Showing posts with label Northern Sky. Show all posts
Showing posts with label Northern Sky. Show all posts

22 October 2020

Share the Night Sky - Broadcast on KPOO

During the recent Bay Area Science Festival, I had the privilege of sharing the night sky with DJ Marilynn and the listeners of KPOO during a special broadcast on Thursday evening October 22nd. Our hour-long broadcast features many different topics: 

  • How to find a good spot for stargazing in the city, and how to prepare for looking at the night sky. 
  • How to find planets such as Jupiter, Saturn and Mars this fall and winter, along with the constellation Sagittarius. 
  • How to find the Summer Triangle and connect it to the Milky Way. 
  • How the view of the sky changes when viewing from different places around the world. 
  • How to understand the motion of the constellations in the northern sky, featuring Cassiopeia and the North Star. 
  • How to enjoy a view of Orion the Hunter later in the evening. 
  • How to further your experience with the night sky. 

Click here to listen to the broadcast. 

Image courtesy of KPOO-FM.

09 January 2011

Northern Lights from 35,000 Feet – The Aurora Borealis

I had the privilege of seeing the Aurora Borealis today while on a flight from San Francisco to Frankfurt, Germany. The Aurora, or Northern Lights, is a beautiful, eerie glow in the sky caused by the light pressure (Solar Wind) from the Sun hitting Earth’s upper atmosphere and causing molecules to glow where the Earth’s magnetic field is concentrated in a circle around the North Magentic Pole.

A bit of science: "Auroral Ovals" are regions on the Earth around the magnetic poles where Aurorae are most likely to occur, and because the Magnetic North Pole is in Northeastern Canada, the auroral oval extends to other reaches of Canada, Greenland, Scandinavia and the Arctic region. The website Spaceweather.com has a daily update on the size and location of the auroral ovals (scroll down and look on the left hand side of the homepage). Since I knew I was going to be on a flight to Europe that would take me far north and near to this region of the Earth, I made sure I had a seat on the left hand side of the plane and once on board, watched the flight map to follow our progress. Like most international flights that travel east, the flight moved quickly into darkness and at about the halfway point at which we were at the Arctic Circle, I started looking out my window. Not surprising at all, I began to see a faint glow on the distant northern horizon. Over the next 30 minutes, the glow became bigger and before long the plane was in the midst of what appeared to be clouds of light, glowing a faint green among the backdrop of circumpolar stars. Luckily there was no moonlight to distract from the view this night.

There is no way to easily describe the Northern Lights except as beautiful curtain-like clouds that glow of their own light, rather than being illuminated by sunlight. The shapes change continuously, and in the more dense regions the wing of the plane outside my window actually was illuminated by the glow. Moving along at high speed the view was always unfolding, always bringing new shapes into view. I watched for about two hours until the intensity began to wane.

If you are traveling a route that takes you far north (any West Coast to Europe flight will do) and it is in the late Fall and early Winter months, you should acquaint yourself with the auroral oval on Spaceweather.com and get a window that faces north (left hand side) when flying east. Be patient, darken your seating area, and look carefully, as you would for any item of astronomical interest. You’ll be rewarded with an unforgettable, magical show.


09 December 2009

The Northern Sky: Circumpolar Stars and Polaris

I enjoy stargazing for many reasons, one of which is to get a sense of the motion of the sky as viewed from our vantage point here on Earth. As I have traveled around the globe, I've always tried to observe how the sky changes depending on where you view it from. One of the more fundamental things you can observe is the dynamic of the stars and constellations in the northern sky. For those of us who dwell in North America, we see the north star, Polaris, at the same height in the sky as we are located north of the equator. That is, for San Francisco at approximately 38 degrees north latitude, Polaris can be found due north, 38 degrees above the horizon.

For reasons you can read about in Wikipedia, Polaris does not move in the sky and therefore is never below the horizon. It is always fixed in the north above the horizon at the same arc as you are located north of the equator. However, the stars that surround Polaris also never dip below the horizon, but rather circle around Polaris in a 24-hour spiral that turns counter-clockwise. Long-exposure photographs show this effect very vividly.

Wonderful constellations and asterisms occupy the circumpolar region of the sky, including the Big and Little Dipper, Cassiopeia, Draco and Cepheus.