Skywatch for the week of February 10, 2020

Tue Feb 11, 2020 NAME THAT PLANET Let’s play, “name that planet.” I’ll give you the names of some or all of the moons that orbit a particular planet, and you have to figure out which planet it is. For example, if I said, “luna” or “moon,” you would respond with “earth.” All right, let’s start. “Phobos” and “Deimos,” which mean “fear” and “panic?” These are the two sons, and also, the two moons, of Mars. Now try “Nix,” “Styx,” “Hydra,” “Kerberos,” and “Charon.” These are the five moons of Pluto. How about, “Juliet,” “Ariel,” “Umbriel,” “Titania,” “Puck,” and “Miranda?” Those are some of the moons of Uranus. “Adrastea,” “Metis,” “Amalthea,” “Callisto,” “Ganymede,” “Europa,” and “Io?” Those belong to Jupiter. Now try, “Rhea,” “Mimas,” “Enceladus,” “Atlas,” “Calypso,” “Dione,” “Epimetheus,” “Pandora,” “Prometheus,” “Janus,” and “Titan?” Those moons orbit Saturn. That leaves us with just Mercury and Venus, but they don’t have any moons!

Wed Feb 12, 2020 SIRIUS There are many bright stars in winter’s early evening sky; most of them can be found in the south, in and near the constellation Orion. The very brightest star is in the southeast, and it’s called Sirius, a name derived from the Greek “seirios,” which means, scorching, or sparkling. So you could say Sirius is the star you meant when you recited “Twinkle, Twinkle” as a kid. This brilliant white star does twinkle, owing to the effects of our earth’s atmosphere, which cause its image to dance and flash. Sirius is also called the Dog Star, because it's supposed to mark the nose of the Big Dog in the sky, Canis Major. Stars have different brightnesses. Some are bright because they're close to us; others are bright because they're either hotter or bigger. In the case of Sirius, it's a little of both - a big, white-hot star, very close to us – only nine light years, or 54 trillion miles away.

Thu Feb 13, 2020 GALILEO’S BIRTHDAY The astronomer and physicist Galileo Galilei was born on February 15 in the year 1564. Galileo did not invent the telescope, but when he heard of its invention, he built his own, and like other astronomers of the 17th century, Galileo aimed his telescope at the sky and made some amazing discoveries. He saw the rough features of the moon, its mountains and craters, which suggested that it was another world in space, like the earth. He discovered the four largest moons of Jupiter, named the Galilean satellites in his honor. Using safe projection methods, he observed the sun and saw dark spots on its face – sunspots. He noted that the planet Venus went through phases like the moon, which showed that it orbited the sun and not the earth. And he saw the myriad stars of the Milky Way - more stars than could be seen by the unaided eye alone. There evidently was much more to the heavens than had heretofore been realized.

Fri Feb 14, 2020 THE PLANET OF LOVE/VENUS SHOW It’s Valentine’s Day, and the planet of love is on high. Why not treat your valentine to a gift that’s truly out of this world and stop by the Hallstrom Planetarium today to find out more about the planet Venus, the Roman goddess of beauty and love? The Planetarium is located on the Fort Pierce campus of Indian River State College, and the shows today are at 6 pm and 7:30 pm. There will also be presentations tomorrow afternoon, at 1 and 2:30 pm. You can get tickets at the IRSC box office - their number is 772-462-4750; or call toll-free at 1-800-220-9915. In addition to the planet Venus in our sky, there is a constellation that also represents her. That constellation is Pisces, and tonight you can find the planet Venus nestled among its stars, over in the western sky after sunset tonight. But Pisces is two fish, not one. One fish is Venus; the other fish is her son Cupid, an avatar of Valentine’s Day.