There’s a bright star close to the waxing gibbous moon on July 9, 2014.
It’s Antares, often called the Heart of the Scorpion in the constellation Scorpius. You might have to look extra hard to see this star in the moon’s glare tonight. But on a dark night, Antares is hard to miss because it’s radiantly bright and distinctly reddish in color. Also, because it’s low in the sky as seen from the Northern Hemisphere, people in this part of the world often notice that Antares twinkles a lot.
You’ll find the moon fairly close to Antares tonight. Because the moon is always moving in orbit around Earth, you’ll find a fuller waxing gibbous moon farther east (left) of Antares tomorrow night. Some years, the moon can actually occult – cover over – this star. But not this year. Every month, the moon will swing to the north of Antares for many years to come. The last lunar occultation of Antares happened on February 7, 2010. The next one won’t be until August 25, 2023.
The moon is a chunk of rock, shining with sunlight that reflects from its surface. It can appear to cover Antares only because the moon is so close to us – and so it looks much larger than the star.
But if you could see it up close, you’d find that Antares is one of the galaxy’s largest stars. Many millions of stars the size of our sun could fit inside it. Antares lies some 600 light-years away, in contrast to only 8 light-minutes for the sun. So, like the moon, our sun appears larger to us than this gigantic star.
Bottom line: Look outside on the night of July 9 for a reddish star near the moon. It’s one of the largest stars known, Antares in the constellation Scorpius. Saturn is also nearby.