Image Credit & Copyright: NASA/ESA Hubble Space Telescope.
On the night of Sunday, September 28, 2014 just after sunset look southwest to the constellation Scorpius to witness a beautiful sight; the red planet will be alongside the red heart of the scorpion, Antares.
The pair will be about three (3) degrees apart low on the horizon so you will need an unobstructed view in that direction and depending on exactly where you are you may not want to wait too long because they will set fairly quickly after sunset. According to http://aa.usno.navy.mil/data/docs/mrst.php I have Mars setting around 21:15 EDT on Sunday, September 28 at my location. That’s with an unobstructed, ocean or desert-like horizon.
This is a great opportunity to see how Antares got its name (anti or ante Ares) as it’s Greek for “rival of Ares” or “equal to Ares.” Ares of course is the Greek God of War, which is actually the counterpart to the Roman God of War and namesake of the planet; Mars. Late this month the two will battle it out and you get to decide who’s most impressive………Pretty cool right?!
All rivalry aside, that’s where the comparisons end……let’s have some thought fun!
When you view these two in the sky, keep in mind that you will be viewing Mars at a distance of roughly 1.4AU (133.4 million mi.) at an apparent magnitude (brightness as we see it) of about 0.8. Antares will be at a similar apparent magnitude of 0.9 but this massive red giant will be slightly further away at a distance of 550 light years. If you were traveling at the speed of light you would reach mars in about 12 minutes and Antares in, well, 550 years!
Let’s have a side by side size comparison! Little old Mars with a diameter of 6,800 km (4,225 mi.) is smaller than Earth and bigger than the Moon. It’s roughly the diameter of the Earth’s outer core and it orbits the Sun at a distance of 1.52 AU or about 50% further away than Earth does. Antares, with a diameter of 1.2 billion km (735 million mi.) or 800 times that of the Sun is one of the largest stars known. Just as you could squeeze 1.3 million Earths into the Sun, you could squeeze about 500 million Suns into Antares!
Here’s what could be the knockout blow to our rusty planetary partner. If you removed the Sun and replaced it with Antares, it would be so big that it would swallow the orbit of Mars and much of the main asteroid belt! It would appear that Mars stands no chance against the red supergiant right? However, this may not be true as Antares goes by the “Live Fast & Die Young” mantra, which means that someday in the future, possibly during this encounter, Antares will detonate into a supernova and if it’s close, it will truly wash Mars out of the sky for a time. But then, it will fade…….and Mars, the God of War will still be there, its rival, gone.
Exact RA/DEC J2000 for Antares: RA 16h 29m 24s / DEC −26° 25′ 55″.
SAO for Antares: 184415.
SIMBAD data for Antares: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+148478
Terrific “Distance to Mars” visual by David Paliwoda & Jesse Williams: http://www.distancetomars.com/