Star searching from the front porch

Bill and Melinda Lord shared their extensive knowledge of astronomy with a group of about 25 people at the Washington Free Public Library Saturday afternoon. The Lords are amateur astronomers but there was nothing amateur about their presentation. They taught the audience interesting facts about the planets and the stars and showed them the means they could use to study those celestial bodies such as telescopes and radios. The talk was sponsored by the Washington County Historical Society.

The Lords set up a table that included meteorites of various sizes, shapes and densities. They had sacks of small meteorites from northwest Africa which they gave to the attendees.

Melinda spoke about the solar system and the fact that only eight planets are recognized now. Pluto, which was previously the ninth planet, was demoted to a ?dwarf ice planet? in 2006 by the International Astronomical Union (IAU). According to the resolution passed by the IAU, Pluto is not a planet because it has not cleared the neighborhood around its orbit. Melinda said she didn?t care for the demotion but was glad that it sparked interest in the field.

?It got people talking about Pluto and it got kids interested in astronomy,? she said.

Melinda told the crowd that the largest planet in the solar system is Jupiter, and by a wide margin. It is more massive than all the other planets combined. Its diameter is more than 11 times larger than Earth?s. Bill said Jupiter is so large that it absorbs many asteroids that might otherwise hit earth. In fact, he said more asteroids used to hit Earth before Jupiter was fully formed. And yet, even gigantic Jupiter pales in comparison to the sun, whose diameter is 10 times larger than Jupiter?s and which accounts for 99.8 percent of the mass in the solar system.

The Lords also talked about how the sun compares to other stars. Melinda said the sun is about average in size and temperature. Bill asked the audience what color of star would be the hottest, and one of the kids answered ?blue star,? which was correct. Bill said that just as blue flame is hotter than red flame, blue stars are hotter than red stars. He said the reason blue stars are hotter is because they burn more hydrogen, which also means they live shorter lives than stars that burn more slowly. He said planets around blue stars would be unable to support life because the stars are too hot.

The sun is classified as a yellow star and has a surface temperature of 6,000 degrees Kelvin, or more than 10,000 degrees Fahrenheit. Melinda showed on a projector how the sun looks compared to much larger stars. The sun is small in relation to stars such as Sirius, which is small compared to Arcturus, which is itself small compared to giants such as Betelgeuse and Antares. According to space.com, the biggest star in the known universe is VY Canus Majoris, which is 2,000 times larger than the sun.

In order to observe these planets and stars, Bill recommended to the attendees that they purchase the largest aperture telescope they can afford because the larger the aperture, the more light is let in. He warned that telescopes should definitely not be used to look at the sun since this can burn your retina. He said there are special solar telescopes for observing the sun.

Melinda talked about using telescopes to view the moon. She said the best time to observe the moon is during a half or quarter moon because that is just the right of amount of light to illuminate the moon?s features such as its craters. She also told the crowd that ?light pollution? caused by terrestrial lights makes it difficult to see celestial objects, so she encouraged everyone to turn off unnecessary lights.

Bill is the president of the Society of Amateur Radio Astronomers and Melinda is the treasurer of the club. The Lords said that radio astronomy is responsible for 85 percent of what humans know about the universe, yet visual astronomy receives much more funding. Bill said that radio astronomy does not necessary entail actually ?listening? to the radio but rather letting a computer do it and then looking at the strip charts the computer produces.

He said radio astronomy has been used to detect solar flares. The flares cause disruptions in radio signals which show up as spikes or dips on the computer read-outs. In the 1800s, a solar flare hit earth that burned large sections of telegraph wires. Bill said that if the same solar flare hit today, it would be devastating to electronic equipment.

Fourth-grader Evea McCracken attended the backyard astronomy event because she is interested in studying the night sky.

?There are things about the stars that are really cool,? she said. ?A star doesn?t look like a big ball of fire but it is!?

McCracken said another thing she finds interesting is that Earth has oxygen while outer space does not. McCracken is the daughter of Faunne McCracken.

Fifth-grader Ashley Dawson said she studied astronomy last year and is very interested in the topic.

?Astronomy is a big thing in school now,? she said.

She was intrigued that the meteorites she held Saturday were quite heavy but in outer space they would weigh nothing at all.

?I don?t have my own telescope, but I did ask for one for Christmas,? she said. ?One of my friends got one, so I went to her house last night (Friday) and got to look through it.?

Dawson is the daughter of Stephanie and James Dawson.

James Lamansky is in eighth grade and enjoyed the presentation Saturday.

?I like reading about space and the planets, stars and galaxies,? he said.

He has a telescope he looks through periodically.

?I usually let my older brothers, Andrew and John, figure out how to find the stars and then I look through it,? he said. ?On their android phones they have a star map that can find the stars.?

Lamansky is the son of Dan and Ann Lamansky.