Skywatch for the week of October 17, 2022
Mon Oct 17, 2022 THE END OF THE WORLD
The astronomer Harlow Shapley once suggested two possible ways that the world could end. In one scenario, the earth loses its forward momentum, and the sun’s gravity pulls our planet inward to a fiery destruction. Another theory supposed the opposite might happen, that the earth might drift outward and suffer a frozen death like Mars. Of course, both “fire and ice,” may be our ultimate fate. Five billion years from now, when the sun runs out of fuel, gravity will take over and collapse it. This will heat it up, and the sun will expand to become a red giant star, engulfing the inner solar system, including earth. Then, when the last bit of helium fuel is exhausted, the sun will collapse again, heating up, turning into a high energy white dwarf! So, let’s make it a point, five billion years from now, to get off the planet!
Tue Oct 18, 2022 PLANETARIUM SHOW – RED PLANET RISING
The planet Mars has now made its way into the late evening sky; you’ll find it as yellow-orange-tinted starlike object lodged in the horns of the constellation Taurus. Toward the end of autumn, our planet will be catching up with and passing Mars at a mere distance of some 50 million miles, which means that Mars will be getting nice and bright over the next few months. Because of this, this Friday night and Saturday afternoon, Indian River State College will be presenting the show, “Red Planet Rising” at the Hallstrom Planetarium. We’ll talk about Mars and the possibility of one day sending people to the red planet to kick over a few of its rocks and see what’s going on up there. Join us starting this Friday night. Call the IRSC Box office at 462-4750 to get tickets and more show information.
Wed Oct 19, 2022 CHANDRASEKHAR AND BLACK HOLES
Subrahmanyan Chandrasekhar, born on October 19th, 1910, was the astronomer who figured out just how massive a star had to be in order to turn into a black hole. If a star is one and a half to almost two and a half times more massive than our sun, when it dies, it explodes and becomes a supernova, then collapses to become a neutron star. But if a star has over 2.4 times the sun’s mass, the final gravitational collapse is so powerful that the star doesn’t blow up – it blows in to become a black hole! The imploding star shrinks down to a singularity, a point of ridiculously high density. We can’t see black holes directly, but we know that they are out there, because as their gravity pulls matter in, x-rays are released, which escape the hole’s event horizon, the point of no return.
Thu Oct 20, 2022 FARTHEST NAKED-EYE OBJECT
What’s the farthest thing you can see without a telescope? In the northeast sky late this evening, you can find the answer to this question, but only if the skies are very clear, and very dark, and you know just where to look. It’s a very dim smudge of light that lies in the direction of the constellation Andromeda. But this smudge has no physical connection with the stars of Andromeda, which are merely trillions of miles away. It’s another galaxy, comprising 300 billion stars and approximately two and a half million light years away. One light year, the distance light can travel in a year, is roughly six trillion miles. So when you see the Andromeda Galaxy, you’re looking at something that is fifteen million trillion miles away – and that’s how far out your eye can see.
Fri Oct 21, 2022 RED PLANET RISING, PLUS TELESCOPE VIEWING
There are three planets that you can see in the sky this evening, and throughout the next couple of months. Folks hear the word “planet,” and think big round worlds, but because of their great distances from earth they simply appear as bright stars in our sky. At a distance of 400 million miles the bright planet Jupiter can be found in the eastern sky after sunset. Saturn appears as a dimmer, yellow-tinted star in the south. The planet Mars shows up in the east in the late evening, but we’re about to pass it in a couple of months, so we’ve got a show called “Red Planet Rising,” that’s all about Mars, and you can come out and see that show tonight and tomorrow afternoon. After tonight’s shows the Treasure Coast Astronomical Society will provide guided telescopic views of these planets, weather permitting.