The large yellow shell depicts a light-year; the smaller yellow shell depicts a light-month. Read more about this image at Wikimedia Commons.Help! EarthSky needs your support to continue. Our yearly crowd-funding campaign is going on now. Donate here.| EarthSky
Use this “handy” guide to measure degrees – or sky measurements – on the dome of the sky. Image via timeanddate.com. Used with permission.How do you describe how far apart something is in the sky? The fact is, the handiest measuring stick for the sky’s dome is the one on the end of your arm. You can use the width of your pinky, fist and more to gauge the distance between sky objects. That comes in handy when you’re observing conjunctions between planets, or close planets and stars...| EarthSky
https://youtu.be/NTo5-YsjWlI Scientists and engineers can infer a spacecraft's location and how fast it's going by measuring changes in the spacecraft's radio| NASA
New Horizons was the first spacecraft to explore Pluto and its five moons up close and, later, made the first close exploration of a Kuiper Belt Object.| NASA Science