Jon U. Bell

Sky Watch Host

Ways to Connect

Some parts of the sky have more bright stars than others. The stars are fairly randomly distributed, but it seems as though most of the really bright ones can be found in the winter evening sky. The evening skies of summer have some bright stars, too, but the fall sky and the spring sky are relatively empty of bright stars.

The earth revolves about the sun, which causes the sun to slowly drift through our sky from west to east. The sun has now entered the constellation Aries, the Ram. This means that because of the earth’s revolutionary motion, the sun is now directly between us and the stars which make up Aries. This obviously is a bad time to be looking for the constellation of the Ram, because the bright sun blocks our view of this part of space. If today’s your birthday, you may have been told that you’re a Taurus, meaning the sun was in Taurus when you were born.

On April 26th in the year 1920, a great debate took place concerning the earth's place in our Milky Way Galaxy. Some astronomers such as Heber Curtis thought we were at the center of our galaxy, for when you looked along the milky band of stars that defines the galactic disc, you saw roughly the same number of stars throughout. Curtis also thought that spiral nebulae were distant galaxies, like our Milky Way, but very far away.

If you were outside this morning before sunrise, and happened to have a clear sky, you may have seen the old gibbous moon, well up in the south. You may have also seen three stars nearby the moon; but only the bottom-most star is actually a star: it’s the red giant Antares, which marks the heart of Scorpius. Just above Antares is another red-tinged star, but that’s not a star at all – it’s Mars. You can see how Antares got its name when you compare it to Mars – they look a lot alike, especially in color. Antares means, “rival of Ares,” the Greek name for Mars.

Since the Hallstrom Planetarium began presenting shows at Indian River State College back in 1993, we have served three distinct groups: college students, who take classes and practical labs in astronomy, celestial navigation, and observations on the basic structure and contents of the Universe; school children, from Kindergarten through 12th grade, come on free field trips and discover the wonders of outer space, viewing exciting programs that are tied in with public, private and home-school curriculums.

Bright moonlight will interfere with our viewing of this year’s Lyrid meteor shower, which is at peak activity tonight. Every year at this time, the earth travels through a portion of its orbit that is littered with bits of ice and dust left in the wake of a passing comet - the Lyrid meteors, so named because they seem to come out of the part of the sky near the constellation Lyra the Harp. It’s been a reliable shower, viewed by millions of people for many years.

Samuel Clemens, better known as Mark Twain, died on April 21st, 1910. Twain was born in 1835, the same year that Halley’s Comet made an appearance in the heavens. In 1909 he wrote, “I came in with Halley's Comet in 1835. It is coming again next year, and I expect to go out with it.

In our Milky Way galaxy alone there are an estimated 200 billion stars. They vary in mass and size. Some, like the red supergiant star Betelgeuse, which can be found in the constellation Orion over in the western sky this evening, are as large as the span of the inner solar system. Others, like the blue giant Rigel, also in Orion, are many times hotter and more massive than the sun. Then there are white dwarf stars like the companion star to Sirius in the southwest - only the size of the earth. Smaller still are neutron stars, just a few miles in diameter.