Highlights for the May 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. 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.
Last year’s big story was the total eclipse. For the year 2018 it is Mars and it will shine brighter than it has in 15 years.
Venus is the highlight of the evening this month shining brightly in the west at dusk. It shines at -3.9 which is really bright. Look for it in the WNW at dusk.
Jupiter rises just after sunset at the beginning of the month. Look for it shining brightly at magnitude -2.5 in the ESE in the nighttime sky.
Mars continues its thrilling rapid increase in both brightness and size as Earth prepares to catch up to it. On the first of May the Red Planet bursts above the ESE horizon after midnight.
Stars and Constellations:
The area around WVE is starting to respond to the increasingly direct rays of our yellow star as the Earth leans more into the Sun. The flowers are starting to poke there way through the soil and we gaze in wonder as the Sun is bringing our planet back to life after a cold winter and the stars of winter are slowly sinking in the west.
This month we are featuring the the “Big Dipper”. (see attached diagram below from Chet Raymo’s book, 365 Starry Nights). Look north and you cannot miss it; however, you might have to explain to the children what a dipper is. People in other parts of the world sometimes refer to it as a plow. The Big Dipper is actually an asterism and not a constellation; it is actually part of the constellation “The Great Bear”. An asterism is defined as a group of stars that are not an official constellation. It is however, probably one of the most famous and familiar of all the asterisms / constellations. No other group of stars, except possible for Orion, is easier to recognize. If you follow the handle of the dipper it will point to the bright star “Arcturus” in the east, which is also known as the “Spring Star”. As your vision travels a little further you will see another bright star “Spica” in the south. Remember, “Follow the arc (handle) to Arcturus and you will spy Spica”.
The two stars that make up the front side of the bowl or cup of the Big Dipper are called the pointer stars (see diagram). If you follow them up they will guide you to Polaris, the North Star (see diagram).
Last month, NASA launched its new exoplanet hunter: a satellite, named TESS. It will stare out at the cosmos searching for never before seen worlds. The spacecraft will be looking for planets circling around stars outside our solar system to help scientists figure out what these planets are made of and if any might be able to support life. TESS will be taking the place of NASA’s old planet hunter Kepler which will run out of fuel in the next few months. TESS is far more sophisticated than Kepler. It will be looking for Earth-sized worlds that are in the right obit around stars where liquid water can exist. TESS will have a field of view 400 times that of Kepler and be able to see as many as 200,000 stars.
Comment / Factoid of the Month:
The scale used to describe brightness is called “apparent magnitude”. It was invented by Hipparchus over 2000 years ago and has stood the test of time. The brightest stars he referred to as first magnitude and the dimmer ones he called sixth magnitude. The scale has been tweaked in recent times. Arcturus has a rating of 0 and Sirius a -1. The more minus the number is the brighter the object.
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)