and use letters with subscript numbers like A1, B1, etc.

Once an asteroid has been observed long enough to have a well established orbit it is given a permanent designation consisting of a number (assigned in chronological order) and a name (usually designated by the discoverer)

For more info on asteroids check Asteroids: Their Nature and Utilization by Charles Kowal (Wiley, 1988)