Highlights for the January Night Sky
Brought to you by Bob Haskins @ Waterville Estates
Do your part and help preserve the dark skies that we are fortunate to have
in Waterville Estates. Pleasd turn off all unnecessary outdoor lighting
Go outside tonight and discover the night sky
The Planets: “Evenings on the Ecliptic” The Sun and the planets all follow an imaginary path in the sky called the ecliptic.
Dusk and into the night:
Jupiter & Saturn both put on a splendid show last month and the event made national headlines with their grand conjunction in the early evening sky. However the show is over unless you have a clear view of the SW horizon during the first week of the month.
Mars is visible in the south high in the sky. The “red planet” is not as bright as it was recently however.
Venus is visible low in SE and shining brightly just before the Sun rises.
Full on the 28th
New on the 13th
Stars and Constellations
The winter constellations have arrived and this month we will focus on the constellation Orion,“the hunter” (refer to attached diagram). Look southeast and about halfway up in the nighttime sky for three equally bright stars all aligned in a row – this is Orion’s belt. Now look to the upper left of the belt and you will see a bright reddish star, this is Betelgeuse, which is pronounced “beetle juice”. This translates as the armpit of the giant.
Betelgeuse is one of the largest stars known to us and if it were our sun its diameter would extend beyond the orbit of Mars. It is a super-giant and nearing the end of its life. It will soon explode as a super nova and seed our milky way galaxy with elements that may someday be part of a future planet orbiting some sun.
Look to the lower right of the belt at the bright whitest star, this is Rigel which is pronounced “rye – jell”. This star is 50X bigger than our sun. Now look below and to the left of Orion and that really bright star is Sirius the “dog star”. Sirius is the brightest star in the nighttime sky and is part of the constellation Canis Major or the big dog. If you imagine the constellation as a stick figure it actually looks like a dog.
If you think the great conjunction of Jupiter and Saturn last month was something special, think again. Every five centuries on average all five naked eye planets can be seen together in the sky. The Babylonian sky watchers were the first to record such an event in the year 185 BCE. At that time Mercury, Venus, Mars, Jupiter and Saturn were within 7 degrees of each other in the twilight sky.
In the past 2,200 years, just four other observable planetary gatherings of the five naked-eye planets have been within 10 degrees of each other; the last one being in 1186. The next great conjunction will occur on October 31th 2040. Be patient.
Factoid / Comment of the Month
- A stars color tells us a lot about its temperature. Betelgeuse in Orion is reddish and is cooler compared to Rigel which is a white / bluish color. Our own star the Sun is yellowish which means it is hotter than Betelgeuse but cooler than Rigel.
- In the 3rd century BC, Eratosthenes of ancient Greece correctly calculated the size of the Earth and Aristarchus stated that the Sun must be at the center of things.
- When Galileo first saw the moons orbiting Jupiter it solidified the Copernican Revolution. It was the first time anyone had seen an object orbiting a star or planet.
Astronomy Websites to explore
- heavens-above.com (satellites that are passing
- skymaps.com (The evening sky map for the month)
- spotthestation.nasa.gov (sign up for alerts for the International Space Station passing overhead in your area)