Don’t miss tonight’s sweet gathering of crescent moon and evening planets. Just look to the southwest in late twilight to spot the trio.
Both Saturn and Mars happen to be exactly the same brightness, shining equally at magnitude 0.8, but each with a distinctly different hue. Can you see the contrast between rusty red Mars and vanilla-white Saturn?
All this happens in Libra, a dim zodiac constellation preceding the brighter and better known Scorpius. Scorpius brightest star, Antares, is similar to Mars in color and just a tad fainter.
Visually, this red supergiant star doesn’t even hint of its true proportions because it’s 620 light years away, too far to appear as anything more than a shifting point of light. Measuring in at three times the diameter of Earth’s orbit, if Antares were put in place of the sun, its bubbly surface extending beyond the orbit of Mars.
Recent research shows the star dominated by enormous bubbles of incandescent hydrogen gas called convective cells. Although it has a mass some 18 times that of the sun, the star’s powerful winds – from convection and sheer radiant energy – blast away something like 3 solar masses of material into space every million years. Unless Antares slims down through mass loss, it’s destined to grow a core of iron, collapse and explode as a supernova in the future.