Highlights for the January Night Sky
By Bob Haskins
Do your part and help preserve the dark skies that we are fortunate to have
in Waterville Estates. Turn off all unnecessary outdoor lighting
Go outside tonight and be a stargazer
The Planets: “Evenings on the Ecliptic”
The Planets: “Evenings on the Ecliptic” The Sun and the planets all follow an imaginary path in the sky called the ecliptic.
This month, as was December, a total loss if you want to spot a planet in the nighttime sky. There are none at all. Hopefully February will be better.
Jupiter and Mars: January starts out with both planets just 2 degrees apart in the SSE. As the month progresses the distance between them increases. Look for them in the SE
Venus and Mercury: At the beginning of the month both are hugging the SE horizon however, by the middle of the month they are lost in the glare of the rising Sun.
Look for the first “Super” Moon of the year on 1/31
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.
Astronomers last month picked up a faint point of light moving across the sky. At first they thought it was an ordinary asteroid but soon realized it was something entirely different. They named it “Oumuamua” and it is like nothing we have ever seen before. It is red, probably made of metal and is shaped like a gaint cigar and at least 400 meters long. Oumuamua may well have been wandering through our Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our solar system.
Researchers estimate that interstellar asteroids pass through our in solar system about once per year, but they are faint and so have been missed until now.
Factoid 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 overhead)
- com (The evening sky map for the month)
- nasa.gov (sign up for alerts for the International Space Station passing overhead in your area)