Skywatch for the week of October 2, 2023
Mon Oct 2, 2023 MOON AND JUPITER TOGETHER
Tonight the moon and the planet Jupiter will rise together out of the east around 9 o’clock in the evening. The moon will be in its old gibbous phase, a lop-sided egg-shaped object in the heavens. The planet Jupiter will appear as a very bright, star-like object a little bit to the southwest of the moon. Both are on the border between the constellations Aries the Ram and Taurus the Bull. A small telescope will reveal the moon’s battered surface, its mountains and craters, especially prominent along the terminator, the shadowy edge of the day-night line on the moon. You should also be able to use a telescope to see the round, banded disc of Jupiter, as well as its four largest moons appearing as tiny stars nearby the planet. Tomorrow night the moon will be found farther to the east, but Jupiter will still be in the same spot in the sky.
Tue Oct 3, 2023 METEORITE – METEORWRONG
People bring me rocks from time to time, wanting to know if they might have found a meteorite. Before you decide to bring it in for me to look at, here are a few simple observations you can make to figure out if what you’ve got is a meteorite – or a meteorwrong. First, is the rock unusually heavy for its size? If not, then it’s probably not a meteorite. Now if it is heavy, get a magnet and see if it sticks to the rock. If not, then again, not a meteorite. Are there little holes in it, called vesicles? If yes, then it’s not a meteorite – those vesicles are usually caused by gas escaping from molten rock as it rapidly cools, and meteorites cool too slowly for that to happen. If it passes those tests, bring it in and I’ll try to help you find out if it truly is a rock from space. E-mail me at firstname.lastname@example.org – that’s j b e l l at I r s c dot e d u.
Wed Oct 4, 2023 FARTHEST NAKED-EYE OBJECT
What’s the farthest thing you can see without a telescope? Off in the northeastern sky 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 small, very dim smudge of light that lies in the direction of the constellation Andromeda. But this little cloud is neither little, nor does it have any physical connection with the stars of Andromeda, which are merely trillions of miles away. It’s another galaxy, comprising hundreds of billions of stars – bigger than our own Milky Way - and it’s about 2 and a half million light years out. So if you ever catch a glimpse of this far-flung object, which we call the Andromeda galaxy, you’ll be looking at something that is 15 million trillion miles away – and that’s how far out your eye can see.
Thu Oct 5, 2023 ROBERT GODDARD
Robert Goddard was born on October 5th, 1882. When he suggested that rockets could take us to the moon, the New York Times announced that he was wrong, because everyone knew that rockets couldn’t work in outer space because there was no air for them to push against. But Goddard understood that a rocket’s exhaust did not push against the air; the action of the combustion in the rocket created the reaction of the exhaust pushing against the rocket itself (Newton’s Third Law). In 1926 he launched the first liquid-fueled rocket which replaced gunpowder-like solid fuel.) The advantage here is that, unlike solid fuel rockets which go until they run out, you can throttle up and throttle back liquid fuel engines and obtain a great deal more control over the speed and flight path of the rocket.
Fri Oct 6, 2023 BRIDE OF THE MORNING STAR
There is a story told by the Blackfoot Indians of Soatsaki, the Feather Woman, who one day decided to marry the Morning Star – what we call the planet Venus. She saw him in the eastern sky before sunrise, as we can even now. One day, Morning Star stood before her on the river path. He said, “I have seen you gazing upward and will take you to the sky country.” He placed an eagle’s feather in her hair, and suddenly she was in the house of the Moon and the Sun, who called her their daughter. Morning Star and Feather Woman were married, and soon they had a son. But one day Soatsaki disobeyed the Moon and dug up the great turnip that grew beside the sky lodge, and she and her son became falling stars, sent back to earth through the hole that had been made. Their sky path became the Milky Way.